import { authService } from './authService';

const API_BASE_URL = import.meta.env.VITE_API_BASE_URL;

export interface OSSUploadResponse {
  url: string;
  filename: string;
  size: number;
}

export interface ApiResponse<T> {
  code: number;
  message: string;
  data: T;
}

class OSSApiService {
  private baseUrl = `${API_BASE_URL}/api/oss`;

  async uploadFile(file: File, prefix: string = 'uploads'): Promise<ApiResponse<OSSUploadResponse>> {
    const formData = new FormData();
    formData.append('file', file);

    const authHeader = authService.getAuthHeader();
    if (!authHeader) {
      throw new Error('未授权：请先登录');
    }

    const response = await fetch(`${this.baseUrl}/upload?prefix=${encodeURIComponent(prefix)}`, {
      method: 'POST',
      headers: { 'Authorization': authHeader },
      body: formData,
    });

    if (!response.ok) {
      if (response.status === 401) {
        authService.logout();
        throw new Error('未授权：请先登录');
      }
      throw new Error(`上传失败: ${response.status}`);
    }

    return response.json();
  }
}

export const ossApi = new OSSApiService();

/**
 * 上传文件到 OSS（带进度回调）
 * @param file 要上传的文件
 * @param prefix OSS 路径前缀
 * @param onProgress 进度回调函数 (0-100)
 * @returns 文件 URL
 */
export async function uploadFile(
  file: File,
  prefix: string = 'uploads',
  onProgress?: (percent: number) => void
): Promise<string> {
  const formData = new FormData();
  formData.append('file', file);

  const authHeader = authService.getAuthHeader();
  if (!authHeader) {
    throw new Error('未授权：请先登录');
  }

  return new Promise((resolve, reject) => {
    const xhr = new XMLHttpRequest();

    // 监听上传进度
    xhr.upload.addEventListener('progress', (e) => {
      if (e.lengthComputable && onProgress) {
        const percent = Math.round((e.loaded / e.total) * 100);
        onProgress(percent);
      }
    });

    // 监听完成
    xhr.addEventListener('load', () => {
      if (xhr.status === 200) {
        try {
          const response: ApiResponse<OSSUploadResponse> = JSON.parse(xhr.responseText);
          if (response.code === 200 && response.data) {
            resolve(response.data.url);
          } else {
            reject(new Error(response.message || '上传失败'));
          }
        } catch (error) {
          reject(new Error('解析响应失败'));
        }
      } else if (xhr.status === 401) {
        authService.logout();
        reject(new Error('未授权：请先登录'));
      } else {
        reject(new Error(`上传失败: ${xhr.status}`));
      }
    });

    // 监听错误
    xhr.addEventListener('error', () => {
      reject(new Error('网络错误'));
    });

    xhr.addEventListener('abort', () => {
      reject(new Error('上传已取消'));
    });

    // 发送请求
    xhr.open('POST', `${API_BASE_URL}/api/oss/upload?prefix=${encodeURIComponent(prefix)}`);
    xhr.setRequestHeader('Authorization', authHeader);
    xhr.send(formData);
  });
}