import 'package:flutter/material.dart';

class AttachmentGalleryScreen extends StatefulWidget {
  final List<ImageProvider> images;
  final int initialIndex;

  const AttachmentGalleryScreen({
    super.key,
    required this.images,
    required this.initialIndex,
  });

  @override
  State<AttachmentGalleryScreen> createState() => _AttachmentGalleryScreenState();
}

class _AttachmentGalleryScreenState extends State<AttachmentGalleryScreen> {
  late PageController _pageController;
  int _currentIndex = 0;

  @override
  void initState() {
    super.initState();
    _currentIndex = widget.initialIndex;
    _pageController = PageController(initialPage: widget.initialIndex);
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.black,
      appBar: AppBar(
        backgroundColor: Colors.black,
        iconTheme: const IconThemeData(color: Colors.white),
        title: Text(
          '${_currentIndex + 1} / ${widget.images.length}',
          style: const TextStyle(color: Colors.white),
        ),
      ),
      body: PageView.builder(
        controller: _pageController,
        onPageChanged: (index) {
          setState(() {
            _currentIndex = index;
          });
        },
        itemCount: widget.images.length,
        itemBuilder: (context, index) {
          return _ZoomableImage(image: widget.images[index]);
        },
      ),
    );
  }
}

class _ZoomableImage extends StatefulWidget {
  final ImageProvider image;
  const _ZoomableImage({required this.image});

  @override
  State<_ZoomableImage> createState() => _ZoomableImageState();
}

class _ZoomableImageState extends State<_ZoomableImage> with SingleTickerProviderStateMixin {
  final TransformationController _transformationController = TransformationController();
  late AnimationController _animationController;
  Animation<Matrix4>? _animation;
  TapDownDetails? _doubleTapDetails;

  @override
  void initState() {
    super.initState();
    _animationController = AnimationController(
      vsync: this,
      duration: const Duration(milliseconds: 200),
    )..addListener(() {
        if (_animation != null) {
          _transformationController.value = _animation!.value;
        }
      });
  }

  @override
  void dispose() {
    _animationController.dispose();
    _transformationController.dispose();
    super.dispose();
  }

  void _handleDoubleTap() {
    if (_doubleTapDetails == null) return;
    final position = _doubleTapDetails!.localPosition;

    final matrix = _transformationController.value;
    final scale = matrix.getMaxScaleOnAxis();

    Matrix4 endMatrix;
    if (scale > 1.0) {
      // Zoom out
      endMatrix = Matrix4.identity();
    } else {
      // Zoom in
      endMatrix = Matrix4.identity()
        ..translate(-position.dx * 1.5, -position.dy * 1.5)
        ..scale(2.5);
    }

    _animation = Matrix4Tween(
      begin: _transformationController.value,
      end: endMatrix,
    ).animate(CurveTween(curve: Curves.easeInOut).animate(_animationController));

    _animationController.forward(from: 0);
  }

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onDoubleTapDown: (d) => _doubleTapDetails = d,
      onDoubleTap: _handleDoubleTap,
      child: InteractiveViewer(
        transformationController: _transformationController,
        minScale: 1.0,
        maxScale: 4.0,
        child: Image(
          image: widget.image,
          fit: BoxFit.contain,
        ),
      ),
    );
  }
}