import 'dart:io';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:matrix/matrix.dart';
import 'package:path_provider/path_provider.dart';
import 'package:pyramid/core/theme.dart';
import 'package:pyramid/features/chat/media_player.dart';
import 'package:pyramid/utils/gif_favorite_service.dart';

/// Overlay viewer for images, GIFs and videos.
/// Uses a semi-transparent backdrop; tapping outside the content closes it.
class MediaViewer extends StatefulWidget {
  final String senderName;
  final Uint8List? bytes;
  final String? networkUrl;
  final String filename;
  final bool isVideo;
  final Event? event;

  const MediaViewer({
    super.key,
    required this.senderName,
    required this.filename,
    this.bytes,
    this.networkUrl,
    this.isVideo = false,
    this.event,
  });

  static Future<void> show(
    BuildContext context, {
    required String senderName,
    required String filename,
    Uint8List? bytes,
    String? networkUrl,
    bool isVideo = false,
    Event? event,
  }) {
    return showGeneralDialog(
      context: context,
      barrierDismissible: true,
      barrierLabel: 'Schließen',
      barrierColor: Colors.black.withAlpha(178),
      transitionDuration: const Duration(milliseconds: 180),
      transitionBuilder: (context, animation, secondaryAnimation, child) =>
          FadeTransition(opacity: animation, child: child),
      pageBuilder: (context, animation, secondaryAnimation) => MediaViewer(
        senderName: senderName,
        filename: filename,
        bytes: bytes,
        networkUrl: networkUrl,
        isVideo: isVideo,
        event: event,
      ),
    );
  }

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

class _MediaViewerState extends State<MediaViewer> {
  final _tc = TransformationController();
  bool _controlsVisible = true;
  bool _saving = false;
  bool _savingSticker = false;

  @override
  void dispose() {
    _tc.dispose();
    super.dispose();
  }

  void _toggle() => setState(() => _controlsVisible = !_controlsVisible);

  void _resetZoom() => _tc.value = Matrix4.identity();

  Future<void> _saveAsSticker() async {
    final event = widget.event;
    if (event == null || _savingSticker) return;
    setState(() => _savingSticker = true);
    final messenger = ScaffoldMessenger.maybeOf(context);
    try {
      final ok = await GifFavoriteService.addImageAsStickerFavorite(event);
      messenger?.showSnackBar(SnackBar(
        content: Text(ok ? 'Als Sticker gespeichert' : 'Fehler beim Speichern'),
        duration: const Duration(seconds: 2),
      ));
    } finally {
      if (mounted) setState(() => _savingSticker = false);
    }
  }

  Future<void> _save() async {
    final b = widget.bytes;
    if (b == null || _saving) return;
    setState(() => _saving = true);
    try {
      Directory? dir;
      if (Platform.isWindows || Platform.isMacOS || Platform.isLinux) {
        dir = await getDownloadsDirectory();
      }
      dir ??= await getTemporaryDirectory();
      final ext = widget.filename.contains('.') ? widget.filename.split('.').last : 'jpg';
      final name = 'pyramid_${DateTime.now().millisecondsSinceEpoch}.$ext';
      final file = File('${dir.path}/$name');
      await file.writeAsBytes(b);
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(SnackBar(
          content: Text('Gespeichert: ${file.path}'),
          duration: const Duration(seconds: 4),
        ));
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(content: Text('Fehler: $e')),
        );
      }
    } finally {
      if (mounted) setState(() => _saving = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final pt = PyramidTheme.of(context);
    final isVideo = widget.isVideo && widget.bytes != null;
    final size = MediaQuery.sizeOf(context);

    final header = AnimatedOpacity(
      opacity: _controlsVisible ? 1 : 0,
      duration: const Duration(milliseconds: 180),
      child: IgnorePointer(
        ignoring: !_controlsVisible,
        child: Container(
          decoration: const BoxDecoration(
            gradient: LinearGradient(
              begin: Alignment.topCenter,
              end: Alignment.bottomCenter,
              colors: [Colors.black54, Colors.transparent],
            ),
          ),
          child: SafeArea(
            bottom: false,
            child: Row(
              children: [
                IconButton(
                  onPressed: () => Navigator.of(context).pop(),
                  icon: const Icon(Icons.close_rounded, color: Colors.white),
                  tooltip: 'Schließen',
                ),
                Expanded(
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    mainAxisSize: MainAxisSize.min,
                    children: [
                      Text(widget.senderName,
                          style: const TextStyle(color: Colors.white, fontSize: 15, fontWeight: FontWeight.w600)),
                      Text(widget.filename,
                          style: const TextStyle(color: Colors.white60, fontSize: 12),
                          overflow: TextOverflow.ellipsis),
                    ],
                  ),
                ),
                if (widget.event != null && !isVideo)
                  IconButton(
                    onPressed: _savingSticker ? null : _saveAsSticker,
                    tooltip: 'Als Sticker speichern',
                    icon: _savingSticker
                        ? const SizedBox(width: 20, height: 20,
                            child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white))
                        : const Icon(Icons.sticky_note_2_outlined, color: Colors.white),
                  ),
                if (widget.bytes != null)
                  IconButton(
                    onPressed: _saving ? null : _save,
                    tooltip: 'Speichern',
                    icon: _saving
                        ? const SizedBox(width: 20, height: 20,
                            child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white))
                        : const Icon(Icons.download_rounded, color: Colors.white),
                  ),
                if (!isVideo)
                  IconButton(
                    onPressed: _resetZoom,
                    tooltip: 'Zoom zurücksetzen',
                    icon: const Icon(Icons.zoom_out_map_rounded, color: Colors.white),
                  ),
              ],
            ),
          ),
        ),
      ),
    );

    // Content area — constrained so the transparent Material outside it lets
    // pointer events through to the barrier (which dismisses on tap).
    final contentMaxW = (size.width - 48).clamp(200.0, 1200.0);
    final contentMaxH = (size.height - 48).clamp(200.0, 900.0);

    if (isVideo) {
      return Material(
        type: MaterialType.transparency,
        child: Center(
          child: SizedBox(
            width: contentMaxW,
            height: contentMaxH,
            child: Stack(
              fit: StackFit.expand,
              children: [
                FullscreenVideoPlayer(bytes: widget.bytes!, filename: widget.filename),
                Positioned(top: 0, left: 0, right: 0, child: header),
              ],
            ),
          ),
        ),
      );
    }

    Widget img;
    if (widget.bytes != null) {
      img = Image.memory(widget.bytes!, fit: BoxFit.contain, gaplessPlayback: true);
    } else if (widget.networkUrl != null) {
      img = Image.network(widget.networkUrl!, fit: BoxFit.contain);
    } else {
      img = Icon(Icons.broken_image_outlined, size: 64, color: pt.fgDim);
    }

    return Material(
      type: MaterialType.transparency,
      child: Center(
        child: SizedBox(
          width: contentMaxW,
          height: contentMaxH,
          child: GestureDetector(
            onTap: _toggle,
            child: Stack(
              fit: StackFit.expand,
              children: [
                InteractiveViewer(
                  transformationController: _tc,
                  minScale: 0.5,
                  maxScale: 10.0,
                  child: Center(child: img),
                ),
                Positioned(top: 0, left: 0, right: 0, child: header),
              ],
            ),
          ),
        ),
      ),
    );
  }
}