feat(backend): Phase 2.1 scaffolding for bookshelf-api + ABS

- Port BookshelfApiService, AudiobookshelfApiService and all models from Book's Story.
- Add Hilt 2.56.1 plugin, @HiltAndroidApp, NetworkModule, BackendModule.
- Add Retrofit/OkHttp/Kotlinx Serialization dependencies.
- Provide minimal SharedPreferences-based ServerSettings for URL/token storage.
- Copy UriUtils (fixUriScheme/normalizeUri) from Book's Story.
- No wiring into UI yet; OPDS/Gutenberg/LocalFolder still present.
- ':app:assembleOssDebug' passes (APK ~80 MB).

app/build.gradle.kts

@@ -11,6 +11,7 @@ plugins {
     alias(libs.plugins.kotlin.compose)
     alias(libs.plugins.kotlin.serialization)
     alias(libs.plugins.kotlin.ksp)
+    alias(libs.plugins.hilt)
     id("com.diffplug.spotless") version "8.2.1"
     alias(libs.plugins.kover)
 }
@@ -228,6 +229,16 @@ dependencies {
     implementation(libs.androidx.material3.window.size.class1.android)
     implementation(libs.androidx.credentials)
 
+    // Hilt
+    implementation(libs.hilt.android)
+    ksp(libs.hilt.compiler)
+    implementation(libs.hilt.navigation.compose)
+
+    // Networking
+    implementation(libs.retrofit)
+    implementation(libs.retrofit.kotlinx.serialization)
+    implementation(libs.okhttp.logging)
+
     androidTestImplementation(libs.androidx.junit)
     androidTestImplementation(libs.androidx.espresso.core)
     androidTestImplementation(platform(libs.androidx.compose.bom))

app/src/main/java/com/dueattendant149/bookreader/reader/MyApplication.kt

@@ -24,9 +24,11 @@ import android.webkit.WebView
 import coil.ImageLoader
 import coil.ImageLoaderFactory
 import coil.decode.SvgDecoder
+import dagger.hilt.android.HiltAndroidApp
 import org.dueattendant149.bookreader.paginatedreader.SvgStringFetcher
 import timber.log.Timber // Add this
 
+@HiltAndroidApp
 class MyApplication : Application(), ImageLoaderFactory {
     override fun onCreate() {
         super.onCreate()

app/src/main/java/org/dueattendant149/bookreader/data/remote/audiobookshelf/AudiobookshelfApiClientFactory.kt

@@ -0,0 +1,76 @@
+package org.dueattendant149.bookreader.data.remote.audiobookshelf
+
+import android.util.Log
+import kotlinx.serialization.json.Json
+import okhttp3.MediaType.Companion.toMediaType
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import org.dueattendant149.bookreader.domain.util.fixUriScheme
+import retrofit2.Retrofit
+import retrofit2.converter.kotlinx.serialization.asConverterFactory
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Builds (and caches) a Retrofit-backed [AudiobookshelfApiService] for the configured
+ * Audiobookshelf instance. All requests are authenticated with the provided bearer token.
+ */
+@Singleton
+class AudiobookshelfApiClientFactory
+    @Inject
+    constructor(
+        private val json: Json,
+        private val okHttpClient: OkHttpClient,
+    ) {
+        private var cachedUrl: String? = null
+        private var cachedToken: String? = null
+        private var cachedClient: AudiobookshelfApiService? = null
+
+        @Synchronized
+        fun provideClient(
+            url: String,
+            token: String,
+        ): AudiobookshelfApiService? {
+            val fixedUrl = url.fixUriScheme()
+            if (fixedUrl == cachedUrl && token == cachedToken && cachedClient != null) {
+                return cachedClient
+            }
+
+            val authClient =
+                okHttpClient
+                    .newBuilder()
+                    .addInterceptor { chain ->
+                        val request =
+                            chain
+                                .request()
+                                .newBuilder()
+                                .header("Authorization", "Bearer $token")
+                                .build()
+                        chain.proceed(request)
+                    }
+                    .addInterceptor(HttpLoggingInterceptor().apply { level = HttpLoggingInterceptor.Level.BASIC })
+                    .build()
+
+            return runCatching {
+                Retrofit
+                    .Builder()
+                    .client(authClient)
+                    .baseUrl(fixedUrl)
+                    .addConverterFactory(json.asConverterFactory("application/json".toMediaType()))
+                    .build()
+                    .create(AudiobookshelfApiService::class.java)
+            }.onFailure {
+                Log.e("AudiobookshelfApiFactory", "Failed to create client for $fixedUrl", it)
+            }.getOrNull().also {
+                cachedUrl = fixedUrl
+                cachedToken = token
+                cachedClient = it
+            }
+        }
+
+        fun clearCache() {
+            cachedUrl = null
+            cachedToken = null
+            cachedClient = null
+        }
+    }

app/src/main/java/org/dueattendant149/bookreader/data/remote/audiobookshelf/AudiobookshelfApiService.kt

@@ -0,0 +1,52 @@
+package org.dueattendant149.bookreader.data.remote.audiobookshelf
+
+import okhttp3.ResponseBody
+import org.dueattendant149.bookreader.data.remote.audiobookshelf.PlaybackProgressUpdateRequest
+import org.dueattendant149.bookreader.data.remote.audiobookshelf.model.AbsItemResponse
+import retrofit2.Response
+import retrofit2.http.Body
+import retrofit2.http.GET
+import retrofit2.http.POST
+import retrofit2.http.Path
+import retrofit2.http.Streaming
+
+/**
+ * Direct Audiobookshelf API calls for audio files and covers.
+ * bookshelf-api does not proxy audio streams, so the app talks to ABS directly.
+ */
+interface AudiobookshelfApiService {
+
+    @Streaming
+    @GET("api/items/{itemId}/file/{fileId}")
+    suspend fun downloadAudioFile(
+        @Path("itemId") itemId: String,
+        @Path("fileId") fileId: String,
+    ): Response<ResponseBody>
+
+    @Streaming
+    @GET("api/items/{itemId}/download")
+    suspend fun downloadBook(
+        @Path("itemId") itemId: String,
+    ): Response<ResponseBody>
+
+    @GET("api/items/{itemId}/cover")
+    suspend fun getCover(
+        @Path("itemId") itemId: String,
+    ): Response<ResponseBody>
+
+    @GET("api/me/progress/{itemId}")
+    suspend fun getProgress(
+        @Path("itemId") itemId: String,
+    ): Response<String>
+
+    @GET("api/items/{itemId}")
+    suspend fun getItem(
+        @Path("itemId") itemId: String,
+    ): Response<AbsItemResponse>
+
+    @POST("api/me/progress/{itemId}")
+    suspend fun updateProgress(
+        @Path("itemId") itemId: String,
+        @Body request: PlaybackProgressUpdateRequest,
+    ): Response<String>
+}

app/src/main/java/org/dueattendant149/bookreader/data/remote/audiobookshelf/PlaybackProgressUpdateRequest.kt

@@ -0,0 +1,21 @@
+package org.dueattendant149.bookreader.data.remote.audiobookshelf
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * Request body for updating media progress directly on an Audiobookshelf server.
+ *
+ * Field names follow the ABS `/api/me/progress/{itemId}` endpoint contract.
+ */
+@Serializable
+data class PlaybackProgressUpdateRequest(
+    @SerialName("currentTime")
+    val currentTime: Double,
+    @SerialName("duration")
+    val duration: Double,
+    @SerialName("progress")
+    val progress: Double,
+    @SerialName("episodeId")
+    val episodeId: String? = null,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/audiobookshelf/model/AbsItemResponse.kt

@@ -0,0 +1,35 @@
+package org.dueattendant149.bookreader.data.remote.audiobookshelf.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class AbsItemResponse(
+    val id: String = "",
+    val media: AbsMedia? = null,
+)
+
+@Serializable
+data class AbsMedia(
+    val metadata: AbsMediaMetadata? = null,
+    @SerialName("audioFiles")
+    val audioFiles: List<AbsAudioFile> = emptyList(),
+)
+
+@Serializable
+data class AbsMediaMetadata(
+    val title: String? = null,
+)
+
+@Serializable
+data class AbsAudioFile(
+    val ino: String = "",
+    val metadata: AbsAudioFileMetadata? = null,
+    val duration: Double = 0.0,
+)
+
+@Serializable
+data class AbsAudioFileMetadata(
+    val filename: String? = null,
+    val ext: String? = null,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/BookshelfApiClientFactory.kt

@@ -0,0 +1,62 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi
+
+import android.util.Log
+import kotlinx.serialization.json.Json
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import org.dueattendant149.bookreader.domain.util.fixUriScheme
+import okhttp3.MediaType.Companion.toMediaType
+import retrofit2.Retrofit
+import retrofit2.converter.kotlinx.serialization.asConverterFactory
+import javax.inject.Inject
+import javax.inject.Singleton
+
+/**
+ * Builds (and caches) a Retrofit-backed [BookshelfApiService] for the configured
+ * bookshelf-api instance.
+ */
+@Singleton
+class BookshelfApiClientFactory
+    @Inject
+    constructor(
+        private val json: Json,
+        private val okHttpClient: OkHttpClient,
+    ) {
+        private var cachedUrl: String? = null
+        private var cachedClient: BookshelfApiService? = null
+
+        @Synchronized
+        fun provideClient(url: String): BookshelfApiService? {
+            val fixedUrl = url.fixUriScheme()
+            if (fixedUrl == cachedUrl && cachedClient != null) {
+                return cachedClient
+            }
+
+            return runCatching {
+                Retrofit
+                    .Builder()
+                    .client(
+                        okHttpClient
+                            .newBuilder()
+                            .addInterceptor(HttpLoggingInterceptor().apply {
+                                level = HttpLoggingInterceptor.Level.BASIC
+                            })
+                            .build(),
+                    )
+                    .baseUrl(fixedUrl)
+                    .addConverterFactory(json.asConverterFactory("application/json".toMediaType()))
+                    .build()
+                    .create(BookshelfApiService::class.java)
+            }.onFailure {
+                Log.e("BookshelfApiClientFactory", "Failed to create BookshelfApiService for $fixedUrl", it)
+            }.getOrNull().also {
+                cachedUrl = fixedUrl
+                cachedClient = it
+            }
+        }
+
+        fun clearCache() {
+            cachedUrl = null
+            cachedClient = null
+        }
+    }

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/BookshelfApiService.kt

@@ -0,0 +1,158 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi
+
+import okhttp3.ResponseBody
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.AudioTrackResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.BookItemResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.DownloadRequest
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.DownloadResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.DownloadsListResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.LibraryItemsResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.LibraryResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.PlaybackProgressUpdateRequest
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.PodcastRequest
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.PodcastResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.ProgressUpdateRequest
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.SearchRequest
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.SearchResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.TtsCreateRequest
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.TtsEnginesResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.TtsJobResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.TtsJobsResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.TtsVoicesResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.UploadBookResponse
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.YandexRequest
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.model.YandexResponse
+import okhttp3.MultipartBody
+import okhttp3.RequestBody
+import retrofit2.Response
+import retrofit2.http.Body
+import retrofit2.http.GET
+import retrofit2.http.Multipart
+import retrofit2.http.Part
+import retrofit2.http.Path
+import retrofit2.http.Query
+import retrofit2.http.Streaming
+import retrofit2.http.POST
+
+/**
+ * Retrofit description of the Bookshelf API (bookshelf-api:8073).
+ * All endpoints are relative to the configured base URL.
+ */
+interface BookshelfApiService {
+
+    // Health
+    @GET("health")
+    suspend fun health(): Response<Unit>
+
+    // Libraries / books
+    @GET("api/v1/books/libraries")
+    suspend fun getLibraries(): Response<List<LibraryResponse>>
+
+    @Streaming
+    @GET("api/v1/books/{itemId}/ebook")
+    suspend fun downloadEbook(
+        @Path("itemId") itemId: String,
+    ): Response<ResponseBody>
+
+    @GET("api/v1/books/{itemId}/tracks")
+    suspend fun getAudioTracks(
+        @Path("itemId") itemId: String,
+    ): Response<List<AudioTrackResponse>>
+
+    @Streaming
+    @GET("api/v1/books/{itemId}/file/{fileId}")
+    suspend fun downloadAudioFile(
+        @Path("itemId") itemId: String,
+        @Path("fileId") fileId: String,
+    ): Response<ResponseBody>
+
+    @Streaming
+    @GET("api/v1/books/{itemId}")
+    suspend fun getBook(
+        @Path("itemId") itemId: String,
+    ): Response<ResponseBody>
+
+    @Streaming
+    @POST("api/v1/books/{itemId}/progress")
+    suspend fun updateReadingProgress(
+        @Path("itemId") itemId: String,
+        @Body request: ProgressUpdateRequest,
+    ): Response<ResponseBody>
+
+    @Streaming
+    @POST("api/v1/books/{itemId}/playback-progress")
+    suspend fun updatePlaybackProgress(
+        @Path("itemId") itemId: String,
+        @Body request: PlaybackProgressUpdateRequest,
+    ): Response<ResponseBody>
+
+    @GET("api/v1/books/library/{libraryId}/items")
+    suspend fun getLibraryItems(
+        @Path("libraryId") libraryId: String,
+    ): Response<LibraryItemsResponse>
+
+    @GET("api/v1/books/library/{libraryId}/search")
+    suspend fun searchLibrary(
+        @Path("libraryId") libraryId: String,
+        @Query("q") query: String,
+    ): Response<List<BookItemResponse>>
+
+    @POST("api/v1/search")
+    suspend fun search(
+        @Body request: SearchRequest,
+    ): Response<SearchResponse>
+
+    // TTS
+    @GET("api/v1/tts/engines")
+    suspend fun getTtsEngines(): Response<TtsEnginesResponse>
+
+    @GET("api/v1/tts/voices")
+    suspend fun getTtsVoices(
+        @Query("engine") engine: String? = null,
+    ): Response<TtsVoicesResponse>
+
+    @POST("api/v1/tts")
+    suspend fun createTtsJob(
+        @Body request: TtsCreateRequest,
+    ): Response<TtsJobResponse>
+
+    @GET("api/v1/tts/{jobId}")
+    suspend fun getTtsJobStatus(
+        @Path("jobId") jobId: String,
+    ): Response<TtsJobResponse>
+
+    @GET("api/v1/tts/jobs/list")
+    suspend fun listTtsJobs(): Response<TtsJobsResponse>
+
+    @Streaming
+    @GET("api/v1/tts/{jobId}/download")
+    suspend fun downloadTtsAudio(
+        @Path("jobId") jobId: String,
+    ): Response<ResponseBody>
+
+    @Multipart
+    @POST("api/v1/upload/book")
+    suspend fun uploadBook(
+        @Part file: MultipartBody.Part,
+        @Part("book_type") bookType: RequestBody,
+    ): Response<UploadBookResponse>
+
+    // Downloads / sources
+    @POST("api/v1/download")
+    suspend fun startDownload(
+        @Body request: DownloadRequest,
+    ): Response<DownloadResponse>
+
+    @GET("api/v1/download/list")
+    suspend fun listDownloads(): Response<DownloadsListResponse>
+
+    @POST("api/v1/podcasts")
+    suspend fun downloadPodcast(
+        @Body request: PodcastRequest,
+    ): Response<PodcastResponse>
+
+    @POST("api/v1/sources/yandex")
+    suspend fun downloadYandex(
+        @Body request: YandexRequest,
+    ): Response<YandexResponse>
+}

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/ServerStatusMonitor.kt

@@ -0,0 +1,61 @@
+/*
+ * Book's Story — free and open-source Material You eBook reader.
+ * Copyright (C) 2024-2026 Acclorite
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package org.dueattendant149.bookreader.data.remote.bookshelfapi
+
+import android.util.Log
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.Job
+import kotlinx.coroutines.SupervisorJob
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
+import kotlinx.coroutines.launch
+import org.dueattendant149.bookreader.data.settings.ServerSettings
+import javax.inject.Inject
+import javax.inject.Singleton
+
+@Singleton
+class ServerStatusMonitor
+    @Inject
+    constructor(
+        private val clientFactory: BookshelfApiClientFactory,
+        private val serverSettings: ServerSettings,
+    ) {
+        private val _isOnline = MutableStateFlow(false)
+        val isOnline = _isOnline.asStateFlow()
+
+        private val scope = CoroutineScope(SupervisorJob() + Dispatchers.IO)
+        private var pingJob: Job? = null
+
+        fun start() {
+            if (pingJob != null) return
+            pingJob = scope.launch {
+                while (true) {
+                    val online = checkHealth()
+                    _isOnline.value = online
+                    delay(30_000L)
+                }
+            }
+        }
+
+        fun stop() {
+            pingJob?.cancel()
+            pingJob = null
+        }
+
+        private suspend fun checkHealth(): Boolean {
+            val url = serverSettings.getBookshelfUrl() ?: return false
+            val client = clientFactory.provideClient(url) ?: return false
+            return runCatching {
+                val response = client.health()
+                response.isSuccessful
+            }.onFailure {
+                Log.d("ServerStatusMonitor", "Health check failed: ${it.message}")
+            }.getOrDefault(false)
+        }
+    }

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/AudioTrackResponse.kt

@@ -0,0 +1,13 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class AudioTrackResponse(
+    @SerialName("file_id")
+    val fileId: String,
+    val title: String = "",
+    val duration: Double = 0.0,
+    val size: Long = 0L,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/BookItemResponse.kt

@@ -0,0 +1,19 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class BookItemResponse(
+    val id: String,
+    val title: String = "",
+    val author: String = "",
+    @SerialName("media_type")
+    val mediaType: String = "",
+    @SerialName("library_id")
+    val libraryId: String = "",
+    @SerialName("cover_url")
+    val coverUrl: String = "",
+    val duration: Double = 0.0,
+    val size: Long = 0L,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/DownloadResponses.kt

@@ -0,0 +1,75 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class DownloadRequest(
+    val source: String = "",
+    val title: String = "",
+    val author: String = "",
+    @SerialName("download_url")
+    val downloadUrl: String? = null,
+    @SerialName("magnet_url")
+    val magnetUrl: String? = null,
+    @SerialName("info_hash")
+    val infoHash: String? = null,
+    val md5: String? = null,
+    val url: String? = null,
+    @SerialName("media_type")
+    val mediaType: String = "ebook",
+    @SerialName("download_protocol")
+    val downloadProtocol: String = "",
+)
+
+@Serializable
+data class DownloadResponse(
+    val success: Boolean = false,
+    val error: String? = null,
+    @SerialName("download_id")
+    val downloadId: String? = null,
+)
+
+@Serializable
+data class DownloadStatusResponse(
+    val title: String = "",
+    val status: String = "",
+    val progress: Double = 0.0,
+    val speed: String = "",
+    val error: String? = null,
+)
+
+@Serializable
+data class DownloadsListResponse(
+    val downloads: List<DownloadStatusResponse> = emptyList(),
+)
+
+@Serializable
+data class PodcastRequest(
+    val url: String,
+    val title: String? = null,
+    val format: String = "m4a",
+)
+
+@Serializable
+data class PodcastResponse(
+    val url: String = "",
+    val title: String = "",
+    val tracks: Int = 0,
+    val files: List<String> = emptyList(),
+    @SerialName("abs_scan_triggered")
+    val absScanTriggered: Boolean = false,
+)
+
+@Serializable
+data class YandexRequest(
+    val bookid: String,
+)
+
+@Serializable
+data class YandexResponse(
+    val bookid: String,
+    val files: List<String> = emptyList(),
+    @SerialName("abs_scan_triggered")
+    val absScanTriggered: Boolean = false,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/LibraryResponse.kt

@@ -0,0 +1,14 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class LibraryResponse(
+    val id: String,
+    val name: String = "",
+    @SerialName("media_type")
+    val mediaType: String = "",
+    @SerialName("item_count")
+    val itemCount: Int = 0,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/PlaybackProgressUpdateRequest.kt

@@ -0,0 +1,20 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * Request body for updating the audio playback progress of a book on the bookshelf-api.
+ */
+@Serializable
+data class PlaybackProgressUpdateRequest(
+    val itemId: String,
+    val libraryId: String,
+    @SerialName("current_file")
+    val currentFile: String,
+    @SerialName("current_position")
+    val currentPosition: Long,
+    val duration: Long,
+    @SerialName("updated_at")
+    val updatedAt: Long,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/ProgressUpdateRequest.kt

@@ -0,0 +1,20 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+/**
+ * Request body for updating the local reading progress of a book on the bookshelf-api.
+ */
+@Serializable
+data class ProgressUpdateRequest(
+    val itemId: String,
+    val libraryId: String,
+    val scrollIndex: Int,
+    val scrollOffset: Int,
+    val progress: Float,
+    @SerialName("last_chapter")
+    val lastChapter: String? = null,
+    @SerialName("updated_at")
+    val updatedAt: Long,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/SearchResponse.kt

@@ -0,0 +1,54 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class SearchResponse(
+    val results: List<SearchResultItemResponse> = emptyList(),
+    @SerialName("search_time_ms")
+    val searchTimeMs: Int = 0,
+    val total: Int = 0,
+)
+
+@Serializable
+data class SearchResultItemResponse(
+    val source: String = "",
+    val title: String = "",
+    val author: String = "",
+    val format: String = "",
+    @SerialName("media_type")
+    val mediaType: String = "",
+    @SerialName("size_human")
+    val sizeHuman: String = "",
+    val seeders: Int? = null,
+    val score: Double = 0.0,
+    val guid: String = "",
+    val md5: String = "",
+    @SerialName("magnet_url")
+    val magnetUrl: String = "",
+    @SerialName("download_url")
+    val downloadUrl: String = "",
+    val url: String = "",
+    @SerialName("cover_url")
+    val coverUrl: String = "",
+    @SerialName("info_hash")
+    val infoHash: String = "",
+    @SerialName("download_protocol")
+    val downloadProtocol: String = "",
+)
+
+@Serializable
+data class SearchRequest(
+    val query: String,
+    val author: String? = null,
+    @SerialName("media_type")
+    val mediaType: String? = null,
+    val format: String? = null,
+    val language: String? = null,
+    @SerialName("year_from")
+    val yearFrom: Int? = null,
+    @SerialName("year_to")
+    val yearTo: Int? = null,
+    val limit: Int = 50,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/TtsResponses.kt

@@ -0,0 +1,91 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class TtsCreateRequest(
+    @SerialName("book_id")
+    val bookId: String,
+    val engine: String = "silero",
+    @SerialName("voice_id")
+    val voiceId: String = "",
+    val speed: Double = 1.0,
+)
+
+@Serializable
+data class TtsJobResponse(
+    @SerialName("job_id")
+    val jobId: String,
+    @SerialName("book_id")
+    val bookId: String,
+    val title: String = "",
+    val author: String = "",
+    val engine: String = "",
+    @SerialName("voice_id")
+    val voiceId: String = "",
+    val speed: Double = 1.0,
+    val status: String = "",
+    val progress: Double = 0.0,
+    @SerialName("current_chapter")
+    val currentChapter: String = "",
+    @SerialName("total_chapters")
+    val totalChapters: Int = 0,
+    @SerialName("completed_chapters")
+    val completedChapters: Int = 0,
+    @SerialName("output_path")
+    val outputPath: String = "",
+    val error: String = "",
+    @SerialName("created_at")
+    val createdAt: Double = 0.0,
+    @SerialName("started_at")
+    val startedAt: Double = 0.0,
+    @SerialName("completed_at")
+    val completedAt: Double = 0.0,
+)
+
+@Serializable
+data class TtsJobsResponse(
+    val jobs: List<TtsJobResponse> = emptyList(),
+)
+
+@Serializable
+data class TtsEnginesResponse(
+    val engines: List<TtsEngineResponse> = emptyList(),
+)
+
+@Serializable
+data class TtsVoicesResponse(
+    val voices: List<TtsVoiceResponse> = emptyList(),
+)
+
+@Serializable
+data class TtsEngineResponse(
+    val id: String,
+    val name: String,
+    val capabilities: TtsEngineCapabilitiesResponse,
+)
+
+@Serializable
+data class TtsEngineCapabilitiesResponse(
+    @SerialName("supports_streaming")
+    val supportsStreaming: Boolean = false,
+    @SerialName("supports_cloning")
+    val supportsCloning: Boolean = false,
+    @SerialName("max_text_length")
+    val maxTextLength: Int = 5000,
+    @SerialName("needs_network")
+    val needsNetwork: Boolean = false,
+)
+
+@Serializable
+data class TtsVoiceResponse(
+    val id: String,
+    val name: String,
+    val language: String,
+    val engine: String,
+    val gender: String = "",
+    val quality: String = "",
+    @SerialName("requires_reference")
+    val requiresReference: Boolean = false,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/UnifiedItemResponse.kt

@@ -0,0 +1,67 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class LibraryItemsResponse(
+    val library: LibraryResponse = LibraryResponse(""),
+    val items: List<UnifiedItemResponse> = emptyList(),
+)
+
+@Serializable
+data class UnifiedItemResponse(
+    val id: String,
+    val title: String = "",
+    val authors: List<String> = emptyList(),
+    val author: String = "",
+    val type: String = "",
+    @SerialName("media_type")
+    val mediaType: String = "",
+    @SerialName("library_id")
+    val libraryId: String = "",
+    @SerialName("cover_url")
+    val coverUrl: String = "",
+    val duration: Double = 0.0,
+    val size: Long = 0L,
+    @SerialName("progress")
+    val progress: UnifiedItemProgressResponse? = null,
+)
+
+@Serializable
+data class UnifiedItemProgressResponse(
+    val reading: ReadingProgressResponse? = null,
+    val playback: PlaybackProgressResponse? = null,
+)
+
+@Serializable
+data class ReadingProgressResponse(
+    @SerialName("itemId")
+    val itemId: String = "",
+    @SerialName("libraryId")
+    val libraryId: String = "",
+    @SerialName("scrollIndex")
+    val scrollIndex: Int = 0,
+    @SerialName("scrollOffset")
+    val scrollOffset: Int = 0,
+    val progress: Float = 0f,
+    @SerialName("last_chapter")
+    val lastChapter: String? = null,
+    @SerialName("updatedAt")
+    val updatedAt: Long = 0L,
+)
+
+@Serializable
+data class PlaybackProgressResponse(
+    @SerialName("itemId")
+    val itemId: String = "",
+    @SerialName("libraryId")
+    val libraryId: String = "",
+    @SerialName("current_file")
+    val currentFile: String = "",
+    @SerialName("current_position")
+    val currentPosition: Long = 0L,
+    val duration: Long = 0L,
+    @SerialName("updatedAt")
+    val updatedAt: Long = 0L,
+)

app/src/main/java/org/dueattendant149/bookreader/data/remote/bookshelfapi/model/UploadBookResponse.kt

@@ -0,0 +1,14 @@
+package org.dueattendant149.bookreader.data.remote.bookshelfapi.model
+
+import kotlinx.serialization.SerialName
+import kotlinx.serialization.Serializable
+
+@Serializable
+data class UploadBookResponse(
+    val success: Boolean = false,
+    val filename: String = "",
+    val type: String = "",
+    val path: String = "",
+    @SerialName("error")
+    val errorMessage: String? = null,
+)

app/src/main/java/org/dueattendant149/bookreader/data/settings/ServerSettings.kt

@@ -0,0 +1,44 @@
+package org.dueattendant149.bookreader.data.settings
+
+import android.content.Context
+import android.content.SharedPreferences
+import androidx.core.content.edit
+import dagger.hilt.android.qualifiers.ApplicationContext
+import javax.inject.Inject
+import javax.inject.Singleton
+
+private const val PREFS_NAME = "book_reader_server_settings"
+private const val KEY_BOOKSHELF_URL = "bookshelf_url"
+private const val KEY_ABS_URL = "abs_url"
+private const val KEY_ABS_TOKEN = "abs_token"
+
+/**
+ * Minimal server URL/token storage. Replaces the full DataStore-based settings
+ * from Book's Story for Phase 2 backend scaffolding.
+ */
+@Singleton
+class ServerSettings
+    @Inject
+    constructor(
+        @ApplicationContext context: Context,
+    ) {
+        private val prefs: SharedPreferences = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+
+        fun getBookshelfUrl(): String? = prefs.getString(KEY_BOOKSHELF_URL, null)
+
+        fun setBookshelfUrl(url: String) {
+            prefs.edit { putString(KEY_BOOKSHELF_URL, url) }
+        }
+
+        fun getAbsUrl(): String? = prefs.getString(KEY_ABS_URL, null)
+
+        fun setAbsUrl(url: String) {
+            prefs.edit { putString(KEY_ABS_URL, url) }
+        }
+
+        fun getAbsToken(): String? = prefs.getString(KEY_ABS_TOKEN, null)
+
+        fun setAbsToken(token: String) {
+            prefs.edit { putString(KEY_ABS_TOKEN, token) }
+        }
+    }

app/src/main/java/org/dueattendant149/bookreader/di/BackendModule.kt

@@ -0,0 +1,37 @@
+package org.dueattendant149.bookreader.di
+
+import android.content.Context
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.android.qualifiers.ApplicationContext
+import dagger.hilt.components.SingletonComponent
+import kotlinx.serialization.json.Json
+import okhttp3.OkHttpClient
+import org.dueattendant149.bookreader.data.remote.audiobookshelf.AudiobookshelfApiClientFactory
+import org.dueattendant149.bookreader.data.remote.bookshelfapi.BookshelfApiClientFactory
+import org.dueattendant149.bookreader.data.settings.ServerSettings
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object BackendModule {
+
+    @Provides
+    @Singleton
+    fun provideServerSettings(@ApplicationContext context: Context): ServerSettings = ServerSettings(context)
+
+    @Provides
+    @Singleton
+    fun provideBookshelfApiClientFactory(
+        json: Json,
+        okHttpClient: OkHttpClient,
+    ): BookshelfApiClientFactory = BookshelfApiClientFactory(json, okHttpClient)
+
+    @Provides
+    @Singleton
+    fun provideAudiobookshelfApiClientFactory(
+        json: Json,
+        okHttpClient: OkHttpClient,
+    ): AudiobookshelfApiClientFactory = AudiobookshelfApiClientFactory(json, okHttpClient)
+}

app/src/main/java/org/dueattendant149/bookreader/di/NetworkModule.kt

@@ -0,0 +1,34 @@
+package org.dueattendant149.bookreader.di
+
+import dagger.Module
+import dagger.Provides
+import dagger.hilt.InstallIn
+import dagger.hilt.components.SingletonComponent
+import kotlinx.serialization.json.Json
+import okhttp3.OkHttpClient
+import okhttp3.logging.HttpLoggingInterceptor
+import javax.inject.Singleton
+
+@Module
+@InstallIn(SingletonComponent::class)
+object NetworkModule {
+
+    @Provides
+    @Singleton
+    fun provideJson(): Json = Json {
+        ignoreUnknownKeys = true
+        explicitNulls = false
+        isLenient = true
+    }
+
+    @Provides
+    @Singleton
+    fun provideOkHttpClient(): OkHttpClient = OkHttpClient
+        .Builder()
+        .addInterceptor(
+            HttpLoggingInterceptor().apply {
+                level = HttpLoggingInterceptor.Level.BASIC
+            }
+        )
+        .build()
+}

app/src/main/java/org/dueattendant149/bookreader/domain/util/UriUtils.kt

@@ -0,0 +1,76 @@
+package org.dueattendant149.bookreader.domain.util
+
+import android.net.Uri
+
+private val URL_SCHEME_REGEX = Regex("^[hH][tT][tT][pP][sS]?://")
+
+/**
+ * Returns true if the string is non-blank, has an http/https scheme,
+ * and can be parsed by [Uri.parse] into a host-bearing URI.
+ */
+fun String.isValidUri(): Boolean {
+    val trimmed = trim()
+    if (trimmed.isBlank()) return false
+    if (!trimmed.hasUriScheme()) return false
+
+    val uri = runCatching { Uri.parse(trimmed) }.getOrNull() ?: return false
+    return !uri.host.isNullOrBlank()
+}
+
+/**
+ * Returns true if the string starts with http:// or https:// (case-insensitive).
+ */
+fun String.hasUriScheme(): Boolean = URL_SCHEME_REGEX.containsMatchIn(this)
+
+private val IP_PATTERN = Regex("^\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}(:\\d+)?$")
+
+/**
+ * Adds https:// (or http:// for bare IP addresses) if the string has no scheme.
+ */
+fun String.ensureUriScheme(): String {
+    val trimmed = trim()
+    if (trimmed.hasUriScheme()) return trimmed
+    val hostPart = trimmed.substringBefore("/")
+    val scheme = if (IP_PATTERN.matches(hostPart)) "http://" else "https://"
+    return "$scheme$trimmed"
+}
+
+/**
+ * Adds a trailing slash if missing.
+ */
+fun String.ensureTrailingSlash(): String {
+    val trimmed = trim()
+    return if (trimmed.endsWith("/")) trimmed else "$trimmed/"
+}
+
+/**
+ * Normalizes a URL for Retrofit: trims whitespace, adds a scheme if missing,
+ * and ensures a trailing slash.
+ */
+fun String.normalizeUri(): String = ensureUriScheme().ensureTrailingSlash()
+
+/**
+ * Legacy alias for [normalizeUri].
+ */
+fun String.fixUriScheme(): String = normalizeUri()
+
+/**
+ * Derives a likely Audiobookshelf URL from a Bookshelf API URL.
+ * Replaces a known bookshelf-api port (8073) with the default ABS port (13378),
+ * or appends :13378 when no port is present. Returns null if the input is invalid.
+ */
+fun String.deriveAbsUrl(): String? {
+    if (!isValidUri()) return null
+    val normalized = normalizeUri()
+    val uri = Uri.parse(normalized)
+    val host = uri.host ?: return null
+    val port = uri.port
+    val scheme = uri.scheme?.lowercase() ?: "https"
+
+    val derivedPort = when (port) {
+        8073 -> 13378
+        -1 -> 13378
+        else -> port
+    }
+    return "$scheme://$host:$derivedPort/"
+}

build.gradle.kts

@@ -6,6 +6,7 @@ plugins {
     alias(libs.plugins.kotlin.compose) apply false
     alias(libs.plugins.kotlin.serialization) apply false
     alias(libs.plugins.kotlin.ksp) apply false
+    alias(libs.plugins.hilt) apply false
     alias(libs.plugins.kover) apply false
 }
 

gradle/libs.versions.toml

@@ -23,6 +23,11 @@ material3WindowSizeClassAndroid = "1.3.2"
 credentials = "1.5.0"
 composeMultiplatform = "1.8.2"
 ksp = "2.2.0-2.0.2"
+hilt = "2.56.1"
+hiltNavigationCompose = "1.2.0"
+retrofit = "2.11.0"
+retrofitKotlinxSerialization = "2.11.0"
+okhttpLogging = "4.12.0"
 
 [libraries]
 androidx-core-ktx = { group = "androidx.core", name = "core-ktx", version.ref = "coreKtx" }
@@ -56,6 +61,13 @@ androidx-runner = { group = "androidx.test", name = "runner", version.ref = "and
 androidx-material3-window-size-class1-android = { group = "androidx.compose.material3", name = "material3-window-size-class-android", version.ref = "material3WindowSizeClassAndroid" }
 androidx-credentials = { group = "androidx.credentials", name = "credentials", version.ref = "credentials" }
 
+hilt-android = { group = "com.google.dagger", name = "hilt-android", version.ref = "hilt" }
+hilt-compiler = { group = "com.google.dagger", name = "hilt-compiler", version.ref = "hilt" }
+hilt-navigation-compose = { group = "androidx.hilt", name = "hilt-navigation-compose", version.ref = "hiltNavigationCompose" }
+retrofit = { group = "com.squareup.retrofit2", name = "retrofit", version.ref = "retrofit" }
+retrofit-kotlinx-serialization = { group = "com.squareup.retrofit2", name = "converter-kotlinx-serialization", version.ref = "retrofitKotlinxSerialization" }
+okhttp-logging = { group = "com.squareup.okhttp3", name = "logging-interceptor", version.ref = "okhttpLogging" }
+
 
 [plugins]
 android-application = { id = "com.android.application", version.ref = "agp" }
@@ -65,6 +77,7 @@ kotlin-compose = { id = "org.jetbrains.kotlin.plugin.compose", version.ref = "ko
 kotlin-ksp = { id = "com.google.devtools.ksp", version.ref = "ksp" }
 kotlin-serialization = { id = "org.jetbrains.kotlin.plugin.serialization", version.ref = "kotlin" }
 compose-multiplatform = { id = "org.jetbrains.compose", version.ref = "composeMultiplatform" }
+hilt = { id = "com.google.dagger.hilt.android", version.ref = "hilt" }
 
 # Add plugins required by pdfiumandroid
 android-library = { id = "com.android.library", version.ref = "agp" }