import 'dart:async';
import 'dart:io' show File;

import 'package:flutter/foundation.dart' show kIsWeb;
import 'package:flutter/material.dart';
import 'package:video_player/video_player.dart';

import '../data/ads_api_client.dart';

/// 统一渲染广告图片/GIF/视频；开屏可优先使用已缓存的本地素材。
class AdMedia extends StatefulWidget {
  const AdMedia({
    super.key,
    required this.ad,
    this.assetPath,
    this.fit = BoxFit.cover,
  });
  final AdCreative ad;
  final String? assetPath;
  final BoxFit fit;
  @override
  State<AdMedia> createState() => _AdMediaState();
}

class _AdMediaState extends State<AdMedia> {
  VideoPlayerController? player;
  bool ready = false, failed = false;
  @override
  void initState() {
    super.initState();
    _load();
  }

  @override
  void didUpdateWidget(covariant AdMedia old) {
    super.didUpdateWidget(old);
    if (old.ad.adId != widget.ad.adId || old.assetPath != widget.assetPath) {
      unawaited(player?.dispose() ?? Future.value());
      player = null;
      ready = false;
      failed = false;
      _load();
    }
  }

  void _load() {
    if (widget.ad.mediaType != AdMediaType.video) return;
    final uri = widget.ad.mediaUri;
    if (uri == null) return;
    final path = widget.assetPath;
    final controller = !kIsWeb && path != null && path.isNotEmpty
        ? VideoPlayerController.file(File(path))
        : VideoPlayerController.networkUrl(uri);
    player = controller;
    unawaited(
      controller
          .initialize()
          .then((_) async {
            await controller.setLooping(true);
            await controller.setVolume(0);
            await controller.play();
            if (mounted) setState(() => ready = true);
          })
          .catchError((_) {
            if (mounted) setState(() => failed = true);
          }),
    );
  }

  @override
  void dispose() {
    player?.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (widget.ad.mediaType != AdMediaType.video) {
      final path = widget.assetPath;
      if (!kIsWeb && path != null && path.isNotEmpty) {
        return Image.file(
          File(path),
          fit: widget.fit,
          width: double.infinity,
          height: double.infinity,
          errorBuilder: (_, _, _) => _error(),
        );
      }
      return Image.network(
        widget.ad.imageUrl,
        fit: widget.fit,
        width: double.infinity,
        height: double.infinity,
        errorBuilder: (_, _, _) => _error(),
      );
    }
    final c = player;
    if (failed) return _error();
    if (c == null || !ready) {
      return const ColoredBox(
        color: Color(0xFF161616),
        child: Center(child: CircularProgressIndicator()),
      );
    }
    return FittedBox(
      fit: widget.fit,
      clipBehavior: Clip.hardEdge,
      child: SizedBox(
        width: c.value.size.width,
        height: c.value.size.height,
        child: VideoPlayer(c),
      ),
    );
  }

  Widget _error() => const ColoredBox(
    color: Color(0xFF161616),
    child: Center(
      child: Icon(Icons.broken_image_outlined, color: Colors.white54),
    ),
  );
}