import 'package:dio/dio.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:path_provider/path_provider.dart';

import '../core/network/api_env.dart';
import '../core/network/api_exception.dart';
import '../core/network/dio_client.dart';
import '../models/photo.dart';

final photoApiProvider = Provider<PhotoApi>((ref) => PhotoApi(ref.watch(dioProvider)));

/// 照片存档接口。
///
/// App 拍完照把**原图**传上来；水印是本地合成的，和这里无关。
/// 上传是「锦上添花」—— 失败了不该影响用户继续编辑和保存照片，
/// 所以调用方要自己吞掉异常并给个「重试」入口。
class PhotoApi {
  PhotoApi(this._dio);

  final Dio _dio;

  /// 上传一张照片，返回后端记录 id
  Future<int?> upload({
    required String filePath,
    double? latitude,
    double? longitude,
    String? address,
    String? weather,
    String? remark,
    DateTime? takenTime,
  }) async {
    try {
      final form = FormData.fromMap({
        'file': await MultipartFile.fromFile(
          filePath,
          filename: _fileName(filePath),
        ),
        'latitude': ?latitude,
        'longitude': ?longitude,
        if (address != null && address.isNotEmpty) 'address': address,
        if (weather != null && weather.isNotEmpty) 'weather': weather,
        if (remark != null && remark.isNotEmpty) 'remark': remark,
        if (takenTime != null) 'takenTime': _formatTime(takenTime),
      });

      final res = await _dio.post<dynamic>(
        '/photos',
        data: form,
        // 原图可能有好几 MB，移动网络下给宽一点
        options: Options(receiveTimeout: const Duration(seconds: 60)),
      );

      final data = res.data;
      if (data is Map) {
        final id = data['id'];
        if (id is int) return id;
      }
      return null;
    } on DioException catch (e) {
      final err = e.error;
      throw err is ApiException ? err : ApiException(-1, '照片上传失败');
    }
  }

  /// 分页列表，最新的在前
  Future<PhotoPage> list({int page = 1, int size = 30}) async {
    try {
      final res = await _dio.get<dynamic>(
        '/photos',
        queryParameters: {'page': page, 'size': size},
      );
      final data = res.data;
      if (data is Map<String, dynamic>) return PhotoPage.fromJson(data);
      if (data is Map) return PhotoPage.fromJson(Map<String, dynamic>.from(data));
      return PhotoPage.empty;
    } on DioException catch (e) {
      final err = e.error;
      throw err is ApiException ? err : ApiException(-1, '照片列表加载失败');
    }
  }

  /// 把原图下载到临时文件，返回本地路径。
  ///
  /// 「重新打水印」必须先有本地文件：编辑页要读它拿尺寸、显示预览、合成成品。
  /// 原图可能好几 MB，所以留了进度回调让界面能显示进度。
  ///
  /// [url] 是后端给的相对地址（`/uploads/...`），这里用 [resolveAssetUrl]
  /// 补成绝对地址 —— `/uploads` 不在 `/api` 前缀下，不能直接丢给 dio。
  Future<String> downloadOriginal(
    String url, {
    void Function(int received, int total)? onProgress,
  }) async {
    try {
      final dir = await getTemporaryDirectory();
      final path = '${dir.path}/photo_${DateTime.now().millisecondsSinceEpoch}.jpg';
      await _dio.download(
        resolveAssetUrl(url),
        path,
        onReceiveProgress: onProgress,
        // 原图几 MB，移动网络下给宽一点
        options: Options(receiveTimeout: const Duration(seconds: 120)),
      );
      return path;
    } on DioException catch (e) {
      final err = e.error;
      throw err is ApiException ? err : ApiException(-1, '原图下载失败');
    }
  }

  /// 从路径里取个带扩展名的文件名，后端靠它判断文件类型
  static String _fileName(String path) {
    final normalized = path.replaceAll('\\', '/');
    final name = normalized.substring(normalized.lastIndexOf('/') + 1);
    return name.isEmpty ? 'photo.jpg' : name;
  }

  static String _formatTime(DateTime time) {
    String two(int n) => n.toString().padLeft(2, '0');
    return '${time.year}-${two(time.month)}-${two(time.day)} '
        '${two(time.hour)}:${two(time.minute)}:${two(time.second)}';
  }
}