feat(api): cover upload for books, read lists and collections

Co-authored-by: Gauthier Roebroeck <gauthier.roebroeck@gmail.com>

komga/src/flyway/resources/db/migration/sqlite/V20211206124920__collection_and_readlist_thumbnails.sql

@@ -0,0 +1,23 @@
+CREATE TABLE THUMBNAIL_COLLECTION
+(
+    ID                 varchar  NOT NULL PRIMARY KEY,
+    SELECTED           boolean  NOT NULL DEFAULT 0,
+    THUMBNAIL          blob     NOT NULL,
+    TYPE               varchar  NOT NULL,
+    COLLECTION_ID      varchar  NOT NULL,
+    CREATED_DATE       datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    LAST_MODIFIED_DATE datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (COLLECTION_ID) REFERENCES COLLECTION (ID)
+);
+
+CREATE TABLE THUMBNAIL_READLIST
+(
+    ID                 varchar  NOT NULL PRIMARY KEY,
+    SELECTED           boolean  NOT NULL DEFAULT 0,
+    THUMBNAIL          blob     NOT NULL,
+    TYPE               varchar  NOT NULL,
+    READLIST_ID        varchar  NOT NULL,
+    CREATED_DATE       datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    LAST_MODIFIED_DATE datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    FOREIGN KEY (READLIST_ID) REFERENCES READLIST (ID)
+);

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

@@ -32,5 +32,14 @@ sealed class DomainEvent : Serializable {
   data class ReadProgressSeriesDeleted(val seriesId: String, val userId: String) : DomainEvent()
 
   data class ThumbnailBookAdded(val thumbnail: ThumbnailBook) : DomainEvent()
+  data class ThumbnailBookDeleted(val thumbnail: ThumbnailBook) : DomainEvent()
+
   data class ThumbnailSeriesAdded(val thumbnail: ThumbnailSeries) : DomainEvent()
+  data class ThumbnailSeriesDeleted(val thumbnail: ThumbnailSeries) : DomainEvent()
+
+  data class ThumbnailSeriesCollectionAdded(val thumbnail: ThumbnailSeriesCollection) : DomainEvent()
+  data class ThumbnailSeriesCollectionDeleted(val thumbnail: ThumbnailSeriesCollection) : DomainEvent()
+
+  data class ThumbnailReadListAdded(val thumbnail: ThumbnailReadList) : DomainEvent()
+  data class ThumbnailReadListDeleted(val thumbnail: ThumbnailReadList) : DomainEvent()
 }

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

@@ -1,5 +1,5 @@
 package org.gotson.komga.domain.model
 
 enum class MarkSelectedPreference {
-  NO, YES, IF_NONE_EXIST
+  NO, YES, IF_NONE_OR_GENERATED
 }

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

@@ -20,7 +20,7 @@ data class ThumbnailBook(
   override val lastModifiedDate: LocalDateTime = createdDate,
 ) : Auditable(), Serializable {
   enum class Type {
-    GENERATED, SIDECAR
+    GENERATED, SIDECAR, USER_UPLOADED
   }
 
   override fun equals(other: Any?): Boolean {

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

@@ -0,0 +1,47 @@
+package org.gotson.komga.domain.model
+
+import com.github.f4b6a3.tsid.TsidCreator
+import java.io.Serializable
+import java.time.LocalDateTime
+
+data class ThumbnailReadList(
+  val thumbnail: ByteArray,
+  val selected: Boolean = false,
+  val type: Type,
+
+  val id: String = TsidCreator.getTsid256().toString(),
+  val readListId: String = "",
+
+  override val createdDate: LocalDateTime = LocalDateTime.now(),
+  override val lastModifiedDate: LocalDateTime = createdDate,
+) : Auditable(), Serializable {
+  enum class Type {
+    USER_UPLOADED
+  }
+
+  override fun equals(other: Any?): Boolean {
+    if (this === other) return true
+    if (other !is ThumbnailReadList) return false
+
+    if (!thumbnail.contentEquals(other.thumbnail)) return false
+    if (selected != other.selected) return false
+    if (type != other.type) return false
+    if (id != other.id) return false
+    if (readListId != other.readListId) return false
+    if (createdDate != other.createdDate) return false
+    if (lastModifiedDate != other.lastModifiedDate) return false
+
+    return true
+  }
+
+  override fun hashCode(): Int {
+    var result = thumbnail.contentHashCode()
+    result = 31 * result + selected.hashCode()
+    result = 31 * result + type.hashCode()
+    result = 31 * result + id.hashCode()
+    result = 31 * result + readListId.hashCode()
+    result = 31 * result + createdDate.hashCode()
+    result = 31 * result + lastModifiedDate.hashCode()
+    return result
+  }
+}

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

@@ -0,0 +1,47 @@
+package org.gotson.komga.domain.model
+
+import com.github.f4b6a3.tsid.TsidCreator
+import java.io.Serializable
+import java.time.LocalDateTime
+
+data class ThumbnailSeriesCollection(
+  val thumbnail: ByteArray,
+  val selected: Boolean = false,
+  val type: Type,
+
+  val id: String = TsidCreator.getTsid256().toString(),
+  val collectionId: String = "",
+
+  override val createdDate: LocalDateTime = LocalDateTime.now(),
+  override val lastModifiedDate: LocalDateTime = createdDate,
+) : Auditable(), Serializable {
+  enum class Type {
+    USER_UPLOADED
+  }
+
+  override fun equals(other: Any?): Boolean {
+    if (this === other) return true
+    if (other !is ThumbnailSeriesCollection) return false
+
+    if (!thumbnail.contentEquals(other.thumbnail)) return false
+    if (selected != other.selected) return false
+    if (type != other.type) return false
+    if (id != other.id) return false
+    if (collectionId != other.collectionId) return false
+    if (createdDate != other.createdDate) return false
+    if (lastModifiedDate != other.lastModifiedDate) return false
+
+    return true
+  }
+
+  override fun hashCode(): Int {
+    var result = thumbnail.contentHashCode()
+    result = 31 * result + selected.hashCode()
+    result = 31 * result + type.hashCode()
+    result = 31 * result + id.hashCode()
+    result = 31 * result + collectionId.hashCode()
+    result = 31 * result + createdDate.hashCode()
+    result = 31 * result + lastModifiedDate.hashCode()
+    return result
+  }
+}

komga/src/main/kotlin/org/gotson/komga/domain/persistence/ThumbnailBookRepository.kt

@@ -3,6 +3,8 @@ package org.gotson.komga.domain.persistence
 import org.gotson.komga.domain.model.ThumbnailBook
 
 interface ThumbnailBookRepository {
+  fun findByIdOrNull(thumbnailId: String): ThumbnailBook?
+
   fun findSelectedByBookIdOrNull(bookId: String): ThumbnailBook?
 
   fun findAllByBookId(bookId: String): Collection<ThumbnailBook>

komga/src/main/kotlin/org/gotson/komga/domain/persistence/ThumbnailReadListRepository.kt

@@ -0,0 +1,17 @@
+package org.gotson.komga.domain.persistence
+
+import org.gotson.komga.domain.model.ThumbnailReadList
+
+interface ThumbnailReadListRepository {
+  fun findByIdOrNull(thumbnailId: String): ThumbnailReadList?
+  fun findSelectedByReadListIdOrNull(readListId: String): ThumbnailReadList?
+  fun findAllByReadListId(readListId: String): Collection<ThumbnailReadList>
+
+  fun insert(thumbnail: ThumbnailReadList)
+  fun update(thumbnail: ThumbnailReadList)
+  fun markSelected(thumbnail: ThumbnailReadList)
+
+  fun delete(thumbnailReadListId: String)
+  fun deleteByReadListId(readListId: String)
+  fun deleteByReadListIds(readListIds: Collection<String>)
+}

komga/src/main/kotlin/org/gotson/komga/domain/persistence/ThumbnailSeriesCollectionRepository.kt

@@ -0,0 +1,17 @@
+package org.gotson.komga.domain.persistence
+
+import org.gotson.komga.domain.model.ThumbnailSeriesCollection
+
+interface ThumbnailSeriesCollectionRepository {
+  fun findByIdOrNull(thumbnailId: String): ThumbnailSeriesCollection?
+  fun findSelectedByCollectionIdOrNull(collectionId: String): ThumbnailSeriesCollection?
+  fun findAllByCollectionId(collectionId: String): Collection<ThumbnailSeriesCollection>
+
+  fun insert(thumbnail: ThumbnailSeriesCollection)
+  fun update(thumbnail: ThumbnailSeriesCollection)
+  fun markSelected(thumbnail: ThumbnailSeriesCollection)
+
+  fun delete(thumbnailCollectionId: String)
+  fun deleteByCollectionId(collectionId: String)
+  fun deleteByCollectionIds(collectionIds: Collection<String>)
+}

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

@@ -8,6 +8,7 @@ import org.gotson.komga.domain.model.BookWithMedia
 import org.gotson.komga.domain.model.DomainEvent
 import org.gotson.komga.domain.model.ImageConversionException
 import org.gotson.komga.domain.model.KomgaUser
+import org.gotson.komga.domain.model.MarkSelectedPreference
 import org.gotson.komga.domain.model.Media
 import org.gotson.komga.domain.model.MediaNotReadyException
 import org.gotson.komga.domain.model.ReadProgress
@@ -82,18 +83,18 @@ class BookLifecycle(
   fun generateThumbnailAndPersist(book: Book) {
     logger.info { "Generate thumbnail and persist for book: $book" }
     try {
-      addThumbnailForBook(bookAnalyzer.generateThumbnail(BookWithMedia(book, mediaRepository.findById(book.id))))
+      addThumbnailForBook(bookAnalyzer.generateThumbnail(BookWithMedia(book, mediaRepository.findById(book.id))), MarkSelectedPreference.IF_NONE_OR_GENERATED)
     } catch (ex: Exception) {
       logger.error(ex) { "Error while creating thumbnail" }
     }
   }
 
-  fun addThumbnailForBook(thumbnail: ThumbnailBook) {
+  fun addThumbnailForBook(thumbnail: ThumbnailBook, markSelected: MarkSelectedPreference) {
     when (thumbnail.type) {
       ThumbnailBook.Type.GENERATED -> {
         // only one generated thumbnail is allowed
         thumbnailBookRepository.deleteByBookIdAndType(thumbnail.bookId, ThumbnailBook.Type.GENERATED)
-        thumbnailBookRepository.insert(thumbnail)
+        thumbnailBookRepository.insert(thumbnail.copy(selected = false))
       }
       ThumbnailBook.Type.SIDECAR -> {
         // delete existing thumbnail with the same url
@@ -102,16 +103,37 @@ class BookLifecycle(
           .forEach {
             thumbnailBookRepository.delete(it.id)
           }
-        thumbnailBookRepository.insert(thumbnail)
+        thumbnailBookRepository.insert(thumbnail.copy(selected = false))
+      }
+      ThumbnailBook.Type.USER_UPLOADED -> {
+        thumbnailBookRepository.insert(thumbnail.copy(selected = false))
+      }
+    }
+
+    when (markSelected) {
+      MarkSelectedPreference.YES -> {
+        thumbnailBookRepository.markSelected(thumbnail)
+      }
+      MarkSelectedPreference.IF_NONE_OR_GENERATED -> {
+        val selectedThumbnail = thumbnailBookRepository.findSelectedByBookIdOrNull(thumbnail.bookId)
+
+        if (selectedThumbnail == null || selectedThumbnail.type == ThumbnailBook.Type.GENERATED)
+          thumbnailBookRepository.markSelected(thumbnail)
+        else thumbnailsHouseKeeping(thumbnail.bookId)
+      }
+      MarkSelectedPreference.NO -> {
+        thumbnailsHouseKeeping(thumbnail.bookId)
       }
     }
 
     eventPublisher.publishEvent(DomainEvent.ThumbnailBookAdded(thumbnail))
+  }
 
-    if (thumbnail.selected)
+  fun deleteThumbnailForBook(thumbnail: ThumbnailBook) {
-      thumbnailBookRepository.markSelected(thumbnail)
+    require(thumbnail.type == ThumbnailBook.Type.USER_UPLOADED) { "Only uploaded thumbnails can be deleted" }
-    else
+    thumbnailBookRepository.delete(thumbnail.id)
-      thumbnailsHouseKeeping(thumbnail.bookId)
+    thumbnailsHouseKeeping(thumbnail.bookId)
+    eventPublisher.publishEvent(DomainEvent.ThumbnailBookDeleted(thumbnail))
   }
 
   fun getThumbnail(bookId: String): ThumbnailBook? {
@@ -136,6 +158,18 @@ class BookLifecycle(
     return null
   }
 
+  fun getThumbnailBytesByThumbnailId(thumbnailId: String): ByteArray? =
+    thumbnailBookRepository.findByIdOrNull(thumbnailId)?.let {
+      getBytesFromThumbnailBook(it)
+    }
+
+  private fun getBytesFromThumbnailBook(thumbnail: ThumbnailBook): ByteArray? =
+    when {
+      thumbnail.thumbnail != null -> thumbnail.thumbnail
+      thumbnail.url != null -> File(thumbnail.url.toURI()).readBytes()
+      else -> null
+    }
+
   private fun thumbnailsHouseKeeping(bookId: String) {
     logger.info { "House keeping thumbnails for book: $bookId" }
     val all = thumbnailBookRepository.findAllByBookId(bookId)

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

@@ -24,7 +24,7 @@ class LocalArtworkLifecycle(
 
     if (library.importLocalArtwork)
       localArtworkProvider.getBookThumbnails(book).forEach {
-        bookLifecycle.addThumbnailForBook(it)
+        bookLifecycle.addThumbnailForBook(it, if (it.selected) MarkSelectedPreference.IF_NONE_OR_GENERATED else MarkSelectedPreference.NO)
       }
     else
       logger.info { "Library is not set to import local artwork, skipping" }
@@ -36,7 +36,7 @@ class LocalArtworkLifecycle(
 
     if (library.importLocalArtwork)
       localArtworkProvider.getSeriesThumbnails(series).forEach {
-        seriesLifecycle.addThumbnailForSeries(it, if (it.selected) MarkSelectedPreference.IF_NONE_EXIST else MarkSelectedPreference.NO)
+        seriesLifecycle.addThumbnailForSeries(it, if (it.selected) MarkSelectedPreference.IF_NONE_OR_GENERATED else MarkSelectedPreference.NO)
       }
     else
       logger.info { "Library is not set to import local artwork, skipping" }

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

@@ -6,21 +6,26 @@ import org.gotson.komga.domain.model.DomainEvent
 import org.gotson.komga.domain.model.DuplicateNameException
 import org.gotson.komga.domain.model.ReadList
 import org.gotson.komga.domain.model.ReadListRequestResult
+import org.gotson.komga.domain.model.ThumbnailReadList
 import org.gotson.komga.domain.persistence.ReadListRepository
+import org.gotson.komga.domain.persistence.ThumbnailReadListRepository
 import org.gotson.komga.infrastructure.image.MosaicGenerator
 import org.gotson.komga.infrastructure.metadata.comicrack.ReadListProvider
 import org.springframework.stereotype.Service
+import org.springframework.transaction.support.TransactionTemplate
 
 private val logger = KotlinLogging.logger {}
 
 @Service
 class ReadListLifecycle(
   private val readListRepository: ReadListRepository,
+  private val thumbnailReadListRepository: ThumbnailReadListRepository,
   private val bookLifecycle: BookLifecycle,
   private val mosaicGenerator: MosaicGenerator,
   private val readListMatcher: ReadListMatcher,
   private val readListProvider: ReadListProvider,
   private val eventPublisher: EventPublisher,
+  private val transactionTemplate: TransactionTemplate,
 ) {
 
   @Throws(
@@ -53,19 +58,57 @@ class ReadListLifecycle(
   }
 
   fun deleteReadList(readList: ReadList) {
-    readListRepository.delete(readList.id)
+    transactionTemplate.executeWithoutResult {
+      thumbnailReadListRepository.deleteByReadListId(readList.id)
+      readListRepository.delete(readList.id)
+    }
 
     eventPublisher.publishEvent(DomainEvent.ReadListDeleted(readList))
   }
 
   fun deleteEmptyReadLists() {
     logger.info { "Deleting empty read lists" }
-    val toDelete = readListRepository.findAllEmpty()
+    transactionTemplate.executeWithoutResult {
-    readListRepository.delete(toDelete.map { it.id })
+      val toDelete = readListRepository.findAllEmpty()
-    toDelete.forEach { eventPublisher.publishEvent(DomainEvent.ReadListDeleted(it)) }
+      readListRepository.delete(toDelete.map { it.id })
+      thumbnailReadListRepository.deleteByReadListIds(toDelete.map { it.id })
+
+      toDelete.forEach { eventPublisher.publishEvent(DomainEvent.ReadListDeleted(it)) }
+    }
   }
 
+  fun addThumbnail(thumbnail: ThumbnailReadList) {
+    when (thumbnail.type) {
+      ThumbnailReadList.Type.USER_UPLOADED -> {
+        thumbnailReadListRepository.insert(thumbnail)
+        if (thumbnail.selected) {
+          thumbnailReadListRepository.markSelected(thumbnail)
+        }
+      }
+    }
+
+    eventPublisher.publishEvent(DomainEvent.ThumbnailReadListAdded(thumbnail))
+  }
+
+  fun markSelectedThumbnail(thumbnail: ThumbnailReadList) {
+    thumbnailReadListRepository.markSelected(thumbnail)
+    eventPublisher.publishEvent(DomainEvent.ThumbnailReadListAdded(thumbnail))
+  }
+
+  fun deleteThumbnail(thumbnail: ThumbnailReadList) {
+    thumbnailReadListRepository.delete(thumbnail.id)
+    thumbnailsHouseKeeping(thumbnail.readListId)
+    eventPublisher.publishEvent(DomainEvent.ThumbnailReadListDeleted(thumbnail))
+  }
+
+  fun getThumbnailBytes(thumbnailId: String): ByteArray? =
+    thumbnailReadListRepository.findByIdOrNull(thumbnailId)?.thumbnail
+
   fun getThumbnailBytes(readList: ReadList): ByteArray {
+    thumbnailReadListRepository.findSelectedByReadListIdOrNull(readList.id)?.let {
+      return it.thumbnail
+    }
+
     val ids = with(mutableListOf<String>()) {
       while (size < 4) {
         this += readList.bookIds.values.take(4)
@@ -93,4 +136,21 @@ class ReadListLifecycle(
       else -> result
     }
   }
+
+  private fun thumbnailsHouseKeeping(readListId: String) {
+    logger.info { "House keeping thumbnails for read list: $readListId" }
+    val all = thumbnailReadListRepository.findAllByReadListId(readListId)
+
+    val selected = all.filter { it.selected }
+    when {
+      selected.size > 1 -> {
+        logger.info { "More than one thumbnail is selected, removing extra ones" }
+        thumbnailReadListRepository.markSelected(selected[0])
+      }
+      selected.isEmpty() && all.isNotEmpty() -> {
+        logger.info { "Read list has no selected thumbnail, choosing one automatically" }
+        thumbnailReadListRepository.markSelected(all.first())
+      }
+    }
+  }
 }

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

@@ -5,18 +5,23 @@ import org.gotson.komga.application.events.EventPublisher
 import org.gotson.komga.domain.model.DomainEvent
 import org.gotson.komga.domain.model.DuplicateNameException
 import org.gotson.komga.domain.model.SeriesCollection
+import org.gotson.komga.domain.model.ThumbnailSeriesCollection
 import org.gotson.komga.domain.persistence.SeriesCollectionRepository
+import org.gotson.komga.domain.persistence.ThumbnailSeriesCollectionRepository
 import org.gotson.komga.infrastructure.image.MosaicGenerator
 import org.springframework.stereotype.Service
+import org.springframework.transaction.support.TransactionTemplate
 
 private val logger = KotlinLogging.logger {}
 
 @Service
 class SeriesCollectionLifecycle(
   private val collectionRepository: SeriesCollectionRepository,
+  private val thumbnailSeriesCollectionRepository: ThumbnailSeriesCollectionRepository,
   private val seriesLifecycle: SeriesLifecycle,
   private val mosaicGenerator: MosaicGenerator,
   private val eventPublisher: EventPublisher,
+  private val transactionTemplate: TransactionTemplate,
 ) {
 
   @Throws(
@@ -50,18 +55,56 @@ class SeriesCollectionLifecycle(
   }
 
   fun deleteCollection(collection: SeriesCollection) {
-    collectionRepository.delete(collection.id)
+    transactionTemplate.executeWithoutResult {
+      thumbnailSeriesCollectionRepository.deleteByCollectionId(collection.id)
+      collectionRepository.delete(collection.id)
+    }
     eventPublisher.publishEvent(DomainEvent.CollectionDeleted(collection))
   }
 
   fun deleteEmptyCollections() {
     logger.info { "Deleting empty collections" }
-    val toDelete = collectionRepository.findAllEmpty()
+    transactionTemplate.executeWithoutResult {
-    collectionRepository.delete(toDelete.map { it.id })
+      val toDelete = collectionRepository.findAllEmpty()
-    toDelete.forEach { eventPublisher.publishEvent(DomainEvent.CollectionDeleted(it)) }
+      thumbnailSeriesCollectionRepository.deleteByCollectionIds(toDelete.map { it.id })
+      collectionRepository.delete(toDelete.map { it.id })
+
+      toDelete.forEach { eventPublisher.publishEvent(DomainEvent.CollectionDeleted(it)) }
+    }
   }
 
+  fun addThumbnail(thumbnail: ThumbnailSeriesCollection) {
+    when (thumbnail.type) {
+      ThumbnailSeriesCollection.Type.USER_UPLOADED -> {
+        thumbnailSeriesCollectionRepository.insert(thumbnail)
+        if (thumbnail.selected) {
+          thumbnailSeriesCollectionRepository.markSelected(thumbnail)
+        }
+      }
+    }
+
+    eventPublisher.publishEvent(DomainEvent.ThumbnailSeriesCollectionAdded(thumbnail))
+  }
+
+  fun markSelectedThumbnail(thumbnail: ThumbnailSeriesCollection) {
+    thumbnailSeriesCollectionRepository.markSelected(thumbnail)
+    eventPublisher.publishEvent(DomainEvent.ThumbnailSeriesCollectionAdded(thumbnail))
+  }
+
+  fun deleteThumbnail(thumbnail: ThumbnailSeriesCollection) {
+    thumbnailSeriesCollectionRepository.delete(thumbnail.id)
+    thumbnailsHouseKeeping(thumbnail.collectionId)
+    eventPublisher.publishEvent(DomainEvent.ThumbnailSeriesCollectionDeleted(thumbnail))
+  }
+
+  fun getThumbnailBytes(thumbnailId: String): ByteArray? =
+    thumbnailSeriesCollectionRepository.findByIdOrNull(thumbnailId)?.thumbnail
+
   fun getThumbnailBytes(collection: SeriesCollection, userId: String): ByteArray {
+    thumbnailSeriesCollectionRepository.findSelectedByCollectionIdOrNull(collection.id)?.let {
+      return it.thumbnail
+    }
+
     val ids = with(mutableListOf<String>()) {
       while (size < 4) {
         this += collection.seriesIds.take(4)
@@ -72,4 +115,21 @@ class SeriesCollectionLifecycle(
     val images = ids.mapNotNull { seriesLifecycle.getThumbnailBytes(it, userId) }
     return mosaicGenerator.createMosaic(images)
   }
+
+  private fun thumbnailsHouseKeeping(collectionId: String) {
+    logger.info { "House keeping thumbnails for collection: $collectionId" }
+    val all = thumbnailSeriesCollectionRepository.findAllByCollectionId(collectionId)
+
+    val selected = all.filter { it.selected }
+    when {
+      selected.size > 1 -> {
+        logger.info { "More than one thumbnail is selected, removing extra ones" }
+        thumbnailSeriesCollectionRepository.markSelected(selected[0])
+      }
+      selected.isEmpty() && all.isNotEmpty() -> {
+        logger.info { "Collection has no selected thumbnail, choosing one automatically" }
+        thumbnailSeriesCollectionRepository.markSelected(all.first())
+      }
+    }
+  }
 }

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

@@ -264,7 +264,7 @@ class SeriesLifecycle(
 
     if (markSelected == MarkSelectedPreference.YES ||
       (
-        markSelected == MarkSelectedPreference.IF_NONE_EXIST &&
+        markSelected == MarkSelectedPreference.IF_NONE_OR_GENERATED &&
           thumbnailsSeriesRepository.findSelectedBySeriesIdOrNull(thumbnail.seriesId) == null
         )
     ) {
@@ -276,6 +276,7 @@ class SeriesLifecycle(
   fun deleteThumbnailForSeries(thumbnail: ThumbnailSeries) {
     require(thumbnail.type == ThumbnailSeries.Type.USER_UPLOADED) { "Only uploaded thumbnails can be deleted" }
     thumbnailsSeriesRepository.delete(thumbnail.id)
+    eventPublisher.publishEvent(DomainEvent.ThumbnailSeriesDeleted(thumbnail))
   }
 
   private fun thumbnailsHouseKeeping(seriesId: String) {

komga/src/main/kotlin/org/gotson/komga/infrastructure/jooq/ThumbnailBookDao.kt

@@ -30,6 +30,12 @@ class ThumbnailBookDao(
       .fetchInto(tb)
       .map { it.toDomain() }
 
+  override fun findByIdOrNull(thumbnailId: String): ThumbnailBook? =
+    dsl.selectFrom(tb)
+      .where(tb.ID.eq(thumbnailId))
+      .fetchOneInto(tb)
+      ?.toDomain()
+
   override fun findSelectedByBookIdOrNull(bookId: String): ThumbnailBook? =
     dsl.selectFrom(tb)
       .where(tb.BOOK_ID.eq(bookId))

komga/src/main/kotlin/org/gotson/komga/infrastructure/jooq/ThumbnailReadListDao.kt

@@ -0,0 +1,95 @@
+package org.gotson.komga.infrastructure.jooq
+
+import org.gotson.komga.domain.model.ThumbnailReadList
+import org.gotson.komga.domain.persistence.ThumbnailReadListRepository
+import org.gotson.komga.jooq.Tables
+import org.gotson.komga.jooq.tables.records.ThumbnailReadlistRecord
+import org.jooq.DSLContext
+import org.springframework.stereotype.Component
+import org.springframework.transaction.annotation.Transactional
+
+@Component
+class ThumbnailReadListDao(
+  private val dsl: DSLContext
+) : ThumbnailReadListRepository {
+  private val tr = Tables.THUMBNAIL_READLIST
+
+  override fun findAllByReadListId(readListId: String): Collection<ThumbnailReadList> =
+    dsl.selectFrom(tr)
+      .where(tr.READLIST_ID.eq(readListId))
+      .fetchInto(tr)
+      .map { it.toDomain() }
+
+  override fun findByIdOrNull(thumbnailId: String): ThumbnailReadList? =
+    dsl.selectFrom(tr)
+      .where(tr.ID.eq(thumbnailId))
+      .fetchOneInto(tr)
+      ?.toDomain()
+
+  override fun findSelectedByReadListIdOrNull(readListId: String): ThumbnailReadList? =
+    dsl.selectFrom(tr)
+      .where(tr.READLIST_ID.eq(readListId))
+      .and(tr.SELECTED.isTrue)
+      .limit(1)
+      .fetchInto(tr)
+      .map { it.toDomain() }
+      .firstOrNull()
+
+  override fun insert(thumbnail: ThumbnailReadList) {
+    dsl.insertInto(tr)
+      .set(tr.ID, thumbnail.id)
+      .set(tr.READLIST_ID, thumbnail.readListId)
+      .set(tr.THUMBNAIL, thumbnail.thumbnail)
+      .set(tr.SELECTED, thumbnail.selected)
+      .set(tr.TYPE, thumbnail.type.toString())
+      .execute()
+  }
+
+  override fun update(thumbnail: ThumbnailReadList) {
+    dsl.update(tr)
+      .set(tr.READLIST_ID, thumbnail.readListId)
+      .set(tr.THUMBNAIL, thumbnail.thumbnail)
+      .set(tr.SELECTED, thumbnail.selected)
+      .set(tr.TYPE, thumbnail.type.toString())
+      .where(tr.ID.eq(thumbnail.id))
+      .execute()
+  }
+
+  @Transactional
+  override fun markSelected(thumbnail: ThumbnailReadList) {
+    dsl.update(tr)
+      .set(tr.SELECTED, false)
+      .where(tr.READLIST_ID.eq(thumbnail.readListId))
+      .and(tr.ID.ne(thumbnail.id))
+      .execute()
+
+    dsl.update(tr)
+      .set(tr.SELECTED, true)
+      .where(tr.READLIST_ID.eq(thumbnail.readListId))
+      .and(tr.ID.eq(thumbnail.id))
+      .execute()
+  }
+
+  override fun delete(thumbnailReadListId: String) {
+    dsl.deleteFrom(tr).where(tr.ID.eq(thumbnailReadListId)).execute()
+  }
+
+  override fun deleteByReadListId(readListId: String) {
+    dsl.deleteFrom(tr).where(tr.READLIST_ID.eq(readListId)).execute()
+  }
+
+  override fun deleteByReadListIds(readListIds: Collection<String>) {
+    dsl.deleteFrom(tr).where(tr.READLIST_ID.`in`(readListIds)).execute()
+  }
+
+  private fun ThumbnailReadlistRecord.toDomain() =
+    ThumbnailReadList(
+      thumbnail = thumbnail,
+      selected = selected,
+      type = ThumbnailReadList.Type.valueOf(type),
+      id = id,
+      readListId = readlistId,
+      createdDate = createdDate,
+      lastModifiedDate = lastModifiedDate
+    )
+}

komga/src/main/kotlin/org/gotson/komga/infrastructure/jooq/ThumbnailSeriesCollectionDao.kt

@@ -0,0 +1,95 @@
+package org.gotson.komga.infrastructure.jooq
+
+import org.gotson.komga.domain.model.ThumbnailSeriesCollection
+import org.gotson.komga.domain.persistence.ThumbnailSeriesCollectionRepository
+import org.gotson.komga.jooq.Tables
+import org.gotson.komga.jooq.tables.records.ThumbnailCollectionRecord
+import org.jooq.DSLContext
+import org.springframework.stereotype.Component
+import org.springframework.transaction.annotation.Transactional
+
+@Component
+class ThumbnailSeriesCollectionDao(
+  private val dsl: DSLContext
+) : ThumbnailSeriesCollectionRepository {
+  private val tc = Tables.THUMBNAIL_COLLECTION
+
+  override fun findByIdOrNull(thumbnailId: String): ThumbnailSeriesCollection? =
+    dsl.selectFrom(tc)
+      .where(tc.ID.eq(thumbnailId))
+      .fetchOneInto(tc)
+      ?.toDomain()
+
+  override fun findSelectedByCollectionIdOrNull(collectionId: String): ThumbnailSeriesCollection? =
+    dsl.selectFrom(tc)
+      .where(tc.COLLECTION_ID.eq(collectionId))
+      .and(tc.SELECTED.isTrue)
+      .limit(1)
+      .fetchInto(tc)
+      .map { it.toDomain() }
+      .firstOrNull()
+
+  override fun findAllByCollectionId(collectionId: String): Collection<ThumbnailSeriesCollection> =
+    dsl.selectFrom(tc)
+      .where(tc.COLLECTION_ID.eq(collectionId))
+      .fetchInto(tc)
+      .map { it.toDomain() }
+
+  override fun insert(thumbnail: ThumbnailSeriesCollection) {
+    dsl.insertInto(tc)
+      .set(tc.ID, thumbnail.id)
+      .set(tc.COLLECTION_ID, thumbnail.collectionId)
+      .set(tc.THUMBNAIL, thumbnail.thumbnail)
+      .set(tc.SELECTED, thumbnail.selected)
+      .set(tc.TYPE, thumbnail.type.toString())
+      .execute()
+  }
+
+  override fun update(thumbnail: ThumbnailSeriesCollection) {
+    dsl.update(tc)
+      .set(tc.COLLECTION_ID, thumbnail.collectionId)
+      .set(tc.THUMBNAIL, thumbnail.thumbnail)
+      .set(tc.SELECTED, thumbnail.selected)
+      .set(tc.TYPE, thumbnail.type.toString())
+      .where(tc.ID.eq(thumbnail.id))
+      .execute()
+  }
+
+  @Transactional
+  override fun markSelected(thumbnail: ThumbnailSeriesCollection) {
+    dsl.update(tc)
+      .set(tc.SELECTED, false)
+      .where(tc.COLLECTION_ID.eq(thumbnail.collectionId))
+      .and(tc.ID.ne(thumbnail.id))
+      .execute()
+
+    dsl.update(tc)
+      .set(tc.SELECTED, true)
+      .where(tc.COLLECTION_ID.eq(thumbnail.collectionId))
+      .and(tc.ID.eq(thumbnail.id))
+      .execute()
+  }
+
+  override fun delete(thumbnailCollectionId: String) {
+    dsl.deleteFrom(tc).where(tc.ID.eq(thumbnailCollectionId)).execute()
+  }
+
+  override fun deleteByCollectionId(collectionId: String) {
+    dsl.deleteFrom(tc).where(tc.COLLECTION_ID.eq(collectionId)).execute()
+  }
+
+  override fun deleteByCollectionIds(collectionIds: Collection<String>) {
+    dsl.deleteFrom(tc).where(tc.COLLECTION_ID.`in`(collectionIds)).execute()
+  }
+
+  private fun ThumbnailCollectionRecord.toDomain() =
+    ThumbnailSeriesCollection(
+      thumbnail = thumbnail,
+      selected = selected,
+      type = ThumbnailSeriesCollection.Type.valueOf(type),
+      id = id,
+      collectionId = collectionId,
+      createdDate = createdDate,
+      lastModifiedDate = lastModifiedDate
+    )
+}

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

@@ -14,16 +14,19 @@ import org.gotson.komga.application.tasks.TaskReceiver
 import org.gotson.komga.domain.model.BookSearchWithReadProgress
 import org.gotson.komga.domain.model.DomainEvent
 import org.gotson.komga.domain.model.ImageConversionException
+import org.gotson.komga.domain.model.MarkSelectedPreference
 import org.gotson.komga.domain.model.Media
 import org.gotson.komga.domain.model.MediaNotReadyException
 import org.gotson.komga.domain.model.ROLE_ADMIN
 import org.gotson.komga.domain.model.ROLE_FILE_DOWNLOAD
 import org.gotson.komga.domain.model.ROLE_PAGE_STREAMING
 import org.gotson.komga.domain.model.ReadStatus
+import org.gotson.komga.domain.model.ThumbnailBook
 import org.gotson.komga.domain.persistence.BookMetadataRepository
 import org.gotson.komga.domain.persistence.BookRepository
 import org.gotson.komga.domain.persistence.MediaRepository
 import org.gotson.komga.domain.persistence.ReadListRepository
+import org.gotson.komga.domain.persistence.ThumbnailBookRepository
 import org.gotson.komga.domain.service.BookLifecycle
 import org.gotson.komga.infrastructure.image.ImageType
 import org.gotson.komga.infrastructure.jooq.UnpagedSorted
@@ -40,6 +43,7 @@ import org.gotson.komga.interfaces.api.rest.dto.BookMetadataUpdateDto
 import org.gotson.komga.interfaces.api.rest.dto.PageDto
 import org.gotson.komga.interfaces.api.rest.dto.ReadListDto
 import org.gotson.komga.interfaces.api.rest.dto.ReadProgressUpdateDto
+import org.gotson.komga.interfaces.api.rest.dto.ThumbnailBookDto
 import org.gotson.komga.interfaces.api.rest.dto.patch
 import org.gotson.komga.interfaces.api.rest.dto.restrictUrl
 import org.gotson.komga.interfaces.api.rest.dto.toDto
@@ -61,6 +65,7 @@ import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.PatchMapping
 import org.springframework.web.bind.annotation.PathVariable
 import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.PutMapping
 import org.springframework.web.bind.annotation.RequestBody
 import org.springframework.web.bind.annotation.RequestMapping
 import org.springframework.web.bind.annotation.RequestParam
@@ -68,6 +73,7 @@ import org.springframework.web.bind.annotation.ResponseStatus
 import org.springframework.web.bind.annotation.RestController
 import org.springframework.web.context.request.ServletWebRequest
 import org.springframework.web.context.request.WebRequest
+import org.springframework.web.multipart.MultipartFile
 import org.springframework.web.server.ResponseStatusException
 import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody
 import java.io.FileNotFoundException
@@ -92,6 +98,7 @@ class BookController(
   private val readListRepository: ReadListRepository,
   private val contentDetector: ContentDetector,
   private val eventPublisher: EventPublisher,
+  private val thumbnailBookRepository: ThumbnailBookRepository
 ) {
 
   @PageableAsQueryParam
@@ -246,6 +253,99 @@ class BookController(
     return bookLifecycle.getThumbnailBytes(bookId) ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
   }
 
+  @ApiResponse(content = [Content(schema = Schema(type = "string", format = "binary"))])
+  @GetMapping(value = ["api/v1/books/{bookId}/thumbnails/{thumbnailId}"], produces = [MediaType.IMAGE_JPEG_VALUE])
+  fun getBookThumbnailById(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "bookId") bookId: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String
+  ): ByteArray {
+    bookRepository.getLibraryIdOrNull(bookId)?.let {
+      if (!principal.user.canAccessLibrary(it)) throw ResponseStatusException(HttpStatus.FORBIDDEN)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+
+    return bookLifecycle.getThumbnailBytesByThumbnailId(thumbnailId)
+      ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @GetMapping(value = ["api/v1/books/{bookId}/thumbnails"], produces = [MediaType.APPLICATION_JSON_VALUE])
+  fun getBookThumbnails(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "bookId") bookId: String,
+  ): Collection<ThumbnailBookDto> {
+    bookRepository.getLibraryIdOrNull(bookId)?.let {
+      if (!principal.user.canAccessLibrary(it)) throw ResponseStatusException(HttpStatus.FORBIDDEN)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+
+    return thumbnailBookRepository.findAllByBookId(bookId)
+      .map { it.toDto() }
+  }
+
+  @PostMapping(value = ["api/v1/books/{bookId}/thumbnails"], consumes = [MediaType.MULTIPART_FORM_DATA_VALUE])
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun addUserUploadedBookThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "bookId") bookId: String,
+    @RequestParam("file") file: MultipartFile,
+    @RequestParam("selected") selected: Boolean = true,
+  ) {
+    val book = bookRepository.findByIdOrNull(bookId) ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+    if (!principal.user.canAccessBook(book)) throw ResponseStatusException(HttpStatus.FORBIDDEN)
+
+    if (!contentDetector.isImage(file.inputStream.buffered().use { contentDetector.detectMediaType(it) }))
+      throw ResponseStatusException(HttpStatus.UNSUPPORTED_MEDIA_TYPE)
+
+    bookLifecycle.addThumbnailForBook(
+      ThumbnailBook(
+        bookId = book.id,
+        thumbnail = file.bytes,
+        type = ThumbnailBook.Type.USER_UPLOADED,
+        selected = selected
+      ),
+      if (selected) MarkSelectedPreference.YES else MarkSelectedPreference.NO
+    )
+  }
+
+  @PutMapping("api/v1/books/{bookId}/thumbnails/{thumbnailId}/selected")
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun markSelectedBookThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "bookId") bookId: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String,
+  ) {
+    bookRepository.findByIdOrNull(bookId)?.let { book ->
+      if (!principal.user.canAccessBook(book)) throw ResponseStatusException(HttpStatus.FORBIDDEN)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+
+    thumbnailBookRepository.findByIdOrNull(thumbnailId)?.let {
+      thumbnailBookRepository.markSelected(it)
+      eventPublisher.publishEvent(DomainEvent.ThumbnailBookAdded(it))
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @DeleteMapping("api/v1/books/{bookId}/thumbnails/{thumbnailId}")
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun deleteUserUploadedBookThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "bookId") bookId: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String,
+  ) {
+    bookRepository.findByIdOrNull(bookId)?.let { book ->
+      if (!principal.user.canAccessBook(book)) throw ResponseStatusException(HttpStatus.FORBIDDEN)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+
+    thumbnailBookRepository.findByIdOrNull(thumbnailId)?.let {
+      try {
+        bookLifecycle.deleteThumbnailForBook(it)
+      } catch (e: IllegalArgumentException) {
+        throw ResponseStatusException(HttpStatus.BAD_REQUEST, e.message)
+      }
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
   @Operation(description = "Download the book file.")
   @GetMapping(
     value = [

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/ReadListController.kt

@@ -16,12 +16,15 @@ import org.gotson.komga.domain.model.ROLE_ADMIN
 import org.gotson.komga.domain.model.ROLE_FILE_DOWNLOAD
 import org.gotson.komga.domain.model.ReadList
 import org.gotson.komga.domain.model.ReadStatus
+import org.gotson.komga.domain.model.ThumbnailReadList
 import org.gotson.komga.domain.persistence.BookRepository
 import org.gotson.komga.domain.persistence.ReadListRepository
+import org.gotson.komga.domain.persistence.ThumbnailReadListRepository
 import org.gotson.komga.domain.service.BookLifecycle
 import org.gotson.komga.domain.service.ReadListLifecycle
 import org.gotson.komga.infrastructure.jooq.UnpagedSorted
 import org.gotson.komga.infrastructure.language.toIndexedMap
+import org.gotson.komga.infrastructure.mediacontainer.ContentDetector
 import org.gotson.komga.infrastructure.security.KomgaPrincipal
 import org.gotson.komga.infrastructure.swagger.AuthorsAsQueryParam
 import org.gotson.komga.infrastructure.swagger.PageableWithoutSortAsQueryParam
@@ -35,6 +38,7 @@ import org.gotson.komga.interfaces.api.rest.dto.ReadListRequestResultDto
 import org.gotson.komga.interfaces.api.rest.dto.ReadListUpdateDto
 import org.gotson.komga.interfaces.api.rest.dto.TachiyomiReadProgressDto
 import org.gotson.komga.interfaces.api.rest.dto.TachiyomiReadProgressUpdateDto
+import org.gotson.komga.interfaces.api.rest.dto.ThumbnailReadListDto
 import org.gotson.komga.interfaces.api.rest.dto.restrictUrl
 import org.gotson.komga.interfaces.api.rest.dto.toDto
 import org.springframework.core.io.FileSystemResource
@@ -79,6 +83,8 @@ class ReadListController(
   private val bookDtoRepository: BookDtoRepository,
   private val bookRepository: BookRepository,
   private val readProgressDtoRepository: ReadProgressDtoRepository,
+  private val thumbnailReadListRepository: ThumbnailReadListRepository,
+  private val contentDetector: ContentDetector,
   private val bookLifecycle: BookLifecycle,
 ) {
 
@@ -152,6 +158,84 @@ class ReadListController(
     } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
   }
 
+  @ApiResponse(content = [Content(schema = Schema(type = "string", format = "binary"))])
+  @GetMapping(value = ["{id}/thumbnails/{thumbnailId}"], produces = [MediaType.IMAGE_JPEG_VALUE])
+  fun getReadListThumbnailById(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String
+  ): ByteArray {
+    readListRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let {
+      return readListLifecycle.getThumbnailBytes(thumbnailId)
+        ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @GetMapping(value = ["{id}/thumbnails"], produces = [MediaType.APPLICATION_JSON_VALUE])
+  fun getReadListThumbnails(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+  ): Collection<ThumbnailReadListDto> {
+    readListRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let {
+      return thumbnailReadListRepository.findAllByReadListId(id).map { it.toDto() }
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @PostMapping(value = ["{id}/thumbnails"], consumes = [MediaType.MULTIPART_FORM_DATA_VALUE])
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun addUserUploadedReadListThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @RequestParam("file") file: MultipartFile,
+    @RequestParam("selected") selected: Boolean = true,
+  ) {
+    readListRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let { readList ->
+
+      if (!contentDetector.isImage(file.inputStream.buffered().use { contentDetector.detectMediaType(it) }))
+        throw ResponseStatusException(HttpStatus.UNSUPPORTED_MEDIA_TYPE)
+
+      readListLifecycle.addThumbnail(
+        ThumbnailReadList(
+          readListId = readList.id,
+          thumbnail = file.bytes,
+          type = ThumbnailReadList.Type.USER_UPLOADED,
+          selected = selected
+        ),
+      )
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @PutMapping("{id}/thumbnails/{thumbnailId}/selected")
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun markSelectedReadListThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String,
+  ) {
+    readListRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let { readList ->
+      thumbnailReadListRepository.findByIdOrNull(thumbnailId)?.let {
+        readListLifecycle.markSelectedThumbnail(it)
+      }
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @DeleteMapping("{id}/thumbnails/{thumbnailId}")
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun deleteUserUploadedReadListThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String,
+  ) {
+    readListRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let { readList ->
+      thumbnailReadListRepository.findByIdOrNull(thumbnailId)?.let {
+        readListLifecycle.deleteThumbnail(it)
+      } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
   @PostMapping
   @PreAuthorize("hasRole('$ROLE_ADMIN')")
   fun addOne(

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/SeriesCollectionController.kt

@@ -12,9 +12,12 @@ import org.gotson.komga.domain.model.ReadStatus
 import org.gotson.komga.domain.model.SeriesCollection
 import org.gotson.komga.domain.model.SeriesMetadata
 import org.gotson.komga.domain.model.SeriesSearchWithReadProgress
+import org.gotson.komga.domain.model.ThumbnailSeriesCollection
 import org.gotson.komga.domain.persistence.SeriesCollectionRepository
+import org.gotson.komga.domain.persistence.ThumbnailSeriesCollectionRepository
 import org.gotson.komga.domain.service.SeriesCollectionLifecycle
 import org.gotson.komga.infrastructure.jooq.UnpagedSorted
+import org.gotson.komga.infrastructure.mediacontainer.ContentDetector
 import org.gotson.komga.infrastructure.security.KomgaPrincipal
 import org.gotson.komga.infrastructure.swagger.AuthorsAsQueryParam
 import org.gotson.komga.infrastructure.swagger.PageableWithoutSortAsQueryParam
@@ -24,6 +27,7 @@ import org.gotson.komga.interfaces.api.rest.dto.CollectionCreationDto
 import org.gotson.komga.interfaces.api.rest.dto.CollectionDto
 import org.gotson.komga.interfaces.api.rest.dto.CollectionUpdateDto
 import org.gotson.komga.interfaces.api.rest.dto.SeriesDto
+import org.gotson.komga.interfaces.api.rest.dto.ThumbnailSeriesCollectionDto
 import org.gotson.komga.interfaces.api.rest.dto.restrictUrl
 import org.gotson.komga.interfaces.api.rest.dto.toDto
 import org.springframework.data.domain.Page
@@ -41,11 +45,13 @@ import org.springframework.web.bind.annotation.GetMapping
 import org.springframework.web.bind.annotation.PatchMapping
 import org.springframework.web.bind.annotation.PathVariable
 import org.springframework.web.bind.annotation.PostMapping
+import org.springframework.web.bind.annotation.PutMapping
 import org.springframework.web.bind.annotation.RequestBody
 import org.springframework.web.bind.annotation.RequestMapping
 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.multipart.MultipartFile
 import org.springframework.web.server.ResponseStatusException
 import java.util.concurrent.TimeUnit
 import javax.validation.Valid
@@ -57,7 +63,9 @@ private val logger = KotlinLogging.logger {}
 class SeriesCollectionController(
   private val collectionRepository: SeriesCollectionRepository,
   private val collectionLifecycle: SeriesCollectionLifecycle,
-  private val seriesDtoRepository: SeriesDtoRepository
+  private val seriesDtoRepository: SeriesDtoRepository,
+  private val contentDetector: ContentDetector,
+  private val thumbnailSeriesCollectionRepository: ThumbnailSeriesCollectionRepository,
 ) {
 
   @PageableWithoutSortAsQueryParam
@@ -112,6 +120,84 @@ class SeriesCollectionController(
     } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
   }
 
+  @ApiResponse(content = [Content(schema = Schema(type = "string", format = "binary"))])
+  @GetMapping(value = ["{id}/thumbnails/{thumbnailId}"], produces = [MediaType.IMAGE_JPEG_VALUE])
+  fun getCollectionThumbnailById(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String
+  ): ByteArray {
+    collectionRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let {
+      return collectionLifecycle.getThumbnailBytes(thumbnailId)
+        ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @GetMapping(value = ["{id}/thumbnails"], produces = [MediaType.APPLICATION_JSON_VALUE])
+  fun getCollectionThumbnails(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+  ): Collection<ThumbnailSeriesCollectionDto> {
+    collectionRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let {
+      return thumbnailSeriesCollectionRepository.findAllByCollectionId(id).map { it.toDto() }
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @PostMapping(value = ["{id}/thumbnails"], consumes = [MediaType.MULTIPART_FORM_DATA_VALUE])
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun addUserUploadedCollectionThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @RequestParam("file") file: MultipartFile,
+    @RequestParam("selected") selected: Boolean = true,
+  ) {
+    collectionRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let { collection ->
+
+      if (!contentDetector.isImage(file.inputStream.buffered().use { contentDetector.detectMediaType(it) }))
+        throw ResponseStatusException(HttpStatus.UNSUPPORTED_MEDIA_TYPE)
+
+      collectionLifecycle.addThumbnail(
+        ThumbnailSeriesCollection(
+          collectionId = collection.id,
+          thumbnail = file.bytes,
+          type = ThumbnailSeriesCollection.Type.USER_UPLOADED,
+          selected = selected
+        ),
+      )
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @PutMapping("{id}/thumbnails/{thumbnailId}/selected")
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun markSelectedCollectionThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String,
+  ) {
+    collectionRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let {
+      thumbnailSeriesCollectionRepository.findByIdOrNull(thumbnailId)?.let {
+        collectionLifecycle.markSelectedThumbnail(it)
+      }
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
+  @DeleteMapping("{id}/thumbnails/{thumbnailId}")
+  @PreAuthorize("hasRole('$ROLE_ADMIN')")
+  @ResponseStatus(HttpStatus.ACCEPTED)
+  fun deleteUserUploadedCollectionThumbnail(
+    @AuthenticationPrincipal principal: KomgaPrincipal,
+    @PathVariable(name = "id") id: String,
+    @PathVariable(name = "thumbnailId") thumbnailId: String,
+  ) {
+    collectionRepository.findByIdOrNull(id, principal.user.getAuthorizedLibraryIds(null))?.let {
+      thumbnailSeriesCollectionRepository.findByIdOrNull(thumbnailId)?.let {
+        collectionLifecycle.deleteThumbnail(it)
+      } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+    } ?: throw ResponseStatusException(HttpStatus.NOT_FOUND)
+  }
+
   @PostMapping
   @PreAuthorize("hasRole('$ROLE_ADMIN')")
   fun addOne(

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/dto/ThumbnailBookDto.kt

@@ -0,0 +1,18 @@
+package org.gotson.komga.interfaces.api.rest.dto
+
+import org.gotson.komga.domain.model.ThumbnailBook
+
+data class ThumbnailBookDto(
+  val id: String,
+  val bookId: String,
+  val type: String,
+  val selected: Boolean
+)
+
+fun ThumbnailBook.toDto() =
+  ThumbnailBookDto(
+    id = id,
+    bookId = bookId,
+    type = type.toString(),
+    selected = selected
+  )

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/dto/ThumbnailReadListDto.kt

@@ -0,0 +1,18 @@
+package org.gotson.komga.interfaces.api.rest.dto
+
+import org.gotson.komga.domain.model.ThumbnailReadList
+
+data class ThumbnailReadListDto(
+  val id: String,
+  val readListId: String,
+  val type: String,
+  val selected: Boolean
+)
+
+fun ThumbnailReadList.toDto() =
+  ThumbnailReadListDto(
+    id = id,
+    readListId = readListId,
+    type = type.toString(),
+    selected = selected
+  )

komga/src/main/kotlin/org/gotson/komga/interfaces/api/rest/dto/ThumbnailSeriesCollectionDto.kt

@@ -0,0 +1,18 @@
+package org.gotson.komga.interfaces.api.rest.dto
+
+import org.gotson.komga.domain.model.ThumbnailSeriesCollection
+
+data class ThumbnailSeriesCollectionDto(
+  val id: String,
+  val collectionId: String,
+  val type: String,
+  val selected: Boolean
+)
+
+fun ThumbnailSeriesCollection.toDto() =
+  ThumbnailSeriesCollectionDto(
+    id = id,
+    collectionId = collectionId,
+    type = type.toString(),
+    selected = selected
+  )

komga/src/main/kotlin/org/gotson/komga/interfaces/sse/SseController.kt

@@ -21,6 +21,8 @@ import org.gotson.komga.interfaces.sse.dto.ReadProgressSseDto
 import org.gotson.komga.interfaces.sse.dto.SeriesSseDto
 import org.gotson.komga.interfaces.sse.dto.TaskQueueSseDto
 import org.gotson.komga.interfaces.sse.dto.ThumbnailBookSseDto
+import org.gotson.komga.interfaces.sse.dto.ThumbnailReadListSseDto
+import org.gotson.komga.interfaces.sse.dto.ThumbnailSeriesCollectionSseDto
 import org.gotson.komga.interfaces.sse.dto.ThumbnailSeriesSseDto
 import org.springframework.http.MediaType
 import org.springframework.jms.annotation.JmsListener
@@ -100,7 +102,13 @@ class SseController(
       is DomainEvent.ReadProgressSeriesDeleted -> emitSse("ReadProgressSeriesDeleted", ReadProgressSeriesSseDto(event.seriesId, event.userId), userIdOnly = event.userId)
 
       is DomainEvent.ThumbnailBookAdded -> emitSse("ThumbnailBookAdded", ThumbnailBookSseDto(event.thumbnail.bookId, bookRepository.getSeriesIdOrNull(event.thumbnail.bookId).orEmpty()))
+      is DomainEvent.ThumbnailBookDeleted -> emitSse("ThumbnailBookDeleted", ThumbnailBookSseDto(event.thumbnail.bookId, bookRepository.getSeriesIdOrNull(event.thumbnail.bookId).orEmpty()))
       is DomainEvent.ThumbnailSeriesAdded -> emitSse("ThumbnailSeriesAdded", ThumbnailSeriesSseDto(event.thumbnail.seriesId))
+      is DomainEvent.ThumbnailSeriesDeleted -> emitSse("ThumbnailSeriesDeleted", ThumbnailSeriesSseDto(event.thumbnail.seriesId))
+      is DomainEvent.ThumbnailSeriesCollectionAdded -> emitSse("ThumbnailSeriesCollectionAdded", ThumbnailSeriesCollectionSseDto(event.thumbnail.collectionId))
+      is DomainEvent.ThumbnailSeriesCollectionDeleted -> emitSse("ThumbnailSeriesCollectionDeleted", ThumbnailSeriesCollectionSseDto(event.thumbnail.collectionId))
+      is DomainEvent.ThumbnailReadListAdded -> emitSse("ThumbnailReadListAdded", ThumbnailReadListSseDto(event.thumbnail.readListId))
+      is DomainEvent.ThumbnailReadListDeleted -> emitSse("ThumbnailReadListDeleted", ThumbnailReadListSseDto(event.thumbnail.readListId))
     }
   }
 

komga/src/main/kotlin/org/gotson/komga/interfaces/sse/dto/ThumbnailReadListSseDto.kt

@@ -0,0 +1,5 @@
+package org.gotson.komga.interfaces.sse.dto
+
+data class ThumbnailReadListSseDto(
+  val readListId: String,
+)

komga/src/main/kotlin/org/gotson/komga/interfaces/sse/dto/ThumbnailSeriesCollectionSseDto.kt

@@ -0,0 +1,5 @@
+package org.gotson.komga.interfaces.sse.dto
+
+data class ThumbnailSeriesCollectionSseDto(
+  val collectionId: String,
+)

komga/src/test/kotlin/org/gotson/komga/domain/service/LibraryContentLifecycleTest.kt

@@ -13,6 +13,7 @@ import org.gotson.komga.domain.model.Book
 import org.gotson.komga.domain.model.BookMetadataPatchCapability
 import org.gotson.komga.domain.model.DirectoryNotFoundException
 import org.gotson.komga.domain.model.KomgaUser
+import org.gotson.komga.domain.model.MarkSelectedPreference
 import org.gotson.komga.domain.model.Media
 import org.gotson.komga.domain.model.ReadList
 import org.gotson.komga.domain.model.ScanResult
@@ -577,8 +578,8 @@ class LibraryContentLifecycleTest(
       bookRepository.findByIdOrNull(book.id)?.let {
         bookRepository.update(it.copy(fileHash = "sameHash"))
         mediaRepository.update(mediaRepository.findById(it.id).copy(status = Media.Status.READY))
-        bookLifecycle.addThumbnailForBook(ThumbnailBook(thumbnail = ByteArray(0), type = ThumbnailBook.Type.GENERATED, bookId = book.id))
+        bookLifecycle.addThumbnailForBook(ThumbnailBook(thumbnail = ByteArray(0), type = ThumbnailBook.Type.GENERATED, bookId = book.id), MarkSelectedPreference.NO)
-        bookLifecycle.addThumbnailForBook(ThumbnailBook(url = URL("file:/sidecar"), type = ThumbnailBook.Type.SIDECAR, bookId = book.id))
+        bookLifecycle.addThumbnailForBook(ThumbnailBook(url = URL("file:/sidecar"), type = ThumbnailBook.Type.SIDECAR, bookId = book.id), MarkSelectedPreference.NO)
       }
 
       every { mockHasher.computeHash(any()) } returns "sameHash"
@@ -623,8 +624,8 @@ class LibraryContentLifecycleTest(
       bookRepository.findByIdOrNull(book.id)?.let {
         bookRepository.update(it.copy(fileHash = "sameHash"))
         mediaRepository.update(mediaRepository.findById(it.id).copy(status = Media.Status.READY))
-        bookLifecycle.addThumbnailForBook(ThumbnailBook(thumbnail = ByteArray(0), type = ThumbnailBook.Type.GENERATED, bookId = book.id))
+        bookLifecycle.addThumbnailForBook(ThumbnailBook(thumbnail = ByteArray(0), type = ThumbnailBook.Type.GENERATED, bookId = book.id), MarkSelectedPreference.NO)
-        bookLifecycle.addThumbnailForBook(ThumbnailBook(url = URL("file:/sidecar"), type = ThumbnailBook.Type.SIDECAR, bookId = book.id))
+        bookLifecycle.addThumbnailForBook(ThumbnailBook(url = URL("file:/sidecar"), type = ThumbnailBook.Type.SIDECAR, bookId = book.id), MarkSelectedPreference.NO)
       }
 
       every { mockHasher.computeHash(any()) } returns "sameHash"

komga/src/test/kotlin/org/gotson/komga/interfaces/api/rest/BookControllerTest.kt

@@ -5,6 +5,7 @@ import org.assertj.core.groups.Tuple.tuple
 import org.gotson.komga.domain.model.Author
 import org.gotson.komga.domain.model.BookPage
 import org.gotson.komga.domain.model.KomgaUser
+import org.gotson.komga.domain.model.MarkSelectedPreference
 import org.gotson.komga.domain.model.Media
 import org.gotson.komga.domain.model.ROLE_ADMIN
 import org.gotson.komga.domain.model.ThumbnailBook
@@ -474,7 +475,8 @@ class BookControllerTest(
           thumbnail = Random.nextBytes(100),
           bookId = book.id,
           type = ThumbnailBook.Type.GENERATED
-        )
+        ),
+        MarkSelectedPreference.YES
       )
 
       val url = "/api/v1/books/${book.id}/thumbnail"
@@ -533,7 +535,8 @@ class BookControllerTest(
           thumbnail = Random.nextBytes(1),
           bookId = book.id,
           type = ThumbnailBook.Type.GENERATED
-        )
+        ),
+        MarkSelectedPreference.YES
       )
 
       val url = "/api/v1/books/${book.id}/thumbnail"
@@ -546,7 +549,8 @@ class BookControllerTest(
           thumbnail = Random.nextBytes(1),
           bookId = book.id,
           type = ThumbnailBook.Type.GENERATED
-        )
+        ),
+        MarkSelectedPreference.YES
       )
 
       mockMvc.get(url) {

komga/src/test/kotlin/org/gotson/komga/interfaces/api/rest/SeriesControllerTest.kt

@@ -3,6 +3,7 @@ package org.gotson.komga.interfaces.api.rest
 import org.assertj.core.api.Assertions.assertThat
 import org.gotson.komga.domain.model.BookPage
 import org.gotson.komga.domain.model.KomgaUser
+import org.gotson.komga.domain.model.MarkSelectedPreference
 import org.gotson.komga.domain.model.Media
 import org.gotson.komga.domain.model.ROLE_ADMIN
 import org.gotson.komga.domain.model.SeriesMetadata
@@ -580,7 +581,8 @@ class SeriesControllerTest(
             thumbnail = Random.nextBytes(1),
             bookId = book.id,
             type = ThumbnailBook.Type.GENERATED
-          )
+          ),
+          MarkSelectedPreference.YES
         )
       }
 
@@ -614,7 +616,8 @@ class SeriesControllerTest(
             thumbnail = Random.nextBytes(1),
             bookId = book.id,
             type = ThumbnailBook.Type.GENERATED
-          )
+          ),
+          MarkSelectedPreference.YES
         )
       }