🚀 Chapters in Reader

* Added chapters in Reader
* ModalDrawer to fast navigate or track current chapter
* Current chapter progress in top bar
* Optimized Reader scroll performance
* Improved EPUB parser
* Fixed incorrect order for chapters(due to no sorting before)
* Remove ZIP parser (replaced with EPUB)

Resolves: #66, #17

app/build.gradle.kts

@@ -166,4 +166,7 @@ dependencies {
 
     // Scrollbar
     implementation("com.github.nanihadesuka:LazyColumnScrollbar:2.2.0")
+
+    // Gson
+    implementation("com.google.code.gson:gson:2.11.0")
 }

app/schemas/ua.acclorite.book_story.data.local.room.BookDatabase/7.json

@@ -0,0 +1,203 @@
+{
+  "formatVersion": 1,
+  "database": {
+    "version": 7,
+    "identityHash": "37c3fbdf5d779680f100fbdfe99121f7",
+    "entities": [
+      {
+        "tableName": "BookEntity",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `title` TEXT NOT NULL, `author` TEXT, `description` TEXT, `textPath` TEXT NOT NULL, `filePath` TEXT NOT NULL, `scrollIndex` INTEGER NOT NULL, `scrollOffset` INTEGER NOT NULL, `progress` REAL NOT NULL, `image` TEXT, `category` TEXT NOT NULL, `chapters` TEXT NOT NULL DEFAULT '[]')",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "title",
+            "columnName": "title",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "author",
+            "columnName": "author",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "description",
+            "columnName": "description",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "textPath",
+            "columnName": "textPath",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "filePath",
+            "columnName": "filePath",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "scrollIndex",
+            "columnName": "scrollIndex",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "scrollOffset",
+            "columnName": "scrollOffset",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "progress",
+            "columnName": "progress",
+            "affinity": "REAL",
+            "notNull": true
+          },
+          {
+            "fieldPath": "image",
+            "columnName": "image",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "category",
+            "columnName": "category",
+            "affinity": "TEXT",
+            "notNull": true
+          },
+          {
+            "fieldPath": "chapters",
+            "columnName": "chapters",
+            "affinity": "TEXT",
+            "notNull": true,
+            "defaultValue": "'[]'"
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": true,
+          "columnNames": [
+            "id"
+          ]
+        },
+        "indices": [],
+        "foreignKeys": []
+      },
+      {
+        "tableName": "HistoryEntity",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT NOT NULL, `bookId` INTEGER NOT NULL, `time` INTEGER NOT NULL)",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "bookId",
+            "columnName": "bookId",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "time",
+            "columnName": "time",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": true,
+          "columnNames": [
+            "id"
+          ]
+        },
+        "indices": [],
+        "foreignKeys": []
+      },
+      {
+        "tableName": "ColorPresetEntity",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`id` INTEGER PRIMARY KEY AUTOINCREMENT, `name` TEXT, `backgroundColor` INTEGER NOT NULL, `fontColor` INTEGER NOT NULL, `isSelected` INTEGER NOT NULL, `order` INTEGER NOT NULL)",
+        "fields": [
+          {
+            "fieldPath": "id",
+            "columnName": "id",
+            "affinity": "INTEGER",
+            "notNull": false
+          },
+          {
+            "fieldPath": "name",
+            "columnName": "name",
+            "affinity": "TEXT",
+            "notNull": false
+          },
+          {
+            "fieldPath": "backgroundColor",
+            "columnName": "backgroundColor",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "fontColor",
+            "columnName": "fontColor",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "isSelected",
+            "columnName": "isSelected",
+            "affinity": "INTEGER",
+            "notNull": true
+          },
+          {
+            "fieldPath": "order",
+            "columnName": "order",
+            "affinity": "INTEGER",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": true,
+          "columnNames": [
+            "id"
+          ]
+        },
+        "indices": [],
+        "foreignKeys": []
+      },
+      {
+        "tableName": "FavoriteDirectoryEntity",
+        "createSql": "CREATE TABLE IF NOT EXISTS `${TABLE_NAME}` (`path` TEXT NOT NULL, PRIMARY KEY(`path`))",
+        "fields": [
+          {
+            "fieldPath": "path",
+            "columnName": "path",
+            "affinity": "TEXT",
+            "notNull": true
+          }
+        ],
+        "primaryKey": {
+          "autoGenerate": false,
+          "columnNames": [
+            "path"
+          ]
+        },
+        "indices": [],
+        "foreignKeys": []
+      }
+    ],
+    "views": [],
+    "setupQueries": [
+      "CREATE TABLE IF NOT EXISTS room_master_table (id INTEGER PRIMARY KEY,identity_hash TEXT)",
+      "INSERT OR REPLACE INTO room_master_table (id,identity_hash) VALUES(42, '37c3fbdf5d779680f100fbdfe99121f7')"
+    ]
+  }
+}

app/src/main/java/ua/acclorite/book_story/data/local/converter/ChapterConverter.kt

@@ -0,0 +1,25 @@
+package ua.acclorite.book_story.data.local.converter
+
+import androidx.room.TypeConverter
+import com.google.common.reflect.TypeToken
+import com.google.gson.Gson
+import com.google.gson.JsonSyntaxException
+import ua.acclorite.book_story.domain.model.Chapter
+
+class ChapterConverter {
+    @TypeConverter
+    fun fromChapterList(chapters: List<Chapter>): String {
+        return Gson().toJson(chapters)
+    }
+
+    @TypeConverter
+    fun toChapterList(data: String): List<Chapter> {
+        val listType = object : TypeToken<List<Chapter>>() {}.type
+        return try {
+            Gson().fromJson<List<Chapter>?>(data, listType).sortedBy { it.index }
+        } catch (j: JsonSyntaxException) {
+            j.printStackTrace()
+            emptyList()
+        }
+    }
+}

app/src/main/java/ua/acclorite/book_story/data/local/dto/BookEntity.kt

@@ -1,16 +1,23 @@
 package ua.acclorite.book_story.data.local.dto
 
+import androidx.room.ColumnInfo
 import androidx.room.Entity
 import androidx.room.PrimaryKey
+import androidx.room.TypeConverters
+import ua.acclorite.book_story.data.local.converter.ChapterConverter
 import ua.acclorite.book_story.domain.model.Category
+import ua.acclorite.book_story.domain.model.Chapter
 
 @Entity
+@TypeConverters(ChapterConverter::class)
 data class BookEntity(
     @PrimaryKey(true) val id: Int = 0,
     val title: String,
     val author: String?,
     val description: String?,
     val textPath: String,
+    @ColumnInfo(defaultValue = "[]")
+    val chapters: List<Chapter>,
     val filePath: String,
     val scrollIndex: Int,
     val scrollOffset: Int,

app/src/main/java/ua/acclorite/book_story/data/local/room/BookDatabase.kt

@@ -20,13 +20,14 @@ import ua.acclorite.book_story.data.local.dto.HistoryEntity
         ColorPresetEntity::class,
         FavoriteDirectoryEntity::class,
     ],
-    version = 6,
+    version = 7,
     autoMigrations = [
         AutoMigration(1, 2),
         AutoMigration(2, 3),
         AutoMigration(3, 4, spec = DatabaseHelper.MIGRATION_3_4::class),
         AutoMigration(4, 5),
         AutoMigration(5, 6),
+        AutoMigration(6, 7),
     ],
     exportSchema = true
 )
@@ -72,7 +73,7 @@ object DatabaseHelper {
         }
     }
 
-    val MIGRATION_5_6 = object : Migration(4, 5) {
+    val MIGRATION_5_6 = object : Migration(5, 6) {
         override fun migrate(db: SupportSQLiteDatabase) {
             db.execSQL(
                 "CREATE TABLE IF NOT EXISTS `FavoriteDirectoryEntity` (" +

app/src/main/java/ua/acclorite/book_story/data/mapper/book/BookMapperImpl.kt

@@ -20,7 +20,8 @@ class BookMapperImpl @Inject constructor() : BookMapper {
             textPath = book.textPath,
             description = book.description,
             image = if (book.coverImage != null) book.coverImage.toString() else null,
-            category = book.category
+            category = book.category,
+            chapters = book.chapters
         )
     }
 
@@ -40,6 +41,7 @@ class BookMapperImpl @Inject constructor() : BookMapper {
             lastOpened = null,
             category = bookEntity.category,
             coverImage = if (bookEntity.image != null) Uri.parse(bookEntity.image) else null,
+            chapters = bookEntity.chapters
         )
     }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/FileParserImpl.kt

@@ -1,28 +1,30 @@
 package ua.acclorite.book_story.data.parser
 
+import android.util.Log
 import ua.acclorite.book_story.data.parser.epub.EpubFileParser
 import ua.acclorite.book_story.data.parser.fb2.Fb2FileParser
 import ua.acclorite.book_story.data.parser.htm.HtmFileParser
 import ua.acclorite.book_story.data.parser.html.HtmlFileParser
 import ua.acclorite.book_story.data.parser.pdf.PdfFileParser
 import ua.acclorite.book_story.data.parser.txt.TxtFileParser
-import ua.acclorite.book_story.data.parser.zip.ZipFileParser
 import ua.acclorite.book_story.domain.model.Book
 import ua.acclorite.book_story.domain.util.CoverImage
 import java.io.File
 import javax.inject.Inject
 
+private const val FILE_PARSER = "File Parser"
+
 class FileParserImpl @Inject constructor(
     private val txtFileParser: TxtFileParser,
     private val pdfFileParser: PdfFileParser,
     private val epubFileParser: EpubFileParser,
     private val fb2FileParser: Fb2FileParser,
-    private val zipFileParser: ZipFileParser,
     private val htmlFileParser: HtmlFileParser,
     private val htmFileParser: HtmFileParser,
 ) : FileParser {
     override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
         if (!file.exists()) {
+            Log.e(FILE_PARSER, "File does not exist.")
             return null
         }
 
@@ -45,7 +47,7 @@ class FileParserImpl @Inject constructor(
             }
 
             ".zip" -> {
-                zipFileParser.parse(file)
+                epubFileParser.parse(file)
             }
 
             ".html" -> {
@@ -56,7 +58,10 @@ class FileParserImpl @Inject constructor(
                 htmFileParser.parse(file)
             }
 
-            else -> null
+            else -> {
+                Log.e(FILE_PARSER, "Wrong file format, could not find supported extension.")
+                null
+            }
         }
     }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/TextParser.kt

@@ -1,8 +1,9 @@
 package ua.acclorite.book_story.data.parser
 
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import java.io.File
 
 interface TextParser {
-    suspend fun parse(file: File): Resource<List<String>>
+    suspend fun parse(file: File): Resource<List<ChapterWithText>>
 }

app/src/main/java/ua/acclorite/book_story/data/parser/TextParserImpl.kt

@@ -1,5 +1,6 @@
 package ua.acclorite.book_story.data.parser
 
+import android.util.Log
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.data.parser.epub.EpubTextParser
 import ua.acclorite.book_story.data.parser.fb2.Fb2TextParser
@@ -7,23 +8,25 @@ import ua.acclorite.book_story.data.parser.htm.HtmTextParser
 import ua.acclorite.book_story.data.parser.html.HtmlTextParser
 import ua.acclorite.book_story.data.parser.pdf.PdfTextParser
 import ua.acclorite.book_story.data.parser.txt.TxtTextParser
-import ua.acclorite.book_story.data.parser.zip.ZipTextParser
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
 import java.io.File
 import javax.inject.Inject
 
+private const val TEXT_PARSER = "Text Parser"
+
 class TextParserImpl @Inject constructor(
     private val txtTextParser: TxtTextParser,
     private val pdfTextParser: PdfTextParser,
     private val epubTextParser: EpubTextParser,
     private val fb2TextParser: Fb2TextParser,
-    private val zipTextParser: ZipTextParser,
     private val htmlTextParser: HtmlTextParser,
     private val htmTextParser: HtmTextParser,
 ) : TextParser {
-    override suspend fun parse(file: File): Resource<List<String>> {
+    override suspend fun parse(file: File): Resource<List<ChapterWithText>> {
         if (!file.exists()) {
+            Log.e(TEXT_PARSER, "File does not exist.")
             return Resource.Error(
                 UIText.StringResource(R.string.error_something_went_wrong_with_file)
             )
@@ -48,7 +51,7 @@ class TextParserImpl @Inject constructor(
             }
 
             ".zip" -> {
-                zipTextParser.parse(file)
+                epubTextParser.parse(file)
             }
 
             ".html" -> {
@@ -59,7 +62,10 @@ class TextParserImpl @Inject constructor(
                 htmTextParser.parse(file)
             }
 
-            else -> Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
+            else -> {
+                Log.e(TEXT_PARSER, "Wrong file format, could not find supported extension.")
+                Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
+            }
         }
     }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/epub/EpubFileParser.kt

@@ -18,11 +18,7 @@ import javax.inject.Inject
 class EpubFileParser @Inject constructor() : FileParser {
 
     override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
-        if (!file.name.endsWith(".epub", true) || !file.exists()) {
+        return try {
-            return null
-        }
-
-        try {
             var book: Pair<Book, CoverImage?>? = null
 
             withContext(Dispatchers.IO) {
@@ -90,15 +86,14 @@ class EpubFileParser @Inject constructor() : FileParser {
                     ) to extractCoverImageBitmap(file, coverImage)
                 }
             }
-            return book
+            book
         } catch (e: Exception) {
             e.printStackTrace()
-            return null
+            null
         }
     }
-}
 
-private fun extractCoverImageBitmap(file: File, coverImagePath: String?): Bitmap? {
+    private fun extractCoverImageBitmap(file: File, coverImagePath: String?): Bitmap? {
         if (coverImagePath.isNullOrBlank()) {
             return null
         }
@@ -113,4 +108,5 @@ private fun extractCoverImageBitmap(file: File, coverImagePath: String?): Bitmap
         }
 
         return null
+    }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/epub/EpubTextParser.kt

@@ -1,64 +1,63 @@
 package ua.acclorite.book_story.data.parser.epub
 
+import android.net.Uri
+import android.util.Log
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import org.jsoup.Jsoup
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.data.parser.TextParser
+import ua.acclorite.book_story.domain.model.Chapter
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
 import java.io.File
+import java.util.zip.ZipEntry
 import java.util.zip.ZipFile
 import javax.inject.Inject
 
+private const val EPUB_TAG = "EPUB Parser"
 
 class EpubTextParser @Inject constructor() : TextParser {
 
-    override suspend fun parse(file: File): Resource<List<String>> {
+    override suspend fun parse(file: File): Resource<List<ChapterWithText>> {
-        if (!file.name.endsWith(".epub", true) || !file.exists()) {
+        Log.i(EPUB_TAG, "Started EPUB parsing: ${file.name}.")
-            return Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
-        }
 
-        try {
+        return try {
-            val lines = mutableListOf<String>()
+            val chapters = mutableListOf<ChapterWithText>()
 
             withContext(Dispatchers.IO) {
                 ZipFile(file).use { zip ->
-                    zip.entries().asSequence().forEach { entry ->
+                    zip.entries().asSequence().find { entry ->
-                        if (
+                        entry.name.endsWith("toc.ncx", ignoreCase = true)
-                            entry.name.endsWith(".xhtml")
+                    }.apply {
-                            || entry.name.endsWith(".html")
+                        if (this == null) {
-                            || entry.name.endsWith(".xml")
+                            Log.w(EPUB_TAG, "toc.ncx was not found.")
-                            || entry.name.endsWith(".htm")
+                            parseWithoutToc(zip)?.let { chapters.addAll(it) }
-                        ) {
+                            return@withContext
-                            val content = zip.getInputStream(entry).bufferedReader()
-                                .use {
-                                    it.readText()
                         }
 
-                            val document = Jsoup.parse(content)
+                        parseWithToc(this, zip).apply {
-                            document.select("p").append("\n")
+                            if (this == null) {
-                            document
+                                parseWithoutToc(zip)?.let { chapters.addAll(it) }
-                                .wholeText()
+                                return@withContext
-                                .lines()
-                                .forEach { line ->
-                                    if (line.isNotBlank()) {
-                                        lines.add(line.trim())
-                                    }
                             }
+
+                            chapters.addAll(this)
                         }
                     }
                 }
             }
 
-            if (lines.isEmpty()) {
+            if (chapters.isEmpty()) {
                 return Resource.Error(UIText.StringResource(R.string.error_file_empty))
             }
 
-            return Resource.Success(lines)
+            Log.i(EPUB_TAG, "Successfully finished EPUB parsing.")
+            Resource.Success(chapters)
         } catch (e: Exception) {
             e.printStackTrace()
-            return Resource.Error(
+            Resource.Error(
                 UIText.StringResource(
                     R.string.error_query,
                     e.message?.take(40)?.trim() ?: ""
@@ -66,4 +65,166 @@ class EpubTextParser @Inject constructor() : TextParser {
             )
         }
     }
+
+    /**
+     * Parses text if no toc.ncx found, which is Table of Content.
+     *
+     * @return Null if could not parse.
+     */
+    private fun parseWithoutToc(zip: ZipFile): List<ChapterWithText>? {
+        val chapters = mutableListOf<ChapterWithText>()
+        var chapterTextIndex = -1
+        var chapterIndex = 1
+
+        zip.entries().asSequence().sortedBy { it.name }.forEach { entry ->
+            if (
+                !entry.name.endsWith(".xhtml")
+                && !entry.name.endsWith(".html")
+                && !entry.name.endsWith(".xml")
+                && !entry.name.endsWith(".htm")
+                || entry.name.endsWith("container.xml")
+            ) return@forEach
+
+            val chapter = zip.parseDocument(entry = entry, fragment = null)
+            if (chapter.isEmpty()) {
+                Log.w(EPUB_TAG, "Chapter ${entry.name} is empty.")
+                return@forEach
+            }
+
+            chapters.add(
+                ChapterWithText(
+                    chapter = Chapter(
+                        index = chapters.size,
+                        title = "Chapter $chapterIndex", // Generic name, but at least something
+                        startIndex = chapterTextIndex + 1,
+                        endIndex = chapterTextIndex + chapter.size
+                    ),
+                    text = chapter
+                )
+            )
+            chapterTextIndex += chapter.size
+            chapterIndex++
+        }
+
+        if (chapters.isEmpty()) {
+            Log.e(EPUB_TAG, "Could not parse file without toc.ncx")
+            return null
+        }
+
+        return chapters
+    }
+
+    /**
+     * Parses text with toc.ncx. Extracts all chapters.
+     *
+     * @return Null if could not parse toc.ncx.
+     */
+    private fun parseWithToc(tocEntry: ZipEntry, zip: ZipFile): List<ChapterWithText>? {
+        Log.i(EPUB_TAG, "TOC Entry: ${tocEntry.name}")
+
+        val chapters = mutableListOf<ChapterWithText>()
+        var emptyChapters = 0
+        var chapterTextIndex = -1
+        var chapterIndex = 1
+
+        val tocContent = zip.getInputStream(tocEntry)
+            .bufferedReader()
+            .use { it.readText() }
+        val tocDocument = Jsoup.parse(tocContent)
+
+        tocDocument.select("navPoint").forEach { navPoint ->
+            val chapterTitle = navPoint.selectFirst("navLabel > text")?.text()?.trim()
+                ?: "Chapter $chapterIndex"
+            val chapterSrc = navPoint.selectFirst("content")?.attr("src")?.trim()
+                .run {
+                    if (this == null) {
+                        Log.e(EPUB_TAG, "No source of the chapter found: $chapterTitle")
+                        return null
+                    }
+
+                    val uri = Uri.parse(this) ?: return@run this to null
+                    (uri.path ?: this) to uri.fragment
+                }
+
+            zip.entries().asSequence().find { entry ->
+                entry.name.endsWith(chapterSrc.first)
+            }.apply {
+                if (this == null) {
+                    Log.e(EPUB_TAG, "No chapter entry found: $chapterTitle")
+                    return null
+                }
+
+                val chapter = zip.parseDocument(
+                    entry = this,
+                    fragment = chapterSrc.second
+                ).dropWhile {
+                    it == chapterTitle // Remove chapter title if present
+                }
+                if (chapter.isEmpty()) {
+                    Log.w(EPUB_TAG, "Chapter $chapterTitle is empty.")
+                    emptyChapters += 1
+                    return@forEach
+                }
+
+                chapters.add(
+                    ChapterWithText(
+                        chapter = Chapter(
+                            index = chapters.size,
+                            title = chapterTitle,
+                            startIndex = chapterTextIndex + 1,
+                            endIndex = chapterTextIndex + chapter.size
+                        ),
+                        text = chapter
+                    )
+                )
+                chapterTextIndex += chapter.size
+                chapterIndex++
+            }
+        }
+
+        if (chapters.isEmpty()) {
+            Log.e(EPUB_TAG, "Could not parse text with toc.ncx")
+            return null
+        }
+
+        if (emptyChapters >= ((emptyChapters + chapters.size) * 0.25f)) {
+            Log.e(EPUB_TAG, "More than 25% of the chapters are empty.")
+            return null
+        }
+
+        return chapters
+    }
+
+    /**
+     * Parses [entry] to get it's text.
+     *
+     * @return Parsed text line by line. Can have line break issues due to bad [entry] formatting.
+     */
+    private fun ZipFile.parseDocument(entry: ZipEntry, fragment: String?): List<String> {
+        val lines = mutableListOf<String>()
+        val content = getInputStream(entry)
+            .bufferedReader()
+            .use {
+                it.readText()
+            }
+
+        val document = Jsoup.parse(content)
+        document.select("p").append("\n")
+        document.select("head > title").remove()
+
+        document
+            .run {
+                fragment?.let { return@run getElementById(it) ?: this }
+                this
+            }
+            .wholeText()
+            .lines()
+            .forEach { line ->
+                if (line.isNotBlank()) {
+                    lines.add(line.trim())
+                }
+            }
+
+        return lines
+    }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/fb2/Fb2FileParser.kt

@@ -17,11 +17,7 @@ import javax.xml.parsers.DocumentBuilderFactory
 class Fb2FileParser @Inject constructor() : FileParser {
 
     override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
-        if (!file.name.endsWith(".fb2", true) || !file.exists()) {
+        return try {
-            return null
-        }
-
-        try {
             val factory = DocumentBuilderFactory.newInstance()
             val builder = factory.newDocumentBuilder()
             val document = withContext(Dispatchers.IO) {
@@ -54,7 +50,7 @@ class Fb2FileParser @Inject constructor() : FileParser {
 
             val descriptionFromFile = extractElementContent(document, "annotation")
 
-            return Book(
+            Book(
                 title = title,
                 author = author,
                 description = descriptionFromFile,
@@ -69,7 +65,7 @@ class Fb2FileParser @Inject constructor() : FileParser {
             ) to null
         } catch (e: Exception) {
             e.printStackTrace()
-            return null
+            null
         }
     }
 

app/src/main/java/ua/acclorite/book_story/data/parser/fb2/Fb2TextParser.kt

@@ -1,23 +1,26 @@
 package ua.acclorite.book_story.data.parser.fb2
 
+import android.util.Log
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import org.w3c.dom.Element
 import org.w3c.dom.NodeList
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.data.parser.TextParser
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
+import ua.acclorite.book_story.presentation.core.constants.Constants
 import java.io.File
 import javax.inject.Inject
 import javax.xml.parsers.DocumentBuilderFactory
 
+private const val FB2_TAG = "FB2 Parser"
+
 class Fb2TextParser @Inject constructor() : TextParser {
 
-    override suspend fun parse(file: File): Resource<List<String>> {
+    override suspend fun parse(file: File): Resource<List<ChapterWithText>> {
-        if (!file.name.endsWith(".fb2", true) || !file.exists()) {
+        Log.i(FB2_TAG, "Started FB2 parsing: ${file.name}.")
-            return Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
-        }
 
         return try {
             val factory = DocumentBuilderFactory.newInstance()
@@ -38,6 +41,7 @@ class Fb2TextParser @Inject constructor() : TextParser {
             val unformattedLines = mutableListOf<String>()
             val bodyNode = bodyNodes.item(0) as Element
             val paragraphNodes = bodyNode.getElementsByTagName("p")
+
             for (element in paragraphNodes.asList()) {
                 if (element.textContent.isBlank()) {
                     continue
@@ -100,7 +104,15 @@ class Fb2TextParser @Inject constructor() : TextParser {
                 return Resource.Error(UIText.StringResource(R.string.error_file_empty))
             }
 
-            Resource.Success(formattedLines)
+            Log.i(FB2_TAG, "Successfully finished FB2 parsing.")
+            Resource.Success(
+                listOf(
+                    ChapterWithText(
+                        chapter = Constants.EMPTY_CHAPTER,
+                        text = formattedLines
+                    )
+                )
+            )
         } catch (e: Exception) {
             e.printStackTrace()
             Resource.Error(

app/src/main/java/ua/acclorite/book_story/data/parser/htm/HtmFileParser.kt

@@ -13,11 +13,7 @@ import javax.inject.Inject
 class HtmFileParser @Inject constructor() : FileParser {
 
     override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
-        if (!file.name.endsWith(".htm", true) || !file.exists()) {
+        return try {
-            return null
-        }
-
-        try {
             val document = Jsoup.parse(file)
 
             val title = document.select("head > title").text().trim().run {
@@ -26,7 +22,7 @@ class HtmFileParser @Inject constructor() : FileParser {
                 }
             }
 
-            return Book(
+            Book(
                 title = title,
                 author = UIText.StringResource(R.string.unknown_author),
                 description = null,
@@ -41,7 +37,7 @@ class HtmFileParser @Inject constructor() : FileParser {
             ) to null
         } catch (e: Exception) {
             e.printStackTrace()
-            return null
+            null
         }
     }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/htm/HtmTextParser.kt

@@ -1,26 +1,30 @@
 package ua.acclorite.book_story.data.parser.htm
 
+import android.util.Log
 import org.jsoup.Jsoup
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.data.parser.TextParser
+import ua.acclorite.book_story.domain.model.Chapter
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
 import java.io.File
 import javax.inject.Inject
 
+private const val HTM_TAG = "HTM Parser"
 
 class HtmTextParser @Inject constructor() : TextParser {
 
-    override suspend fun parse(file: File): Resource<List<String>> {
+    override suspend fun parse(file: File): Resource<List<ChapterWithText>> {
-        if (!file.name.endsWith(".htm", true) || !file.exists()) {
+        Log.i(HTM_TAG, "Started HTM parsing: ${file.name}.")
-            return Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
-        }
 
-        try {
+        return try {
             val lines = mutableListOf<String>()
 
             val document = Jsoup.parse(file)
             document.select("p").append("\n")
+            document.select("head > title").remove()
+
             document
                 .wholeText()
                 .lines()
@@ -34,10 +38,18 @@ class HtmTextParser @Inject constructor() : TextParser {
                 return Resource.Error(UIText.StringResource(R.string.error_file_empty))
             }
 
-            return Resource.Success(lines)
+            Log.i(HTM_TAG, "Successfully finished HTM parsing.")
+            Resource.Success(
+                listOf(
+                    ChapterWithText(
+                        chapter = Chapter(title = "", startIndex = 0, endIndex = 0),
+                        text = lines
+                    )
+                )
+            )
         } catch (e: Exception) {
             e.printStackTrace()
-            return Resource.Error(
+            Resource.Error(
                 UIText.StringResource(
                     R.string.error_query,
                     e.message?.take(40)?.trim() ?: ""

app/src/main/java/ua/acclorite/book_story/data/parser/html/HtmlFileParser.kt

@@ -13,11 +13,7 @@ import javax.inject.Inject
 class HtmlFileParser @Inject constructor() : FileParser {
 
     override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
-        if (!file.name.endsWith(".html", true) || !file.exists()) {
+        return try {
-            return null
-        }
-
-        try {
             val document = Jsoup.parse(file)
 
             val title = document.select("head > title").text().trim().run {
@@ -26,7 +22,7 @@ class HtmlFileParser @Inject constructor() : FileParser {
                 }
             }
 
-            return Book(
+            Book(
                 title = title,
                 author = UIText.StringResource(R.string.unknown_author),
                 description = null,
@@ -41,7 +37,7 @@ class HtmlFileParser @Inject constructor() : FileParser {
             ) to null
         } catch (e: Exception) {
             e.printStackTrace()
-            return null
+            null
         }
     }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/html/HtmlTextParser.kt

@@ -1,26 +1,30 @@
 package ua.acclorite.book_story.data.parser.html
 
+import android.util.Log
 import org.jsoup.Jsoup
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.data.parser.TextParser
+import ua.acclorite.book_story.domain.model.Chapter
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
 import java.io.File
 import javax.inject.Inject
 
+private const val HTML_TAG = "HTML Parser"
 
 class HtmlTextParser @Inject constructor() : TextParser {
 
-    override suspend fun parse(file: File): Resource<List<String>> {
+    override suspend fun parse(file: File): Resource<List<ChapterWithText>> {
-        if (!file.name.endsWith(".html", true) || !file.exists()) {
+        Log.i(HTML_TAG, "Started HTML parsing: ${file.name}.")
-            return Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
-        }
 
-        try {
+        return try {
             val lines = mutableListOf<String>()
 
             val document = Jsoup.parse(file)
             document.select("p").append("\n")
+            document.select("head > title").remove()
+
             document
                 .wholeText()
                 .lines()
@@ -34,10 +38,18 @@ class HtmlTextParser @Inject constructor() : TextParser {
                 return Resource.Error(UIText.StringResource(R.string.error_file_empty))
             }
 
-            return Resource.Success(lines)
+            Log.i(HTML_TAG, "Successfully finished HTML parsing.")
+            Resource.Success(
+                listOf(
+                    ChapterWithText(
+                        chapter = Chapter(title = "", startIndex = 0, endIndex = 0),
+                        text = lines
+                    )
+                )
+            )
         } catch (e: Exception) {
             e.printStackTrace()
-            return Resource.Error(
+            Resource.Error(
                 UIText.StringResource(
                     R.string.error_query,
                     e.message?.take(40)?.trim() ?: ""

app/src/main/java/ua/acclorite/book_story/data/parser/pdf/PdfFileParser.kt

@@ -15,11 +15,7 @@ import javax.inject.Inject
 class PdfFileParser @Inject constructor(private val application: Application) : FileParser {
 
     override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
-        if (!file.name.endsWith(".pdf", true) || !file.exists()) {
+        return try {
-            return null
-        }
-
-        try {
             PDFBoxResourceLoader.init(application)
 
             val document = PDDocument.load(file)
@@ -33,7 +29,7 @@ class PdfFileParser @Inject constructor(private val application: Application) :
 
             document.close()
 
-            return Book(
+            Book(
                 title = title,
                 author = author,
                 description = description,
@@ -48,7 +44,7 @@ class PdfFileParser @Inject constructor(private val application: Application) :
             ) to null
         } catch (e: Exception) {
             e.printStackTrace()
-            return null
+            null
         }
     }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/pdf/PdfTextParser.kt

@@ -1,26 +1,25 @@
 package ua.acclorite.book_story.data.parser.pdf
 
-import android.app.Application
+import android.util.Log
-import com.tom_roush.pdfbox.android.PDFBoxResourceLoader
 import com.tom_roush.pdfbox.pdmodel.PDDocument
 import com.tom_roush.pdfbox.text.PDFTextStripper
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.data.parser.TextParser
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
+import ua.acclorite.book_story.presentation.core.constants.Constants
 import java.io.File
 import javax.inject.Inject
 
-class PdfTextParser @Inject constructor(private val application: Application) : TextParser {
+private const val PDF_TAG = "PDF Parser"
 
-    override suspend fun parse(file: File): Resource<List<String>> {
+class PdfTextParser @Inject constructor() : TextParser {
-        if (!file.name.endsWith(".pdf", true) || !file.exists()) {
-            return Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
-        }
 
-        try {
+    override suspend fun parse(file: File): Resource<List<ChapterWithText>> {
-            PDFBoxResourceLoader.init(application)
+        Log.i(PDF_TAG, "Started PDF parsing: ${file.name}.")
 
+        return try {
             val document = PDDocument.load(file)
             val strings = mutableListOf<String>()
 
@@ -95,10 +94,18 @@ class PdfTextParser @Inject constructor(private val application: Application) :
                 return Resource.Error(UIText.StringResource(R.string.error_file_empty))
             }
 
-            return Resource.Success(strings)
+            Log.i(PDF_TAG, "Successfully finished PDF parsing.")
+            Resource.Success(
+                listOf(
+                    ChapterWithText(
+                        chapter = Constants.EMPTY_CHAPTER,
+                        text = strings
+                    )
+                )
+            )
         } catch (e: Exception) {
             e.printStackTrace()
-            return Resource.Error(
+            Resource.Error(
                 UIText.StringResource(
                     R.string.error_query,
                     e.message?.take(40)?.trim() ?: ""

app/src/main/java/ua/acclorite/book_story/data/parser/txt/TxtFileParser.kt

@@ -12,15 +12,11 @@ import javax.inject.Inject
 class TxtFileParser @Inject constructor() : FileParser {
 
     override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
-        if (!file.name.endsWith(".txt", true) || !file.exists()) {
+        return try {
-            return null
-        }
-
-        try {
             val title = file.nameWithoutExtension.trim()
             val author = UIText.StringResource(R.string.unknown_author)
 
-            return Book(
+            Book(
                 title = title,
                 author = author,
                 description = null,
@@ -35,7 +31,7 @@ class TxtFileParser @Inject constructor() : FileParser {
             ) to null
         } catch (e: Exception) {
             e.printStackTrace()
-            return null
+            null
         }
     }
 }

app/src/main/java/ua/acclorite/book_story/data/parser/txt/TxtTextParser.kt

@@ -1,41 +1,52 @@
 package ua.acclorite.book_story.data.parser.txt
 
+import android.util.Log
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import ua.acclorite.book_story.R
 import ua.acclorite.book_story.data.parser.TextParser
+import ua.acclorite.book_story.domain.model.ChapterWithText
 import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
+import ua.acclorite.book_story.presentation.core.constants.Constants
 import java.io.BufferedReader
 import java.io.File
 import java.io.FileReader
 import javax.inject.Inject
 
+private const val TXT_TAG = "TXT Parser"
+
 class TxtTextParser @Inject constructor() : TextParser {
 
-    override suspend fun parse(file: File): Resource<List<String>> {
+    override suspend fun parse(file: File): Resource<List<ChapterWithText>> {
-        if (!file.name.endsWith(".txt", true) || !file.exists()) {
+        Log.i(TXT_TAG, "Started TXT parsing: ${file.name}.")
-            return Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
-        }
 
         return try {
-            val formattedLines = mutableListOf<String>()
+            val lines = mutableListOf<String>()
 
             withContext(Dispatchers.IO) {
                 BufferedReader(FileReader(file)).forEachLine { line ->
                     if (line.isNotBlank()) {
-                        formattedLines.add(
+                        lines.add(
                             line.trim()
                         )
                     }
                 }
             }
 
-            if (formattedLines.isEmpty()) {
+            if (lines.isEmpty()) {
                 return Resource.Error(UIText.StringResource(R.string.error_file_empty))
             }
 
-            Resource.Success(formattedLines)
+            Log.i(TXT_TAG, "Successfully finished TXT parsing.")
+            Resource.Success(
+                listOf(
+                    ChapterWithText(
+                        chapter = Constants.EMPTY_CHAPTER,
+                        text = lines
+                    )
+                )
+            )
         } catch (e: Exception) {
             e.printStackTrace()
             Resource.Error(

app/src/main/java/ua/acclorite/book_story/data/parser/zip/ZipFileParser.kt

@@ -1,116 +0,0 @@
-package ua.acclorite.book_story.data.parser.zip
-
-import android.graphics.Bitmap
-import android.graphics.BitmapFactory
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.withContext
-import org.jsoup.Jsoup
-import ua.acclorite.book_story.R
-import ua.acclorite.book_story.data.parser.FileParser
-import ua.acclorite.book_story.domain.model.Book
-import ua.acclorite.book_story.domain.model.Category
-import ua.acclorite.book_story.domain.util.CoverImage
-import ua.acclorite.book_story.domain.util.UIText
-import java.io.File
-import java.util.zip.ZipFile
-import javax.inject.Inject
-
-class ZipFileParser @Inject constructor() : FileParser {
-
-    override suspend fun parse(file: File): Pair<Book, CoverImage?>? {
-        if (!file.name.endsWith(".zip", true) || !file.exists()) {
-            return null
-        }
-
-        try {
-            var book: Pair<Book, CoverImage?>? = null
-
-            withContext(Dispatchers.IO) {
-                ZipFile(file).use { zip ->
-                    val opfEntry = zip.entries().asSequence().find { entry ->
-                        entry.name.endsWith(".opf")
-                    } ?: return@withContext
-
-                    val opfContent = zip
-                        .getInputStream(opfEntry)
-                        .bufferedReader()
-                        .use { it.readText() }
-                    val document = Jsoup.parse(opfContent)
-
-                    val title = document.select("metadata > dc|title").text().trim().run {
-                        ifBlank {
-                            file.nameWithoutExtension.trim()
-                        }
-                    }
-
-                    val author = document.select("metadata > dc|creator").text().trim().run {
-                        if (isBlank()) {
-                            UIText.StringResource(R.string.unknown_author)
-                        } else {
-                            UIText.StringValue(this)
-                        }
-                    }
-
-                    val description = Jsoup.parse(
-                        document.select("metadata > dc|description").text()
-                    ).text().run {
-                        ifBlank {
-                            null
-                        }
-                    }
-
-                    val coverImage = document
-                        .select("metadata > meta[name=cover]")
-                        .attr("content")
-                        .run {
-                            if (isNotBlank()) {
-                                document
-                                    .select("manifest > item[id=$this]")
-                                    .attr("href")
-                                    .apply { if (isNotBlank()) return@run this }
-                            }
-
-                            document
-                                .select("manifest > item[media-type*=image]")
-                                .firstOrNull()?.attr("href")
-                        }
-
-                    book = Book(
-                        title = title,
-                        author = author,
-                        description = description,
-                        textPath = "",
-                        scrollIndex = 0,
-                        scrollOffset = 0,
-                        progress = 0f,
-                        filePath = file.path,
-                        lastOpened = null,
-                        category = Category.entries[0],
-                        coverImage = null
-                    ) to extractCoverImageBitmap(file, coverImage)
-                }
-            }
-            return book
-        } catch (e: Exception) {
-            e.printStackTrace()
-            return null
-        }
-    }
-}
-
-private fun extractCoverImageBitmap(file: File, coverImagePath: String?): Bitmap? {
-    if (coverImagePath.isNullOrBlank()) {
-        return null
-    }
-
-    ZipFile(file).use { zip ->
-        zip.entries().asSequence().forEach { entry ->
-            if (entry.name.endsWith(coverImagePath)) {
-                val imageBytes = zip.getInputStream(entry).readBytes()
-                return BitmapFactory.decodeByteArray(imageBytes, 0, imageBytes.size)
-            }
-        }
-    }
-
-    return null
-}

app/src/main/java/ua/acclorite/book_story/data/parser/zip/ZipTextParser.kt

@@ -1,69 +0,0 @@
-package ua.acclorite.book_story.data.parser.zip
-
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.withContext
-import org.jsoup.Jsoup
-import ua.acclorite.book_story.R
-import ua.acclorite.book_story.data.parser.TextParser
-import ua.acclorite.book_story.domain.util.Resource
-import ua.acclorite.book_story.domain.util.UIText
-import java.io.File
-import java.util.zip.ZipFile
-import javax.inject.Inject
-
-
-class ZipTextParser @Inject constructor() : TextParser {
-
-    override suspend fun parse(file: File): Resource<List<String>> {
-        if (!file.name.endsWith(".zip", true) || !file.exists()) {
-            return Resource.Error(UIText.StringResource(R.string.error_wrong_file_format))
-        }
-
-        try {
-            val lines = mutableListOf<String>()
-
-            withContext(Dispatchers.IO) {
-                ZipFile(file).use { zip ->
-                    zip.entries().asSequence().forEach { entry ->
-                        if (
-                            entry.name.endsWith(".xhtml")
-                            || entry.name.endsWith(".html")
-                            || entry.name.endsWith(".xml")
-                            || entry.name.endsWith(".htm")
-                        ) {
-                            val content = zip.getInputStream(entry).bufferedReader()
-                                .use {
-                                    it.readText()
-                                }
-
-                            val document = Jsoup.parse(content)
-                            document.select("p").append("\n")
-                            document
-                                .wholeText()
-                                .lines()
-                                .forEach { line ->
-                                    if (line.isNotBlank()) {
-                                        lines.add(line.trim())
-                                    }
-                                }
-                        }
-                    }
-                }
-            }
-
-            if (lines.isEmpty()) {
-                return Resource.Error(UIText.StringResource(R.string.error_file_empty))
-            }
-
-            return Resource.Success(lines)
-        } catch (e: Exception) {
-            e.printStackTrace()
-            return Resource.Error(
-                UIText.StringResource(
-                    R.string.error_query,
-                    e.message?.take(40)?.trim() ?: ""
-                )
-            )
-        }
-    }
-}

app/src/main/java/ua/acclorite/book_story/data/repository/BookRepositoryImpl.kt

@@ -40,13 +40,18 @@ import ua.acclorite.book_story.domain.util.Resource
 import ua.acclorite.book_story.domain.util.UIText
 import ua.acclorite.book_story.presentation.core.constants.Constants
 import ua.acclorite.book_story.presentation.data.MainState
+import java.io.BufferedReader
 import java.io.ByteArrayOutputStream
 import java.io.File
 import java.io.FileOutputStream
+import java.io.FileReader
 import java.util.UUID
 import javax.inject.Inject
 import javax.inject.Singleton
 
+private const val GET_BOOK_FROM_FILE = "GET BOOK FROM FILE, REPOSITORY"
+private const val GET_TEXT = "GET TEXT, REPOSITORY"
+
 @Suppress("DEPRECATION")
 @Singleton
 class BookRepositoryImpl @Inject constructor(
@@ -96,21 +101,31 @@ class BookRepositoryImpl @Inject constructor(
         }
     }
 
+    /**
+     * Loads text from given path. Should be .txt.
+     * Used to get text from book and load Reader.
+     */
     override suspend fun getBookText(textPath: String): List<String> {
         val textFile = File(textPath)
+        val lines = mutableListOf<String>()
 
-        if (textPath.isBlank() || !textFile.exists()) {
+        if (textPath.isBlank() || !textFile.exists() || textFile.extension != "txt") {
-            Log.w("BOOK TEXT", "Failed to load file")
+            Log.w(GET_TEXT, "Failed to load file: $textPath")
             return emptyList()
         }
 
-        val text = textParser.parse(textFile)
+        withContext(Dispatchers.IO) {
-
+            BufferedReader(FileReader(textFile)).forEachLine { line ->
-        if (text.data.isNullOrEmpty()) {
+                if (line.isNotBlank()) {
-            return emptyList()
+                    lines.add(
+                        line.trim()
+                    )
+                }
+            }
         }
 
-        return text.data
+        Log.i(GET_TEXT, "Successfully loaded text.")
+        return lines
     }
 
     override suspend fun insertBook(
@@ -555,74 +570,40 @@ class BookRepositoryImpl @Inject constructor(
         return rootDirectory.getAllFiles()
     }
 
-    override suspend fun getBooksFromFiles(files: List<File>): List<NullableBook> {
+    /**
-        val books = mutableListOf<NullableBook>()
+     * Gets book from given file. If error happened, returns [NullableBook.Null].
-
+     */
-        for (file in files) {
+    override suspend fun getBookFromFile(file: File): NullableBook {
-            val parsedBook = if (Constants.EXTENSIONS.any { file.name.endsWith(it, true) }) {
+        val parsedBook = fileParser.parse(file)
-                fileParser.parse(file)
-            } else {
-                books.add(
-                    NullableBook.Null(
-                        file.name,
-                        UIText.StringResource(R.string.error_wrong_file_format)
-                    )
-                )
-                continue
-            }
-
-            val parsedText = if (Constants.EXTENSIONS.any { file.name.endsWith(it, true) }) {
-                textParser.parse(file)
-            } else {
-                books.add(
-                    NullableBook.Null(
-                        file.name,
-                        UIText.StringResource(R.string.error_wrong_file_format)
-                    )
-                )
-                continue
-            }
-
         if (parsedBook == null) {
-                books.add(
+            Log.w(GET_BOOK_FROM_FILE, "Parsed book(${file.name}) is null.")
-                    NullableBook.Null(
+            return NullableBook.Null(
                 file.name,
-                        UIText.StringResource(R.string.error_something_went_wrong_with_file)
+                UIText.StringResource(R.string.error_wrong_file_format)
             )
-                )
-                continue
         }
 
+        val parsedText = textParser.parse(file)
         if (parsedText is Resource.Error) {
-                books.add(
+            Log.w(GET_BOOK_FROM_FILE, "Parsed text(${file.name}) has error.")
-                    NullableBook.Null(
+            return NullableBook.Null(
                 file.name,
                 parsedText.message
             )
-                )
-                continue
         }
 
-            if (parsedText.data == null) {
+        return NullableBook.NotNull(
-                books.add(
+            book = parsedBook.first.copy(
-                    NullableBook.Null(
+                chapters = parsedText.data!!.map { it.chapter }.run {
-                        file.name,
+                    if (this.size == 1) return@run emptyList()
-                        UIText.StringResource(R.string.error_file_empty)
+                    this
-                    )
-                )
-                continue
                 }
-
+            ),
-            books.add(
-                NullableBook.NotNull(
-                    book = parsedBook.first,
             coverImage = parsedBook.second,
-                    text = parsedText.data
+            text = parsedText.data.map {
+                it.text
+            }.flatten()
         )
-            )
-        }
-
-        return books
     }
 
     override suspend fun insertHistory(history: List<History>) {

app/src/main/java/ua/acclorite/book_story/domain/model/Book.kt

@@ -19,6 +19,7 @@ data class Book(
     val scrollIndex: Int,
     val scrollOffset: Int,
     val progress: Float,
+    val chapters: List<Chapter> = emptyList(),
 
     val lastOpened: Long?,
     val category: Category,

app/src/main/java/ua/acclorite/book_story/domain/model/Chapter.kt

@@ -0,0 +1,20 @@
+package ua.acclorite.book_story.domain.model
+
+import android.os.Parcelable
+import androidx.compose.runtime.Immutable
+import kotlinx.parcelize.Parcelize
+
+@Parcelize
+@Immutable
+data class Chapter(
+    val index: Int = 0,
+    val title: String,
+    val startIndex: Int,
+    val endIndex: Int
+) : Parcelable
+
+@Immutable
+data class ChapterWithText(
+    val chapter: Chapter,
+    val text: List<String>
+)

app/src/main/java/ua/acclorite/book_story/domain/repository/BookRepository.kt

@@ -68,7 +68,7 @@ interface BookRepository {
 
     suspend fun getFilesFromDevice(query: String = ""): List<SelectableFile>
 
-    suspend fun getBooksFromFiles(files: List<File>): List<NullableBook>
+    suspend fun getBookFromFile(file: File): NullableBook
 
 
     suspend fun insertHistory(history: List<History>)

app/src/main/java/ua/acclorite/book_story/domain/use_case/GetBookFromFile.kt

@@ -10,6 +10,6 @@ class GetBookFromFile @Inject constructor(
 ) {
 
     suspend fun execute(file: File): NullableBook {
-        return repository.getBooksFromFiles(listOf(file)).first()
+        return repository.getBookFromFile(file)
     }
 }

app/src/main/java/ua/acclorite/book_story/domain/use_case/UpdateBook.kt

@@ -4,9 +4,9 @@ import ua.acclorite.book_story.domain.model.Book
 import ua.acclorite.book_story.domain.repository.BookRepository
 import javax.inject.Inject
 
-class UpdateBooks @Inject constructor(private val repository: BookRepository) {
+class UpdateBook @Inject constructor(private val repository: BookRepository) {
 
-    suspend fun execute(books: List<Book>) {
+    suspend fun execute(book: Book) {
-        repository.updateBooks(books)
+        repository.updateBooks(listOf(book))
     }
 }

app/src/main/java/ua/acclorite/book_story/presentation/core/constants/Constants.kt

@@ -19,6 +19,7 @@ import ua.acclorite.book_story.R
 import ua.acclorite.book_story.domain.model.Badge
 import ua.acclorite.book_story.domain.model.Book
 import ua.acclorite.book_story.domain.model.Category
+import ua.acclorite.book_story.domain.model.Chapter
 import ua.acclorite.book_story.domain.model.ColorPreset
 import ua.acclorite.book_story.domain.model.Credit
 import ua.acclorite.book_story.domain.model.FontWithName
@@ -64,6 +65,9 @@ object Constants {
     // Default Color Preset (Used when creating new color presets)
     val DEFAULT_COLOR_PRESET = provideDefaultColorPreset()
 
+    // Empty Chapter
+    val EMPTY_CHAPTER = provideEmptyChapter()
+
     // Scrollbars (Primary unused, awaiting for fixes)
     val PRIMARY_SCROLLBAR @Composable get() = providePrimaryScrollbar()
     val SECONDARY_SCROLLBAR @Composable get() = provideSecondaryScrollbar()
@@ -582,6 +586,13 @@ private fun provideDefaultColorPreset() = ColorPreset(
     isSelected = false
 )
 
+private fun provideEmptyChapter() = Chapter(
+    index = 0,
+    title = "",
+    startIndex = 0,
+    endIndex = 0
+)
+
 @Composable
 private fun providePrimaryScrollbar() = ScrollbarSettings(
     thumbUnselectedColor = MaterialTheme.colorScheme.primary,

app/src/main/java/ua/acclorite/book_story/presentation/screens/book_info/data/BookInfoViewModel.kt

@@ -30,8 +30,8 @@ import ua.acclorite.book_story.domain.use_case.GetBookFromFile
 import ua.acclorite.book_story.domain.use_case.GetText
 import ua.acclorite.book_story.domain.use_case.InsertHistory
 import ua.acclorite.book_story.domain.use_case.ResetCoverImage
+import ua.acclorite.book_story.domain.use_case.UpdateBook
 import ua.acclorite.book_story.domain.use_case.UpdateBookWithText
-import ua.acclorite.book_story.domain.use_case.UpdateBooks
 import ua.acclorite.book_story.domain.use_case.UpdateCoverImageOfBook
 import ua.acclorite.book_story.domain.util.OnNavigate
 import ua.acclorite.book_story.domain.util.UIText
@@ -44,7 +44,7 @@ import javax.inject.Inject
 
 @HiltViewModel
 class BookInfoViewModel @Inject constructor(
-    private val updateBooks: UpdateBooks,
+    private val updateBook: UpdateBook,
     private val updateBookWithText: UpdateBookWithText,
     private val updateCoverImageOfBook: UpdateCoverImageOfBook,
     private val insertHistory: InsertHistory,
@@ -307,7 +307,7 @@ class BookInfoViewModel @Inject constructor(
                             else _state.value.book.description
                         )
 
-                        updateBooks.execute(listOf(book))
+                        updateBook.execute(book)
                         _state.update {
                             it.copy(
                                 book = book
@@ -385,7 +385,7 @@ class BookInfoViewModel @Inject constructor(
                                 )
                             )
                         }
-                        updateBooks.execute(listOf(_state.value.book))
+                        updateBook.execute(_state.value.book)
 
                         event.refreshList(_state.value.book)
                         event.updatePage(

app/src/main/java/ua/acclorite/book_story/presentation/screens/library/data/LibraryViewModel.kt

@@ -16,7 +16,7 @@ import ua.acclorite.book_story.domain.model.History
 import ua.acclorite.book_story.domain.use_case.DeleteBooks
 import ua.acclorite.book_story.domain.use_case.GetBooks
 import ua.acclorite.book_story.domain.use_case.InsertHistory
-import ua.acclorite.book_story.domain.use_case.UpdateBooks
+import ua.acclorite.book_story.domain.use_case.UpdateBook
 import ua.acclorite.book_story.presentation.core.navigation.Screen
 import ua.acclorite.book_story.presentation.core.util.BaseViewModel
 import java.util.Date
@@ -25,7 +25,7 @@ import javax.inject.Inject
 @HiltViewModel
 class LibraryViewModel @Inject constructor(
     private val getBooks: GetBooks,
-    private val updateBooks: UpdateBooks,
+    private val updateBook: UpdateBook,
     private val deleteBooks: DeleteBooks,
     private val insertHistory: InsertHistory
 ) : BaseViewModel<LibraryState, LibraryEvent>() {
@@ -240,7 +240,7 @@ class LibraryViewModel @Inject constructor(
                     val books = _state.value.books.filter {
                         it.second
                     }.map { it.first.copy(category = _state.value.selectedCategory) }
-                    updateBooks.execute(books)
+                    books.forEach { updateBook.execute(it) }
 
                     _state.update {
                         it.copy(

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/ReaderScreen.kt

@@ -60,6 +60,7 @@ import androidx.core.view.WindowInsetsCompat
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 import ua.acclorite.book_story.R
+import ua.acclorite.book_story.domain.model.Chapter
 import ua.acclorite.book_story.presentation.core.components.CustomAnimatedVisibility
 import ua.acclorite.book_story.presentation.core.components.CustomSelectionContainer
 import ua.acclorite.book_story.presentation.core.components.LocalHistoryViewModel
@@ -76,6 +77,8 @@ import ua.acclorite.book_story.presentation.core.util.noRippleClickable
 import ua.acclorite.book_story.presentation.core.util.showToast
 import ua.acclorite.book_story.presentation.screens.history.data.HistoryEvent
 import ua.acclorite.book_story.presentation.screens.library.data.LibraryEvent
+import ua.acclorite.book_story.presentation.screens.reader.components.ReaderChapter
+import ua.acclorite.book_story.presentation.screens.reader.components.ReaderChaptersDrawer
 import ua.acclorite.book_story.presentation.screens.reader.components.ReaderTextParagraph
 import ua.acclorite.book_story.presentation.screens.reader.components.app_bar.ReaderBottomBar
 import ua.acclorite.book_story.presentation.screens.reader.components.app_bar.ReaderTopBar
@@ -158,6 +161,7 @@ fun ReaderScreenRoot(screen: Screen.Reader) {
             onLibraryEvent(LibraryEvent.OnUpdateBook(it))
             onHistoryEvent(HistoryEvent.OnUpdateBook(it))
         }
+        viewModel.onUpdateCurrentChapter()
     }
 
     ReaderScreen(lazyListState = lazyListState)
@@ -322,6 +326,15 @@ private fun ReaderScreen(lazyListState: LazyListState) {
         )
     }
 
+    val chapters = remember(state.value.book.chapters) {
+        val chapters = mutableMapOf<Int, Chapter>()
+        state.value.book.chapters.forEach {
+            chapters[it.startIndex] = it
+        }
+        chapters
+    }
+
+    // Bottom sheets & Dialogs
     if (state.value.showSettingsBottomSheet) {
         ReaderSettingsBottomSheet()
     }
@@ -460,7 +473,13 @@ private fun ReaderScreen(lazyListState: LazyListState) {
             ) {
                 customItemsIndexed(
                     state.value.text, key = { _, index -> index }
-                ) { _, line ->
+                ) { index, line ->
+                    ReaderChapter(
+                        chapter = chapters[index], // Shows only when matching startIndex of chapter.
+                        fontColor = fontColor.value,
+                        sidePadding = sidePadding
+                    )
+
                     ReaderTextParagraph(
                         line = line,
                         context = context,
@@ -531,6 +550,9 @@ private fun ReaderScreen(lazyListState: LazyListState) {
         }
     }
 
+    // Drawers
+    ReaderChaptersDrawer()
+
     BackHandler {
         onEvent(
             ReaderEvent.OnGoBack(

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/components/ReaderChapter.kt

@@ -0,0 +1,38 @@
+package ua.acclorite.book_story.presentation.screens.reader.components
+
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.material3.HorizontalDivider
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.unit.Dp
+import androidx.compose.ui.unit.dp
+import ua.acclorite.book_story.domain.model.Chapter
+
+/**
+ * Reader Chapter.
+ * Displays chapter title. Null if no chapter should be shown.
+ *
+ * @param chapter [Chapter].
+ * @param fontColor Font color to use for title and divider.
+ * @param sidePadding Side padding to apply to title.
+ */
+@Composable
+fun ReaderChapter(chapter: Chapter?, fontColor: Color, sidePadding: Dp) {
+    chapter?.let {
+        Spacer(modifier = Modifier.height(22.dp))
+        Text(
+            text = chapter.title,
+            style = MaterialTheme.typography.headlineMedium,
+            color = fontColor,
+            modifier = Modifier.padding(horizontal = sidePadding)
+        )
+        Spacer(modifier = Modifier.height(16.dp))
+        HorizontalDivider(color = fontColor.copy(0.4f))
+        Spacer(modifier = Modifier.height(16.dp))
+    }
+}

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/components/ReaderChaptersDrawer.kt

@@ -0,0 +1,81 @@
+package ua.acclorite.book_story.presentation.screens.reader.components
+
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.width
+import androidx.compose.material3.Text
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.saveable.rememberSaveable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.res.stringResource
+import androidx.compose.ui.text.style.TextOverflow
+import androidx.compose.ui.unit.dp
+import ua.acclorite.book_story.R
+import ua.acclorite.book_story.presentation.core.components.LocalHistoryViewModel
+import ua.acclorite.book_story.presentation.core.components.LocalLibraryViewModel
+import ua.acclorite.book_story.presentation.core.components.LocalReaderViewModel
+import ua.acclorite.book_story.presentation.core.components.customItems
+import ua.acclorite.book_story.presentation.core.components.custom_drawer.CustomModalDrawer
+import ua.acclorite.book_story.presentation.core.components.custom_drawer.CustomModalDrawerSelectableItem
+import ua.acclorite.book_story.presentation.core.components.custom_drawer.CustomModalDrawerTitleItem
+import ua.acclorite.book_story.presentation.core.util.calculateProgress
+import ua.acclorite.book_story.presentation.screens.history.data.HistoryEvent
+import ua.acclorite.book_story.presentation.screens.library.data.LibraryEvent
+import ua.acclorite.book_story.presentation.screens.reader.data.ReaderEvent
+
+/**
+ * Reader Chapters Drawer.
+ * Shows the list of all chapter, current chapter and lets user to go to specific chapter.
+ */
+@Composable
+fun ReaderChaptersDrawer() {
+    val state = LocalReaderViewModel.current.state
+    val onEvent = LocalReaderViewModel.current.onEvent
+    val onLibraryEvent = LocalLibraryViewModel.current.onEvent
+    val onHistoryEvent = LocalHistoryViewModel.current.onEvent
+
+    CustomModalDrawer(
+        show = state.value.showChaptersDrawer,
+        startIndex = state.value.currentChapter?.index ?: 0,
+        onDismissRequest = { onEvent(ReaderEvent.OnShowHideChaptersDrawer(false)) },
+        header = {
+            CustomModalDrawerTitleItem(
+                title = stringResource(id = R.string.chapters)
+            )
+        }
+    ) {
+        customItems(state.value.book.chapters, key = { it.index }) { chapter ->
+            val selected = rememberSaveable(state.value.currentChapter) {
+                chapter.index == state.value.currentChapter?.index
+            }
+
+            CustomModalDrawerSelectableItem(
+                selected = selected,
+                onClick = {
+                    onEvent(
+                        ReaderEvent.OnScrollToChapter(
+                            chapterStartIndex = chapter.startIndex,
+                            refreshList = { book ->
+                                onLibraryEvent(LibraryEvent.OnUpdateBook(book))
+                                onHistoryEvent(HistoryEvent.OnUpdateBook(book))
+                            }
+                        )
+                    )
+                    onEvent(ReaderEvent.OnShowHideChaptersDrawer(false))
+                }
+            ) {
+                Text(
+                    text = chapter.title,
+                    modifier = Modifier.weight(1f),
+                    maxLines = 1,
+                    overflow = TextOverflow.Ellipsis
+                )
+                if (selected) {
+                    Spacer(modifier = Modifier.width(18.dp))
+                    Text(
+                        text = "${state.value.currentChapterProgress.calculateProgress(1)}%"
+                    )
+                }
+            }
+        }
+    }
+}

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/components/app_bar/ReaderBottomBar.kt

@@ -102,10 +102,9 @@ fun ReaderBottomBar() {
             modifier = Modifier.padding(top = 3.dp, bottom = 5.dp),
             verticalAlignment = Alignment.CenterVertically
         ) {
-            CustomAnimatedVisibility(
+            HorizontalExpandingAnimation(
                 visible = arrowDirection == Direction.START,
-                enter = expandHorizontally(expandFrom = Alignment.Start) + fadeIn() + slideInHorizontally { -it },
+                startDirection = true
-                exit = shrinkHorizontally(shrinkTowards = Alignment.Start) + fadeOut() + slideOutHorizontally { -it }
             ) {
                 CustomIconButton(
                     icon = Icons.AutoMirrored.Default.ArrowBack,
@@ -127,6 +126,47 @@ fun ReaderBottomBar() {
                 modifier = Modifier.weight(1f),
                 contentAlignment = Alignment.CenterStart
             ) {
+                BottomBarSlider()
+
+                if (arrowDirection != Direction.NEUTRAL) {
+                    SliderIndicator(progress = checkpointProgress)
+                }
+            }
+
+            HorizontalExpandingAnimation(
+                visible = arrowDirection == Direction.END,
+                startDirection = false
+            ) {
+                CustomIconButton(
+                    icon = Icons.AutoMirrored.Default.ArrowForward,
+                    contentDescription = R.string.checkpoint_forward_content_desc,
+                    modifier = Modifier.size(24.dp),
+                    color = MaterialTheme.colorScheme.primary,
+                    disableOnClick = false
+                ) {
+                    onEvent(
+                        ReaderEvent.OnRestoreCheckpoint { book ->
+                            onLibraryEvent(LibraryEvent.OnUpdateBook(book))
+                            onHistoryEvent(HistoryEvent.OnUpdateBook(book))
+                        }
+                    )
+                }
+            }
+        }
+    }
+}
+
+/**
+ * Bottom Bar Slider.
+ * Has semi-transparent track color.
+ */
+@Composable
+private fun BottomBarSlider() {
+    val state = LocalReaderViewModel.current.state
+    val onEvent = LocalReaderViewModel.current.onEvent
+    val onLibraryEvent = LocalLibraryViewModel.current.onEvent
+    val onHistoryEvent = LocalHistoryViewModel.current.onEvent
+
     Slider(
         value = state.value.book.progress,
         enabled = !state.value.lockMenu,
@@ -153,10 +193,17 @@ fun ReaderBottomBar() {
             disabledInactiveTrackColor = MaterialTheme.colorScheme.secondary.copy(0.15f),
         )
     )
-                if (arrowDirection != Direction.NEUTRAL) {
+}
+
+/**
+ * Slider Indicator.
+ * Shows an indicator at desired progress.
+ */
+@Composable
+private fun SliderIndicator(progress: Float) {
     Row(Modifier.fillMaxWidth()) {
         Spacer(
-                            modifier = Modifier.fillMaxWidth(checkpointProgress)
+            modifier = Modifier.fillMaxWidth(progress)
         )
         Box(
             Modifier
@@ -168,29 +215,45 @@ fun ReaderBottomBar() {
                 )
         )
     }
+}
+
+/**
+ * Horizontal Expanding Animation.
+ */
+@Composable
+private fun HorizontalExpandingAnimation(
+    visible: Boolean,
+    startDirection: Boolean,
+    content: @Composable () -> Unit,
+) {
+    val enterAnimation = remember(startDirection) {
+        when (startDirection) {
+            true -> {
+                expandHorizontally(expandFrom = Alignment.Start) + fadeIn() + slideInHorizontally { -it }
+            }
+
+            false -> {
+                expandHorizontally() + fadeIn() + slideInHorizontally { it }
+            }
+        }
+    }
+    val exitAnimation = remember(startDirection) {
+        when (startDirection) {
+            true -> {
+                shrinkHorizontally(shrinkTowards = Alignment.Start) + fadeOut() + slideOutHorizontally { -it }
+            }
+
+            false -> {
+                shrinkHorizontally() + fadeOut() + slideOutHorizontally { it }
+            }
         }
     }
 
     CustomAnimatedVisibility(
-                visible = arrowDirection == Direction.END,
+        visible = visible,
-                enter = expandHorizontally() + fadeIn() + slideInHorizontally { it },
+        enter = enterAnimation,
-                exit = shrinkHorizontally() + fadeOut() + slideOutHorizontally { it }
+        exit = exitAnimation
     ) {
-                CustomIconButton(
+        content()
-                    icon = Icons.AutoMirrored.Default.ArrowForward,
-                    contentDescription = R.string.checkpoint_forward_content_desc,
-                    modifier = Modifier.size(24.dp),
-                    color = MaterialTheme.colorScheme.primary,
-                    disableOnClick = false
-                ) {
-                    onEvent(
-                        ReaderEvent.OnRestoreCheckpoint { book ->
-                            onLibraryEvent(LibraryEvent.OnUpdateBook(book))
-                            onHistoryEvent(HistoryEvent.OnUpdateBook(book))
-                        }
-                    )
-                }
-            }
-        }
     }
 }

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/components/app_bar/ReaderTopBar.kt

@@ -1,19 +1,25 @@
 package ua.acclorite.book_story.presentation.screens.reader.components.app_bar
 
 import androidx.activity.ComponentActivity
+import androidx.compose.animation.core.animateFloatAsState
+import androidx.compose.foundation.background
 import androidx.compose.foundation.basicMarquee
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.fillMaxWidth
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.automirrored.outlined.ArrowBack
 import androidx.compose.material.icons.filled.Settings
+import androidx.compose.material.icons.rounded.Menu
 import androidx.compose.material3.ExperimentalMaterial3Api
+import androidx.compose.material3.LinearProgressIndicator
 import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.Text
 import androidx.compose.material3.TopAppBar
 import androidx.compose.material3.TopAppBarDefaults
 import androidx.compose.runtime.Composable
 import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
 import androidx.compose.ui.platform.LocalContext
 import androidx.compose.ui.text.font.FontFamily
 import androidx.compose.ui.text.font.FontWeight
@@ -45,6 +51,15 @@ fun ReaderTopBar() {
     val context = LocalContext.current as ComponentActivity
     val onNavigate = LocalOnNavigate.current
 
+    val animatedChapterProgress = animateFloatAsState(
+        targetValue = state.value.currentChapterProgress
+    )
+
+    Column(
+        Modifier
+            .fillMaxWidth()
+            .background(Colors.readerSystemBarsColor)
+    ) {
         TopAppBar(
             navigationIcon = {
                 CustomIconButton(
@@ -107,7 +122,8 @@ fun ReaderTopBar() {
                             )
                     )
                     Text(
-                    state.value.book.author.asString(),
+                        state.value.currentChapter?.title
+                            ?: context.getString(R.string.no_chapters),
                         color = MaterialTheme.colorScheme.onSurfaceVariant,
                         style = MaterialTheme.typography.bodyLarge,
                         maxLines = 1,
@@ -116,17 +132,40 @@ fun ReaderTopBar() {
                 }
             },
             actions = {
+                if (state.value.currentChapter != null) {
+                    CustomIconButton(
+                        icon = Icons.Rounded.Menu,
+                        contentDescription = R.string.chapters_content_desc,
+                        disableOnClick = false,
+                        enabled = !state.value.lockMenu &&
+                                !state.value.showChaptersDrawer &&
+                                !state.value.showSettingsBottomSheet
+                    ) {
+                        onEvent(ReaderEvent.OnShowHideChaptersDrawer(true))
+                    }
+                }
+
                 CustomIconButton(
                     icon = Icons.Default.Settings,
                     contentDescription = R.string.open_reader_settings_content_desc,
                     disableOnClick = false,
-                enabled = !state.value.lockMenu
+                    enabled = !state.value.lockMenu &&
+                            !state.value.showChaptersDrawer &&
+                            !state.value.showSettingsBottomSheet
                 ) {
-                onEvent(ReaderEvent.OnShowHideSettingsBottomSheet)
+                    onEvent(ReaderEvent.OnShowHideSettingsBottomSheet(true))
                 }
             },
             colors = TopAppBarDefaults.topAppBarColors(
-            containerColor = Colors.readerSystemBarsColor
+                containerColor = Color.Transparent
             )
         )
+
+        if (state.value.currentChapter != null) {
+            LinearProgressIndicator(
+                progress = { animatedChapterProgress.value },
+                modifier = Modifier.fillMaxWidth()
+            )
+        }
+    }
 }

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/components/settings_bottom_sheet/ReaderSettingsBottomSheet.kt

@@ -79,7 +79,7 @@ fun ReaderSettingsBottomSheet() {
             .fillMaxHeight(animatedHeight),
         dragHandle = {},
         onDismissRequest = {
-            onEvent(ReaderEvent.OnShowHideSettingsBottomSheet)
+            onEvent(ReaderEvent.OnShowHideSettingsBottomSheet(false))
         }
     ) {
         ReaderSettingsBottomSheetTabRow(pagerState = pagerState)

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/data/ReaderEvent.kt

@@ -9,6 +9,7 @@ import ua.acclorite.book_story.domain.util.UIText
 @Immutable
 sealed class ReaderEvent {
     data object OnTextIsEmpty : ReaderEvent()
+
     data class OnLoadText(
         val refreshList: (Book) -> Unit,
         val onError: (UIText) -> Unit,
@@ -39,9 +40,28 @@ sealed class ReaderEvent {
         val refreshList: (Book) -> Unit
     ) : ReaderEvent()
 
-    data class OnScroll(val progress: Float) : ReaderEvent()
+    data class OnScroll(
-    data object OnShowHideSettingsBottomSheet : ReaderEvent()
+        val progress: Float
-    data class OnScrollToSettingsPage(val page: Int, val pagerState: PagerState?) : ReaderEvent()
+    ) : ReaderEvent()
+
+    data class OnScrollToChapter(
+        val chapterStartIndex: Int,
+        val refreshList: (Book) -> Unit
+    ) : ReaderEvent()
+
+    data class OnShowHideSettingsBottomSheet(
+        val show: Boolean
+    ) : ReaderEvent()
+
+    data class OnShowHideChaptersDrawer(
+        val show: Boolean
+    ) : ReaderEvent()
+
+    data class OnScrollToSettingsPage(
+        val page: Int,
+        val pagerState: PagerState?
+    ) : ReaderEvent()
+
     data class OnOpenTranslator(
         val textToTranslate: String,
         val translateWholeParagraph: Boolean,

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/data/ReaderState.kt

@@ -3,6 +3,7 @@ package ua.acclorite.book_story.presentation.screens.reader.data
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.runtime.Immutable
 import ua.acclorite.book_story.domain.model.Book
+import ua.acclorite.book_story.domain.model.Chapter
 import ua.acclorite.book_story.domain.util.UIText
 import ua.acclorite.book_story.presentation.core.constants.Constants
 
@@ -12,6 +13,10 @@ data class ReaderState(
     val text: List<String> = emptyList(),
     val listState: LazyListState = LazyListState(),
 
+    val currentChapter: Chapter? = null,
+    val currentChapterProgress: Float = 0f,
+    val showChaptersDrawer: Boolean = false,
+
     val errorMessage: UIText? = null,
     val loading: Boolean = true,
 

app/src/main/java/ua/acclorite/book_story/presentation/screens/reader/data/ReaderViewModel.kt

@@ -3,7 +3,6 @@ package ua.acclorite.book_story.presentation.screens.reader.data
 import android.app.SearchManager
 import android.content.Intent
 import android.net.Uri
-import android.util.Log
 import androidx.activity.ComponentActivity
 import androidx.compose.runtime.snapshotFlow
 import androidx.core.view.WindowCompat
@@ -13,6 +12,7 @@ import androidx.lifecycle.viewModelScope
 import dagger.hilt.android.lifecycle.HiltViewModel
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.MutableStateFlow
@@ -28,7 +28,7 @@ import ua.acclorite.book_story.domain.model.Book
 import ua.acclorite.book_story.domain.use_case.GetBookById
 import ua.acclorite.book_story.domain.use_case.GetLatestHistory
 import ua.acclorite.book_story.domain.use_case.GetText
-import ua.acclorite.book_story.domain.use_case.UpdateBooks
+import ua.acclorite.book_story.domain.use_case.UpdateBook
 import ua.acclorite.book_story.domain.util.OnNavigate
 import ua.acclorite.book_story.domain.util.UIText
 import ua.acclorite.book_story.presentation.core.navigation.Screen
@@ -40,7 +40,7 @@ import kotlin.math.roundToInt
 @Suppress("LABEL_NAME_CLASH")
 @HiltViewModel
 class ReaderViewModel @Inject constructor(
-    private val updateBooks: UpdateBooks,
+    private val updateBook: UpdateBook,
     private val getText: GetText,
     private val getLatestHistory: GetLatestHistory,
     private val getBookById: GetBookById
@@ -50,6 +50,7 @@ class ReaderViewModel @Inject constructor(
     override val state = _state.asStateFlow()
 
     private var eventJob = SupervisorJob()
+    private var scrollJob: Job? = null
 
     override fun onEvent(event: ReaderEvent) {
         viewModelScope.launch(eventJob + Dispatchers.Main) {
@@ -73,60 +74,26 @@ class ReaderViewModel @Inject constructor(
 
                         _state.update {
                             it.copy(
+                                book = it.book.copy(
+                                    lastOpened = getLatestHistory.execute(_state.value.book.id)?.time
+                                ),
                                 text = text
                             )
                         }
 
-                        val history = _state.value.book.id.let {
+                        updateBook.execute(_state.value.book)
-                            getLatestHistory.execute(
-                                it
-                            )
-                        }
-
-                        _state.update {
-                            it.copy(
-                                book = it.book.copy(
-                                    lastOpened = history?.time,
-                                )
-                            )
-                        }
-
-                        updateBooks.execute(
-                            listOf(_state.value.book)
-                        )
                         event.refreshList(_state.value.book)
 
                         launch {
                             snapshotFlow {
                                 _state.value.listState.layoutInfo.totalItemsCount
                             }.collectLatest { itemsCount ->
-                                val index = _state.value.book.scrollIndex
+                                if (itemsCount < _state.value.text.size) return@collectLatest
-                                val offset = _state.value.book.scrollOffset
 
-                                if (itemsCount >= _state.value.text.size) {
-                                    if (index > 0 || offset > 0) {
-                                        var loaded = false
-                                        for (i in 1..100) {
-                                            try {
                                 _state.value.listState.requestScrollToItem(
-                                                    index,
+                                    _state.value.book.scrollIndex,
-                                                    offset
+                                    _state.value.book.scrollOffset
                                 )
-                                                loaded = true
-                                                break
-                                            } catch (e: Exception) {
-                                                Log.w(
-                                                    "READER",
-                                                    "Couldn't scroll to desired index and offset"
-                                                )
-                                                delay(100)
-                                            }
-                                        }
-
-                                        if (!loaded) {
-                                            event.onTextIsEmpty()
-                                        }
-                                    }
 
                                 delay(100)
                                 _state.update {
@@ -140,7 +107,6 @@ class ReaderViewModel @Inject constructor(
                         }
                     }
                 }
-                }
 
                 is ReaderEvent.OnShowHideMenu -> {
                     launch {
@@ -171,7 +137,7 @@ class ReaderViewModel @Inject constructor(
                 }
 
                 is ReaderEvent.OnRestoreCheckpoint -> {
-                    launch(Dispatchers.Main) {
+                    launch {
                         _state.value.listState.requestScrollToItem(
                             _state.value.checkpoint.first,
                             _state.value.checkpoint.second
@@ -217,9 +183,7 @@ class ReaderViewModel @Inject constructor(
                                 )
                             }
 
-                            updateBooks.execute(
+                            updateBook.execute(_state.value.book)
-                                listOf(_state.value.book)
-                            )
                             event.refreshList(_state.value.book)
                         }
 
@@ -233,11 +197,30 @@ class ReaderViewModel @Inject constructor(
                 }
 
                 is ReaderEvent.OnScroll -> {
-                    launch {
+                    scrollJob?.cancel()
-                        val scrollTo = (_state.value.text.size * event.progress).roundToInt()
+                    scrollJob = launch {
+                        delay(300)
 
-                        _state.value.listState.scrollToItem(
+                        yield()
-                            scrollTo
+
+                        val scrollTo = (_state.value.text.size * event.progress).roundToInt()
+                        _state.value.listState.requestScrollToItem(scrollTo)
+                    }
+                }
+
+                is ReaderEvent.OnScrollToChapter -> {
+                    launch {
+                        _state.value.listState.requestScrollToItem(
+                            event.chapterStartIndex
+                        )
+                        updateChapter(index = event.chapterStartIndex)
+                        onEvent(
+                            ReaderEvent.OnChangeProgress(
+                                progress = calculateProgress(event.chapterStartIndex),
+                                firstVisibleItemIndex = event.chapterStartIndex,
+                                firstVisibleItemOffset = 0,
+                                refreshList = event.refreshList
+                            )
                         )
                     }
                 }
@@ -254,28 +237,32 @@ class ReaderViewModel @Inject constructor(
                             )
                         }
 
-                        updateBooks.execute(
+                        updateBook.execute(_state.value.book)
-                            listOf(_state.value.book)
-                        )
                         event.refreshList(_state.value.book)
                     }
                 }
 
                 is ReaderEvent.OnShowHideSettingsBottomSheet -> {
-                    launch(Dispatchers.IO) {
                     _state.update {
                         it.copy(
-                                showSettingsBottomSheet = !it.showSettingsBottomSheet
+                            showSettingsBottomSheet = event.show
                         )
                     }
                 }
+
+                is ReaderEvent.OnShowHideChaptersDrawer -> {
+                    _state.update {
+                        it.copy(
+                            showChaptersDrawer = event.show
+                        )
+                    }
                 }
 
                 is ReaderEvent.OnScrollToSettingsPage -> {
                     launch {
-                        _state.update {
+                        event.pagerState?.requestScrollToPage(event.page)
-                            event.pagerState?.scrollToPage(event.page)
 
+                        _state.update {
                             it.copy(
                                 currentPage = event.page
                             )
@@ -465,7 +452,7 @@ class ReaderViewModel @Inject constructor(
 
     @OptIn(FlowPreview::class)
     fun onUpdateProgress(refreshList: (Book) -> Unit) {
-        viewModelScope.launch {
+        viewModelScope.launch(Dispatchers.IO) {
             snapshotFlow {
                 _state.value.listState.firstVisibleItemIndex to _state.value.listState.firstVisibleItemScrollOffset
             }
@@ -490,6 +477,49 @@ class ReaderViewModel @Inject constructor(
         }
     }
 
+    @OptIn(FlowPreview::class)
+    fun onUpdateCurrentChapter() {
+        viewModelScope.launch(Dispatchers.IO) {
+            snapshotFlow {
+                _state.value.listState.firstVisibleItemIndex
+            }
+                .distinctUntilChanged()
+                .debounce(300)
+                .collectLatest { index ->
+                    if (_state.value.book.chapters.size < 2) {
+                        _state.update {
+                            it.copy(
+                                currentChapter = null
+                            )
+                        }
+                        return@collectLatest
+                    }
+
+                    updateChapter(index)
+                }
+        }
+    }
+
+    private fun updateChapter(index: Int) {
+        val currentChapter = _state.value.book.chapters.find { chapter ->
+            index in chapter.startIndex..chapter.endIndex
+        }
+        val currentChapterProgress = currentChapter.run {
+            if (this == null) return@run 0f
+
+            val currentIndex = index - startIndex
+            val endIndex = endIndex - startIndex
+            currentIndex / endIndex.toFloat()
+        }
+
+        _state.update {
+            it.copy(
+                currentChapter = currentChapter,
+                currentChapterProgress = currentChapterProgress
+            )
+        }
+    }
+
     private fun calculateProgress(firstVisibleItemIndex: Int? = null): Float {
         return _state.value.run {
             if (

app/src/main/res/values-uk/strings.xml

@@ -352,6 +352,8 @@
 
     <!-- Reader -->
     <string name="loading">Завантаження…</string>
+    <string name="no_chapters">Немає розділів</string>
+    <string name="chapters">Розділи</string>
 
     <!-- About -->
     <string name="app_version_option">Версія застосунка</string>
@@ -596,5 +598,6 @@
     <string name="filter_content_desc">Фільтр</string>
     <string name="checkpoint_back_content_desc">Чекпоінт назад</string>
     <string name="checkpoint_forward_content_desc">Чекпоінт вперед</string>
+    <string name="chapters_content_desc">Розділи</string>
 
 </resources>

app/src/main/res/values/strings.xml

@@ -355,6 +355,8 @@
 
     <!-- Reader -->
     <string name="loading">Loading…</string>
+    <string name="no_chapters">No chapters</string>
+    <string name="chapters">Chapters</string>
 
     <!-- About -->
     <string name="app_version_option">App version</string>
@@ -601,5 +603,6 @@
     <string name="filter_content_desc">Filter</string>
     <string name="checkpoint_back_content_desc">Checkpoint back</string>
     <string name="checkpoint_forward_content_desc">Checkpoint forward</string>
+    <string name="chapters_content_desc">Chapters</string>
 
 </resources>