Support opds (#133)

* Add OPDS catalog support for book discovery and downloading

* Implement OPDS search, improved book discovery, and enhanced UI details.

* Improve OPDS search and catalog management

* Add authentication support and extended metadata to the OPDS reader.

* Add support for OPDS 2.0 (JSON) feeds

* Enhance OPDS book downloading with progress tracking and multi-format support.

* Enhance OPDS book management and UI

* Add support for OPDS-PSE (Page Streaming Extension) streaming

* Improve OPDS streaming and catalog management

app/src/main/AndroidManifest.xml

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="utf-8"?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
+    <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" android:maxSdkVersion="32" />
     <uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
     <uses-permission android:name="android.permission.FOREGROUND_SERVICE_MEDIA_PLAYBACK" />

app/src/main/java/com/aryan/reader/HomeScreen.kt

@@ -55,6 +55,7 @@ import androidx.compose.foundation.lazy.items
 import androidx.compose.foundation.shape.CircleShape
 import androidx.compose.material.icons.Icons
 import androidx.compose.material.icons.filled.Check
+import androidx.compose.material.icons.filled.Cloud
 import androidx.compose.material.icons.filled.Folder
 import androidx.compose.material.icons.filled.FolderSpecial
 import androidx.compose.material.icons.filled.FormatListNumbered
@@ -656,6 +657,27 @@ fun RecentFileCard(
                     }
                 }
 
+                val isOpdsStream = item.uriString?.startsWith("opds-pse://") == true
+                if (isOpdsStream) {
+                    Box(
+                        modifier = Modifier
+                            .align(Alignment.TopEnd)
+                            .padding(8.dp)
+                            .background(
+                                color = MaterialTheme.colorScheme.tertiaryContainer,
+                                shape = CircleShape
+                            )
+                            .padding(4.dp)
+                    ) {
+                        Icon(
+                            imageVector = Icons.Default.Cloud,
+                            contentDescription = "OPDS Stream",
+                            modifier = Modifier.size(16.dp),
+                            tint = MaterialTheme.colorScheme.onTertiaryContainer
+                        )
+                    }
+                }
+
                 if (isPinned) {
                     Box(
                         modifier = Modifier

app/src/main/java/com/aryan/reader/MainViewModel.kt

@@ -455,6 +455,46 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
         }
     }
 
+    fun streamOpdsBook(
+        bookId: String,
+        title: String,
+        urlTemplate: String,
+        pageCount: Int,
+        catalogId: String?
+    ) {
+        val encodedUrl = Uri.encode(urlTemplate)
+        val safeId = Uri.encode(bookId)
+        val catId = catalogId?.let { "&catalogId=${Uri.encode(it)}" } ?: ""
+
+        val uriString = "opds-pse://stream?id=$safeId&count=$pageCount&url=$encodedUrl$catId"
+        openBook(uriString.toUri(), bookId, FileType.CBZ, title)
+    }
+
+    fun deleteStreamedBooksForCatalog(catalogId: String) {
+        viewModelScope.launch(Dispatchers.IO) {
+            val filesToDelete = recentFilesRepository.getAllFilesForSync().filter {
+                it.uriString?.contains("catalogId=$catalogId") == true
+            }
+            if (filesToDelete.isNotEmpty()) {
+                val ids = filesToDelete.map { it.bookId }
+                ids.forEach { bookId ->
+                    pdfTextRepository.clearBookText(bookId)
+                    clearImportedFileCache(bookId)
+                    try {
+                        val cacheDir = File(appContext.cacheDir, "opds_stream_${bookId.hashCode()}")
+                        if (cacheDir.exists()) cacheDir.deleteRecursively()
+                    } catch (e: Exception) {
+                        Timber.e(e, "Failed to clean stream cache for $bookId")
+                    }
+                }
+                recentFilesRepository.deleteFilePermanently(ids)
+                withContext(Dispatchers.Main) {
+                    showBanner("Removed ${filesToDelete.size} streaming books.")
+                }
+            }
+        }
+    }
+
     private val _reviewRequestEvent = Channel<Unit>(Channel.BUFFERED)
     val reviewRequestEvent = _reviewRequestEvent.receiveAsFlow()
     private var hasRequestedReviewInThisSession = false
@@ -1169,6 +1209,11 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
     private fun uploadSingleBookMetadata(book: RecentFileItem) {
         if (!uiState.value.isSyncEnabled) return
 
+        if (book.uriString?.startsWith("opds-pse") == true) {
+            Timber.d("Skipping metadata sync for OPDS stream book: ${book.displayName}")
+            return
+        }
+
         if (book.sourceFolderUri != null) {
             Timber.d("Skipping metadata sync for local folder book: ${book.displayName}")
             return
@@ -2027,11 +2072,12 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
             }
             val localBooks = withContext(Dispatchers.IO) {
                 val allFiles = recentFilesRepository.getAllFilesForSync()
-                if (_internalState.value.isFolderSyncEnabled) {
+                val filtered = if (_internalState.value.isFolderSyncEnabled) {
                     allFiles
                 } else {
                     allFiles.filter { it.sourceFolderUri == null }
                 }
+                filtered.filterNot { it.uriString?.startsWith("opds-pse") == true }
             }
 
             val localShelfNames = prefs.getStringSet(KEY_SHELVES, emptySet()).orEmpty()
@@ -2424,7 +2470,7 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
                 if (coverBitmap != null) {
                     coverPath = recentFilesRepository.saveCoverToCache(coverBitmap, uri)
                 }
-            } else if (type == FileType.CBZ || type == FileType.CBR || type == FileType.CB7) {
+            } else if (uri.scheme != "opds-pse" && (type == FileType.CBZ || type == FileType.CBR || type == FileType.CB7)) {
                 var cacheFile: File? = null
                 try {
                     cacheFile = File(appContext.cacheDir, "temp_archive_cover_${System.currentTimeMillis()}.${type.name.lowercase()}")
@@ -2524,6 +2570,7 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
 
                 val oneHourAgo = System.currentTimeMillis() - TimeUnit.HOURS.toMillis(1)
                 val allDbIds = recentFilesRepository.getAllFilesForSync().map { it.bookId }.toSet()
+                val validStreamHashes = allDbIds.map { it.hashCode().toString() }.toSet()
 
                 cacheDir.listFiles()?.forEach { file ->
                     val name = file.name
@@ -2538,6 +2585,12 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
                             val deleted = file.deleteRecursively()
                             if (deleted) Timber.d("Sweeper cleaned orphaned extracted cache for: $bookId")
                         }
+                    } else if (name.startsWith("opds_stream_")) {
+                        val bookIdHash = name.removePrefix("opds_stream_")
+                        if (bookIdHash !in validStreamHashes) {
+                            val deleted = if (file.isDirectory) file.deleteRecursively() else file.delete()
+                            if (deleted) Timber.d("Sweeper cleaned orphaned OPDS stream cache for hash: $bookIdHash")
+                        }
                     }
                 }
                 val legacyExtractedDir = File(cacheDir, "extracted_epubs")
@@ -2837,20 +2890,22 @@ open class MainViewModel(application: Application) : AndroidViewModel(applicatio
         Timber.tag("FileOpenPerf")
             .d("[$bookId] openBook START | type=$type | displayName=$originalDisplayName")
 
-        try {
-            val cursor = appContext.contentResolver.query(uri, null, null, null, null)
-            cursor?.use {
-                if (it.moveToFirst()) {
-                    val sizeIndex = it.getColumnIndex(OpenableColumns.SIZE)
-                    val nameIndex = it.getColumnIndex(OpenableColumns.DISPLAY_NAME)
-                    val size = if (sizeIndex != -1) it.getLong(sizeIndex) else -1L
-                    val name = if (nameIndex != -1) it.getString(nameIndex) else "unknown"
-                    Timber.tag("FileOpenPerf")
-                        .d("[$bookId] File details | name=$name | size=${size} bytes | sizeMB=${size / (1024.0 * 1024)}")
+        if (uri.scheme != "opds-pse") {
+            try {
+                val cursor = appContext.contentResolver.query(uri, null, null, null, null)
+                cursor?.use {
+                    if (it.moveToFirst()) {
+                        val sizeIndex = it.getColumnIndex(OpenableColumns.SIZE)
+                        val nameIndex = it.getColumnIndex(OpenableColumns.DISPLAY_NAME)
+                        val size = if (sizeIndex != -1) it.getLong(sizeIndex) else -1L
+                        val name = if (nameIndex != -1) it.getString(nameIndex) else "unknown"
+                        Timber.tag("FileOpenPerf")
+                            .d("[$bookId] File details | name=$name | size=${size} bytes | sizeMB=${size / (1024.0 * 1024)}")
+                    }
                 }
+            } catch (e: Exception) {
+                Timber.tag("FileOpenPerf").e(e, "[$bookId] Failed to get file details")
             }
-        } catch (e: Exception) {
-            Timber.tag("FileOpenPerf").e(e, "[$bookId] Failed to get file details")
         }
 
         viewModelScope.launch {

app/src/main/java/com/aryan/reader/SharedComposables.kt

@@ -335,8 +335,11 @@ fun FileInfoDialog(item: RecentFileItem, onDismiss: () -> Unit, onUpdateName: (S
     }
 
     val context = LocalContext.current
+    val isOpdsStream = item.uriString?.startsWith("opds-pse://") == true
     val pathText = remember(item.sourceFolderUri, item.uriString, item.displayName, context) {
-        if (item.sourceFolderUri != null && item.uriString != null) {
+        if (isOpdsStream) {
+            "Source: OPDS Stream"
+        } else if (item.sourceFolderUri != null && item.uriString != null) {
             try {
                 val uri = item.uriString.toUri()
                 val docId = if (android.provider.DocumentsContract.isDocumentUri(context, uri)) {

app/src/main/java/com/aryan/reader/opds/OpdsModels.kt

@@ -0,0 +1,93 @@
+// OpdsModels.kt
+package com.aryan.reader.opds
+
+data class OpdsCatalog(
+    val id: String,
+    val title: String,
+    val url: String,
+    val isDefault: Boolean = false,
+    val username: String? = null,
+    val password: String? = null
+)
+
+data class OpdsFacet(
+    val title: String,
+    val group: String,
+    val url: String,
+    val isActive: Boolean
+)
+
+data class OpdsFeed(
+    val title: String,
+    val entries: List<OpdsEntry>,
+    val nextUrl: String?,
+    val searchUrl: String? = null,
+    val facets: List<OpdsFacet> = emptyList()
+)
+
+data class OpdsAuthor(
+    val name: String,
+    val url: String?
+)
+
+data class OpdsAcquisition(
+    val url: String,
+    val mimeType: String
+) {
+    val formatName: String
+        get() = when {
+            mimeType.contains("epub") -> "EPUB"
+            mimeType.contains("pdf") -> "PDF"
+            mimeType.contains("mobi") || mimeType.contains("x-mobipocket-ebook") -> "MOBI"
+            mimeType.contains("fictionbook") || mimeType.contains("fb2") -> "FB2"
+            mimeType.contains("cbz") || mimeType.contains("comicbook") -> "CBZ"
+            mimeType.contains("cbr") || mimeType.contains("rar") -> "CBR"
+            mimeType.contains("txt") || mimeType.contains("text/plain") -> "TXT"
+            else -> mimeType.substringAfterLast("/").uppercase()
+        }
+
+    val priority: Int
+        get() = when (formatName) {
+            "EPUB" -> 5
+            "PDF" -> 4
+            "MOBI" -> 3
+            "FB2" -> 2
+            "CBZ" -> 1
+            "TXT" -> 0
+            else -> -1
+        }
+}
+
+data class OpdsEntry(
+    val id: String,
+    val title: String,
+    val summary: String?,
+    val authors: List<OpdsAuthor> = emptyList(),
+    val coverUrl: String?,
+    val acquisitions: List<OpdsAcquisition> = emptyList(),
+    val navigationUrl: String?,
+    val publisher: String? = null,
+    val published: String? = null,
+    val language: String? = null,
+    val series: String? = null,
+    val seriesIndex: String? = null,
+    val categories: List<String> = emptyList(),
+    // ADD THESE:
+    val pseCount: Int? = null,
+    val pseUrlTemplate: String? = null
+) {
+    val author: String?
+        get() = authors.firstOrNull()?.name
+
+    val bestAcquisition: OpdsAcquisition?
+        get() = acquisitions.maxByOrNull { it.priority }
+
+    val isAcquisition: Boolean
+        get() = acquisitions.isNotEmpty()
+
+    val isNavigation: Boolean
+        get() = navigationUrl != null && acquisitions.isEmpty()
+
+    val isStreamable: Boolean
+        get() = pseUrlTemplate != null && pseCount != null && pseCount > 0
+}

app/src/main/java/com/aryan/reader/opds/OpdsParser.kt

@@ -0,0 +1,486 @@
+// OpdsParser.kt
+package com.aryan.reader.opds
+
+import android.util.Xml
+import org.json.JSONArray
+import org.json.JSONObject
+import org.xmlpull.v1.XmlPullParser
+import timber.log.Timber
+import java.io.InputStream
+import java.util.UUID
+
+class OpdsParser {
+
+    fun parse(bodyString: String, baseUrl: String): OpdsFeed {
+        val trimmed = bodyString.trimStart()
+        return if (trimmed.startsWith("{")) {
+            Timber.tag("OpdsDebug").d("Detected OPDS 2.0 (JSON) feed")
+            parseOpds2(trimmed, baseUrl)
+        } else {
+            Timber.tag("OpdsDebug").d("Detected OPDS 1.x (XML) feed")
+            parseOpds1(trimmed.byteInputStream(), baseUrl)
+        }
+    }
+
+    // --- OPDS 2.0 (JSON) Parsing ---
+
+    private fun parseOpds2(jsonString: String, baseUrl: String): OpdsFeed {
+        val root = JSONObject(jsonString)
+        val metadata = root.optJSONObject("metadata")
+        val title = metadata?.optString("title") ?: "OPDS 2.0 Feed"
+
+        var nextUrl: String? = null
+        var searchUrl: String? = null
+        val facets = mutableListOf<OpdsFacet>()
+
+        // Root Links
+        val links = root.optJSONArray("links")
+        if (links != null) {
+            for (i in 0 until links.length()) {
+                val link = links.getJSONObject(i)
+                val relArray = link.optJSONArray("rel")
+                val rels = mutableListOf<String>()
+                if (relArray != null) {
+                    for (j in 0 until relArray.length()) rels.add(relArray.getString(j))
+                } else if (link.has("rel")) {
+                    val rel = link.optString("rel")
+                    if (rel.isNotBlank()) rels.add(rel)
+                }
+
+                val href = link.optString("href")
+                if (href.isNotEmpty()) {
+                    val resolvedHref = resolveUrl(baseUrl, href)
+                    if (rels.contains("next")) {
+                        nextUrl = resolvedHref
+                    } else if (rels.contains("search")) {
+                        searchUrl = resolvedHref
+                    }
+                }
+            }
+        }
+
+        // Facets
+        val facetsArray = root.optJSONArray("facets")
+        if (facetsArray != null) {
+            for (i in 0 until facetsArray.length()) {
+                val facetObj = facetsArray.getJSONObject(i)
+                val group = facetObj.optJSONObject("metadata")?.optString("title") ?: "Filter"
+                val facetLinks = facetObj.optJSONArray("links")
+                if (facetLinks != null) {
+                    for (j in 0 until facetLinks.length()) {
+                        val link = facetLinks.getJSONObject(j)
+                        val href = link.optString("href")
+                        if (href.isNotEmpty()) {
+                            val titleFacet = link.optString("title", "Facet")
+                            val properties = link.optJSONObject("properties")
+                            val active = properties?.optBoolean("active", false) ?: false
+                            facets.add(OpdsFacet(titleFacet, group, resolveUrl(baseUrl, href), active))
+                        }
+                    }
+                }
+            }
+        }
+
+        val entries = mutableListOf<OpdsEntry>()
+
+        // Publications
+        val publications = root.optJSONArray("publications")
+        if (publications != null) {
+            for (i in 0 until publications.length()) {
+                entries.add(parseOpds2Publication(publications.getJSONObject(i), baseUrl))
+            }
+        }
+
+        // Navigation
+        val navigation = root.optJSONArray("navigation")
+        if (navigation != null) {
+            for (i in 0 until navigation.length()) {
+                entries.add(parseOpds2Navigation(navigation.getJSONObject(i), baseUrl))
+            }
+        }
+
+        // Groups (Collections containing sub-navigation or sub-publications)
+        val groups = root.optJSONArray("groups")
+        if (groups != null) {
+            for (i in 0 until groups.length()) {
+                val group = groups.getJSONObject(i)
+                val groupTitle = group.optJSONObject("metadata")?.optString("title") ?: ""
+
+                val groupNav = group.optJSONArray("navigation")
+                if (groupNav != null) {
+                    for (j in 0 until groupNav.length()) {
+                        entries.add(parseOpds2Navigation(groupNav.getJSONObject(j), baseUrl))
+                    }
+                }
+
+                val groupPubs = group.optJSONArray("publications")
+                if (groupPubs != null) {
+                    for (j in 0 until groupPubs.length()) {
+                        entries.add(parseOpds2Publication(groupPubs.getJSONObject(j), baseUrl))
+                    }
+                }
+
+                val groupLinks = group.optJSONArray("links")
+                if (groupLinks != null) {
+                    for (j in 0 until groupLinks.length()) {
+                        val link = groupLinks.getJSONObject(j)
+                        val href = link.optString("href")
+                        if (href.isNotEmpty()) {
+                            val linkTitle = link.optString("title", groupTitle)
+                            entries.add(OpdsEntry(
+                                id = href,
+                                title = linkTitle,
+                                summary = null,
+                                authors = emptyList(),
+                                coverUrl = null,
+                                acquisitions = emptyList(),
+                                navigationUrl = resolveUrl(baseUrl, href)
+                            ))
+                        }
+                    }
+                }
+            }
+        }
+
+        return OpdsFeed(title, entries, nextUrl, searchUrl, facets)
+    }
+
+    private fun parseOpds2Publication(pub: JSONObject, baseUrl: String): OpdsEntry {
+        val metadata = pub.optJSONObject("metadata")
+        val title = metadata?.optString("title") ?: "Unknown Title"
+        val id = metadata?.optString("identifier") ?: pub.optString("id", UUID.randomUUID().toString())
+        val summary = metadata?.optString("description") ?: metadata?.optString("summary")
+        val language = metadata?.optString("language")
+        val publisher = metadata?.optString("publisher")
+        val published = metadata?.optString("published")
+
+        val authors = mutableListOf<OpdsAuthor>()
+        val authorObj = metadata?.opt("author")
+        if (authorObj is String) {
+            authors.add(OpdsAuthor(authorObj, null))
+        } else if (authorObj is JSONArray) {
+            for (i in 0 until authorObj.length()) {
+                val item = authorObj.get(i)
+                if (item is String) authors.add(OpdsAuthor(item, null))
+                else if (item is JSONObject) {
+                    val name = item.optString("name")
+                    var uri: String? = null
+                    val links = item.optJSONArray("links")
+                    if (links != null && links.length() > 0) {
+                        uri = resolveUrl(baseUrl, links.getJSONObject(0).optString("href"))
+                    }
+                    if (name.isNotBlank()) authors.add(OpdsAuthor(name, uri))
+                }
+            }
+        } else if (authorObj is JSONObject) {
+            val name = authorObj.optString("name")
+            var uri: String? = null
+            val links = authorObj.optJSONArray("links")
+            if (links != null && links.length() > 0) {
+                uri = resolveUrl(baseUrl, links.getJSONObject(0).optString("href"))
+            }
+            if (name.isNotBlank()) authors.add(OpdsAuthor(name, uri))
+        }
+
+        val categories = mutableListOf<String>()
+        when (val subjectObj = metadata?.opt("subject")) {
+            is String -> categories.add(subjectObj)
+            is JSONArray -> {
+                for (i in 0 until subjectObj.length()) {
+                    val subj = subjectObj.get(i)
+                    if (subj is String) categories.add(subj)
+                    else if (subj is JSONObject) categories.add(subj.optString("name"))
+                }
+            }
+            is JSONObject -> {
+                categories.add(subjectObj.optString("name"))
+            }
+        }
+
+        var series: String? = null
+        var seriesIndex: String? = null
+        val belongsTo = metadata?.optJSONObject("belongsTo")
+        if (belongsTo != null) {
+            val seriesObj = belongsTo.opt("series")
+            if (seriesObj is String) {
+                series = seriesObj
+            } else if (seriesObj is JSONObject) {
+                series = seriesObj.optString("name")
+                if (seriesObj.has("position")) {
+                    seriesIndex = seriesObj.optDouble("position").toString().removeSuffix(".0")
+                }
+            } else if (seriesObj is JSONArray && seriesObj.length() > 0) {
+                val firstSeries = seriesObj.get(0)
+                if (firstSeries is String) {
+                    series = firstSeries
+                } else if (firstSeries is JSONObject) {
+                    series = firstSeries.optString("name")
+                    if (firstSeries.has("position")) {
+                        seriesIndex = firstSeries.optDouble("position").toString().removeSuffix(".0")
+                    }
+                }
+            }
+        }
+
+        var coverUrl: String? = null
+        val images = pub.optJSONArray("images")
+        if (images != null && images.length() > 0) {
+            for (i in 0 until images.length()) {
+                val image = images.getJSONObject(i)
+                val href = image.optString("href")
+                if (href.isNotEmpty()) {
+                    val resolvedHref = resolveUrl(baseUrl, href)
+                    if (coverUrl == null) coverUrl = resolvedHref
+                    val rels = image.opt("rel")
+                    var isCover = false
+                    if (rels is String && rels == "cover") isCover = true
+                    else if (rels is JSONArray) {
+                        for (j in 0 until rels.length()) if (rels.optString(j) == "cover") isCover = true
+                    }
+                    if (isCover) {
+                        coverUrl = resolvedHref
+                        break
+                    }
+                }
+            }
+        }
+
+        val acquisitions = mutableListOf<OpdsAcquisition>()
+        var pseCount: Int? = null
+        var pseUrlTemplate: String? = null
+
+        val links = pub.optJSONArray("links")
+        if (links != null) {
+            for (i in 0 until links.length()) {
+                val link = links.getJSONObject(i)
+                val href = link.optString("href")
+                if (href.isNotEmpty()) {
+                    val rels = link.opt("rel")
+
+                    var isStream = false
+                    if (rels is String && rels == "http://vaemendis.net/opds-pse/stream") isStream = true
+                    else if (rels is JSONArray) {
+                        for (j in 0 until rels.length()) if (rels.optString(j) == "http://vaemendis.net/opds-pse/stream") isStream = true
+                    }
+                    if (isStream) {
+                        pseUrlTemplate = resolveUrl(baseUrl, href)
+                        val properties = link.optJSONObject("properties")
+                        pseCount = properties?.optInt("numberOfItems")?.takeIf { it > 0 }
+                    }
+
+                    var isAcquisition = false
+                    if (rels is String && rels.contains("acquisition")) isAcquisition = true
+                    else if (rels is JSONArray) {
+                        for (j in 0 until rels.length()) if (rels.optString(j).contains("acquisition")) isAcquisition = true
+                    }
+
+                    if (isAcquisition) {
+                        val type = link.optString("type") ?: ""
+                        acquisitions.add(OpdsAcquisition(resolveUrl(baseUrl, href), type))
+                    }
+                }
+            }
+        }
+
+        return OpdsEntry(
+            id = id, title = title, summary = summary, authors = authors,
+            coverUrl = coverUrl, acquisitions = acquisitions,
+            navigationUrl = null, publisher = publisher, published = published,
+            language = language, series = series, seriesIndex = seriesIndex, categories = categories,
+            pseCount = pseCount, pseUrlTemplate = pseUrlTemplate
+        )
+    }
+
+    private fun parseOpds2Navigation(nav: JSONObject, baseUrl: String): OpdsEntry {
+        val title = nav.optString("title", "Unknown")
+        val href = nav.optString("href")
+        val summary = nav.optString("description", null)
+        val navigationUrl = if (href.isNotEmpty()) resolveUrl(baseUrl, href) else null
+
+        return OpdsEntry(
+            id = href, title = title, summary = summary, authors = emptyList(),
+            coverUrl = null, acquisitions = emptyList(),
+            navigationUrl = navigationUrl
+        )
+    }
+
+    // --- OPDS 1.x (XML) Parsing ---
+
+    private fun parseOpds1(inputStream: InputStream, baseUrl: String): OpdsFeed {
+        return inputStream.use {
+            val parser: XmlPullParser = Xml.newPullParser()
+            parser.setFeature(XmlPullParser.FEATURE_PROCESS_NAMESPACES, false)
+            parser.setInput(it, null)
+            parser.nextTag()
+            Timber.tag("OpdsDebug").d($$"Parser started at root tag: <${parser.name}>")
+            readFeed(parser, baseUrl)
+        }
+    }
+
+    private fun readFeed(parser: XmlPullParser, baseUrl: String): OpdsFeed {
+        var title = ""
+        var nextUrl: String? = null
+        var searchUrl: String? = null
+        val entries = mutableListOf<OpdsEntry>()
+        val facets = mutableListOf<OpdsFacet>()
+
+        parser.require(XmlPullParser.START_TAG, null, "feed")
+        while (parser.next() != XmlPullParser.END_TAG) {
+            if (parser.eventType != XmlPullParser.START_TAG) continue
+
+            when (parser.name.substringAfter(":")) {
+                "title" -> title = readText(parser)
+                "entry" -> entries.add(readEntry(parser, baseUrl))
+                "link" -> {
+                    val rel = parser.getAttributeValue(null, "rel")
+                    val href = parser.getAttributeValue(null, "href")
+                    val linkTitle = parser.getAttributeValue(null, "title")
+                    val facetGroup = parser.getAttributeValue(null, "opds:facetGroup") ?: "Filter"
+                    val activeFacet = parser.getAttributeValue(null, "opds:activeFacet") == "true"
+
+                    if (rel == "next") {
+                        nextUrl = resolveUrl(baseUrl, href ?: "")
+                    } else if (rel == "search") {
+                        searchUrl = resolveUrl(baseUrl, href ?: "")
+                    } else if (rel == "facet" || rel == "http://opds-spec.org/facet") {
+                        if (href != null && linkTitle != null) {
+                            facets.add(OpdsFacet(linkTitle, facetGroup, resolveUrl(baseUrl, href), activeFacet))
+                        }
+                    }
+                    skip(parser)
+                }
+                else -> skip(parser)
+            }
+        }
+        return OpdsFeed(title, entries, nextUrl, searchUrl, facets)
+    }
+
+    private fun readEntry(parser: XmlPullParser, baseUrl: String): OpdsEntry {
+        parser.require(XmlPullParser.START_TAG, null, "entry")
+        var id = ""; var title = ""; var summary: String? = null
+        var coverUrl: String? = null; var navigationUrl: String? = null
+        var publisher: String? = null; var published: String? = null; var language: String? = null
+        var series: String? = null; var seriesIndex: String? = null
+        var pseCount: Int? = null
+        var pseUrlTemplate: String? = null
+        val authors = mutableListOf<OpdsAuthor>()
+        val categories = mutableListOf<String>()
+        val acquisitions = mutableListOf<OpdsAcquisition>()
+
+        while (parser.next() != XmlPullParser.END_TAG) {
+            if (parser.eventType != XmlPullParser.START_TAG) continue
+
+            when (val tagName = parser.name.substringAfter(":")) {
+                "id" -> id = readText(parser)
+                "title" -> title = readText(parser)
+                "summary", "content" -> summary = readText(parser)
+                "author" -> authors.add(readAuthor(parser, baseUrl))
+                "publisher" -> publisher = readText(parser)
+                "language" -> language = language ?: readText(parser)
+                "issued", "published", "updated" -> {
+                    val date = readText(parser)
+                    if (published == null || tagName != "updated") published = date
+                }
+                "category" -> {
+                    val label = parser.getAttributeValue(null, "label")
+                    val term = parser.getAttributeValue(null, "term")
+                    val cat = label ?: term
+                    if (!cat.isNullOrBlank()) categories.add(cat)
+                    skip(parser)
+                }
+                "meta" -> {
+                    val property = parser.getAttributeValue(null, "property") ?: parser.getAttributeValue(null, "name")
+                    val content = parser.getAttributeValue(null, "content")
+                    val textContent = readText(parser)
+                    if (property == "calibre:series") series = content ?: textContent.takeIf { it.isNotBlank() }
+                    else if (property == "calibre:series_index") seriesIndex = content ?: textContent.takeIf { it.isNotBlank() }
+                }
+                "link" -> {
+                    val rel = parser.getAttributeValue(null, "rel") ?: ""
+                    val href = parser.getAttributeValue(null, "href") ?: ""
+                    val type = parser.getAttributeValue(null, "type") ?: ""
+                    val linkTitle = parser.getAttributeValue(null, "title")
+
+                    if (rel == "http://vaemendis.net/opds-pse/stream") {
+                        pseUrlTemplate = resolveUrl(baseUrl, href)
+                        val countStr = parser.getAttributeValue(null, "pse:count")
+                        pseCount = countStr?.toIntOrNull()
+                    }
+
+                    if (rel == "http://calibre-ebook.com/opds/series") {
+                        if (series == null) series = linkTitle
+                    }
+
+                    if (href.isNotEmpty()) {
+                        val absoluteUrl = resolveUrl(baseUrl, href)
+
+                        if (rel.contains("http://opds-spec.org/image")) {
+                            if (coverUrl == null || rel.contains("thumbnail")) coverUrl = absoluteUrl
+                        } else if (rel.contains("http://opds-spec.org/acquisition")) {
+                            acquisitions.add(OpdsAcquisition(absoluteUrl, type))
+                        } else if (type.contains("profile=opds-catalog") || type.contains("application/atom+xml")) {
+                            if (navigationUrl == null) navigationUrl = absoluteUrl
+                        } else if (rel == "subsection" || rel == "collection" || rel == "start") {
+                            if (navigationUrl == null) navigationUrl = absoluteUrl
+                        }
+                    }
+                    skip(parser)
+                }
+                else -> skip(parser)
+            }
+        }
+        return OpdsEntry(id, title, summary, authors, coverUrl, acquisitions, navigationUrl, publisher, published, language, series, seriesIndex, categories, pseCount, pseUrlTemplate)
+    }
+
+    private fun readAuthor(parser: XmlPullParser, baseUrl: String): OpdsAuthor {
+        var name = ""
+        var uri: String? = null
+        while (parser.next() != XmlPullParser.END_TAG) {
+            if (parser.eventType != XmlPullParser.START_TAG) continue
+            when (parser.name.substringAfter(":")) {
+                "name" -> name = readText(parser)
+                "uri" -> uri = resolveUrl(baseUrl, readText(parser))
+                else -> skip(parser)
+            }
+        }
+        return OpdsAuthor(name, uri)
+    }
+
+    private fun readText(parser: XmlPullParser): String {
+        val result = StringBuilder()
+        var depth = 1
+
+        while (depth != 0) {
+            when (parser.next()) {
+                XmlPullParser.TEXT, XmlPullParser.CDSECT, XmlPullParser.ENTITY_REF -> {
+                    result.append(parser.text)
+                }
+                XmlPullParser.START_TAG -> depth++
+                XmlPullParser.END_TAG -> depth--
+            }
+        }
+        return result.toString().trim()
+    }
+
+    private fun skip(parser: XmlPullParser) {
+        if (parser.eventType != XmlPullParser.START_TAG) throw java.lang.IllegalStateException()
+        var depth = 1
+        while (depth != 0) {
+            when (parser.next()) {
+                XmlPullParser.END_TAG -> depth--
+                XmlPullParser.START_TAG -> depth++
+            }
+        }
+    }
+
+    private fun resolveUrl(baseUrl: String, href: String): String {
+        return try {
+            val resolved = java.net.URL(java.net.URL(baseUrl), href).toString()
+
+            resolved.replace("http://m.gutenberg.org", "https://m.gutenberg.org")
+                .replace("http://www.gutenberg.org", "https://www.gutenberg.org")
+        } catch (_: Exception) {
+            href
+        }
+    }
+}

app/src/main/java/com/aryan/reader/opds/OpdsRepository.kt

@@ -0,0 +1,265 @@
+package com.aryan.reader.opds
+
+import android.content.Context
+import android.content.SharedPreferences
+import androidx.core.content.edit
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.withContext
+import okhttp3.OkHttpClient
+import okhttp3.Request
+import org.json.JSONArray
+import org.json.JSONObject
+import timber.log.Timber
+import java.security.MessageDigest
+import java.util.UUID
+
+class OpdsRepository(context: Context) {
+    private val prefs: SharedPreferences = context.getSharedPreferences("reader_opds_prefs", Context.MODE_PRIVATE)
+    private val parser = OpdsParser()
+
+    companion object {
+        private const val KEY_CATALOGS_JSON = "opds_catalogs_json"
+
+        val sharedHttpClient: OkHttpClient by lazy {
+            OkHttpClient.Builder().build()
+        }
+    }
+
+    private val httpClient = sharedHttpClient
+
+    fun getCatalogs(): List<OpdsCatalog> {
+        val jsonString = prefs.getString(KEY_CATALOGS_JSON, null)
+        val catalogs = mutableListOf<OpdsCatalog>()
+
+        if (jsonString != null) {
+            try {
+                val jsonArray = JSONArray(jsonString)
+                for (i in 0 until jsonArray.length()) {
+                    val obj = jsonArray.getJSONObject(i)
+                    catalogs.add(
+                        OpdsCatalog(
+                            id = obj.getString("id"),
+                            title = obj.getString("title"),
+                            url = obj.getString("url"),
+                            isDefault = obj.optBoolean("isDefault", false),
+                            username = obj.optString("username", "").takeIf { it.isNotBlank() },
+                            password = obj.optString("password", "").takeIf { it.isNotBlank() }
+                        )
+                    )
+                }
+            } catch (e: Exception) {
+                e.printStackTrace()
+            }
+        }
+
+        if (catalogs.isEmpty()) {
+            catalogs.add(OpdsCatalog(UUID.randomUUID().toString(), "Project Gutenberg", "https://m.gutenberg.org/ebooks.opds/", isDefault = true))
+            saveCatalogs(catalogs)
+        }
+
+        return catalogs
+    }
+
+    private fun resolveUrl(baseUrl: String, href: String): String {
+        return try {
+            val resolved = java.net.URL(java.net.URL(baseUrl), href).toString()
+
+            resolved.replace("http://m.gutenberg.org", "https://m.gutenberg.org")
+                .replace("http://www.gutenberg.org", "https://www.gutenberg.org")
+        } catch (_: Exception) {
+            href
+        }
+    }
+
+    suspend fun getSearchTemplate(openSearchUrl: String): String? = withContext(Dispatchers.IO) {
+        try {
+            val request = Request.Builder().url(openSearchUrl).build()
+            val response = httpClient.newCall(request).execute()
+            val body = response.body?.string() ?: return@withContext null
+
+            val parser = android.util.Xml.newPullParser()
+            parser.setFeature(org.xmlpull.v1.XmlPullParser.FEATURE_PROCESS_NAMESPACES, false)
+            parser.setInput(body.byteInputStream(), null)
+            var eventType = parser.eventType
+
+            while (eventType != org.xmlpull.v1.XmlPullParser.END_DOCUMENT) {
+                if (eventType == org.xmlpull.v1.XmlPullParser.START_TAG && parser.name.equals("Url", ignoreCase = true)) {
+                    val type = parser.getAttributeValue(null, "type")
+                    if (type != null && (type.contains("atom+xml") || type.contains("opds+xml"))) {
+                        val template = parser.getAttributeValue(null, "template")
+                        if (template != null) {
+                            val resolvedTemplate = resolveUrl(openSearchUrl, template)
+                            Timber.tag("OpdsDebug").d("Resolved search template: $resolvedTemplate")
+                            return@withContext resolvedTemplate
+                        }
+                    }
+                }
+                eventType = parser.next()
+            }
+            null
+        } catch (e: Exception) {
+            Timber.e(e, "Failed to fetch OpenSearch template")
+            null
+        }
+    }
+
+    fun addCatalog(title: String, url: String, username: String? = null, password: String? = null) {
+        val current = getCatalogs().toMutableList()
+        current.add(OpdsCatalog(UUID.randomUUID().toString(), title, url, username = username, password = password))
+        saveCatalogs(current)
+    }
+
+    fun updateCatalog(id: String, title: String, url: String, username: String?, password: String?) {
+        val current = getCatalogs().toMutableList()
+        val index = current.indexOfFirst { it.id == id }
+        if (index != -1 && !current[index].isDefault) {
+            current[index] = current[index].copy(
+                title = title.trim(),
+                url = url.trim(),
+                username = username?.trim().takeIf { !it.isNullOrBlank() },
+                password = password?.trim().takeIf { !it.isNullOrBlank() }
+            )
+            saveCatalogs(current)
+        }
+    }
+
+    fun removeCatalog(id: String) {
+        val current = getCatalogs().toMutableList()
+        val toRemove = current.find { it.id == id }
+        if (toRemove?.isDefault == true) {
+            return
+        }
+        current.removeAll { it.id == id }
+        saveCatalogs(current)
+    }
+
+    private fun saveCatalogs(catalogs: List<OpdsCatalog>) {
+        val jsonArray = JSONArray()
+        catalogs.forEach { catalog ->
+            val obj = JSONObject()
+            obj.put("id", catalog.id)
+            obj.put("title", catalog.title)
+            obj.put("url", catalog.url)
+            obj.put("isDefault", catalog.isDefault)
+            if (catalog.username != null) obj.put("username", catalog.username)
+            if (catalog.password != null) obj.put("password", catalog.password)
+            jsonArray.put(obj)
+        }
+        prefs.edit { putString(KEY_CATALOGS_JSON, jsonArray.toString()) }
+    }
+
+    fun getAuthenticatedClient(username: String?, password: String?): OkHttpClient {
+        return httpClient.newBuilder()
+            .authenticator(OpdsAuthenticator(username, password))
+            .build()
+    }
+
+    class OpdsAuthenticator(private val user: String?, private val pass: String?) : okhttp3.Authenticator {
+        private var cnonceCount = 0
+
+        override fun authenticate(route: okhttp3.Route?, response: okhttp3.Response): Request? {
+            if (user.isNullOrBlank() || pass.isNullOrBlank()) return null
+
+            if (response.request.header("Authorization") != null) {
+                return null
+            }
+
+            val wwwAuth = response.header("WWW-Authenticate") ?: return null
+
+            if (wwwAuth.startsWith("Basic", ignoreCase = true)) {
+                val credential = okhttp3.Credentials.basic(user, pass)
+                return response.request.newBuilder().header("Authorization", credential).build()
+            }
+
+            if (wwwAuth.startsWith("Digest", ignoreCase = true)) {
+                val realm = extractParam(wwwAuth, "realm") ?: ""
+                val nonce = extractParam(wwwAuth, "nonce") ?: ""
+                val qop = extractParam(wwwAuth, "qop")
+                val opaque = extractParam(wwwAuth, "opaque")
+
+                cnonceCount++
+                val nc = String.format("%08x", cnonceCount)
+                val cnonce = UUID.randomUUID().toString().replace("-", "")
+
+                val url = response.request.url
+                val uri = url.encodedPath + (if (url.encodedQuery != null) "?${url.encodedQuery}" else "")
+
+                val ha1 = md5("$user:$realm:$pass")
+                val ha2 = md5("${response.request.method}:$uri")
+
+                val responseHash = if (qop != null) {
+                    md5("$ha1:$nonce:$nc:$cnonce:$qop:$ha2")
+                } else {
+                    md5("$ha1:$nonce:$ha2")
+                }
+
+                val digestHeader = buildString {
+                    append("Digest username=\"$user\", ")
+                    append("realm=\"$realm\", ")
+                    append("nonce=\"$nonce\", ")
+                    append("uri=\"$uri\", ")
+                    append("response=\"$responseHash\"")
+                    if (qop != null) {
+                        append(", qop=$qop, nc=$nc, cnonce=\"$cnonce\"")
+                    }
+                    if (opaque != null) {
+                        append(", opaque=\"$opaque\"")
+                    }
+                }
+
+                return response.request.newBuilder()
+                    .header("Authorization", digestHeader)
+                    .build()
+            }
+
+            return null
+        }
+
+        private fun extractParam(header: String, param: String): String? {
+            val match = Regex("$param=\"([^\"]+)\"").find(header) ?: Regex("$param=([^,\\s]+)").find(header)
+            return match?.groupValues?.get(1)
+        }
+
+        private fun md5(input: String): String {
+            val bytes = MessageDigest.getInstance("MD5").digest(input.toByteArray())
+            return bytes.joinToString("") { "%02x".format(it) }
+        }
+    }
+
+
+    suspend fun fetchFeed(url: String, username: String? = null, password: String? = null): Result<OpdsFeed> = withContext(Dispatchers.IO) {
+        Timber.tag("OpdsDebug").d("Starting fetch for URL: $url")
+        try {
+            val client = getAuthenticatedClient(username, password)
+
+            val request = Request.Builder()
+                .url(url.trim())
+                .header("User-Agent", "EpistemeReader/1.0 (Android)")
+                .build()
+
+            Timber.tag("OpdsDebug").d("Executing network call...")
+            val response = client.newCall(request).execute()
+
+            Timber.tag("OpdsDebug").d("Response Code: ${response.code}")
+
+            if (!response.isSuccessful) {
+                val errorMsg = "HTTP ${response.code}: ${response.message}"
+                Timber.tag("OpdsDebug").e("Fetch failed: $errorMsg")
+                return@withContext Result.failure(Exception(errorMsg))
+            }
+
+            val bodyString = response.body?.string()
+            if (bodyString.isNullOrBlank()) {
+                return@withContext Result.failure(Exception("Empty response body"))
+            }
+
+            val feed = parser.parse(bodyString, url)
+
+            Timber.tag("OpdsDebug").d("Parsing complete. Found ${feed.entries.size} entries.")
+            Result.success(feed)
+        } catch (e: Exception) {
+            Timber.tag("OpdsDebug").e(e, "Exception during fetch/parse at URL: $url")
+            Result.failure(e)
+        }
+    }
+}

app/src/main/java/com/aryan/reader/opds/OpdsViewModel.kt

@@ -0,0 +1,224 @@
+package com.aryan.reader.opds
+
+import android.app.Application
+import android.content.Context
+import android.net.Uri
+import androidx.lifecycle.AndroidViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.flow.update
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.withContext
+import okhttp3.Request
+import timber.log.Timber
+import java.io.File
+
+data class OpdsScreenState(
+    val catalogs: List<OpdsCatalog> = emptyList(),
+    val currentCatalog: OpdsCatalog? = null,
+    val currentFeed: OpdsFeed? = null,
+    val isLoading: Boolean = false,
+    val errorMessage: String? = null,
+    val isViewingCatalog: Boolean = false,
+    val searchUrlTemplate: String? = null
+)
+
+class OpdsViewModel(application: Application) : AndroidViewModel(application) {
+    private val repository = OpdsRepository(application)
+
+    private val _uiState = MutableStateFlow(OpdsScreenState())
+    val uiState: StateFlow<OpdsScreenState> = _uiState.asStateFlow()
+
+    private val urlStack = mutableListOf<String>()
+
+    private val _downloadingEntries = MutableStateFlow<Set<String>>(emptySet())
+    val downloadingEntries: StateFlow<Set<String>> = _downloadingEntries.asStateFlow()
+
+    private fun fetchUrl(url: String, isPagination: Boolean = false) {
+        viewModelScope.launch {
+            val catalog = _uiState.value.currentCatalog
+            _uiState.update { it.copy(isLoading = true, errorMessage = null, isViewingCatalog = true) }
+
+            val result = repository.fetchFeed(url, catalog?.username, catalog?.password)
+            result.onSuccess { newFeed ->
+                val template = newFeed.searchUrl ?: _uiState.value.searchUrlTemplate
+                if (!isPagination) {
+                    if (urlStack.isEmpty() || urlStack.last() != url) {
+                        urlStack.add(url)
+                    }
+                    _uiState.update { it.copy(isLoading = false, currentFeed = newFeed, searchUrlTemplate = template) }
+                } else {
+                    _uiState.update { state ->
+                        val currentEntries = state.currentFeed?.entries ?: emptyList()
+                        state.copy(
+                            isLoading = false,
+                            currentFeed = newFeed.copy(entries = currentEntries + newFeed.entries),
+                            searchUrlTemplate = template
+                        )
+                    }
+                }
+            }.onFailure { e ->
+                _uiState.update { it.copy(isLoading = false, errorMessage = "Failed to load feed: ${e.message}") }
+            }
+        }
+    }
+
+    fun loadNextPage() {
+        val nextUrl = _uiState.value.currentFeed?.nextUrl
+        if (nextUrl != null && !_uiState.value.isLoading) {
+            fetchUrl(nextUrl, isPagination = true)
+        }
+    }
+
+    data class DownloadState(val isDownloading: Boolean, val progress: Float? = null)
+
+    private val _downloadingState = MutableStateFlow<Map<String, DownloadState>>(emptyMap())
+    val downloadingState: StateFlow<Map<String, DownloadState>> = _downloadingState.asStateFlow()
+
+    fun downloadBook(entry: OpdsEntry, acquisition: OpdsAcquisition, context: Context, onDownloaded: (Uri) -> Unit) {
+        val downloadUrl = acquisition.url
+        val catalog = _uiState.value.currentCatalog
+        viewModelScope.launch(Dispatchers.IO) {
+            _downloadingState.update { it + (entry.id to DownloadState(true, 0f)) }
+            try {
+                val client = repository.getAuthenticatedClient(catalog?.username, catalog?.password)
+                val request = Request.Builder().url(downloadUrl).build()
+
+                val response = client.newCall(request).execute()
+
+                if (response.isSuccessful) {
+                    val body = response.body ?: throw Exception("Empty body")
+                    val contentLength = body.contentLength()
+
+                    val ext = when (acquisition.formatName) {
+                        "EPUB" -> ".epub"
+                        "PDF" -> ".pdf"
+                        "MOBI" -> ".mobi"
+                        "FB2" -> ".fb2"
+                        "CBZ" -> ".cbz"
+                        "CBR" -> ".cbr"
+                        "TXT" -> ".txt"
+                        else -> ".epub"
+                    }
+
+                    val safeTitle = entry.title.replace(Regex("[^a-zA-Z0-9.-]"), "_").take(50)
+                    val tempFile = File(context.cacheDir, "opds_dl_${safeTitle}$ext")
+
+                    val input = body.byteStream()
+                    val output = tempFile.outputStream()
+                    val buffer = ByteArray(8 * 1024)
+                    var bytesRead: Int
+                    var totalRead = 0L
+                    var lastProgressUpdate = System.currentTimeMillis()
+
+                    input.use { inp ->
+                        output.use { out ->
+                            while (inp.read(buffer).also { bytesRead = it } != -1) {
+                                out.write(buffer, 0, bytesRead)
+                                totalRead += bytesRead
+                                if (contentLength > 0) {
+                                    val now = System.currentTimeMillis()
+                                    // Throttle UI updates to 4-5 fps
+                                    if (now - lastProgressUpdate > 200) {
+                                        val progress = totalRead.toFloat() / contentLength.toFloat()
+                                        _downloadingState.update { it + (entry.id to DownloadState(true, progress)) }
+                                        lastProgressUpdate = now
+                                    }
+                                }
+                            }
+                        }
+                    }
+
+                    withContext(Dispatchers.Main) {
+                        onDownloaded(Uri.fromFile(tempFile))
+                    }
+                } else {
+                    Timber.e("Download failed: ${response.code}")
+                    _uiState.update { it.copy(errorMessage = "Download failed: ${response.message}") }
+                }
+            } catch (e: Exception) {
+                Timber.e(e, "Download error")
+                _uiState.update { it.copy(errorMessage = "Download error: ${e.message}") }
+            } finally {
+                _downloadingState.update { it - entry.id }
+            }
+        }
+    }
+
+    init {
+        loadCatalogs()
+    }
+
+    private fun loadCatalogs() {
+        _uiState.update { it.copy(catalogs = repository.getCatalogs()) }
+    }
+
+    fun addCatalog(title: String, url: String, username: String?, password: String?) {
+        repository.addCatalog(title, url, username, password)
+        loadCatalogs()
+    }
+
+    fun removeCatalog(id: String) {
+        repository.removeCatalog(id)
+        loadCatalogs()
+    }
+
+    fun openCatalog(catalog: OpdsCatalog) {
+        urlStack.clear()
+        _uiState.update { it.copy(searchUrlTemplate = null, currentCatalog = catalog) }
+        fetchUrl(catalog.url)
+    }
+
+    fun openFeedUrl(url: String) {
+        fetchUrl(url)
+    }
+
+    fun navigateBack(): Boolean {
+        if (urlStack.size > 1) {
+            urlStack.removeAt(urlStack.lastIndex)
+            val previousUrl = urlStack.last()
+            urlStack.removeAt(urlStack.lastIndex)
+            fetchUrl(previousUrl)
+            return true
+        } else {
+            urlStack.clear()
+            _uiState.update { it.copy(isViewingCatalog = false, currentFeed = null, searchUrlTemplate = null, currentCatalog = null) }
+            return false
+        }
+    }
+
+    fun updateCatalog(id: String, title: String, url: String, username: String?, password: String?) {
+        repository.updateCatalog(id, title, url, username, password)
+        loadCatalogs()
+    }
+
+    fun search(query: String) {
+        val searchLink = _uiState.value.searchUrlTemplate ?: return
+
+        viewModelScope.launch {
+            _uiState.update { it.copy(isLoading = true, errorMessage = null) }
+
+            val template = if (!searchLink.contains("{searchTerms}")) {
+                repository.getSearchTemplate(searchLink) ?: searchLink
+            } else {
+                searchLink
+            }
+
+            val finalUrl = if (template.contains("{searchTerms}")) {
+                template.replace("{searchTerms}", Uri.encode(query))
+            } else {
+                val separator = if (template.contains("?")) "&" else "?"
+                "$template${separator}query=${Uri.encode(query)}"
+            }
+
+            openFeedUrl(finalUrl)
+        }
+    }
+
+    fun clearError() {
+        _uiState.update { it.copy(errorMessage = null) }
+    }
+}

app/src/main/java/com/aryan/reader/pdf/PdfViewerScreen.kt

@@ -3089,14 +3089,17 @@ fun PdfViewerScreen(
         try {
             withContext(Dispatchers.IO) {
                 Timber.d("Opening ParcelFileDescriptor for URI: $pdfUri")
-                currentPfdOpened = context.contentResolver.openFileDescriptor(pdfUri, "r")
-                if (currentPfdOpened == null) throw Exception("Failed to open ParcelFileDescriptor")
+
+                if (pdfUri.scheme != "opds-pse") {
+                    currentPfdOpened = context.contentResolver.openFileDescriptor(pdfUri, "r")
+                    if (currentPfdOpened == null) throw Exception("Failed to open ParcelFileDescriptor")
+                }
 
                 val doc = DocumentFactory.loadDocument(context, pdfUri, uiState.selectedFileType ?: FileType.PDF, documentPassword, pdfiumCore)
 
                 if (!isActive) {
                     doc.close()
-                    currentPfdOpened.close()
+                    currentPfdOpened?.close()
                     return@withContext
                 }
 

app/src/main/java/com/aryan/reader/pdf/UniversalDocument.kt

@@ -24,9 +24,11 @@ import java.io.File
 import me.zhanghai.android.libarchive.Archive
 import me.zhanghai.android.libarchive.ArchiveEntry
 import me.zhanghai.android.libarchive.ArchiveException
+import okhttp3.Request
 import timber.log.Timber
 import java.util.UUID
 import java.util.zip.ZipFile
+import androidx.core.graphics.createBitmap
 
 interface ReaderDocument : AutoCloseable {
     suspend fun getPageCount(): Int
@@ -68,6 +70,13 @@ interface ReaderWebLinks : AutoCloseable {
 
 object DocumentFactory {
     suspend fun loadDocument(context: Context, uri: Uri, type: FileType, password: String?, pdfiumCore: PdfiumCoreKt): ReaderDocument {
+        if (uri.scheme == "opds-pse") {
+            val bookId = uri.getQueryParameter("id") ?: UUID.randomUUID().toString()
+            val urlTemplate = uri.getQueryParameter("url") ?: ""
+            val count = uri.getQueryParameter("count")?.toIntOrNull() ?: 0
+            val catalogId = uri.getQueryParameter("catalogId")
+            return OpdsStreamDocumentWrapper(context, bookId, urlTemplate, count, catalogId)
+        }
         return if (type == FileType.CBZ || type == FileType.CBR || type == FileType.CB7) {
             val cacheFile = File(context.cacheDir, "temp_comic_${System.currentTimeMillis()}.${type.name.lowercase()}")
             withContext(Dispatchers.IO) {
@@ -117,13 +126,36 @@ class PdfPageWrapper(val pdfPage: PdfPageKt) : ReaderPage {
     }
 
     override fun getNativePointer(): Long {
-        return try {
-            val field = pdfPage.javaClass.getDeclaredField("mNativePagePtr")
-            field.isAccessible = true
-            field.get(pdfPage) as? Long ?: 0L
-        } catch (_: Exception) {
-            0L
+        return extractNativePointer(pdfPage)
+    }
+
+    private fun extractNativePointer(obj: Any): Long {
+        val priorityFields = listOf("page", "mNativePagePtr", "pagePtr", "mNativePage")
+
+        for (name in priorityFields) {
+            try {
+                val field = obj.javaClass.getDeclaredField(name)
+                field.isAccessible = true
+                val value = field.get(obj)
+                if (value is Long && value != 0L) return value
+                if (value != null && value !is Long) {
+                    val nestedPtr = extractNativePointer(value)
+                    if (nestedPtr != 0L) return nestedPtr
+                }
+            } catch (_: Exception) {}
         }
+
+        try {
+            for (field in obj.javaClass.declaredFields) {
+                if (field.type == Long::class.java || field.type == Long::class.javaPrimitiveType) {
+                    field.isAccessible = true
+                    val value = field.get(obj) as Long
+                    if (value > 0xFFFFFFFFL) return value
+                }
+            }
+        } catch (_: Exception) {}
+
+        return 0L
     }
 
     override fun close() { pdfPage.close() }
@@ -388,4 +420,93 @@ class ArchivePageWrapper(imageBytes: ByteArray) : ReaderPage {
     override fun close() {
         decoder?.recycle()
     }
+}
+
+class OpdsStreamDocumentWrapper(
+    private val context: Context,
+    private val bookId: String,
+    private val urlTemplate: String,
+    private val pageCount: Int,
+    private val catalogId: String?
+) : ReaderDocument {
+    private val cacheDir = File(context.cacheDir, "opds_stream_${bookId.hashCode()}").apply { mkdirs() }
+
+    private val catalog = catalogId?.let {
+        com.aryan.reader.opds.OpdsRepository(context).getCatalogs().find { c -> c.id == it }
+    }
+
+    private val client = com.aryan.reader.opds.OpdsRepository.sharedHttpClient.newBuilder()
+        .apply {
+            if (!catalog?.username.isNullOrBlank() && !catalog.password.isNullOrBlank()) {
+                authenticator(com.aryan.reader.opds.OpdsRepository.OpdsAuthenticator(catalog.username, catalog.password))
+            }
+        }
+        .build()
+
+    private fun createErrorPageBytes(): ByteArray {
+        val bitmap = createBitmap(800, 1200)
+        val canvas = Canvas(bitmap)
+        canvas.drawColor(android.graphics.Color.DKGRAY)
+        val paint = Paint().apply {
+            color = android.graphics.Color.WHITE
+            textSize = 40f
+            textAlign = Paint.Align.CENTER
+        }
+        canvas.drawText("Page Unavailable", 400f, 600f, paint)
+        val stream = java.io.ByteArrayOutputStream()
+        bitmap.compress(Bitmap.CompressFormat.JPEG, 80, stream)
+        return stream.toByteArray()
+    }
+
+    override suspend fun getPageCount() = pageCount
+
+    override suspend fun openPage(pageIndex: Int): ReaderPage? = withContext(Dispatchers.IO) {
+        if (pageIndex !in 0 until pageCount) return@withContext null
+
+        val cachedFile = File(cacheDir, "page_$pageIndex.jpg")
+        if (cachedFile.exists() && cachedFile.length() > 0) {
+            try {
+                return@withContext ArchivePageWrapper(cachedFile.readBytes())
+            } catch (e: Exception) {
+                Timber.e(e, "Failed to read cached stream page")
+            }
+        }
+
+        val finalUrlTemplate = if (catalog != null && urlTemplate.startsWith("http")) {
+            try {
+                val oldUrl = java.net.URL(urlTemplate)
+                val newUrl = java.net.URL(catalog.url)
+                val oldBase = "${oldUrl.protocol}://${oldUrl.authority}"
+                val newBase = "${newUrl.protocol}://${newUrl.authority}"
+                urlTemplate.replace(oldBase, newBase)
+            } catch (_: Exception) {
+                urlTemplate
+            }
+        } else urlTemplate
+
+        val url = finalUrlTemplate.replace("{pageNumber}", pageIndex.toString())
+            .replace("{maxWidth}", "1600")
+
+        val request = Request.Builder().url(url).build()
+        try {
+            val response = client.newCall(request).execute()
+            if (response.isSuccessful) {
+                val bytes = response.body?.bytes()
+                if (bytes != null && bytes.isNotEmpty()) {
+                    cachedFile.writeBytes(bytes)
+                    return@withContext ArchivePageWrapper(bytes)
+                }
+            } else {
+                Timber.e("Stream page failed with HTTP ${response.code}")
+            }
+        } catch (e: Exception) {
+            Timber.e(e, "Failed to fetch stream page $pageIndex")
+        }
+
+        return@withContext ArchivePageWrapper(createErrorPageBytes())
+    }
+
+    override suspend fun getTableOfContents() = emptyList<Bookmark>()
+
+    override fun close() {}
 }

app/src/main/res/xml/network_security_config.xml

@@ -1,9 +1,8 @@
 <?xml version="1.0" encoding="utf-8"?>
 <network-security-config>
-    <domain-config cleartextTrafficPermitted="true">
-        <domain includeSubdomains="true">192.168.141.181</domain>
-    </domain-config>
-    <domain-config cleartextTrafficPermitted="true">
-        <domain includeSubdomains="true">192.168.31.49</domain>
-    </domain-config>
+    <base-config cleartextTrafficPermitted="true">
+        <trust-anchors>
+            <certificates src="system" />
+        </trust-anchors>
+    </base-config>
 </network-security-config>