@file:GenerateKoinDefinition("baseJsonProvider", Json::class)
package dev.inmo.micro_utils.startup.launcher

import dev.inmo.kslog.common.i
import dev.inmo.kslog.common.taggedLogger
import dev.inmo.kslog.common.w
import dev.inmo.micro_utils.coroutines.runCatchingSafely
import dev.inmo.micro_utils.koin.annotations.GenerateKoinDefinition
import dev.inmo.micro_utils.startup.launcher.StartLauncherPlugin.setupDI
import dev.inmo.micro_utils.startup.launcher.StartLauncherPlugin.startPlugin
import dev.inmo.micro_utils.startup.plugin.StartPlugin
import kotlinx.coroutines.*
import kotlinx.serialization.SerialFormat
import kotlinx.serialization.StringFormat
import kotlinx.serialization.json.Json
import kotlinx.serialization.json.JsonObject
import kotlinx.serialization.json.jsonObject
import kotlinx.serialization.modules.SerializersModule
import org.koin.core.Koin
import org.koin.core.KoinApplication
import org.koin.core.context.startKoin
import org.koin.core.module.Module
import org.koin.dsl.binds
import org.koin.dsl.module

/**
 * Default startup plugin. See [setupDI] and [startPlugin] for more info
 */
object StartLauncherPlugin : StartPlugin {
    internal val logger = taggedLogger(this)

    fun Module.setupDI(config: Config, rawJsonObject: JsonObject? = null) {
        val rawJsonObject = rawJsonObject ?: defaultJson.encodeToJsonElement(Config.serializer(), config).jsonObject

        single { rawJsonObject }
        single { config }
        single { CoroutineScope(Dispatchers.Default) }
        single {
            val serializersModules = getAll<SerializersModule>().distinct()
            val baseJson = baseJsonProvider ?: defaultJson
            if (serializersModules.isEmpty()) {
                baseJson
            } else {
                Json(baseJson) {
                    serializersModule = SerializersModule {
                        include(baseJson.serializersModule)
                        serializersModules.forEach { include(it) }
                    }
                }
            }
        } binds arrayOf(StringFormat::class, SerialFormat::class)

        includes(
            config.plugins.mapNotNull {
                val pluginName = it::class.simpleName ?: it.toString()
                runCatching {
                    logger.i { "Start koin module registration for $pluginName" }
                    module {
                        with(it) {
                            setupDI(rawJsonObject)
                        }
                    }
                }.onFailure { e ->
                    logger.w("Unable to register koin module of $pluginName", e)
                }.onSuccess {
                    logger.i("Successfully registered koin module of $pluginName")
                }.getOrNull()
            }
        )
    }

    /**
     * Will deserialize [Config] from [config], register it in receiver [Module] (as well as [CoroutineScope] and
     * [kotlinx.serialization.json.Json])
     *
     * Besides, in this method will be called [StartPlugin.setupDI] on each plugin from [Config.plugins]. In case when
     * some plugin will not be loaded correctly it will be reported throw the [logger]
     */
    override fun Module.setupDI(config: JsonObject) {
        logger.i("Koin for current module has started setup")
        setupDI(
            defaultJson.decodeFromJsonElement(Config.serializer(), config),
            config
        )
        logger.i("Koin for current module has been setup")
    }

    /**
     * Takes [CoroutineScope] and [Config] from the [koin], and call starting of each plugin from [Config.plugins]
     * ASYNCHRONOUSLY. Just like in [setupDI], in case of fail in some plugin it will be reported using [logger]
     */
    override suspend fun startPlugin(koin: Koin) {
        logger.i("Start starting of subplugins")
        val scope = koin.get<CoroutineScope>()
        koin.get<Config>().plugins.map { plugin ->
            val pluginName = plugin::class.simpleName ?: plugin.toString()
            scope.launch {
                runCatchingSafely {
                    logger.i("Start loading of $pluginName")
                    with(plugin) {
                        startPlugin(koin)
                    }
                }.onFailure { e ->
                    logger.w("Unable to start plugin $pluginName", e)
                }.onSuccess {
                    logger.i("Complete loading of $pluginName")
                }
            }
        }.joinAll()
        logger.i("Complete subplugins start")
    }

    /**
     * Will create [KoinApplication], init, load modules using [StartLauncherPlugin] and start plugins using the same base
     * plugin. It is basic [start] method which accepts both [config] and [rawConfig] which suppose to be the same or
     * at least [rawConfig] must contain serialized variant of [config].
     *
     * Koin part will be started in-place. This means, that after ending of this method call you will be able to
     * take any declared dependency from koin
     *
     * @param rawConfig It is expected that this [JsonObject] will contain serialized [Config] ([StartLauncherPlugin] will
     * deserialize it in its [StartLauncherPlugin.setupDI]
     * @return [KoinApplication] of current start and [Job] which can be used to call [CoroutineScope.join]
     */
    fun startAsync(config: Config, rawConfig: JsonObject): Pair<KoinApplication, Job> {

        logger.i("Start initialization")
        val koinApp = KoinApplication.init()
        koinApp.modules(
            module {
                setupDI(config, rawConfig)
            }
        )
        logger.i("Modules loaded")
        startKoin(koinApp)
        logger.i("Koin started")
        val launchJob = koinApp.koin.get<CoroutineScope>().launch {
            startPlugin(koinApp.koin)
            logger.i("App has been started")
        }

        return koinApp to launchJob
    }

    /**
     * Will create [KoinApplication], init, load modules using [StartLauncherPlugin] and start plugins using the same base
     * plugin. It is basic [start] method which accepts both [config] and [rawConfig] which suppose to be the same or
     * at least [rawConfig] must contain serialized variant of [config]
     *
     * @param rawConfig It is expected that this [JsonObject] will contain serialized [Config] ([StartLauncherPlugin] will
     * deserialize it in its [StartLauncherPlugin.setupDI]
     * @return [KoinApplication] of current launch
     */
    suspend fun start(config: Config, rawConfig: JsonObject): KoinApplication {

        val (koinApp, job) = startAsync(config, rawConfig)

        job.join()

        return koinApp
    }

    /**
     * Call [start] with deserialized [Config] as config and [rawConfig] as is
     *
     * Koin part will be started in-place. This means, that after ending of this method call you will be able to
     * take any declared dependency from koin
     *
     * @param rawConfig It is expected that this [JsonObject] will contain serialized [Config]
     * @return [KoinApplication] of current launch and [Job] of starting launch
     */
    fun startAsync(rawConfig: JsonObject): Pair<KoinApplication, Job> {

        return startAsync(defaultJson.decodeFromJsonElement(Config.serializer(), rawConfig), rawConfig)

    }

    /**
     * Call [start] with deserialized [Config] as config and [rawConfig] as is
     *
     * @param rawConfig It is expected that this [JsonObject] will contain serialized [Config]
     */
    suspend fun start(rawConfig: JsonObject): KoinApplication {

        val (koinApp, job) = startAsync(rawConfig)

        job.join()

        return koinApp

    }

    /**
     * Call [start] with deserialized [Config] as is and serialize it to [JsonObject] to pass as the first parameter
     * to the basic [start] method
     *
     * Koin part will be started in-place. This means, that after ending of this method call you will be able to
     * take any declared dependency from koin
     *
     * @param config Will be converted to [JsonObject] as raw config. That means that all plugins from [config] will
     * receive serialized version of [config] in [StartPlugin.setupDI] method
     * @return [KoinApplication] of current launch and [Job] of starting launch
     */
    fun startAsync(config: Config): Pair<KoinApplication, Job> {

        return startAsync(config, defaultJson.encodeToJsonElement(Config.serializer(), config).jsonObject)

    }

    /**
     * Call [start] with deserialized [Config] as is and serialize it to [JsonObject] to pass as the first parameter
     * to the basic [start] method
     *
     * @param config Will be converted to [JsonObject] as raw config. That means that all plugins from [config] will
     * receive serialized version of [config] in [StartPlugin.setupDI] method
     */
    suspend fun start(config: Config): KoinApplication {

        val (koinApp, job) = startAsync(config)

        job.join()

        return koinApp

    }
}