package com.example.livestreaming;

import android.graphics.SurfaceTexture;
import android.os.Bundle;
import android.view.Surface;
import android.view.TextureView;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import androidx.media3.common.MediaItem;
import androidx.media3.common.PlaybackException;
import androidx.media3.common.Player;
import androidx.media3.exoplayer.ExoPlayer;

import com.example.livestreaming.databinding.ActivityPlayerBinding;

import tv.danmaku.ijk.media.player.IMediaPlayer;
import tv.danmaku.ijk.media.player.IjkMediaPlayer;

public class PlayerActivity extends AppCompatActivity {

    public static final String EXTRA_PLAY_URL = "extra_play_url";
    public static final String EXTRA_TITLE = "extra_title";

    private ActivityPlayerBinding binding;
    private ExoPlayer player;
    private boolean triedAltUrl = false;

    private IjkMediaPlayer ijkPlayer;
    private Surface ijkSurface;
    private String ijkUrl;
    private String ijkFallbackHlsUrl;
    private boolean ijkFallbackTried;

    private static boolean ijkLibLoaded;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        binding = ActivityPlayerBinding.inflate(getLayoutInflater());
        setContentView(binding.getRoot());

        String t = getIntent().getStringExtra(EXTRA_TITLE);
        setTitle(t != null ? t : "Live");
    }

    @Override
    protected void onStart() {
        super.onStart();
        // TODO: 接入后端接口 - 记录播放开始
        // 接口路径: POST /api/play/start
        // 请求参数:
        //   - userId: 当前用户ID（从token中获取，可选）
        //   - roomId: 房间ID（从Intent中获取）
        //   - playUrl: 播放地址
        //   - timestamp: 开始播放时间戳
        // 返回数据格式: ApiResponse<{success: boolean}>
        // 用于统计播放数据和用户行为分析
        String url = getIntent().getStringExtra(EXTRA_PLAY_URL);
        if (url == null || url.trim().isEmpty()) return;

        triedAltUrl = false;

        if (url.endsWith(".flv")) {
            startFlv(url, null);
            return;
        }

        startHls(url, null);
    }

    private void startHls(String url, @Nullable String altUrl) {
        releaseIjkPlayer();
        if (binding != null) {
            binding.flvTextureView.setVisibility(android.view.View.GONE);
            binding.playerView.setVisibility(android.view.View.VISIBLE);
        }

        releaseExoPlayer();
        triedAltUrl = false;

        // 优化缓冲配置 - 针对低延迟 HLS（1秒分片）
        androidx.media3.exoplayer.DefaultLoadControl loadControl = 
            new androidx.media3.exoplayer.DefaultLoadControl.Builder()
                .setBufferDurationsMs(
                        2500,    // 最小缓冲 2.5秒
                        10000,   // 最大缓冲 10秒
                        1500,    // 播放前缓冲 1.5秒
                        2500     // 重新缓冲 2.5秒
                )
                .setPrioritizeTimeOverSizeThresholds(true)
                .build();

        ExoPlayer exo = new ExoPlayer.Builder(this)
                .setLoadControl(loadControl)
                .build();
        
        binding.playerView.setPlayer(exo);
        binding.playerView.setUseController(true);
        binding.playerView.setControllerAutoShow(false);

        String computedAltUrl = altUrl;
        if (computedAltUrl == null || computedAltUrl.trim().isEmpty()) {
            computedAltUrl = getAltHlsUrl(url);
        }

        String finalComputedAltUrl = computedAltUrl;
        exo.addListener(new Player.Listener() {
            @Override
            public void onPlayerError(PlaybackException error) {
                android.util.Log.e("PlayerActivity", "播放错误: " + error.getMessage());
                if (triedAltUrl) return;
                if (finalComputedAltUrl == null || finalComputedAltUrl.trim().isEmpty()) return;
                triedAltUrl = true;

                exo.setMediaItem(MediaItem.fromUri(finalComputedAltUrl));
                exo.prepare();
                exo.setPlayWhenReady(true);
            }
        });

        android.util.Log.d("PlayerActivity", "开始播放: " + url);
        exo.setMediaItem(MediaItem.fromUri(url));
        exo.prepare();
        exo.setPlayWhenReady(true);
        player = exo;
    }

    @Override
    protected void onStop() {
        super.onStop();
        // TODO: 接入后端接口 - 记录播放结束
        // 接口路径: POST /api/play/end
        // 请求参数:
        //   - userId: 当前用户ID（从token中获取，可选）
        //   - roomId: 房间ID（从Intent中获取）
        //   - playDuration: 播放时长（秒）
        //   - timestamp: 结束播放时间戳
        // 返回数据格式: ApiResponse<{success: boolean}>
        // 用于统计播放时长和用户观看行为
        releaseExoPlayer();
        releaseIjkPlayer();
    }

    private void startFlv(String flvUrl, @Nullable String fallbackHlsUrl) {
        android.util.Log.d("PlayerActivity", "使用IJK播放FLV流: " + flvUrl);
        
        // 释放 ExoPlayer
        releaseExoPlayer();
        releaseIjkPlayer();
        
        // 确保 IJK 库已加载
        ensureIjkLibsLoaded();
        
        // 保存回退地址
        ijkUrl = flvUrl;
        ijkFallbackHlsUrl = fallbackHlsUrl;
        if (ijkFallbackHlsUrl == null || ijkFallbackHlsUrl.trim().isEmpty()) {
            ijkFallbackHlsUrl = flvUrl.replace(".flv", ".m3u8");
        }
        ijkFallbackTried = false;
        
        // 显示 TextureView，隐藏 ExoPlayer 的 PlayerView
        if (binding != null) {
            binding.playerView.setVisibility(android.view.View.GONE);
            binding.flvTextureView.setVisibility(android.view.View.VISIBLE);
            
            // 设置 TextureView 监听器
            binding.flvTextureView.setSurfaceTextureListener(new TextureView.SurfaceTextureListener() {
                @Override
                public void onSurfaceTextureAvailable(android.graphics.SurfaceTexture surface, int width, int height) {
                    android.util.Log.d("PlayerActivity", "SurfaceTexture可用，准备IJK播放器");
                    ijkSurface = new Surface(surface);
                    prepareIjk(flvUrl);
                }

                @Override
                public void onSurfaceTextureSizeChanged(android.graphics.SurfaceTexture surface, int width, int height) {
                    // 尺寸变化时不需要处理
                }

                @Override
                public boolean onSurfaceTextureDestroyed(android.graphics.SurfaceTexture surface) {
                    android.util.Log.d("PlayerActivity", "SurfaceTexture销毁");
                    releaseIjkPlayer();
                    return true;
                }

                @Override
                public void onSurfaceTextureUpdated(android.graphics.SurfaceTexture surface) {
                    // 更新时不需要处理
                }
            });
            
            // 如果 TextureView 已经可用，直接准备播放
            if (binding.flvTextureView.isAvailable()) {
                android.util.Log.d("PlayerActivity", "TextureView已可用，直接准备IJK播放器");
                ijkSurface = new Surface(binding.flvTextureView.getSurfaceTexture());
                prepareIjk(flvUrl);
            }
        }
    }

    private void prepareIjk(String url) {
        if (ijkSurface == null) return;

        IjkMediaPlayer p = new IjkMediaPlayer();
        
        // ========== 超低延迟核心配置 ==========
        // 禁用数据包缓冲，直接播放
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "packet-buffering", 0);
        // 准备好立即播放
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "start-on-prepared", 1);
        // 无限缓冲模式（配合max_cached_duration使用）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "infbuf", 1);
        // 最大缓存时长 200ms（极低延迟）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "max_cached_duration", 200);
        // 最小帧数 2（快速启动）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "min-frames", 2);
        // 允许丢帧追赶延迟
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "framedrop", 5);
        // 同步类型：视频为主
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "sync-av-start", 0);
        
        // ========== 格式/解复用配置 ==========
        // 禁用缓冲
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "fflags", "nobuffer");
        // 分析时长 100us（极短）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "analyzeduration", 100);
        // 探测大小 1KB（极小）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "probesize", 1024);
        // 刷新数据包
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "flush_packets", 1);
        // 禁用DNS缓存
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "dns_cache_clear", 1);
        
        // ========== 编解码配置 ==========
        // 使用硬件解码（如果可用）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "mediacodec", 1);
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "mediacodec-auto-rotate", 1);
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "mediacodec-handle-resolution-change", 1);
        // 跳过循环滤波（加速解码）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_CODEC, "skip_loop_filter", 48);
        // 跳过帧（加速解码）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_CODEC, "skip_frame", 0);
        
        // ========== 网络配置 ==========
        // 重连次数
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "reconnect", 1);
        // 超时时间 3秒
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_FORMAT, "timeout", 3000000);
        
        // ========== 音频配置 ==========
        // 开启音频
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "an", 0);
        // OpenSL ES 音频输出（低延迟）
        p.setOption(IjkMediaPlayer.OPT_CATEGORY_PLAYER, "opensles", 1);

        p.setOnPreparedListener(mp -> {
            android.util.Log.d("PlayerActivity", "IJK播放器准备完成，开始播放");
            mp.start();
        });
        
        p.setOnInfoListener((mp, what, extra) -> {
            if (what == IMediaPlayer.MEDIA_INFO_VIDEO_RENDERING_START) {
                android.util.Log.d("PlayerActivity", "IJK首帧渲染完成");
            } else if (what == IMediaPlayer.MEDIA_INFO_BUFFERING_START) {
                android.util.Log.d("PlayerActivity", "IJK开始缓冲");
            } else if (what == IMediaPlayer.MEDIA_INFO_BUFFERING_END) {
                android.util.Log.d("PlayerActivity", "IJK缓冲结束");
            }
            return false;
        });
        
        p.setOnErrorListener((IMediaPlayer mp, int what, int extra) -> {
            android.util.Log.e("PlayerActivity", "IJK播放错误: what=" + what + ", extra=" + extra);
            if (ijkFallbackTried || ijkFallbackHlsUrl == null || ijkFallbackHlsUrl.trim().isEmpty()) return true;
            ijkFallbackTried = true;
            startHls(ijkFallbackHlsUrl, null);
            return true;
        });

        ijkPlayer = p;
        try {
            p.setSurface(ijkSurface);
            p.setDataSource(url);
            android.util.Log.d("PlayerActivity", "IJK开始准备播放: " + url);
            p.prepareAsync();
        } catch (Exception e) {
            android.util.Log.e("PlayerActivity", "IJK播放异常: " + e.getMessage());
            if (ijkFallbackHlsUrl != null && !ijkFallbackHlsUrl.trim().isEmpty()) {
                startHls(ijkFallbackHlsUrl, null);
            }
        }
    }

    private static void ensureIjkLibsLoaded() {
        if (ijkLibLoaded) return;
        try {
            IjkMediaPlayer.loadLibrariesOnce(null);
            IjkMediaPlayer.native_profileBegin("libijkplayer.so");
        } catch (Throwable ignored) {
        }
        ijkLibLoaded = true;
    }

    private void releaseExoPlayer() {
        if (player != null) {
            player.release();
            player = null;
        }
        if (binding != null) binding.playerView.setPlayer(null);
    }

    private void releaseIjkPlayer() {
        if (ijkPlayer != null) {
            ijkPlayer.reset();
            ijkPlayer.release();
            ijkPlayer = null;
        }
        if (ijkSurface != null) {
            ijkSurface.release();
            ijkSurface = null;
        }
        ijkUrl = null;
        ijkFallbackHlsUrl = null;
        ijkFallbackTried = false;
        if (binding != null) {
            binding.flvTextureView.setVisibility(android.view.View.GONE);
            binding.playerView.setVisibility(android.view.View.VISIBLE);
        }
    }

    private String getAltHlsUrl(String url) {
        if (!url.endsWith(".m3u8")) return null;
        if (url.contains("/index.m3u8")) return null;

        return url.substring(0, url.length() - ".m3u8".length()) + "/index.m3u8";
    }
}