client-web/src/api/http.ts

import axios, { AxiosError, type AxiosRequestConfig, type InternalAxiosRequestConfig } from 'axios'
import { clearSessionTokens, getAccessToken, getRefreshToken, persistTokenPair, type TokenPair } from '@/api/session'
import { ApiError, asFieldErrors, isApiEnvelope, type ApiEnvelope } from '@/api/types'

const transport = axios.create({
  baseURL: import.meta.env.VITE_API_BASE_URL || '/api',
  timeout: 15_000,
})

interface RetryableRequest extends InternalAxiosRequestConfig {
  _retriedAfterRefresh?: boolean
}

function unwrap<T>(envelope: ApiEnvelope<T>) {
  if (envelope.code !== '0') {
    throw new ApiError(envelope.message || '请求失败', envelope.code, undefined, asFieldErrors(envelope.data), envelope.traceId)
  }
  return envelope.data
}

function mapError(error: unknown) {
  if (error instanceof ApiError) return error
  if (!axios.isAxiosError(error)) return new ApiError(error instanceof Error ? error.message : '请求失败')

  const body = error.response?.data
  if (isApiEnvelope(body)) {
    return new ApiError(
      body.message || '请求失败',
      body.code,
      error.response?.status,
      asFieldErrors(body.data),
      typeof body.traceId === 'string' ? body.traceId : null,
    )
  }
  if (error.code === AxiosError.ERR_NETWORK) return new ApiError('无法连接服务器，请确认后端服务已启动', 'NETWORK_ERROR')
  if (error.code === AxiosError.ECONNABORTED) return new ApiError('请求超时，请稍后重试', 'TIMEOUT')
  return new ApiError(error.message || '请求失败', 'HTTP_ERROR', error.response?.status)
}

let refreshPromise: Promise<TokenPair> | null = null

async function refreshSession() {
  const refreshToken = getRefreshToken()
  if (!refreshToken) throw new ApiError('登录已过期，请重新登录', 'A0401', 401)
  if (!refreshPromise) {
    refreshPromise = transport
      .post<ApiEnvelope<TokenPair>>('/auth/refresh', { refreshToken })
      .then((response) => unwrap(response.data))
      .then((tokens) => {
        persistTokenPair(tokens)
        return tokens
      })
      .finally(() => {
        refreshPromise = null
      })
  }
  return refreshPromise
}

transport.interceptors.request.use((config) => {
  const token = getAccessToken()
  if (token) config.headers.Authorization = `Bearer ${token}`
  return config
})

transport.interceptors.response.use(
  (response) => response,
  async (error: AxiosError) => {
    const request = error.config as RetryableRequest | undefined
    const publicAuthPaths = ['/auth/login', '/auth/register', '/auth/refresh']
    const isPublicAuthRequest = publicAuthPaths.some((path) => request?.url?.endsWith(path))
    if (error.response?.status !== 401 || !request || request._retriedAfterRefresh || isPublicAuthRequest) {
      throw mapError(error)
    }

    request._retriedAfterRefresh = true
    try {
      const tokens = await refreshSession()
      request.headers.Authorization = `Bearer ${tokens.accessToken}`
      return await transport.request(request)
    } catch (refreshError) {
      clearSessionTokens()
      window.dispatchEvent(new CustomEvent('cc-client-session-expired'))
      throw mapError(refreshError)
    }
  },
)

export async function apiRequest<T>(config: AxiosRequestConfig) {
  try {
    const response = await transport.request<ApiEnvelope<T>>(config)
    return unwrap(response.data)
  } catch (error) {
    throw mapError(error)
  }
}

export async function apiBlobRequest(config: AxiosRequestConfig) {
  try {
    const response = await transport.request<Blob>({ ...config, responseType: 'blob' })
    return response.data
  } catch (error) {
    throw mapError(error)
  }
}

export { ApiError }