MWClash/android/app/src/main/kotlin/com/follow/clash/GlobalState.kt

package com.follow.clash

import androidx.lifecycle.MutableLiveData
import com.follow.clash.plugins.AppPlugin
import com.follow.clash.plugins.TilePlugin
import com.follow.clash.plugins.VpnPlugin
import io.flutter.FlutterInjector
import io.flutter.embedding.engine.FlutterEngine
import io.flutter.embedding.engine.dart.DartExecutor
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers
import kotlinx.coroutines.launch
import kotlinx.coroutines.withContext
import java.util.concurrent.locks.ReentrantLock
import kotlin.concurrent.withLock

enum class RunState {
    START,
    PENDING,
    STOP
}


object GlobalState {
    val runLock = ReentrantLock()

    const val NOTIFICATION_CHANNEL = "FlClash"

    const val NOTIFICATION_ID = 1

    val runState: MutableLiveData<RunState> = MutableLiveData<RunState>(RunState.STOP)
    var flutterEngine: FlutterEngine? = null
    private var serviceEngine: FlutterEngine? = null

    fun getCurrentAppPlugin(): AppPlugin? {
        val currentEngine = if (flutterEngine != null) flutterEngine else serviceEngine
        return currentEngine?.plugins?.get(AppPlugin::class.java) as AppPlugin?
    }

    fun syncStatus() {
        CoroutineScope(Dispatchers.Default).launch {
            val status = getCurrentVPNPlugin()?.getStatus() ?: false
            withContext(Dispatchers.Main){
                runState.value = if (status) RunState.START else RunState.STOP
            }
        }
    }

    suspend fun getText(text: String): String {
        return getCurrentAppPlugin()?.getText(text) ?: ""
    }

    fun getCurrentTilePlugin(): TilePlugin? {
        val currentEngine = if (flutterEngine != null) flutterEngine else serviceEngine
        return currentEngine?.plugins?.get(TilePlugin::class.java) as TilePlugin?
    }

    fun getCurrentVPNPlugin(): VpnPlugin? {
        return serviceEngine?.plugins?.get(VpnPlugin::class.java) as VpnPlugin?
    }

    fun handleToggle() {
        val starting = handleStart()
        if (!starting) {
            handleStop()
        }
    }

    fun handleStart(): Boolean {
        if (runState.value == RunState.STOP) {
            runState.value = RunState.PENDING
            runLock.lock()
            val tilePlugin = getCurrentTilePlugin()
            if (tilePlugin != null) {
                tilePlugin.handleStart()
            } else {
                initServiceEngine()
            }
            return true
        }
        return false
    }

    fun handleStop() {
        if (runState.value == RunState.START) {
            runState.value = RunState.PENDING
            runLock.lock()
            getCurrentTilePlugin()?.handleStop()
        }
    }

    fun handleTryDestroy() {
        if (flutterEngine == null) {
            destroyServiceEngine()
        }
    }

    fun destroyServiceEngine() {
        runLock.withLock {
            serviceEngine?.destroy()
            serviceEngine = null
        }
    }

    fun initServiceEngine() {
        if (serviceEngine != null) return
        destroyServiceEngine()
        runLock.withLock {
            serviceEngine = FlutterEngine(FlClashApplication.getAppContext())
            serviceEngine?.plugins?.add(VpnPlugin)
            serviceEngine?.plugins?.add(AppPlugin())
            serviceEngine?.plugins?.add(TilePlugin())
            val vpnService = DartExecutor.DartEntrypoint(
                FlutterInjector.instance().flutterLoader().findAppBundlePath(),
                "_service"
            )
            serviceEngine?.dartExecutor?.executeDartEntrypoint(
                vpnService,
                if (flutterEngine == null) listOf("quick") else null
            )
        }
    }
}