import { API_BASE_URL, REQUEST_TIMEOUT_MS } from './config.js'

/**
 * 解析后端统一响应。成功返回 data；失败抛 Error（message 为业务文案）。
 * @param {{ code?: number, message?: string, data?: any }} body
 * @param {number} [httpStatus]
 */
export function unwrapResponse(body, httpStatus) {
  if (body == null || typeof body !== 'object') {
    const err = new Error('网络异常，请稍后重试')
    err.code = 'BAD_RESPONSE'
    throw err
  }
  const code = body.code
  if (code === 200) {
    return body.data
  }
  const msg =
    (typeof body.message === 'string' && body.message.trim()) ||
    '请求失败'
  const err = new Error(msg)
  err.code = code
  err.httpStatus = httpStatus
  throw err
}

function joinUrl(path) {
  const base = (API_BASE_URL || '').replace(/\/$/, '')
  const p = path.startsWith('/') ? path : `/${path}`
  return `${base}${p}`
}

/**
 * @param {{ url: string, method?: string, data?: any, header?: Record<string, string> }} options
 * @returns {Promise<any>} data 字段
 */
export function request(options) {
  const method = (options.method || 'GET').toUpperCase()
  const url = joinUrl(options.url)
  const header = Object.assign(
    { 'Content-Type': 'application/json' },
    options.header || {}
  )

  return new Promise((resolve, reject) => {
    uni.request({
      url,
      method,
      data: options.data,
      header,
      timeout: REQUEST_TIMEOUT_MS,
      success(res) {
        try {
          if (res.statusCode >= 200 && res.statusCode < 300) {
            resolve(unwrapResponse(res.data, res.statusCode))
            return
          }
          // HTTP 非 2xx：若 body 仍是业务包，优先展示 message
          try {
            resolve(unwrapResponse(res.data, res.statusCode))
          } catch (bizErr) {
            reject(bizErr)
          }
        } catch (e) {
          reject(e)
        }
      },
      fail() {
        const err = new Error('网络异常，请稍后重试')
        err.code = 'NETWORK'
        reject(err)
      }
    })
  })
}

export function get(url, header) {
  return request({ url, method: 'GET', header })
}

export function post(url, data, header) {
  return request({ url, method: 'POST', data, header })
}