import 'dart:io';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:video_player/video_player.dart';
import 'package:open_filex/open_filex.dart';
import 'package:flutter/gestures.dart';

class MediaItem {
  final String path;
  final bool isVideo;

  MediaItem({required this.path, required this.isVideo});
}

class MediaViewer extends StatefulWidget {
  final List<MediaItem> items;
  final int initialIndex;

  const MediaViewer({super.key, required this.items, this.initialIndex = 0});

  @override
  State<MediaViewer> createState() => _MediaViewerState();
}

class _MediaViewerState extends State<MediaViewer> {
  late PageController _pageController;
  VideoPlayerController? _videoController;
  String? _videoInitError;

  final FocusNode _focusNode = FocusNode();

  int _index = 0;
  bool _uiVisible = true;
  bool _isLandscape = false;

  @override
  void initState() {
    super.initState();

    _index = widget.initialIndex;
    _pageController = PageController(initialPage: _index);

    print("MediaViewer: Initial index set to $_index");
    print("MediaViewer: Total items = ${widget.items.length}");
    print(
      "MediaViewer: Initial media item = ${widget.items[_index].path}, isVideo = ${widget.items[_index].isVideo}",
    );

    _hideSystemUI();
    _initVideoIfNeeded(_index);
    _focusNode.requestFocus();
  }

  void _handleKeyEvent(KeyEvent event) {
    if (event is! KeyDownEvent) return;

    final item = widget.items[_index];
    if (!item.isVideo ||
        _videoController == null ||
        !_videoController!.value.isInitialized)
      return;

    final c = _videoController!;

    if (event.logicalKey == LogicalKeyboardKey.space) {
      setState(() {
        c.value.isPlaying ? c.pause() : c.play();
      });
    } else if (event.logicalKey == LogicalKeyboardKey.arrowLeft) {
      final currentPos = c.value.position;
      final newPos = currentPos - const Duration(seconds: 5);
      c.seekTo(newPos < Duration.zero ? Duration.zero : newPos);
    } else if (event.logicalKey == LogicalKeyboardKey.arrowRight) {
      final currentPos = c.value.position;
      final maxDur = c.value.duration;
      final newPos = currentPos + const Duration(seconds: 5);
      c.seekTo(newPos > maxDur ? maxDur : newPos);
    }
  }

  Future<void> _initVideoIfNeeded(int index) async {
    _videoController?.removeListener(_videoListener);
    _videoController?.dispose();
    _videoController = null;
    _videoInitError = null;

    final item = widget.items[index];

    if (!item.isVideo) return;

    final controller = VideoPlayerController.file(File(item.path));
    _videoController = controller;

    try {
      await controller.initialize();
      _videoController!.addListener(_videoListener);
      controller.setLooping(false);
      controller.play();
      _videoInitError = null;
    } catch (e) {
      _videoInitError = e.toString();
      _videoController?.removeListener(_videoListener);
      await _videoController?.dispose().catchError((_) {});
      _videoController = null;
    } finally {
      if (mounted) setState(() {});
    }
  }

  void _videoListener() {
    if (mounted) {
      setState(() {});
    }
  }

  void _hideSystemUI() {
    if (Platform.isAndroid || Platform.isIOS) {
      SystemChrome.setEnabledSystemUIMode(SystemUiMode.immersiveSticky);
    }
  }

  void _showSystemUI() {
    if (Platform.isAndroid || Platform.isIOS) {
      SystemChrome.setEnabledSystemUIMode(
        SystemUiMode.manual,
        overlays: SystemUiOverlay.values,
      );
    }
  }

  void _toggleOrientation() {
    setState(() {
      _isLandscape = !_isLandscape;
    });

    if (_isLandscape) {
      SystemChrome.setPreferredOrientations([
        DeviceOrientation.landscapeLeft,
        DeviceOrientation.landscapeRight,
      ]);
    } else {
      SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
    }
  }

  @override
  void dispose() {
    _videoController?.removeListener(_videoListener);
    _videoController?.dispose();
    _pageController.dispose();

    _showSystemUI();
    SystemChrome.setPreferredOrientations([DeviceOrientation.portraitUp]);
    super.dispose();
  }

  void _toggleUI() {
    setState(() => _uiVisible = !_uiVisible);
  }

  String _format(Duration d) {
    String two(int n) => n.toString().padLeft(2, '0');
    return "${two(d.inMinutes.remainder(60))}:${two(d.inSeconds.remainder(60))}";
  }

  @override
  Widget build(BuildContext context) {
    final isVideoReady = widget.items[_index].isVideo &&
        _videoController != null &&
        _videoController!.value.isInitialized;

    return Scaffold(
      backgroundColor: Colors.black,
      body: KeyboardListener(
        focusNode: _focusNode,
        autofocus: true,
        onKeyEvent: _handleKeyEvent,
        child: SafeArea(
          child: GestureDetector(
            onTap: _toggleUI,
            onLongPress: () {
              if (isVideoReady) {
                final currentSpeed = _videoController!.value.playbackSpeed;
                _videoController!.setPlaybackSpeed(
                  currentSpeed == 1.0 ? 2.0 : 1.0,
                );
              }
            },
            behavior: HitTestBehavior.opaque,
            child: Stack(
              children: [
                // MEDIA PAGES
                Positioned.fill(
                  child: ScrollConfiguration(
                    behavior: ScrollConfiguration.of(context).copyWith(
                      dragDevices: {
                        PointerDeviceKind.touch,
                        PointerDeviceKind.mouse,
                        PointerDeviceKind.trackpad,
                      },
                    ),
                    child: PageView.builder(
                      controller: _pageController,
                      onPageChanged: (i) async {
                        setState(() => _index = i);
                        await _initVideoIfNeeded(i);
                      },
                      itemCount: widget.items.length,
                      itemBuilder: (context, i) {
                        final item = widget.items[i];

                        if (item.isVideo) {
                          if (_videoInitError != null) {
                            return _buildVideoInitErrorFallback(item.path);
                          }

                          if (_videoController == null ||
                              !_videoController!.value.isInitialized) {
                            return const Center(
                              child: CircularProgressIndicator(
                                color: Colors.white,
                              ),
                            );
                          }

                          return Center(
                            child: AspectRatio(
                              aspectRatio: _videoController!.value.aspectRatio,
                              child: VideoPlayer(_videoController!),
                            ),
                          );
                        }

                        return Center(
                          child: InteractiveViewer(
                            maxScale: 4.0,
                            child: Image.file(
                              File(item.path),
                              fit: BoxFit.contain,
                            ),
                          ),
                        );
                      },
                    ),
                  ),
                ),

                // ЦЕНТРАЛЬНАЯ КНОПКА ПЛЕЙ/ПАУЗА
                if (_uiVisible && isVideoReady)
                  Center(
                    child: Container(
                      decoration: const BoxDecoration(
                        color: Colors.black38,
                        shape: BoxShape.circle,
                      ),
                      child: IconButton(
                        iconSize: 64,
                        icon: Icon(
                          _videoController!.value.isPlaying
                              ? Icons.pause
                              : Icons.play_arrow,
                          color: Colors.white,
                        ),
                        onPressed: () {
                          setState(() {
                            _videoController!.value.isPlaying
                                ? _videoController!.pause()
                                : _videoController!.play();
                          });
                        },
                      ),
                    ),
                  ),

                // TOP BAR
                if (_uiVisible)
                  Positioned(
                    top: 10,
                    left: 16,
                    right: 16,
                    child: Row(
                      mainAxisAlignment: MainAxisAlignment.spaceBetween,
                      children: [
                        IconButton(
                          icon: const Icon(
                            Icons.close,
                            color: Colors.white,
                            size: 28,
                          ),
                          onPressed: () => Navigator.pop(context),
                        ),
                        IconButton(
                          icon: const Icon(
                            Icons.screen_rotation,
                            color: Colors.white,
                            size: 26,
                          ),
                          onPressed: _toggleOrientation,
                        ),
                      ],
                    ),
                  ),

                // VIDEO CONTROLS
                if (_uiVisible && isVideoReady)
                  Positioned(
                    bottom: 10,
                    left: 16,
                    right: 16,
                    child: _buildVideoControls(),
                  ),
              ],
            ),
          ),
        ),
      ),
    );
  }

  Widget _buildVideoControls() {
    final c = _videoController!;
    final pos = c.value.position;
    final dur = c.value.duration;

    final posMs = pos.inMilliseconds.toDouble();
    final maxMs = dur.inMilliseconds
        .toDouble()
        .clamp(1, double.infinity)
        .toDouble();

    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
      decoration: BoxDecoration(
        color: Colors.black54,
        borderRadius: BorderRadius.circular(30),
      ),
      child: Row(
        children: [
          IconButton(
            icon: Icon(
              c.value.isPlaying ? Icons.pause : Icons.play_arrow,
              color: Colors.white,
              size: 28,
            ),
            onPressed: () {
              setState(() {
                c.value.isPlaying ? c.pause() : c.play();
              });
            },
          ),
          Expanded(
            child: SliderTheme(
              data: SliderTheme.of(context).copyWith(
                trackHeight: 4,
                activeTrackColor: Colors.white60,
                inactiveTrackColor: Colors.white30,
                thumbColor: Colors.white,
                thumbShape: const RoundSliderThumbShape(enabledThumbRadius: 6),
                overlayColor: Colors.transparent,
              ),
              child: Slider(
                value: posMs.clamp(0, maxMs),
                min: 0,
                max: maxMs,
                onChanged: (v) {
                  c.seekTo(Duration(milliseconds: v.toInt()));
                },
              ),
            ),
          ),
          const SizedBox(width: 8),
          Text(
            "${_format(pos)} / ${_format(dur)}",
            style: const TextStyle(
              color: Colors.white,
              fontSize: 12,
              fontWeight: FontWeight.bold,
            ),
          ),
          const SizedBox(width: 8),
        ],
      ),
    );
  }

  Widget _buildVideoInitErrorFallback(String path) {
    return Center(
      child: Column(
        mainAxisSize: MainAxisSize.min,
        children: [
          const Icon(Icons.play_disabled, color: Colors.white70, size: 56),
          const SizedBox(height: 10),
          const Text(
            'Видео не воспроизводится на этом устройстве',
            textAlign: TextAlign.center,
            style: TextStyle(color: Colors.white70),
          ),
          const SizedBox(height: 10),
          OutlinedButton.icon(
            onPressed: () async {
              try {
                await OpenFilex.open(path);
              } catch (_) {}
            },
            icon: const Icon(Icons.open_in_new, color: Colors.white70),
            label: const Text(
              'Открыть внешним плеером',
              style: TextStyle(color: Colors.white70),
            ),
          ),
        ],
      ),
    );
  }
}