export type ApiSession = {
  baseUrl: string
  token: string
}

type RequestOptions = {
  method?: string
  body?: unknown
  token?: string
}

let configuredBaseUrl = normalizeBaseUrl(import.meta.env.VITE_API_BASE_URL ?? 'http://127.0.0.1:18080')

export function setApiBaseUrl(baseUrl: string) {
  configuredBaseUrl = normalizeBaseUrl(baseUrl)
}

export function getApiBaseUrl() {
  return configuredBaseUrl
}

export async function login(email: string, password: string): Promise<ApiSession> {
  const response = await apiRequest<{ token: string }>('/api/auth/login', {
    method: 'POST',
    body: { email, password },
  })
  return { baseUrl: configuredBaseUrl, token: response.token }
}

export async function apiRequest<T>(path: string, options: RequestOptions = {}): Promise<T> {
  const response = await fetch(`${configuredBaseUrl}${path}`, {
    method: options.method ?? 'GET',
    headers: {
      'Content-Type': 'application/json',
      ...(options.token ? { Authorization: `Bearer ${options.token}` } : {}),
    },
    body: options.body === undefined ? undefined : JSON.stringify(options.body),
  })

  if (!response.ok) {
    let message = `请求失败：${response.status}`
    try {
      const payload = await response.json()
      if (typeof payload.error === 'string') message = payload.error
    } catch {
      // Keep the status-based message when the server does not return JSON.
    }
    throw new Error(message)
  }

  return response.json() as Promise<T>
}

function normalizeBaseUrl(value: string) {
  const trimmed = value.trim()
  return trimmed.endsWith('/') ? trimmed.slice(0, -1) : trimmed
}