import 'dart:async';
import 'dart:convert';
import 'dart:typed_data';

import 'package:patbond_flutter/features/community/community_models.dart';
import 'package:patbond_flutter/features/community/media_compression.dart';
import 'package:patbond_flutter/features/community/media_direct_upload.dart';
import 'package:patbond_flutter/features/community/media_picking.dart';

/// media 上传链路测试件（T3-13）：假选择器/压缩器/直传客户端,
/// 全部支持 Completer 控时序（helpers 既有先例）。

PickedMediaImage pickedImage({int seed = 1, int size = 64}) => PickedMediaImage(
  bytes: Uint8List.fromList(List.filled(size, seed)),
  name: 'img-$seed.jpg',
);

/// 1x1 真 PNG 字节（70B）：widget 测试里九宫格格子要真解码出图,
/// 用可解码的最小合法图片避免 Image.memory 走 errorBuilder 兜底。
final Uint8List tinyPngBytes = base64Decode(
  'iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAADUlEQVR42mP8z8DwHwAF'
  'AAH/q842iQAAAABJRU5ErkJggg==',
);

/// 可解码预览的选图（发布页 widget 测试用）。
PickedMediaImage decodablePickedImage({int seed = 1}) =>
    PickedMediaImage(bytes: tinyPngBytes, name: 'img-$seed.png');

MediaUploadCredentials credentials({
  String assetId = 'a-1',
  DateTime? expiresAt,
}) => MediaUploadCredentials(
  assetId: assetId,
  uploadUrl:
      'http://minio.local/patbond-media/post_image/$assetId?X-Amz-Signature=sig',
  method: 'PUT',
  requiredHeaders: const {'Content-Type': 'image/jpeg'},
  expiresAt: expiresAt ?? DateTime.now().add(const Duration(minutes: 10)),
);

MediaAsset readyAsset({String assetId = 'a-1'}) => MediaAsset(
  id: assetId,
  kind: MediaKind.image,
  purpose: 'post_image',
  mimeType: 'image/jpeg',
  byteSize: 1024,
  widthPx: 1080,
  heightPx: 810,
  status: MediaAssetStatus.ready,
  url: 'http://minio.local/p.jpg?X-Amz-Signature=sig',
  readyAt: DateTime.utc(2026, 9, 9),
  createdAt: DateTime.utc(2026, 9, 9),
);

class FakeMediaImagePicker implements MediaImagePicker {
  FakeMediaImagePicker(this.results);

  final List<PickedMediaImage> results;
  final List<int> limits = [];

  /// 非 null 时 pickImages 挂起等待（picking 态观测用）。
  Completer<void>? gate;

  @override
  Future<List<PickedMediaImage>> pickImages({required int limit}) async {
    limits.add(limit);
    await gate?.future;
    return results.take(limit).toList();
  }
}

/// 假压缩器：默认原样透传出 image/jpeg；[sizePerQuality] 指定各降质档
/// 的产物大小（超限阶梯测试用）。
class FakeMediaCompressor implements MediaImageCompressor {
  final List<int> qualities = [];
  Map<int, int>? sizePerQuality;
  Exception? error;

  @override
  Future<CompressedMediaImage> compress(
    PickedMediaImage source, {
    required int quality,
  }) async {
    qualities.add(quality);
    if (error != null) throw error!;
    final size = sizePerQuality?[quality];
    return CompressedMediaImage(
      bytes: size == null
          ? source.bytes
          : Uint8List.fromList(List.filled(size, 0)),
      mimeType: 'image/jpeg',
    );
  }
}

/// 一次直传调用的观测句柄（进度回调驱动 + 结局手动控制）。
class DirectUploadCall {
  DirectUploadCall({
    required this.url,
    required this.headers,
    required this.bytes,
    required this.onProgress,
  });

  final String url;
  final Map<String, String> headers;
  final Uint8List bytes;
  final void Function(int sent, int total)? onProgress;
  final Completer<void> completer = Completer<void>();

  void emitProgress(int sent, int total) => onProgress?.call(sent, total);
  void succeed() => completer.complete();
  void fail(MediaDirectUploadException error) => completer.completeError(error);
}

class FakeDirectUploadClient implements MediaDirectUploadClient {
  final List<DirectUploadCall> calls = [];

  /// 非 null 时每次 put 自动以该结果收尾（null = 自动成功）；
  /// 设为 manual 后由测试经 [calls] 手动驱动。
  bool manual = false;
  final List<MediaDirectUploadException?> scriptedOutcomes = [];

  @override
  Future<void> put({
    required String url,
    required Map<String, String> headers,
    required Uint8List bytes,
    void Function(int sent, int total)? onProgress,
  }) {
    final call = DirectUploadCall(
      url: url,
      headers: headers,
      bytes: bytes,
      onProgress: onProgress,
    );
    calls.add(call);
    if (!manual) {
      final outcome = scriptedOutcomes.isEmpty
          ? null
          : scriptedOutcomes.removeAt(0);
      if (outcome == null) {
        call.succeed();
      } else {
        call.fail(outcome);
      }
    }
    return call.completer.future;
  }
}