package suwayomi.tachidesk.graphql.mutations

import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
import org.jetbrains.exposed.sql.and
import org.jetbrains.exposed.sql.deleteWhere
import org.jetbrains.exposed.sql.select
import org.jetbrains.exposed.sql.transactions.transaction
import org.jetbrains.exposed.sql.update
import suwayomi.tachidesk.graphql.types.ChapterMetaType
import suwayomi.tachidesk.graphql.types.ChapterType
import suwayomi.tachidesk.manga.impl.Chapter
import suwayomi.tachidesk.manga.impl.chapter.getChapterDownloadReadyById
import suwayomi.tachidesk.manga.model.table.ChapterMetaTable
import suwayomi.tachidesk.manga.model.table.ChapterTable
import suwayomi.tachidesk.server.JavalinSetup.future
import java.time.Instant
import java.util.concurrent.CompletableFuture

/**
 * TODO Mutations
 * - Download
 * - Delete download
 */
class ChapterMutation {
    data class UpdateChapterPatch(
        val isBookmarked: Boolean? = null,
        val isRead: Boolean? = null,
        val lastPageRead: Int? = null,
    )

    data class UpdateChapterPayload(
        val clientMutationId: String?,
        val chapter: ChapterType,
    )

    data class UpdateChapterInput(
        val clientMutationId: String? = null,
        val id: Int,
        val patch: UpdateChapterPatch,
    )

    data class UpdateChaptersPayload(
        val clientMutationId: String?,
        val chapters: List<ChapterType>,
    )

    data class UpdateChaptersInput(
        val clientMutationId: String? = null,
        val ids: List<Int>,
        val patch: UpdateChapterPatch,
    )

    private fun updateChapters(
        ids: List<Int>,
        patch: UpdateChapterPatch,
    ) {
        transaction {
            if (patch.isRead != null || patch.isBookmarked != null || patch.lastPageRead != null) {
                val now = Instant.now().epochSecond
                ChapterTable.update({ ChapterTable.id inList ids }) { update ->
                    patch.isRead?.also {
                        update[isRead] = it
                    }
                    patch.isBookmarked?.also {
                        update[isBookmarked] = it
                    }
                    patch.lastPageRead?.also {
                        update[lastPageRead] = it
                        update[lastReadAt] = now
                    }
                }
            }
        }
    }

    fun updateChapter(input: UpdateChapterInput): UpdateChapterPayload {
        val (clientMutationId, id, patch) = input

        updateChapters(listOf(id), patch)

        val chapter =
            transaction {
                ChapterType(ChapterTable.select { ChapterTable.id eq id }.first())
            }

        return UpdateChapterPayload(
            clientMutationId = clientMutationId,
            chapter = chapter,
        )
    }

    fun updateChapters(input: UpdateChaptersInput): UpdateChaptersPayload {
        val (clientMutationId, ids, patch) = input

        updateChapters(ids, patch)

        val chapters =
            transaction {
                ChapterTable.select { ChapterTable.id inList ids }.map { ChapterType(it) }
            }

        return UpdateChaptersPayload(
            clientMutationId = clientMutationId,
            chapters = chapters,
        )
    }

    data class FetchChaptersInput(
        val clientMutationId: String? = null,
        val mangaId: Int,
    )

    data class FetchChaptersPayload(
        val clientMutationId: String?,
        val chapters: List<ChapterType>,
    )

    fun fetchChapters(input: FetchChaptersInput): CompletableFuture<FetchChaptersPayload> {
        val (clientMutationId, mangaId) = input

        return future {
            Chapter.fetchChapterList(mangaId)
        }.thenApply {
            val chapters =
                transaction {
                    ChapterTable.select { ChapterTable.manga eq mangaId }
                        .orderBy(ChapterTable.sourceOrder)
                        .map { ChapterType(it) }
                }

            FetchChaptersPayload(
                clientMutationId = clientMutationId,
                chapters = chapters,
            )
        }
    }

    data class SetChapterMetaInput(
        val clientMutationId: String? = null,
        val meta: ChapterMetaType,
    )

    data class SetChapterMetaPayload(
        val clientMutationId: String?,
        val meta: ChapterMetaType,
    )

    fun setChapterMeta(input: SetChapterMetaInput): SetChapterMetaPayload {
        val (clientMutationId, meta) = input

        Chapter.modifyChapterMeta(meta.chapterId, meta.key, meta.value)

        return SetChapterMetaPayload(clientMutationId, meta)
    }

    data class DeleteChapterMetaInput(
        val clientMutationId: String? = null,
        val chapterId: Int,
        val key: String,
    )

    data class DeleteChapterMetaPayload(
        val clientMutationId: String?,
        val meta: ChapterMetaType?,
        val chapter: ChapterType,
    )

    fun deleteChapterMeta(input: DeleteChapterMetaInput): DeleteChapterMetaPayload {
        val (clientMutationId, chapterId, key) = input

        val (meta, chapter) =
            transaction {
                val meta =
                    ChapterMetaTable.select { (ChapterMetaTable.ref eq chapterId) and (ChapterMetaTable.key eq key) }
                        .firstOrNull()

                ChapterMetaTable.deleteWhere { (ChapterMetaTable.ref eq chapterId) and (ChapterMetaTable.key eq key) }

                val chapter =
                    transaction {
                        ChapterType(ChapterTable.select { ChapterTable.id eq chapterId }.first())
                    }

                if (meta != null) {
                    ChapterMetaType(meta)
                } else {
                    null
                } to chapter
            }

        return DeleteChapterMetaPayload(clientMutationId, meta, chapter)
    }

    data class FetchChapterPagesInput(
        val clientMutationId: String? = null,
        val chapterId: Int,
    )

    data class FetchChapterPagesPayload(
        val clientMutationId: String?,
        val pages: List<String>,
        val chapter: ChapterType,
    )

    fun fetchChapterPages(input: FetchChapterPagesInput): CompletableFuture<FetchChapterPagesPayload> {
        val (clientMutationId, chapterId) = input

        return future {
            getChapterDownloadReadyById(chapterId)
        }.thenApply { chapter ->
            FetchChapterPagesPayload(
                clientMutationId = clientMutationId,
                pages =
                    List(chapter.pageCount) { index ->
                        "/api/v1/manga/${chapter.mangaId}/chapter/${chapter.index}/page/$index"
                    },
                chapter = ChapterType(chapter),
            )
        }
    }
}