fix: Handle one edge-case in reader & some other improvements

Signed-off-by: starry-shivam <[email protected]>

app/src/main/java/com/starry/myne/di/MainModule.kt

@@ -20,7 +20,6 @@ package com.starry.myne.di
 import android.content.Context
 import com.starry.myne.api.BookAPI
 import com.starry.myne.database.MyneDatabase
-import com.starry.myne.epub.EpubCache
 import com.starry.myne.epub.EpubParser
 import com.starry.myne.helpers.PreferenceUtil
 import com.starry.myne.helpers.book.BookDownloader
@@ -65,12 +64,7 @@ class MainModule {
 
     @Singleton
     @Provides
-    fun provideEpubcahe(@ApplicationContext context: Context) = EpubCache(context)
-
-    @Singleton
-    @Provides
-    fun provideEpubParser(@ApplicationContext context: Context, epubCache: EpubCache) =
-        EpubParser(context, epubCache)
+    fun provideEpubParser(@ApplicationContext context: Context) = EpubParser(context)
 
     @Provides
     @Singleton

app/src/main/java/com/starry/myne/epub/EpubCache.kt

@@ -126,6 +126,22 @@ class EpubCache(private val context: Context) {
         }
     }
 
+    /**
+     * Removes a book from the cache.
+     *
+     * @param filepath The path to the book file.
+     */
+    fun remove(filepath: String): Boolean {
+        Log.d(TAG, "Removing book from cache: $filepath")
+        val fileName = File(filepath).nameWithoutExtension
+        val bookFile = File(getPath(), "$fileName.json")
+        return if (bookFile.exists()) {
+            bookFile.delete()
+        } else {
+            false
+        }
+    }
+
     /**
      * Checks if a book is cached.
      *

app/src/main/java/com/starry/myne/epub/EpubParser.kt

@@ -31,14 +31,15 @@ import org.w3c.dom.Node
 import java.io.File
 import java.io.FileInputStream
 import java.io.InputStream
+import java.util.concurrent.ThreadLocalRandom
 import java.util.zip.ZipFile
 import java.util.zip.ZipInputStream
 
 
 /**
  * Parses an EPUB file and creates an [EpubBook] object.
  */
-class EpubParser(private val context: Context, private val epubCache: EpubCache) {
+class EpubParser(private val context: Context) {
 
     /**
      * Represents an EPUB document.
@@ -104,6 +105,8 @@ class EpubParser(private val context: Context, private val epubCache: EpubCache)
         const val TAG = "EpubParser"
     }
 
+    private val epubCache = EpubCache(context)
+
     /**
      * Creates an [EpubBook] object from an EPUB file.
      *
@@ -154,6 +157,15 @@ class EpubParser(private val context: Context, private val epubCache: EpubCache)
         return epubCache.isCached(filePath)
     }
 
+    /**
+     * Removes an EPUB book from the cache.
+     *
+     * @param filePath The file path of the EPUB file.
+     */
+    fun removeBookFromCache(filePath: String): Boolean {
+        return epubCache.remove(filePath)
+    }
+
     /**
      * Parses and creates an [EpubBook] object from the EPUB files and document.
      * This function is called from [createEpubBook] and [createEpubBook].
@@ -191,9 +203,9 @@ class EpubParser(private val context: Context, private val epubCache: EpubCache)
         }
 
         // Determine the method of parsing chapters based on the presence of ToC and
-        // the shouldUseToc flag. If tocNavPoints is not null or empty and shouldUseToc
-        // is true, use the ToC file for parsing. Otherwise, parse using the spine.
-        val chapters = if (!tocNavPoints.isNullOrEmpty() && shouldUseToc) {
+        // the shouldUseToc flag. We also check if the ToC file has more than one navPoint
+        // to ensure that it is a valid ToC file.
+        val chapters = if (shouldUseToc && !tocNavPoints.isNullOrEmpty() && tocNavPoints.size > 1) {
             Log.d(TAG, "Parsing based on ToC file")
             parseUsingTocFile(tocNavPoints, files, hrefRootPath, document, manifestItems)
         } else {
@@ -231,17 +243,17 @@ class EpubParser(private val context: Context, private val epubCache: EpubCache)
         val epubDocument = try {
             createEpubDocument(files)
         } catch (exc: EpubParserException) {
-            // In some rare cases, the ZipInputStream does not contains / fails to read all of the files
+            // In some rare cases, the ZipInputStream does not contain or fails to read all of the files
             // required to parse the EPUB archive, even though the zip file itself contains them.
             // In such cases, retry parsing the EPUB file by directly using the ZipFile API.
             // Since ZipFile requires a file path, we need to create a temporary file from the input stream.
             //
-            // Reasons for this issue are unknown and may be related to how the EPUB file is compressed
-            // i.e. weather it is missing some metadata or file/folder entry in it's header or how the
+            // The reasons for this issue are unknown and may be related to how the EPUB file is compressed,
+            // i.e., whether it is missing some metadata or file/folder entry in its header, or how the
             // ZipInputStream reads the file.
             //
-            // If someone knows the exact reason for this issue, or have dealt with it before, please
-            // let me know or feel free to create a PR with a better solution.
+            // If anyone knows the exact reason for this issue or has dealt with it before, please
+            // let me know, or feel free to create a PR with a better solution.
             if (exc.message == "META-INF/container.xml file missing"
                 || exc.message == ".opf file missing"
             ) {
@@ -413,6 +425,17 @@ class EpubParser(private val context: Context, private val epubCache: EpubCache)
         return navPoints
     }
 
+    /**
+     * Generate a unique ID for a chapter.
+     *
+     * @return The generated ID.
+     */
+    private fun generateId(): String {
+        val timestamp = System.currentTimeMillis()
+        val randomSuffix = ThreadLocalRandom.current().nextInt(1000, 9999)
+        return "$timestamp-$randomSuffix"
+    }
+
     /**
      * Parse the EPUB file using the table of contents (ToC) file.
      * This method is called from [parseAndCreateEbook].
@@ -468,6 +491,7 @@ class EpubParser(private val context: Context, private val epubCache: EpubCache)
                 if (res != null) {
                     listOf(
                         EpubChapter(
+                            chapterId = generateId(),
                             absPath = chapterSrc,
                             title = title?.takeIf { it.isNotEmpty() } ?: "Chapter $index",
                             body = res.body
@@ -548,6 +572,7 @@ class EpubParser(private val context: Context, private val epubCache: EpubCache)
                 it.chapterIndex
             }.map { (index, list) ->
                 EpubChapter(
+                    chapterId = generateId(),
                     absPath = list.first().url,
                     title = list.first().title?.takeIf { it.isNotBlank() } ?: "Chapter $index",
                     body = list.joinToString("\n\n") { it.body }

app/src/main/java/com/starry/myne/epub/models/EpubChapter.kt

@@ -28,6 +28,7 @@ import kotlinx.serialization.Serializable
  */
 @Serializable
 data class EpubChapter(
+    val chapterId: String,
     val absPath: String,
     val title: String,
     val body: String

app/src/main/java/com/starry/myne/ui/screens/library/viewmodels/LibraryViewModel.kt

@@ -55,6 +55,7 @@ class LibraryViewModel @Inject constructor(
     val showOnboardingTapTargets: State<Boolean> = _showOnboardingTapTargets
 
     fun deleteItemFromDB(item: LibraryItem) {
+        epubParser.removeBookFromCache(item.filePath)
         viewModelScope.launch(Dispatchers.IO) { libraryDao.delete(item) }
     }
 

app/src/main/java/com/starry/myne/ui/screens/reader/activities/ReaderActivity.kt

@@ -27,6 +27,7 @@ import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.foundation.lazy.LazyListState
 import androidx.compose.foundation.lazy.rememberLazyListState
 import androidx.compose.runtime.LaunchedEffect
+import androidx.compose.runtime.remember
 import androidx.compose.runtime.rememberCoroutineScope
 import androidx.compose.runtime.snapshotFlow
 import androidx.core.view.WindowCompat
@@ -36,7 +37,7 @@ import androidx.lifecycle.ViewModelProvider
 import com.starry.myne.R
 import com.starry.myne.helpers.Constants
 import com.starry.myne.helpers.toToast
-import com.starry.myne.ui.screens.reader.composables.ReaderContent
+import com.starry.myne.ui.screens.reader.composables.ChaptersContent
 import com.starry.myne.ui.screens.reader.composables.ReaderScreen
 import com.starry.myne.ui.screens.reader.viewmodels.ReaderViewModel
 import com.starry.myne.ui.screens.settings.viewmodels.SettingsViewModel
@@ -80,40 +81,39 @@ class ReaderActivity : AppCompatActivity() {
         // Set UI contents.
         setContent {
             MyneTheme(settingsViewModel = settingsViewModel) {
-
                 val lazyListState = rememberLazyListState()
                 val coroutineScope = rememberCoroutineScope()
-
                 // Handle intent and load epub book.
-                val intentData = handleIntent(intent = intent,
-                    viewModel = viewModel,
-                    contentResolver = contentResolver,
-                    scrollToPosition = { index, offset ->
-                        coroutineScope.launch {
-                            lazyListState.scrollToItem(index, offset)
-                        }
-                    },
-                    onError = {
-                        getString(R.string.error).toToast(this)
-                        finish()
-                    })
+                val intentData = remember {
+                    handleIntent(intent = intent,
+                        viewModel = viewModel,
+                        contentResolver = contentResolver,
+                        scrollToPosition = { index, offset ->
+                            coroutineScope.launch {
+                                lazyListState.scrollToItem(index, offset)
+                            }
+                        },
+                        onError = {
+                            getString(R.string.error).toToast(this)
+                            finish()
+                        })
+                }
 
                 ReaderScreen(
                     viewModel = viewModel,
-                    lazyListState = lazyListState,
-                    readerContent = {
+                    onScrollToChapter = { lazyListState.scrollToItem(it) },
+                    chaptersContent = {
                         LaunchedEffect(lazyListState) {
                             snapshotFlow {
                                 lazyListState.firstVisibleItemScrollOffset
                             }.collect { visibleChapterOffset ->
-                                // fetch last visible chapter position and offset.
+                                // Get the currently visible chapter index.
                                 val visibleChapterIdx = lazyListState.firstVisibleItemIndex
                                 // Set currently visible chapter & index.
                                 viewModel.setVisibleChapterIndex(visibleChapterIdx)
                                 viewModel.setChapterScrollPercent(
                                     calculateChapterPercentage(lazyListState)
                                 )
-
                                 // If book was not opened from external epub file, update the
                                 // reading progress into the database.
                                 if (!intentData.isExternalFile) {
@@ -129,13 +129,14 @@ class ReaderActivity : AppCompatActivity() {
                         }
 
                         // Reader content lazy column.
-                        ReaderContent(
+                        ChaptersContent(
                             state = viewModel.state,
                             lazyListState = lazyListState,
                             onToggleReaderMenu = {
                                 viewModel.toggleReaderMenu()
                                 toggleSystemBars(viewModel.state.showReaderMenu)
-                            })
+                            }
+                        )
                     })
             }
         }

app/src/main/java/com/starry/myne/ui/screens/reader/composables/ReaderContent.kt → app/src/main/java/com/starry/myne/ui/screens/reader/composables/ChaptersContent.kt

@@ -61,7 +61,7 @@ import com.starry.myne.ui.theme.pacificoFont
 
 
 @Composable
-fun ReaderContent(
+fun ChaptersContent(
     state: ReaderScreenState,
     lazyListState: LazyListState,
     onToggleReaderMenu: () -> Unit
@@ -72,7 +72,7 @@ fun ReaderContent(
     ) {
         items(
             count = state.epubBook!!.chapters.size,
-            key = { index -> state.epubBook.chapters[index].hashCode() }
+            key = { index -> state.epubBook.chapters[index].chapterId }
         ) { index ->
             val chapter = state.epubBook.chapters[index]
             ChapterLazyItemItem(
@@ -194,9 +194,7 @@ private fun ChapterLazyItemItem(
                             onClick()
                         }
                     }
-
                 }
-            //  .noRippleClickable { onClick() }
         ) {
             Text(
                 modifier = Modifier.padding(start = 12.dp, end = 4.dp, top = 10.dp),