Add Kavita EPUB reader handoff

src/all/kavita/build.gradle

@@ -2,7 +2,7 @@ ext {
     kmkVersionCode = 1
     extName = 'Kavita'
     extClass = '.KavitaFactory'
-    extVersionCode = 32
+    extVersionCode = 33
     isNsfw = false
 }
 

src/all/kavita/src/eu/kanade/tachiyomi/extension/all/kavita/Kavita.kt

@@ -81,6 +81,7 @@ import uy.kohesive.injekt.Injekt
 import uy.kohesive.injekt.api.get
 import uy.kohesive.injekt.injectLazy
 import java.io.IOException
+import java.net.URLEncoder
 import java.security.MessageDigest
 import java.util.Calendar
 import java.util.Locale
@@ -1774,6 +1775,9 @@ class Kavita(private val suffix: String = "") : ConfigurableSource, UnmeteredSou
             params += "pages=$pageCount"
         }
         params += "extractPdf=${shouldExtractPdf(chapter, forceExtractPdf)}"
+        if (isEpubChapter(chapter)) {
+            params += "epub=true"
+        }
         if (chapter.fileCount > 1) {
             params += "split=${chapter.fileCount}"
         }
@@ -1797,6 +1801,16 @@ class Kavita(private val suffix: String = "") : ConfigurableSource, UnmeteredSou
             file.format == MangaFormat.Pdf.format || file.extension.equals("pdf", ignoreCase = true)
         }
 
+    private fun isEpubChapter(chapter: ChapterDto): Boolean =
+        chapter.files.orEmpty().any { file ->
+            file.format == MangaFormat.Epub.format || file.extension.equals("epub", ignoreCase = true)
+        }
+
+    private fun isEpubFromChapterUrl(chapter: SChapter): Boolean =
+        chapter.url.substringAfter("epub=", "")
+            .substringBefore("&")
+            .equals("true", ignoreCase = true)
+
     private fun isPdfSeries(seriesId: Int?): Boolean =
         seriesId?.let { id ->
             series.find { it.id == id }?.format == MangaFormat.Pdf.format ||
@@ -1830,6 +1844,22 @@ class Kavita(private val suffix: String = "") : ConfigurableSource, UnmeteredSou
         return Page(index = index, url = imageUrl, imageUrl = imageUrl)
     }
 
+    private fun readerEpubPage(chapterId: Any, pageCount: Int, title: String? = null): Page {
+        val params = mutableListOf(
+            "apiUrl=${apiUrl.urlEncode()}",
+            "apiKey=${apiKey.urlEncode()}",
+            "chapterId=${chapterId.toString().urlEncode()}",
+            "pages=${pageCount.coerceAtLeast(1)}",
+        )
+        if (!title.isNullOrBlank()) {
+            params += "title=${title.urlEncode()}"
+        }
+        val url = "kavita-epub://reader?${params.joinToString("&")}"
+        return Page(index = 0, url = url, imageUrl = null)
+    }
+
+    private fun String.urlEncode(): String = URLEncoder.encode(this, Charsets.UTF_8.name())
+
     override suspend fun getPageList(chapter: SChapter): List<Page> = withContext(Dispatchers.IO) {
         // Check if this is a reading list item (has readingListId in URL)
         if (chapter.url.contains("readingListId=")) {
@@ -1877,6 +1907,9 @@ class Kavita(private val suffix: String = "") : ConfigurableSource, UnmeteredSou
                 }
 
                 // Generate pages with consistent URL format
+                if (isEpubChapter(chapterDetails)) {
+                    return@withContext listOf(readerEpubPage(chapterDetails.id, chapterDetails.pages, chapterDetails.titleName ?: chapterDetails.title))
+                }
                 val extractPdf = shouldExtractPdf(chapterDetails, isPdfSeries(seriesId))
                 return@withContext (0 until chapterDetails.pages).map { i -> readerPage(i, chapterDetails.id, extractPdf = extractPdf) }
             } catch (e: Exception) {
@@ -1913,6 +1946,9 @@ class Kavita(private val suffix: String = "") : ConfigurableSource, UnmeteredSou
                     .runningFold(0) { acc, chapter -> acc + chapter.pages }
                     .zip(volume.chapters.sortedBy { it.number.toFloatOrNull() ?: 0f })
                     .flatMap { (startIndex, chapter) ->
+                        if (isEpubChapter(chapter)) {
+                            return@withContext listOf(readerEpubPage(chapter.id, chapter.pages, chapter.titleName ?: chapter.title))
+                        }
                         val extractPdf = shouldExtractPdf(chapter, isPdfSeries(volume.seriesId))
                         (0 until chapter.pages).map { i ->
                             readerPage(startIndex + i, chapter.id, i, extractPdf)
@@ -1930,6 +1966,9 @@ class Kavita(private val suffix: String = "") : ConfigurableSource, UnmeteredSou
 
                 val extractPdf = extractPdfFromChapterUrl(chapter)
                 pageCountFromChapterUrl(chapter)?.let { pageCount ->
+                    if (isEpubFromChapterUrl(chapter)) {
+                        return@withContext listOf(readerEpubPage(chapterId, pageCount, chapter.name))
+                    }
                     return@withContext (0 until pageCount).map { i -> readerPage(i, chapterId, extractPdf = extractPdf) }
                 }
 
@@ -1952,6 +1991,9 @@ class Kavita(private val suffix: String = "") : ConfigurableSource, UnmeteredSou
                 }
 
                 val fetchedExtractPdf = extractPdf || shouldExtractPdf(chapterDetails)
+                if (isEpubChapter(chapterDetails)) {
+                    return@withContext listOf(readerEpubPage(chapterId, chapterDetails.pages, chapterDetails.titleName ?: chapterDetails.title))
+                }
                 return@withContext (0 until chapterDetails.pages).map { i -> readerPage(i, chapterId, extractPdf = fetchedExtractPdf) }
             }
         } catch (e: Exception) {