feat: Add custom cover backend to controllers

This helps answer gotson#63.

To change a series cover, one adds an image (jpg/jpeg/png) file with the
same directory name prefix, i.e:
- One Piece
- One Piece.jpg

To change a chapter cover, one needs to name it the same way as a chapter
file, changing the extension to (jpg/jpeg/png), i.e:
- One Piece
  - Chapter 1.cbz
  - Chapter 1.jpg

.gitignore

@@ -8,6 +8,10 @@ node_modules
 ### Logs
 *.log
 *.log.*.gz
+*.log.*.tmp
+
+### Home-dir, TODO: use user.home var
+~
 
 ### H2 databases
 *.mv.db

komga/src/main/kotlin/org/gotson/komga/interfaces/rest/BookController.kt

@@ -6,6 +6,7 @@ import io.swagger.v3.oas.annotations.media.Content
 import io.swagger.v3.oas.annotations.media.Schema
 import io.swagger.v3.oas.annotations.responses.ApiResponse
 import mu.KotlinLogging
+import org.apache.commons.io.FilenameUtils
 import org.gotson.komga.application.tasks.TaskReceiver
 import org.gotson.komga.domain.model.Author
 import org.gotson.komga.domain.model.BookSearchWithReadProgress
@@ -52,14 +53,19 @@ import org.springframework.web.bind.annotation.ResponseStatus
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.context.request.WebRequest
 import org.springframework.web.server.ResponseStatusException
+import java.io.File
 import java.io.FileNotFoundException
+import java.nio.file.Files
 import java.nio.file.NoSuchFileException
+import java.nio.file.Path
 import java.time.ZoneOffset
 import java.util.concurrent.TimeUnit
 import javax.validation.Valid
 
 private val logger = KotlinLogging.logger {}
 
+internal val COVER_EXTS = arrayOf("jpg", "jpeg", "png")
+
 @RestController
 @RequestMapping(produces = [MediaType.APPLICATION_JSON_VALUE])
 class BookController(
@@ -193,6 +199,23 @@ class BookController(
       if (!principal.user.canAccessLibrary(it)) throw ResponseStatusException(HttpStatus.UNAUTHORIZED)
     } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
 
+    bookRepository.findByIdOrNull(bookId)?.let { book ->
+      val fileExtension = FilenameUtils.getExtension(book.fileName())
+      val filePath = book.path().toString()
+      val thumbPrefix = filePath.substring(0, filePath.lastIndexOf(".$fileExtension"))
+
+      val thumbExts = arrayOf("jpg", "png", "jpeg")
+      for (ext in thumbExts) {
+        val thumbFile = File("$thumbPrefix.$ext")
+        if (thumbFile.exists()) {
+          val fileBytes = thumbFile.toURI().toURL().readBytes()
+          return ResponseEntity.ok()
+            .setCachePrivate()
+            .body(fileBytes)
+        }
+      }
+    }
+
     return mediaRepository.getThumbnail(bookId)?.let {
       ResponseEntity.ok()
         .setCachePrivate()

komga/src/main/kotlin/org/gotson/komga/interfaces/rest/SeriesController.kt

@@ -6,6 +6,7 @@ import io.swagger.v3.oas.annotations.media.Content
 import io.swagger.v3.oas.annotations.media.Schema
 import io.swagger.v3.oas.annotations.responses.ApiResponse
 import mu.KotlinLogging
+import org.apache.commons.io.FilenameUtils
 import org.gotson.komga.application.tasks.TaskReceiver
 import org.gotson.komga.domain.model.BookSearchWithReadProgress
 import org.gotson.komga.domain.model.Media
@@ -25,10 +26,12 @@ import org.gotson.komga.interfaces.rest.dto.SeriesMetadataUpdateDto
 import org.gotson.komga.interfaces.rest.dto.restrictUrl
 import org.gotson.komga.interfaces.rest.persistence.BookDtoRepository
 import org.gotson.komga.interfaces.rest.persistence.SeriesDtoRepository
+import org.springframework.core.io.FileSystemResource
 import org.springframework.data.domain.Page
 import org.springframework.data.domain.PageRequest
 import org.springframework.data.domain.Pageable
 import org.springframework.data.domain.Sort
+import org.springframework.http.CacheControl
 import org.springframework.http.HttpStatus
 import org.springframework.http.MediaType
 import org.springframework.http.ResponseEntity
@@ -45,6 +48,10 @@ import org.springframework.web.bind.annotation.RequestParam
 import org.springframework.web.bind.annotation.ResponseStatus
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.server.ResponseStatusException
+import java.io.File
+import java.nio.file.Files
+import java.nio.file.Path
+import java.util.concurrent.TimeUnit
 import javax.validation.Valid
 
 private val logger = KotlinLogging.logger {}
@@ -177,7 +184,31 @@ class SeriesController(
     } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
 
     return bookRepository.findFirstIdInSeries(seriesId)?.let {
-      bookController.getBookThumbnail(principal, it)
+      bookRepository.findByIdOrNull(it)?.let { firstBook ->
+        var dirPath = firstBook.path().parent.toString()
+        if (dirPath.endsWith(File.separatorChar)) {
+          dirPath = dirPath.substring(0, dirPath.length - 1)
+        }
+
+        var response: ResponseEntity<ByteArray>? = null
+
+        for (ext in COVER_EXTS) {
+          val thumbFile = FileSystemResource(File("$dirPath.$ext").toPath())
+          if (thumbFile.exists()) {
+            val fileBytes = thumbFile.uri.toURL().readBytes()
+            response = ResponseEntity.ok()
+              .setCachePrivate()
+              .body(fileBytes)
+            break
+          }
+        }
+
+        if (response == null) {
+          response = bookController.getBookThumbnail(principal, it)
+        }
+
+        return response
+      } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
     } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
   }
 
@@ -282,4 +313,10 @@ class SeriesController(
       bookLifecycle.deleteReadProgress(it, principal.user)
     }
   }
+
+  private fun ResponseEntity.BodyBuilder.setCachePrivate() =
+    this.cacheControl(CacheControl.maxAge(0, TimeUnit.SECONDS)
+      .cachePrivate()
+      .mustRevalidate()
+    )
 }