import {
  API_BASE_URL,
  type ApiResponse,
  CLIENT_ID,
  CLIENT_SECRET,
  UnauthorizedError,
} from "@/lib/api"

let deviceToken: string | null = null
let deviceTokenExpire: Date | null = null

async function call<T = undefined>(
  endpoint: string,
  body?: string,
  auth?: string,
): Promise<ApiResponse<T>> {
  try {
    const headers: HeadersInit = {
      "Content-Type": "application/json",
    }
    if (auth) headers["Authorization"] = auth

    const response = await fetch(`${API_BASE_URL}${endpoint}`, {
      method: "POST",
      headers,
      body,
    })

    if (response.status === 401) {
      // 如果是 刷新Token 的接口本身报 401，说明 RefreshToken 彻底失效，直接抛出错误
      if (
        endpoint.includes("/auth/token") ||
        endpoint.includes("/auth/revoke")
      ) {
        throw UnauthorizedError
      }

      // 动态引入 auth.ts 里的刷新函数，避免循环引用报错
      const { refreshAuth } = await import("./auth")

      // 尝试刷新 Token
      const newTokens = await refreshAuth()

      if (newTokens) {
        // 刷新成功，用新 Token 重试当前请求（递归调用）
        return call(endpoint, body, `Bearer ${newTokens.access_token}`)
      } else {
        // 刷新失败，抛出 401 错误，让上层处理跳转
        throw UnauthorizedError
      }
    }

    const contentType = response.headers.get("Content-Type") ?? "text/plain"

    if (contentType.includes("text/plain")) {
      const text = await response.text()
      if (!response.ok) {
        return {
          success: false,
          status: response.status,
          message: text || "请求失败",
        }
      }
      return { success: true, data: undefined as T }
    }

    if (contentType.includes("application/json")) {
      const json = await response.json()
      if (!response.ok) {
        return {
          success: false,
          status: response.status,
          message: json.message || json.error_description || "请求失败",
        }
      }
      return { success: true, data: json }
    }

    throw new Error(`无法解析响应数据: ${contentType}`)
  } catch (e) {
    console.error("后端请求异常:", e)
    return {
      success: false,
      status: 500,
      message: (e as Error).message || "网络错误",
    }
  }
}

// ======================
// Public
// ======================
async function callPublic<R = undefined>(
  endpoint: string,
  data?: unknown,
): Promise<ApiResponse<R>> {
  return call(endpoint, data ? JSON.stringify(data) : undefined)
}

// ======================
// Device
// ======================
async function callByDevice<R = undefined>(
  endpoint: string,
  data?: unknown,
): Promise<ApiResponse<R>> {
  // 检查内存中的 Token 是否过期
  if (!deviceToken || !deviceTokenExpire || new Date() >= deviceTokenExpire) {
    // 用 btoa 生成 Basic 认证头
    const basic = btoa(`${CLIENT_ID}:${CLIENT_SECRET}`)
    const resp = await call<{
      access_token: string
      expires_in: number
    }>(
      "/api/auth/token",
      JSON.stringify({ grant_type: "client_credentials" }),
      `Basic ${basic}`,
    )

    if (!resp.success) {
      return resp
    }
    deviceToken = resp.data.access_token
    // 提前 60 秒过期，防止临界点失效
    deviceTokenExpire = new Date(
      Date.now() + (resp.data.expires_in - 60) * 1000,
    )
  }

  return call(
    endpoint,
    data ? JSON.stringify(data) : undefined,
    `Bearer ${deviceToken}`,
  )
}

// ======================
// User
// ======================
async function callByUser<R = undefined>(
  endpoint: string,
  data?: unknown,
): Promise<ApiResponse<R>> {
  // 这里我们假设用户登录后的 Token 存在 localStorage 里
  // 如果你是用 Cookie 存 Token，这里用 js-cookie 的 get 方法替换即可
  const token = localStorage.getItem("auth_token")

  if (!token) {
    throw UnauthorizedError
  }
  return call(
    endpoint,
    data ? JSON.stringify(data) : undefined,
    `Bearer ${token}`,
  )
}

export { callByDevice, callByUser, callPublic }