import { API_BASE_URL, REQUEST_TIMEOUT_MS } from './config.js'
import { forceRelogin } from './auth-session.js'

/** 这些接口的业务 code=401 表示凭据错误等，不是会话过期 */
const AUTH_EXEMPT_PATHS = [
  '/web/auth/login',
  '/web/auth/login-rsa-public-key',
  '/web/auth/refresh-token',
  '/mini/auth/wechat-login',
  '/mini/auth/web-qr-scanned',
  '/mini/auth/web-qr-confirm'
]

function isAuthExemptPath(path) {
  const p = String(path || '')
  for (let i = 0; i < AUTH_EXEMPT_PATHS.length; i++) {
    if (p.indexOf(AUTH_EXEMPT_PATHS[i]) !== -1) return true
  }
  return false
}

function hasBearerToken(header) {
  const auth = (header && header.Authorization) || ''
  return /^Bearer\s+\S+/i.test(String(auth))
}

/**
 * HTTP 401，或已带 token 的业务 code=401 → 强制重新登录。
 * 登录接口豁免，避免「账号密码错误」被当成会话失效。
 */
function maybeForceRelogin(options, httpStatus, body) {
  if (isAuthExemptPath(options && options.url)) return
  const bizCode = body && body.code
  const msg =
    (body && typeof body.message === 'string' && body.message.trim()) ||
    (body && typeof body.detail === 'string' && body.detail.trim()) ||
    ''
  if (httpStatus === 401 || (bizCode === 401 && hasBearerToken(options && options.header))) {
    forceRelogin(msg || '登录已失效，请重新登录')
  }
}

/**
 * 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 || {}
  )
  const reqOpts = { url: options.url, header }

  return new Promise((resolve, reject) => {
    uni.request({
      url,
      method,
      data: options.data,
      header,
      timeout: REQUEST_TIMEOUT_MS,
      success(res) {
        try {
          const body = res.data
          maybeForceRelogin(reqOpts, res.statusCode, body)

          if (res.statusCode >= 200 && res.statusCode < 300) {
            resolve(unwrapResponse(body, res.statusCode))
            return
          }
          // HTTP 非 2xx：若 body 仍是业务包，优先展示 message
          try {
            resolve(unwrapResponse(body, 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 })
}