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

class ImageCanvas extends StatefulWidget {
  final String filePath;

  const ImageCanvas({super.key, required this.filePath});

  @override
  State<ImageCanvas> createState() => _ImageCanvasState();
}

class _ImageCanvasState extends State<ImageCanvas> {
  late TransformationController _controller;
  double _currentScale = 1.0;

  @override
  void initState() {
    super.initState();
    _controller = TransformationController();
    _controller.addListener(_onTransformChanged);
  }

  @override
  void didUpdateWidget(ImageCanvas oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.filePath != widget.filePath) {
      _resetView();
    }
  }

  void _resetView() {
    _controller.value = Matrix4.identity();
    _currentScale = 1.0;
  }

  void _onTransformChanged() {
    _currentScale = _controller.value.getMaxScaleOnAxis();
  }

  void _handleScroll(PointerScrollEvent event) {
    final renderBox = context.findRenderObject() as RenderBox?;
    if (renderBox == null) return;

    final localPosition = renderBox.globalToLocal(event.position);

    final delta = event.scrollDelta.dy;
    final scaleFactor = delta < 0 ? 1.1 : 1 / 1.1;

    final newScale = (_currentScale * scaleFactor).clamp(0.1, 10.0);
    if (newScale <= 0.1 || newScale >= 10.0) return;

    final actualScale = newScale / _currentScale;

    // Decompose current matrix: widget_point = scale * child_point + translation
    // So: child_point = (widget_point - translation) / scale
    final matrix = _controller.value;
    final tx = matrix.getTranslation().x;
    final ty = matrix.getTranslation().y;

    final childX = (localPosition.dx - tx) / _currentScale;
    final childY = (localPosition.dy - ty) / _currentScale;

    // Build new matrix: zoom around child_point, then re-apply
    final newMatrix = Matrix4.identity()
      // ignore: deprecated_member_use
      ..translate(childX, childY)
      // ignore: deprecated_member_use
      ..scale(actualScale)
      // ignore: deprecated_member_use
      ..translate(-childX, -childY)
      ..multiply(_controller.value);

    _controller.value = newMatrix;
  }

  @override
  void dispose() {
    _controller.removeListener(_onTransformChanged);
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Listener(
      onPointerSignal: (event) {
        if (event is PointerScrollEvent) {
          _handleScroll(event);
        }
      },
      child: InteractiveViewer(
        transformationController: _controller,
        boundaryMargin: const EdgeInsets.all(double.infinity),
        minScale: 0.1,
        maxScale: 10.0,
        panEnabled: true,
        scaleEnabled: false,
        child: Center(
          child: Image.file(
            File(widget.filePath),
            fit: BoxFit.contain,
            filterQuality: FilterQuality.high,
            errorBuilder: (context, error, stackTrace) {
              return const Center(
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Icon(Icons.broken_image, size: 48, color: Colors.white38),
                    SizedBox(height: 8),
                    Text(
                      'Resim yüklenemedi',
                      style: TextStyle(color: Colors.white38),
                    ),
                  ],
                ),
              );
            },
          ),
        ),
      ),
    );
  }
}