package com.aros.apron.manager;

import android.os.Handler;
import android.os.Looper;

import androidx.annotation.NonNull;

import com.aros.apron.tools.LogUtil;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
import java.net.UnknownHostException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.atomic.AtomicBoolean;

import dji.sdk.keyvalue.value.common.ComponentIndexType;
import dji.v5.manager.datacenter.MediaDataCenter;
import dji.v5.manager.datacenter.camera.StreamInfo;
import dji.v5.manager.interfaces.ICameraStreamManager;

/**
 * UDP视频流推送管理类
 * 负责从视频监听器获取码流数据并通过UDP协议推送
 */
public class UdpStreamManager {
    private static final String TAG = "UdpStreamManager";

    // 线程池和主线程Handler
    private final ExecutorService udpExecutor = Executors.newSingleThreadExecutor();
    private final Handler mainHandler = new Handler(Looper.getMainLooper());

    // 单例模式
    private static class UdpStreamHolder {
        private static final UdpStreamManager INSTANCE = new UdpStreamManager();
    }

    public static UdpStreamManager getInstance() {
        return UdpStreamHolder.INSTANCE;
    }

    // UDP配置
    private static final String DEFAULT_HOST = "127.0.0.1";
    private static final int DEFAULT_PORT_1_PORT = 8080;
    private static final int DEFAULT_FPV_PORT = 8081;
    private String targetHost = DEFAULT_HOST;
    private int port1Port = DEFAULT_PORT_1_PORT;
    private int fpvPort = DEFAULT_FPV_PORT;

    // 状态管理
    private final AtomicBoolean isStreaming = new AtomicBoolean(false);
    private final AtomicBoolean isInitialized = new AtomicBoolean(false);

    // UDP相关
    private DatagramSocket port1UdpSocket;
    private DatagramSocket fpvUdpSocket;
    private InetAddress targetAddress;

    // 视频码流监听器
    private ICameraStreamManager.ReceiveStreamListener port1StreamListener;
    private ICameraStreamManager.ReceiveStreamListener fpvStreamListener;

    private UdpStreamManager() {
    }

    /**
     * 初始化UDP流管理器
     * @param host 目标主机地址
     * @param port1Port PORT_1相机的目标端口
     * @param fpvPort FPV相机的目标端口
     */
    public void init(String host, int port1Port, int fpvPort) {
        if (isInitialized.get()) {
            LogUtil.log(TAG, "UDP流管理器已初始化");
            return;
        }

        targetHost = host != null ? host : DEFAULT_HOST;
        this.port1Port = port1Port > 0 ? port1Port : DEFAULT_PORT_1_PORT;
        this.fpvPort = fpvPort > 0 ? fpvPort : DEFAULT_FPV_PORT;

        udpExecutor.execute(() -> {
            try {
                // 初始化UDP socket
                port1UdpSocket = new DatagramSocket();
                fpvUdpSocket = new DatagramSocket();
                targetAddress = InetAddress.getByName(targetHost);

                // 初始化视频码流监听器
                initStreamListeners();

                isInitialized.set(true);
                LogUtil.log(TAG, "UDP流管理器初始化成功，目标地址: " + targetHost + ", PORT_1端口: " + this.port1Port + ", FPV端口: " + this.fpvPort);
            } catch (SocketException e) {
                LogUtil.log(TAG, "UDP socket初始化失败: " + e.getMessage());
                e.printStackTrace();
            } catch (UnknownHostException e) {
                LogUtil.log(TAG, "无法解析目标地址: " + e.getMessage());
                e.printStackTrace();
            }
        });
    }

    /**
     * 初始化UDP流管理器（使用默认端口）
     * @param host 目标主机地址
     */
    public void init(String host) {
        init(host, DEFAULT_PORT_1_PORT, DEFAULT_FPV_PORT);
    }

    /**
     * 初始化UDP流管理器（使用默认地址和端口）
     */
    public void init() {
        init(DEFAULT_HOST, DEFAULT_PORT_1_PORT, DEFAULT_FPV_PORT);
    }

    /**
     * 初始化视频码流监听器
     */
    private void initStreamListeners() {
        ICameraStreamManager cameraManager = MediaDataCenter.getInstance().getCameraStreamManager();
        if (cameraManager == null) {
            LogUtil.log(TAG, "CameraStreamManager获取失败");
            return;
        }

        port1StreamListener=new ICameraStreamManager.ReceiveStreamListener() {
            @Override
            public void onReceiveStream(@NonNull byte[] data, int offset, int length, @NonNull StreamInfo info) {
                if (isStreaming.get()) {
                    // 截取有效数据
                    byte[] streamData = new byte[length];
                    System.arraycopy(data, offset, streamData, 0, length);
                    sendStreamData(streamData, ComponentIndexType.PORT_1);
                }
            }
        };

        // FPV相机码流监听器
        fpvStreamListener=new ICameraStreamManager.ReceiveStreamListener() {
            @Override
            public void onReceiveStream(@NonNull byte[] data, int offset, int length, @NonNull StreamInfo info) {
                if (isStreaming.get()) {
                    // 截取有效数据
                    byte[] streamData = new byte[length];
                    System.arraycopy(data, offset, streamData, 0, length);
                    sendStreamData(streamData, ComponentIndexType.FPV);
                }
            }
        };


        // 注册监听器
        cameraManager.addReceiveStreamListener(ComponentIndexType.PORT_1, port1StreamListener);
        cameraManager.addReceiveStreamListener(ComponentIndexType.FPV, fpvStreamListener);

        LogUtil.log(TAG, "视频码流监听器注册成功");
    }

    /**
     * 发送码流数据
     * @param streamData 码流数据
     * @param componentIndex 相机组件索引
     */
    private void sendStreamData(byte[] streamData, ComponentIndexType componentIndex) {
        if (targetAddress == null) {
            return;
        }

        try {
            // 选择对应的UDP socket和端口
            DatagramSocket socket = null;
            int port = 0;

            if (componentIndex == ComponentIndexType.PORT_1) {
                socket = port1UdpSocket;
                port = port1Port;
            } else if (componentIndex == ComponentIndexType.FPV) {
                socket = fpvUdpSocket;
                port = fpvPort;
            }

            if (socket == null) {
                return;
            }

            // 构造UDP数据包
            // 前4字节表示相机索引（1: PORT_1, 2: FPV）
            // 接下来4字节表示数据长度
            // 剩余部分为码流数据
            int headerSize = 8;
            byte[] packetData = new byte[headerSize + streamData.length];

            // 写入相机索引
            int cameraIndex = componentIndex == ComponentIndexType.PORT_1 ? 1 : 2;
            packetData[0] = (byte) (cameraIndex >> 24);
            packetData[1] = (byte) (cameraIndex >> 16);
            packetData[2] = (byte) (cameraIndex >> 8);
            packetData[3] = (byte) cameraIndex;

            // 写入数据长度
            packetData[4] = (byte) (streamData.length >> 24);
            packetData[5] = (byte) (streamData.length >> 16);
            packetData[6] = (byte) (streamData.length >> 8);
            packetData[7] = (byte) streamData.length;

            // 写入码流数据
            System.arraycopy(streamData, 0, packetData, headerSize, streamData.length);

            // 发送UDP数据包
            DatagramPacket packet = new DatagramPacket(
                    packetData,
                    packetData.length,
                    targetAddress,
                    port
            );

            socket.send(packet);

        } catch (IOException e) {
            LogUtil.log(TAG, "发送UDP数据包失败: " + e.getMessage());
            e.printStackTrace();
        }
    }

    /**
     * 开始UDP流推送
     */
    public void startStreaming() {
        if (!isInitialized.get()) {
            LogUtil.log(TAG, "UDP流管理器未初始化，请先调用init方法");
            return;
        }

        isStreaming.set(true);
        LogUtil.log(TAG, "UDP流推送已启动");
    }

    /**
     * 停止UDP流推送
     */
    public void stopStreaming() {
        isStreaming.set(false);
        LogUtil.log(TAG, "UDP流推送已停止");
    }

    /**
     * 关闭UDP流管理器
     */
    public void close() {
        stopStreaming();

        // 移除视频码流监听器
        ICameraStreamManager cameraManager = MediaDataCenter.getInstance().getCameraStreamManager();
        if (cameraManager != null) {
            if (port1StreamListener != null) {
                cameraManager.removeReceiveStreamListener(port1StreamListener);
            }
            if (fpvStreamListener != null) {
                cameraManager.removeReceiveStreamListener(fpvStreamListener);
            }
        }

        // 关闭UDP socket
        if (port1UdpSocket != null) {
            port1UdpSocket.close();
            port1UdpSocket = null;
        }
        if (fpvUdpSocket != null) {
            fpvUdpSocket.close();
            fpvUdpSocket = null;
        }

        isInitialized.set(false);
        LogUtil.log(TAG, "UDP流管理器已关闭");
    }

    /**
     * 设置目标地址
     * @param host 目标主机地址
     * @param port1Port PORT_1相机的目标端口
     * @param fpvPort FPV相机的目标端口
     */
    public void setTargetAddress(String host, int port1Port, int fpvPort) {
        if (host != null) {
            targetHost = host;
        }
        if (port1Port > 0) {
            this.port1Port = port1Port;
        }
        if (fpvPort > 0) {
            this.fpvPort = fpvPort;
        }

        udpExecutor.execute(() -> {
            try {
                targetAddress = InetAddress.getByName(targetHost);
                LogUtil.log(TAG, "目标地址已更新: " + targetHost + ", PORT_1端口: " + this.port1Port + ", FPV端口: " + this.fpvPort);
            } catch (UnknownHostException e) {
                LogUtil.log(TAG, "无法解析新目标地址: " + e.getMessage());
                e.printStackTrace();
            }
        });
    }

    /**
     * 获取UDP流推送状态
     */
    public boolean isStreaming() {
        return isStreaming.get();
    }

    /**
     * 获取UDP流管理器初始化状态
     */
    public boolean isInitialized() {
        return isInitialized.get();
    }

    /**
     * 获取当前目标地址
     */
    public String getTargetAddress() {
        return targetHost + ", PORT_1端口: " + port1Port + ", FPV端口: " + fpvPort;
    }
}