import axios from 'axios'
import { ElMessage, ElLoading } from 'element-plus'
import { getToken, removeToken } from './auth'

// 创建axios实例
const service = axios.create({
  baseURL: process.env.VUE_APP_BASE_API || '/',
  timeout: 30000 // 30秒超时
})

// 请求拦截器
service.interceptors.request.use(
  config => {
    // 添加token
    const token = getToken()
    if (token) {
      config.headers['Authorization'] = `Bearer ${token}`
    }
    
    // 添加请求头
    config.headers['Content-Type'] = 'application/json;charset=UTF-8'
    
    return config
  },
  error => {
    console.error('请求错误:', error)
    return Promise.reject(error)
  }
)

// 响应拦截器
service.interceptors.response.use(
  response => {
    const { data, config } = response
    
    // 处理文件下载
    if (config.responseType === 'blob') {
      return response
    }
    
    // 处理正常响应
    if (data.code === 200 || data.success) {
      return data
    } else {
      ElMessage.error(data.message || '请求失败')
      return Promise.reject(new Error(data.message || 'Error'))
    }
  },
  error => {
    console.error('响应错误:', error)
    
    const { response } = error
    
    if (response) {
      const { status, data } = response
      
      switch (status) {
        case 400:
          ElMessage.error(data.message || '请求参数错误')
          break
        case 401:
          ElMessage.error('登录已过期，请重新登录')
          removeToken()
          window.location.href = '/login'
          break
        case 403:
          ElMessage.error('没有权限访问')
          break
        case 404:
          ElMessage.error('请求的资源不存在')
          break
        case 500:
          ElMessage.error('服务器内部错误')
          break
        default:
          ElMessage.error(data.message || '请求失败')
      }
    } else {
      ElMessage.error('网络连接错误')
    }
    
    return Promise.reject(error)
  }
)

// 封装请求方法
export default service

// 导出常用方法
export function get(url, params = {}, config = {}) {
  return service.get(url, { params, ...config })
}

export function post(url, data = {}, config = {}) {
  return service.post(url, data, config)
}

export function put(url, data = {}, config = {}) {
  return service.put(url, data, config)
}

export function del(url, config = {}) {
  return service.delete(url, config)
}

// 文件上传
export function upload(url, file, data = {}) {
  const formData = new FormData()
  formData.append('file', file)
  
  Object.keys(data).forEach(key => {
    formData.append(key, data[key])
  })
  
  return service.post(url, formData, {
    headers: {
      'Content-Type': 'multipart/form-data'
    }
  })
}

// 文件下载
export function download(url, params = {}, filename = '') {
  return service.get(url, {
    params,
    responseType: 'blob'
  }).then(response => {
    const blob = new Blob([response.data])
    const downloadUrl = window.URL.createObjectURL(blob)
    const link = document.createElement('a')
    link.href = downloadUrl
    link.download = filename || 'download'
    document.body.appendChild(link)
    link.click()
    document.body.removeChild(link)
    window.URL.revokeObjectURL(downloadUrl)
  })
}