import React, { useEffect, useRef, useState, useCallback, useMemo } from 'react';
import { Platform, Animated, TouchableWithoutFeedback, View } from 'react-native';
import Video, { VideoRef, SelectedTrack, BufferingStrategyType, ResizeMode } from 'react-native-video';
import RNImmersiveMode from 'react-native-immersive-mode';

// Subtitle style configuration interface - matches ExoPlayer's SubtitleStyle
export interface SubtitleStyleConfig {
  // Font size in SP (scale-independent pixels) for subtitle text
  // Default: -1 (uses system default)
  fontSize?: number;
  
  // Padding values in pixels
  paddingTop?: number;
  paddingBottom?: number;
  paddingLeft?: number;
  paddingRight?: number;
  
  // Opacity of subtitles (0.0 to 1.0)
  // 0 = hidden, 1 = fully visible
  opacity?: number;
  
  // Whether subtitles should follow video position when video is resized
  // true = subtitles stay within video bounds
  // false = subtitles can extend beyond video bounds
  subtitlesFollowVideo?: boolean;
}

// Default subtitle style configuration
export const DEFAULT_SUBTITLE_STYLE: SubtitleStyleConfig = {
  fontSize: 18,
  paddingTop: 0,
  paddingBottom: 60,
  paddingLeft: 16,
  paddingRight: 16,
  opacity: 1,
  subtitlesFollowVideo: true,
};

interface VideoPlayerProps {
  src: string;
  headers?: { [key: string]: string };
  paused: boolean;
  volume: number;
  currentTime: number;
  selectedAudioTrack?: SelectedTrack;
  selectedTextTrack?: SelectedTrack;
  resizeMode?: ResizeMode;
  // Subtitle customization - pass custom subtitle styling
  subtitleStyle?: SubtitleStyleConfig;
  onProgress?: (data: { currentTime: number; playableDuration: number }) => void;
  onLoad?: (data: { duration: number }) => void;
  onError?: (error: any) => void;
  onBuffer?: (data: { isBuffering: boolean }) => void;
  onSeek?: (data: { currentTime: number; seekTime: number }) => void;
  onEnd?: () => void;
}

export const AndroidVideoPlayer: React.FC<VideoPlayerProps> = ({
  src,
  headers,
  paused,
  volume,
  currentTime,
  selectedAudioTrack,
  selectedTextTrack,
  resizeMode = 'contain' as ResizeMode,
  subtitleStyle: customSubtitleStyle,
  onProgress,
  onLoad,
  onError,
  onBuffer,
  onSeek,
  onEnd,
}) => {
  const videoRef = useRef<VideoRef>(null);
  const [isLoaded, setIsLoaded] = useState(false);
  const [isSeeking, setIsSeeking] = useState(false);
  const [lastSeekTime, setLastSeekTime] = useState<number>(0);

  // Merge custom subtitle style with defaults
  const subtitleStyle = useMemo(() => ({
    ...DEFAULT_SUBTITLE_STYLE,
    ...customSubtitleStyle,
  }), [customSubtitleStyle]);

  // Enable immersive mode when video player mounts, disable when it unmounts
  useEffect(() => {
    if (Platform.OS === 'android') {
      try {
        RNImmersiveMode.setBarMode('Bottom');
        RNImmersiveMode.fullLayout(true);
      } catch (error) {
        console.log('Immersive mode error:', error);
      }

      return () => {
        // Restore navigation bar when video player unmounts
        try {
          RNImmersiveMode.setBarMode('Normal');
          RNImmersiveMode.fullLayout(false);
        } catch (error) {
          console.log('Immersive mode cleanup error:', error);
        }
      };
    }
  }, []);

  // Only render on Android
  if (Platform.OS !== 'android') {
    return null;
  }

  useEffect(() => {
    if (isLoaded && !isSeeking && Math.abs(currentTime - lastSeekTime) > 1) {
      setIsSeeking(true);
      videoRef.current?.seek(currentTime);
      setLastSeekTime(currentTime);
    }
  }, [currentTime, isLoaded, isSeeking, lastSeekTime]);

  const handleLoad = (data: any) => {
    setIsLoaded(true);
    onLoad?.(data);
  };

  const handleProgress = (data: any) => {
    if (!isSeeking) {
      onProgress?.(data);
    }
  };

  const handleSeek = (data: any) => {
    setIsSeeking(false);
    onSeek?.(data);
  };

  const handleBuffer = (data: any) => {
    onBuffer?.(data);
  };

  const handleError = (error: any) => {
    console.error('Video playback error:', error);
    onError?.(error);
  };

  const handleEnd = () => {
    onEnd?.();
  };

  return (
    <Video
      ref={videoRef}
      source={headers ? { uri: src, headers } : { uri: src }}
      style={{ flex: 1 }}
      paused={paused}
      volume={volume}
      selectedAudioTrack={selectedAudioTrack}
      selectedTextTrack={selectedTextTrack}
      onLoad={handleLoad}
      onProgress={handleProgress}
      onSeek={handleSeek}
      onBuffer={handleBuffer}
      onError={handleError}
      onEnd={handleEnd}
      resizeMode={resizeMode}
      controls={false}
      playInBackground={false}
      playWhenInactive={false}
      progressUpdateInterval={250}
      allowsExternalPlayback={false}
      bufferingStrategy={BufferingStrategyType.DEFAULT}
      ignoreSilentSwitch="ignore"
      mixWithOthers="inherit"
      rate={1.0}
      repeat={false}
      reportBandwidth={true}
      useTextureView={true}
      disableFocus={false}
      minLoadRetryCount={3}
      automaticallyWaitsToMinimizeStalling={true}
      hideShutterView={false}
      shutterColor="#000000"
      subtitleStyle={{
        fontSize: subtitleStyle.fontSize,
        paddingTop: subtitleStyle.paddingTop,
        paddingBottom: subtitleStyle.paddingBottom,
        paddingLeft: subtitleStyle.paddingLeft,
        paddingRight: subtitleStyle.paddingRight,
        opacity: subtitleStyle.opacity,
        subtitlesFollowVideo: subtitleStyle.subtitlesFollowVideo,
      }}
    />
  );
};

export default AndroidVideoPlayer;