package org.openrndr.extra.olive

import io.github.oshai.kotlinlogging.KotlinLogging
import kotlinx.coroutines.DelicateCoroutinesApi
import kotlinx.coroutines.GlobalScope
import kotlinx.coroutines.async

import org.openrndr.Extension
import org.openrndr.Program
import org.openrndr.draw.Session
import org.openrndr.events.Event
import org.openrndr.exceptions.stackRootClassName
import org.openrndr.extra.kotlinparser.extractProgram
import org.openrndr.launch
import org.openrndr.extra.filewatcher.watchFile
import java.io.File

private val logger = KotlinLogging.logger {}


private fun <T> Event<T>.saveListeners(store: MutableMap<Event<*>, List<(Any) -> Unit>>) {
    @Suppress("UNCHECKED_CAST")
    store[this] = listeners.map { it } as List<(Any) -> Unit>
}

private fun <T> Event<T>.restoreListeners(store: Map<Event<*>, List<(Any) -> Unit>>) {
    listeners.retainAll(store[this] ?: emptyList<T>())
}

enum class OliveScriptHost {
    JSR223,
    JSR223_REUSE,
    KOTLIN_SCRIPT
}

data class ScriptLoadedEvent(val scriptFile: String)

enum class ScriptMode {
    KOTLIN_SCRIPT,
    OLIVE_PROGRAM
}

class Olive<P : Program>(val resources: Resources? = null, private var scriptMode: ScriptMode = ScriptMode.KOTLIN_SCRIPT) : Extension {
    override var enabled: Boolean = true
    var session: Session? = null
    var scriptHost = OliveScriptHost.JSR223_REUSE

    val scriptLoaded = Event<ScriptLoadedEvent>()

    internal var scriptChange: (String) -> Unit = {}

    var script = when (scriptMode) {
        ScriptMode.KOTLIN_SCRIPT -> "src/main/kotlin/${stackRootClassName().split(".").last()}.kts"
        else -> "src/main/kotlin/${stackRootClassName().split(".").last()}.kt"
    }
        set(value) {
            field = value
            scriptChange(value)
        }

    /**
     * reloads the active script
     */
    fun reload() {
   //     watcher?.triggerChange()
    }

    class ScriptWatcher



    private var watcherRequestStopEvent = Event<Unit>()
    private var watcher: (() -> Unit)? = null

    @OptIn(DelicateCoroutinesApi::class)
    override fun setup(program: Program) {
        System.setProperty("idea.io.use.fallback", "true")
        System.setProperty("org.openrndr.ignoreShadeStyleErrors", "true")

        val store = mutableMapOf<Event<*>, List<(Any) -> Unit>>()
        val originalExtensions = program.extensions.map { it }
        val trackedListeners = listOf<Event<*>>(program.mouse.buttonDown,
            program.mouse.buttonUp,
            program.mouse.dragged,
            program.mouse.moved,
            program.mouse.scrolled,
            program.keyboard.keyUp,
            program.keyboard.keyDown,
            program.keyboard.keyRepeat,
            program.keyboard.character,
            program.window.drop,
            program.window.focused,
            program.window.minimized,
            program.window.moved,
            program.window.sized,
            program.window.unfocused,
            program.requestAssets,
            program.produceAssets
        )

        trackedListeners.forEach { it.saveListeners(store) }

        val originalAssetMetadata = program.assetMetadata
        val originalAssetProperties = program.assetProperties.toMutableMap()

        fun setupScript(scriptFile: String) {
            if (watcher != null) {
                logger.info { "requesting watcher stop" }
                watcherRequestStopEvent.trigger(Unit)
            } else {
                logger.info { "no existing watcher" }
            }
            val f = File(scriptFile)
            if (!f.exists()) {
                f.parentFile.mkdirs()
                var className = program.javaClass.name
                if (className.contains("$"))
                    className = "Program"

                f.writeText("""
                @file:Suppress("UNUSED_LAMBDA_EXPRESSION")
                import org.openrndr.Program
                import org.openrndr.draw.*

                { program: $className ->
                    program.apply {
                        extend {

                        }
                    }
                }
            """.trimIndent())
            }

            val jsr233ObjectLoader = if (scriptHost == OliveScriptHost.JSR223_REUSE) ScriptObjectLoader() else null

            watcher = watchFile(File(script), requestStopEvent = watcherRequestStopEvent) {
                try {
                    logger.info { "change detected, reloading script" }

                    val scriptContents = when (scriptMode) {
                        ScriptMode.KOTLIN_SCRIPT -> it.readText()
                        ScriptMode.OLIVE_PROGRAM -> {
                            val source = it.readText()
                            val programSource = extractProgram(source, programIdentifier = "oliveProgram")
                            generateScript<OliveProgram>(programSource)
                        }
                    }

                    val futureFunc = GlobalScope.async {
                        val start = System.currentTimeMillis()
                        val loadedFunction = when (scriptHost) {
                            OliveScriptHost.JSR223_REUSE -> loadFromScriptContents(scriptContents, jsr233ObjectLoader!!)
                            OliveScriptHost.JSR223 -> loadFromScriptContents(scriptContents)
                            OliveScriptHost.KOTLIN_SCRIPT -> loadFromScriptContentsKSH<P.() -> Unit>(scriptContents)
                        }

                        val end = System.currentTimeMillis()
                        logger.info { "loading script took ${end - start}ms" }
                        loadedFunction
                    }

                    program.launch {
                        val func = futureFunc.await()
                        program.extensions.forEach {extension ->
                            extension.shutdown(program)
                        }
                        program.extensions.clear()
                        program.extensions.addAll(originalExtensions)
                        program.assetMetadata = originalAssetMetadata
                        program.assetProperties = originalAssetProperties

                        trackedListeners.forEach { l -> l.restoreListeners(store) }
                        session?.end()
                        session = Session.root.fork()

                        @Suppress("UNCHECKED_CAST")
                        func(program as P)
                        scriptLoaded.trigger(ScriptLoadedEvent(scriptFile))
                        Unit
                    }
                    Unit
                } catch (e: Throwable) {
                    e.printStackTrace()
                }
            }
        }
        setupScript(script)
        scriptChange = ::setupScript

        if (resources != null) {
            val srcPath = "src/main/resources"
            var src = File(srcPath)

            resources.watch(src) { file ->
                val dest = "build/resources/main"
                val filePath = file.path.split(Regex(srcPath), 2).getOrNull(1)

                val destFile = File("$dest/${filePath}").absoluteFile

                watchFile(file) {
                    if (resources[file]!! && filePath != null) {
                        file.copyTo(destFile, overwrite = true)
                        reload()
                    } else {
                        resources[file] = true
                    }
                }
            }
        }
    }
}