import 'package:cached_network_image/cached_network_image.dart';
import 'package:flutter/material.dart';
import 'package:shimmer/shimmer.dart';
import 'package:real_estate_mobile/core/utils/image_url_resolver.dart';

/// Displays an image from an S3 key or full URL.
/// Resolves S3 keys to presigned download URLs via the backend API.
class S3Image extends StatefulWidget {
  final String? imageUrl;
  final double? width;
  final double? height;
  final BoxFit fit;
  final Alignment alignment;
  final Widget Function(BuildContext context)? placeholder;
  final Widget Function(BuildContext context)? errorWidget;

  const S3Image({
    super.key,
    required this.imageUrl,
    this.width,
    this.height,
    this.fit = BoxFit.cover,
    this.alignment = Alignment.center,
    this.placeholder,
    this.errorWidget,
  });

  @override
  State<S3Image> createState() => _S3ImageState();
}

class _S3ImageState extends State<S3Image> {
  String? _resolvedUrl;
  bool _loading = true;
  bool _failed = false;
  bool _retried = false;

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

  @override
  void didUpdateWidget(S3Image oldWidget) {
    super.didUpdateWidget(oldWidget);
    if (oldWidget.imageUrl != widget.imageUrl) {
      _resolve();
    }
  }

  Future<void> _resolve() async {
    if (widget.imageUrl == null || widget.imageUrl!.isEmpty) {
      if (mounted) setState(() { _loading = false; _failed = true; });
      return;
    }

    // If already a full URL, skip resolution
    if (widget.imageUrl!.startsWith('http://') || widget.imageUrl!.startsWith('https://')) {
      if (mounted) setState(() { _resolvedUrl = widget.imageUrl; _loading = false; });
      return;
    }

    try {
      final url = await ImageUrlResolver.instance.resolve(widget.imageUrl);
      if (mounted) {
        setState(() {
          _resolvedUrl = url;
          _loading = false;
          _failed = url == null;
        });
      }
    } catch (_) {
      if (mounted) setState(() { _loading = false; _failed = true; });
    }
  }

  Widget _buildShimmerPlaceholder() {
    return Shimmer.fromColors(
      baseColor: const Color(0xFFE0E0E0),
      highlightColor: const Color(0xFFF5F5F5),
      child: Container(
        width: widget.width,
        height: widget.height,
        color: Colors.white,
      ),
    );
  }

  Widget _buildPlaceholder(BuildContext context) {
    return widget.placeholder?.call(context) ?? _buildShimmerPlaceholder();
  }

  Widget _buildError(BuildContext context) {
    return widget.errorWidget?.call(context) ?? Container(
      width: widget.width,
      height: widget.height,
      color: const Color(0xFFC4D9D4),
      child: const Icon(Icons.person, size: 60, color: Color(0xFF00293D)),
    );
  }

  @override
  Widget build(BuildContext context) {
    if (_loading) return _buildPlaceholder(context);
    if (_failed || _resolvedUrl == null) return _buildError(context);

    return CachedNetworkImage(
      imageUrl: _resolvedUrl!,
      cacheKey: widget.imageUrl ?? _resolvedUrl!,
      width: widget.width,
      height: widget.height,
      fit: widget.fit,
      alignment: widget.alignment,
      placeholder: (ctx, _) => _buildPlaceholder(ctx),
      errorWidget: (ctx, _, err) {
        // On error (expired URL), evict and retry once
        if (!_retried) {
          _retried = true;
          ImageUrlResolver.instance.evict(widget.imageUrl);
          _resolve();
          return _buildPlaceholder(ctx);
        }
        return _buildError(ctx);
      },
    );
  }
}