后端迁移到fastapi (#3)

Reviewed-on: #3

src/lib/api.ts

@@ -0,0 +1,134 @@
+import type { AuthResponse } from '@/types/api'
+
+const DEFAULT_API_URL = 'http://localhost:8000/api/v1'
+
+export const API_URL = (import.meta.env.VITE_API_URL || DEFAULT_API_URL).replace(/\/$/, '')
+export const AUTH_UPDATED_EVENT = 'opencloud:auth-updated'
+export const AUTH_EXPIRED_EVENT = 'opencloud:auth-expired'
+
+let accessToken: string | null = null
+let refreshPromise: Promise<AuthResponse> | null = null
+
+export class ApiError extends Error {
+  status: number
+  detail: unknown
+
+  constructor(message: string, status: number, detail?: unknown) {
+    super(message)
+    this.name = 'ApiError'
+    this.status = status
+    this.detail = detail
+  }
+}
+
+interface ApiRequestOptions extends Omit<RequestInit, 'body'> {
+  body?: BodyInit | Record<string, unknown> | null
+  auth?: boolean
+  retry?: boolean
+}
+
+function isJsonBody(body: ApiRequestOptions['body']): body is Record<string, unknown> {
+  return !!body
+    && typeof body === 'object'
+    && !(body instanceof FormData)
+    && !(body instanceof Blob)
+    && !(body instanceof URLSearchParams)
+    && !(body instanceof ArrayBuffer)
+}
+
+function detailToMessage(detail: unknown, fallback: string) {
+  if (typeof detail === 'string') return detail
+  if (Array.isArray(detail)) {
+    const messages = detail
+      .map(item => item && typeof item === 'object' && 'msg' in item ? String(item.msg) : '')
+      .filter(Boolean)
+    if (messages.length) return messages.join('；')
+  }
+  return fallback
+}
+
+async function toApiError(response: Response) {
+  let detail: unknown
+  try {
+    const payload = await response.json() as { detail?: unknown }
+    detail = payload.detail
+  } catch {
+    detail = undefined
+  }
+
+  return new ApiError(
+    detailToMessage(detail, `请求失败（${response.status}）`),
+    response.status,
+    detail,
+  )
+}
+
+export function setAccessToken(token: string | null) {
+  accessToken = token
+}
+
+export function clearAccessToken() {
+  accessToken = null
+}
+
+async function request<T>(path: string, options: ApiRequestOptions = {}) {
+  const { body, auth = true, retry = true, ...requestOptions } = options
+  const headers = new Headers(requestOptions.headers)
+  let requestBody: BodyInit | null | undefined = body as BodyInit | null | undefined
+
+  if (isJsonBody(body)) {
+    headers.set('Content-Type', 'application/json')
+    requestBody = JSON.stringify(body)
+  }
+
+  if (auth && accessToken) {
+    headers.set('Authorization', `Bearer ${accessToken}`)
+  }
+
+  const response = await fetch(`${API_URL}${path}`, {
+    ...requestOptions,
+    body: requestBody,
+    headers,
+    credentials: 'include',
+  })
+
+  if (response.status === 401 && auth && accessToken && retry) {
+    try {
+      const authResponse = await refreshSession()
+      window.dispatchEvent(new CustomEvent<AuthResponse>(AUTH_UPDATED_EVENT, { detail: authResponse }))
+      return request<T>(path, { ...options, retry: false })
+    } catch {
+      clearAccessToken()
+      window.dispatchEvent(new Event(AUTH_EXPIRED_EVENT))
+    }
+  }
+
+  if (!response.ok) throw await toApiError(response)
+  if (response.status === 204) return undefined as T
+
+  return response.json() as Promise<T>
+}
+
+export function apiRequest<T>(path: string, options: ApiRequestOptions = {}) {
+  return request<T>(path, options)
+}
+
+export function refreshSession() {
+  if (!refreshPromise) {
+    refreshPromise = (async () => {
+      const response = await fetch(`${API_URL}/auth/refresh`, {
+        method: 'POST',
+        credentials: 'include',
+      })
+      if (!response.ok) throw await toApiError(response)
+
+      const authResponse = await response.json() as AuthResponse
+      setAccessToken(authResponse.access_token)
+      return authResponse
+    })().finally(() => {
+      refreshPromise = null
+    })
+  }
+
+  return refreshPromise
+}