package jp.juggler.subwaytooter.column

import android.content.Context
import android.content.SharedPreferences
import android.os.SystemClock
import jp.juggler.subwaytooter.api.ApiPath
import jp.juggler.subwaytooter.api.TootApiClient
import jp.juggler.subwaytooter.api.TootApiResult
import jp.juggler.subwaytooter.api.TootParser
import jp.juggler.subwaytooter.api.entity.TimelineItem
import jp.juggler.subwaytooter.api.entity.TootAnnouncement
import jp.juggler.subwaytooter.api.entity.TootInstance
import jp.juggler.subwaytooter.api.entity.parseList
import jp.juggler.subwaytooter.global.appDispatchers
import jp.juggler.subwaytooter.table.SavedAccount
import jp.juggler.util.*
import kotlinx.coroutines.CancellationException
import kotlinx.coroutines.Job
import kotlinx.coroutines.withContext
import java.util.concurrent.atomic.AtomicBoolean

enum class ColumnTaskType(val marker: Char) {
    LOADING('L'),
    REFRESH_TOP('T'),
    REFRESH_BOTTOM('B'),
    GAP('G')
}

abstract class ColumnTask(
    val column: Column,
    val ctType: ColumnTaskType,
) {
    companion object {
        private val log = LogCategory("ColumnTask")
    }

    val ctStarted = AtomicBoolean(false)
    val ctClosed = AtomicBoolean(false)

    private var job: Job? = null

    val isCancelled: Boolean
        get() = job?.isCancelled ?: false

    var parser = TootParser(context, accessInfo, highlightTrie = highlightTrie)

    var listTmp: ArrayList<TimelineItem>? = null

    val context: Context
        get() = column.context

    val accessInfo: SavedAccount
        get() = column.accessInfo

    val highlightTrie: WordTrieTree?
        get() = column.highlightTrie

    val isPseudo: Boolean
        get() = accessInfo.isPseudo

    private val isMastodon: Boolean
        get() = accessInfo.isMastodon

    val isMisskey: Boolean
        get() = accessInfo.isMisskey

    val misskeyVersion: Int
        get() = accessInfo.misskeyVersion

    val pref: SharedPreferences
        get() = column.appState.pref

    internal fun JsonObject.addMisskeyNotificationFilter() = addMisskeyNotificationFilter(column)
    internal fun JsonObject.addRangeMisskey(bBottom: Boolean) = addRangeMisskey(column, bBottom)

    internal val profileDirectoryPath: String
        get() {
            val order = when (val q = column.searchQuery) {
                "new" -> q
                else -> "active"
            }
            val local = !column.searchResolve
            return "${ApiPath.PATH_PROFILE_DIRECTORY}&order=$order&local=$local"
        }

    internal suspend fun getAnnouncements(
        client: TootApiClient,
        force: Boolean = false,
    ): TootApiResult? {
        // announcements is shown only mastodon home timeline, not pseudo.
        if (isMastodon && !isPseudo) {
            // force (initial loading) always reload announcements
            // other (refresh,gap) may reload announcements if last load is too old
            if (force || SystemClock.elapsedRealtime() - column.announcementUpdated >= 15 * 60000L) {
                if (force) {
                    log.d("announcements reset")
                    column.announcements = null
                    column.announcementUpdated = SystemClock.elapsedRealtime()
                }
                val (instance, _) = TootInstance.get(client)
                if (instance?.versionGE(TootInstance.VERSION_3_1_0_rc1) == true) {
                    val result = client.request("/api/v1/announcements")
                        ?: return null // cancelled.
                    when (result.response?.code ?: 0) {
                        // just skip load announcements for 4xx error if server does not support announcements.
                        in 400 until 500 -> Unit

                        else -> {
                            column.announcements =
                                parseList(::TootAnnouncement, parser, result.jsonArray)
                                    .notEmpty()
                            column.announcementUpdated = SystemClock.elapsedRealtime()
                            client.publishApiProgress("announcements loaded")
                            // other errors such as network or server fails will stop column loading.
                            return result
                        }
                    }
                }
            }
        }
        return TootApiResult()
    }

    abstract suspend fun background(): TootApiResult?
    abstract suspend fun handleResult(result: TootApiResult?)

    fun cancel() {
        job?.cancel()
    }

    fun start() {
        job = launchMain {
            val result = try {
                withContext(appDispatchers.io) { background() }
            } catch (ignored: CancellationException) {
                null // キャンセルされたらresult==nullとする
            } catch (ex: Throwable) {
                // その他のエラー
                TootApiResult(ex.withCaption("error"))
            }
            handleResult(result)
        }
    }
}