import 'dart:convert';
import 'dart:io';

import 'package:crypto/crypto.dart';
import 'package:dio/dio.dart';
import 'package:file_picker/file_picker.dart';
import 'package:image_picker/image_picker.dart';

import 'api_client.dart';
import 'cos/cos_client.dart';

/// 公司介绍（小类/详情）图片与视频上传服务。
///
/// 对齐 Web 端 `company-intro-subcategory-form.vue` 使用的上传通道：
///   1. 计算文件 MD5；
///   2. `GET /theme/resource/check-md5` 判断是否已存在（秒传，跳过 COS）；
///   3. `GET /theme/upload/credential` 获取腾讯云 STS 临时凭证（含 bucket/region/key）；
///   4. 用 STS 临时密钥直传 COS（putObject，原生签名 q-sign-algorithm=sha1）；
///   5. `POST /theme/resource/register` 注册 tv_resource；
///   6. 解析访问 URL（`theme/` 走 ipscdn CDN）返回。
///
/// 复用 [ApiClient.instance.dio]，自动携带 Bearer 令牌、解包 `{code,msg,data}` 信封。
class UploadService {
  UploadService({Dio? dio}) : _dio = dio ?? ApiClient.instance.dio;

  final Dio _dio;

  /// 主题上传资源 CDN 根地址（与 Web 端 themeCdnBase 一致）。
  static const String _themeCdnBase = 'https://ipscdn.ainetv.cn';

  /// 上传单张图片/视频，返回可访问的 CDN URL。
  ///
  /// [mediaType] 资源类型：image | video | file，用于后端凭证与落库。
  ///
  /// 失败统一抛出 [ApiException]，message 为可展示的中文错误。
  Future<String> uploadImage(XFile file, {String mediaType = 'image'}) async {
    final ext = _suffixOf(file.path);
    final bytes = await file.readAsBytes();
    final fileMd5 = md5.convert(bytes).toString(); // 32 位小写十六进制

    // 1. 秒传判断：已存在则直接返回 URL，跳过 COS 直传。
    final instant = await _tryInstantUpload(fileMd5);
    if (instant != null) return instant;

    // 2. 获取 STS 临时凭证（含 bucket / region / key）。
    final cred = await _fetchStsCredential(fileMd5, ext, mediaType);
    if (cred.key.isEmpty || cred.bucket.isEmpty || cred.region.isEmpty) {
      throw const ApiException(500, '上传凭证数据不完整（缺少 key/bucket/region）');
    }

    // 3. 用 STS 临时密钥直传 COS。
    final provider = TemporaryCredentialProvider(
      fetchCredentials: () async => CosCredentialData(
        startTime: cred.startTime,
        expiredTime: cred.expiredTime,
        credentials: CosCredential(
          tmpSecretId: cred.tmpSecretId,
          tmpSecretKey: cred.tmpSecretKey,
          sessionToken: cred.securityToken,
        ),
        requestId: '',
      ),
    );
    final cos = CosClient.withTemporaryCredential(
      temporaryCredentialProvider: provider,
      region: cred.region,
      bucket: cred.bucket,
    );
    final result = await cos.putObjectFromFile(
      objectKey: cred.key,
      file: File(file.path),
    );
    if (!result.success) {
      throw ApiException(500, '云存储上传失败：${result.message ?? "未知错误"}');
    }

    // 4. 解析可访问 URL（theme/ 走 ipscdn CDN）。
    final url = _resolveUrl(cred.key, cred.url);

    // 5. 注册 tv_resource（落库，供后续秒传与关联）。
    await _registerResource(
      fileName: file.name,
      fileKey: cred.key,
      fileUrl: url,
      fileType: mediaType,
      fileSize: bytes.length,
      suffix: ext,
      fileMd5: fileMd5,
    );

    return url;
  }

  /// 按原文件名上传 APK 文件（对齐 Web 端 `uploadThemeFileByOriginalName`）。
  ///
  /// 流程：
  ///   1. `GET /theme/upload/credential?fileName=<原始文件名>&suffix=apk&type=file` 获取 STS 凭证；
  ///   2. 用 STS 临时密钥直传 COS（putObject）；
  ///   3. 返回可访问 URL（不注册 tv_resource，APK 不走 MD5 秒传）。
  ///
  /// [onProgress] 上传进度回调（0~100）。
  ///
  /// 失败抛出 [ApiException]。
  Future<String> uploadApkByOriginalName(
    PlatformFile file, {
    void Function(int percent)? onProgress,
  }) async {
    final fileName = file.name.trim();
    if (fileName.isEmpty) {
      throw const ApiException(400, '文件名不能为空');
    }
    final ext = _suffixOf(fileName);
    final safeExt = (ext == 'apk') ? 'apk' : (ext.isNotEmpty ? ext : 'apk');

    // 1. 获取 STS 凭证（fileName = 原始文件名，非 MD5）。
    final cred = await _fetchStsCredentialByName(
      fileName: fileName,
      suffix: safeExt,
      type: 'file',
    );
    if (cred.key.isEmpty || cred.bucket.isEmpty || cred.region.isEmpty) {
      throw const ApiException(500, '上传凭证数据不完整（缺少 key/bucket/region）');
    }

    // 2. 直传 COS。
    final provider = TemporaryCredentialProvider(
      fetchCredentials: () async => CosCredentialData(
        startTime: cred.startTime,
        expiredTime: cred.expiredTime,
        credentials: CosCredential(
          tmpSecretId: cred.tmpSecretId,
          tmpSecretKey: cred.tmpSecretKey,
          sessionToken: cred.securityToken,
        ),
        requestId: '',
      ),
    );
    final cos = CosClient.withTemporaryCredential(
      temporaryCredentialProvider: provider,
      region: cred.region,
      bucket: cred.bucket,
    );

    // file_picker 的 PlatformFile 可能有 path（Android 通常有）。
    final filePath = file.path;
    if (filePath == null || filePath.isEmpty) {
      throw const ApiException(400, '无法读取选中文件的路径');
    }
    final localFile = File(filePath);
    if (!localFile.existsSync()) {
      throw ApiException(400, '文件不存在：$filePath');
    }

    final result = await cos.putObjectFromFile(
      objectKey: cred.key,
      file: localFile,
      contentType: 'application/vnd.android.package-archive',
      onProgress: (count, total) {
        if (total > 0 && onProgress != null) {
          onProgress(((count / total) * 100).round());
        }
      },
    );
    if (!result.success) {
      throw ApiException(500, '云存储上传失败：${result.message ?? "未知错误"}');
    }

    // 3. 解析访问 URL。
    final url = _resolveUrl(cred.key, cred.url);
    if (url.isEmpty) {
      throw const ApiException(500, '未返回访问地址');
    }

    return url;
  }

  /// 打开系统文件选择器，仅允许 .apk 文件。
  ///
  /// 返回选中的 [PlatformFile]，用户取消返回 null。
  static Future<PlatformFile?> pickApkFile() async {
    final result = await FilePicker.platform.pickFiles(
      type: FileType.custom,
      allowedExtensions: ['apk'],
    );
    final files = result?.files;
    if (files == null || files.isEmpty) return null;
    return files.first;
  }

  /// 取文件扩展名（不含点，小写）。
  String _suffixOf(String path) {
    final name = path.split(Platform.pathSeparator).last;
    final idx = name.lastIndexOf('.');
    return idx > 0 ? name.substring(idx + 1).toLowerCase() : '';
  }

  /// 秒传判断：已存在同 MD5 资源则直接返回其访问 URL，否则返回 null。
  ///
  /// 任何异常都不阻塞主流程（当作未命中秒传）。
  Future<String?> _tryInstantUpload(String fileMd5) async {
    try {
      final resp = await _dio.get<Map<String, dynamic>>(
        '/theme/resource/check-md5',
        queryParameters: {'fileMd5': fileMd5},
      );
      final data = resp.data;
      if (data == null) return null;

      bool uploaded = data['uploaded'] == true;
      dynamic resourceRaw = data['resource'];
      if (data['data'] is Map) {
        final inner = data['data'] as Map;
        if (inner['uploaded'] == true) {
          uploaded = true;
          resourceRaw ??= inner['resource'] ?? inner;
        }
      }
      if (!uploaded) return null;

      final r = resourceRaw is Map
          ? Map<String, dynamic>.from(resourceRaw as Map)
          : null;
      if (r == null) return null;
      final id = r['id'] ?? r['resourceId'] ?? r['resource_id'];
      if (id == null || id == 0) return null;

      final key = (r['key'] ?? r['fileKey'] ?? '').toString();
      final rawUrl = (r['url'] ?? r['fileUrl'] ?? '').toString();
      final url = _resolveUrl(key, rawUrl);
      return url.isNotEmpty ? url : null;
    } catch (_) {
      return null;
    }
  }

  /// 获取 STS 临时凭证（以文件 MD5 作为 fileName，用于主题资源秒传）。
  Future<_StsCred> _fetchStsCredential(
    String fileMd5,
    String ext,
    String mediaType,
  ) async {
    final resp = await _dio.get<Map<String, dynamic>>(
      '/theme/upload/credential',
      queryParameters: <String, dynamic>{
        'fileName': fileMd5,
        if (ext.isNotEmpty) 'suffix': ext,
        'type': mediaType,
      },
    );
    final data = resp.data;
    if (data == null) {
      throw const ApiException(500, '获取上传凭证失败：响应为空');
    }
    return _StsCred.fromJson(Map<String, dynamic>.from(data as Map));
  }

  /// 获取 STS 临时凭证（以原始文件名作为 fileName，用于 APK 等需保留原名的场景）。
  ///
  /// 对齐 Web 端 `fetchThemeCredentialByOriginalName`：
  /// `GET /theme/upload/credential?fileName=<原始名>&suffix=<扩展名>&type=file`
  Future<_StsCred> _fetchStsCredentialByName({
    required String fileName,
    required String suffix,
    required String type,
  }) async {
    final resp = await _dio.get<Map<String, dynamic>>(
      '/theme/upload/credential',
      queryParameters: <String, dynamic>{
        'fileName': fileName,
        'suffix': suffix,
        'type': type,
      },
    );
    final data = resp.data;
    if (data == null) {
      throw const ApiException(500, '获取上传凭证失败：响应为空');
    }
    return _StsCred.fromJson(Map<String, dynamic>.from(data as Map));
  }

  /// 注册 tv_resource。
  Future<void> _registerResource({
    required String fileName,
    required String fileKey,
    required String fileUrl,
    required String fileType,
    required int fileSize,
    required String suffix,
    required String fileMd5,
  }) async {
    try {
      await _dio.post<Map<String, dynamic>>(
        '/theme/resource/register',
        data: <String, dynamic>{
          'fileName': fileName,
          'fileKey': fileKey,
          'fileUrl': fileUrl,
          'fileType': fileType,
          'fileSize': fileSize,
          'suffix': suffix,
          'fileMd5': fileMd5,
        },
      );
    } catch (e) {
      // 直传已成功，但资源记录未落库：影响后续秒传与关联，明确提示。
      throw ApiException(500, '资源注册失败：${formatApiError(e)}');
    }
  }

  /// 解析访问 URL：theme/ 路径走 ipscdn CDN，其余沿用后端 url 或历史 CDN。
  static String _resolveUrl(String key, String apiUrl) {
    final k = key.replaceFirst(RegExp(r'^/+'), '');
    if (k.startsWith('theme/')) {
      return '$_themeCdnBase/$k';
    }
    if (apiUrl.startsWith('http')) return apiUrl;
    if (k.startsWith('CloudMedia')) return 'https://metarialcdn.ainetv.cn/$k';
    return apiUrl.isNotEmpty ? apiUrl : '$_themeCdnBase/$k';
  }
}

/// 归一化后的 STS 临时凭证（兼容后端大小写字段名）。
class _StsCred {
  _StsCred({
    required this.tmpSecretId,
    required this.tmpSecretKey,
    required this.securityToken,
    required this.startTime,
    required this.expiredTime,
    required this.bucket,
    required this.region,
    required this.key,
    required this.url,
  });

  final String tmpSecretId;
  final String tmpSecretKey;
  final String securityToken;
  final int startTime;
  final int expiredTime;
  final String bucket;
  final String region;
  final String key;
  final String url;

  static String _pick(Map m, List<String> keys) {
    for (final k in keys) {
      final v = m[k];
      if (v != null && v.toString().trim().isNotEmpty) return v.toString().trim();
    }
    return '';
  }

  static int _pickInt(Map m, List<String> keys) {
    for (final k in keys) {
      final v = m[k];
      if (v != null) {
        final n = v is int ? v : int.tryParse(v.toString());
        if (n != null && n > 0) return n;
      }
    }
    return 0;
  }

  factory _StsCred.fromJson(Map<String, dynamic> m) {
    final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;
    var start = _pickInt(m, ['StartTime', 'startTime']);
    if (start == 0) start = now - 60;
    var exp = _pickInt(m, ['ExpiredTime', 'expiredTime']);
    if (exp == 0) exp = now + 1800;
    return _StsCred(
      tmpSecretId: _pick(m, ['TmpSecretId', 'tmpSecretId']),
      tmpSecretKey: _pick(m, ['TmpSecretKey', 'tmpSecretKey']),
      securityToken: _pick(m, ['SecurityToken', 'securityToken', 'sessionToken']),
      startTime: start,
      expiredTime: exp,
      bucket: _pick(m, ['bucket', 'Bucket']),
      region: _pick(m, ['region', 'Region']),
      key: _pick(m, ['key', 'Key']),
      url: _pick(m, ['url']),
    );
  }
}