added thumbnail generation

komga/build.gradle.kts

@@ -58,6 +58,8 @@ dependencies {
   implementation("com.github.junrar:junrar:4.0.0")
   implementation("net.grey-panther:natural-comparator:1.1")
 
+  implementation("net.coobird:thumbnailator:0.4.8")
+
   runtimeOnly("com.h2database:h2:1.4.199")
 
   testImplementation("org.springframework.boot:spring-boot-starter-test") {

komga/src/main/kotlin/org/gotson/komga/domain/model/BookMetadata.kt

@@ -10,6 +10,7 @@ import javax.persistence.FetchType
 import javax.persistence.GeneratedValue
 import javax.persistence.Id
 import javax.persistence.JoinColumn
+import javax.persistence.Lob
 import javax.persistence.OneToOne
 import javax.persistence.Table
 
@@ -23,6 +24,10 @@ class BookMetadata(
     @Column(name = "media_type")
     val mediaType: String? = null,
 
+    @Column(name = "thumbnail")
+    @Lob
+    val thumbnail: ByteArray? = null,
+
     pages: List<BookPage> = emptyList()
 ) {
   @Id

komga/src/main/kotlin/org/gotson/komga/domain/service/BookParser.kt

@@ -1,6 +1,7 @@
 package org.gotson.komga.domain.service
 
 import mu.KotlinLogging
+import net.coobird.thumbnailator.Thumbnails
 import org.gotson.komga.domain.model.Book
 import org.gotson.komga.domain.model.BookMetadata
 import org.gotson.komga.domain.model.Status
@@ -9,6 +10,7 @@ import org.gotson.komga.infrastructure.archive.ContentDetector
 import org.gotson.komga.infrastructure.archive.RarExtractor
 import org.gotson.komga.infrastructure.archive.ZipExtractor
 import org.springframework.stereotype.Service
+import java.io.ByteArrayOutputStream
 import java.io.InputStream
 
 private val logger = KotlinLogging.logger {}
@@ -25,6 +27,9 @@ class BookParser(
       "application/x-rar-compressed" to rarExtractor
   )
 
+  private val thumbnailSize = 300
+  private val thumbnailFormat = "png"
+
   fun parse(book: Book): BookMetadata {
     logger.info { "Trying to parse book: ${book.url}" }
 
@@ -36,7 +41,20 @@ class BookParser(
     val pages = supportedMediaTypes.getValue(mediaType).getPagesList(book.path())
     logger.info { "Book has ${pages.size} pages" }
 
-    return BookMetadata(mediaType = mediaType, status = Status.READY, pages = pages)
+    val thumbnail = try {
+      ByteArrayOutputStream().let {
+        Thumbnails.of(supportedMediaTypes.getValue(mediaType).getPageStream(book.path(), pages.first().fileName))
+            .size(thumbnailSize, thumbnailSize)
+            .outputFormat(thumbnailFormat)
+            .toOutputStream(it)
+        it.toByteArray()
+      }
+    } catch (ex: Exception) {
+      logger.warn(ex) { "Could not generate thumbnail for book: ${book.url}" }
+      null
+    }
+
+    return BookMetadata(mediaType = mediaType, status = Status.READY, pages = pages, thumbnail = thumbnail)
   }
 
   fun getPageStream(book: Book, number: Int): InputStream {

komga/src/main/kotlin/org/gotson/komga/interfaces/web/SerieController.kt

@@ -73,6 +73,18 @@ class SerieController(
     return bookRepository.findByIdOrNull(bookId)?.toDto() ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
   }
 
+  @GetMapping(value = ["{serieId}/books/{bookId}/thumbnail"], produces = [MediaType.IMAGE_PNG_VALUE])
+  fun getBookThumbnail(
+      @PathVariable serieId: Long,
+      @PathVariable bookId: Long
+  ): ByteArray {
+    if (!serieRepository.existsById(serieId)) throw ResponseStatusException(HttpStatus.NOT_FOUND)
+
+    return bookRepository.findByIdOrNull(bookId)?.let {
+      it.metadata.thumbnail ?: throw ResponseStatusException(HttpStatus.NO_CONTENT)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
   @GetMapping(value = ["{serieId}/books/{bookId}/content"], produces = [MediaType.APPLICATION_OCTET_STREAM_VALUE])
   fun getBookContent(
       @PathVariable serieId: Long,