import { Router } from "express";
import deviceCodeStore from "../utils/deviceCodeStore.js";
import errors from "../utils/errors.js";
import { PrismaClient } from "@prisma/client";

const router = Router();
const prisma = new PrismaClient();



/**
 * POST /device/code
 * 生成设备授权码
 *
 * 应用调用此接口获取一个设备代码，返回给用户在前端进行授权
 *
 * Response:
 * {
 *   "device_code": "1234-ABCD",
 *   "expires_in": 900 (秒)
 * }
 */
router.post(
  "/device/code",
  errors.catchAsync(async (req, res) => {
    const deviceCode = deviceCodeStore.create();

    return res.json({
      device_code: deviceCode,
      expires_in: 900, // 15分钟
      message: "请在前端输入此代码进行授权",
    });
  })
);

/**
 * POST /device/bind
 * 绑定令牌到设备代码
 *
 * 前端用户授权后调用此接口，将token绑定到设备代码
 * 此接口独立于授权流程，可单独调用
 *
 * Request Body:
 * {
 *   "device_code": "1234-ABCD",
 *   "token": "actual-token-string"
 * }
 *
 * Response:
 * {
 *   "success": true,
 *   "message": "令牌已成功绑定到设备代码"
 * }
 */
router.post(
  "/device/bind",
  errors.catchAsync(async (req, res, next) => {
    const { device_code, token } = req.body;

    if (!device_code || !token) {
      return next(
        errors.createError(400, "请提供 device_code 和 token")
      );
    }

    // 验证token是否有效（检查数据库）
    const appInstall = await prisma.appInstall.findUnique({
      where: { token },
    });

    if (!appInstall) {
      return next(errors.createError(400, "无效的令牌"));
    }

    // 绑定令牌到设备代码
    const success = deviceCodeStore.bindToken(device_code, token);

    if (!success) {
      return next(
        errors.createError(400, "设备代码不存在或已过期")
      );
    }

    return res.json({
      success: true,
      message: "令牌已成功绑定到设备代码",
    });
  })
);

/**
 * GET /device/token
 * 轮询获取令牌
 *
 * 应用通过设备代码轮询此接口，获取用户授权后的token
 * 获取成功后，服务端会删除此设备代码
 *
 * Query Parameters:
 * - device_code: 设备代码
 *
 * Response (pending):
 * {
 *   "status": "pending",
 *   "message": "等待用户授权"
 * }
 *
 * Response (success):
 * {
 *   "status": "success",
 *   "token": "actual-token-string"
 * }
 *
 * Response (expired):
 * {
 *   "status": "expired",
 *   "message": "设备代码已过期"
 * }
 */
router.get(
  "/device/token",
  errors.catchAsync(async (req, res, next) => {
    const { device_code } = req.query;

    if (!device_code) {
      return next(errors.createError(400, "请提供 device_code"));
    }

    // 尝试获取并移除令牌
    const token = deviceCodeStore.getAndRemove(device_code);

    if (token) {
      // 令牌已绑定，返回并删除
      return res.json({
        status: "success",
        token,
      });
    }

    // 检查设备代码是否存在
    const status = deviceCodeStore.getStatus(device_code);

    if (!status) {
      // 设备代码不存在或已过期
      return res.json({
        status: "expired",
        message: "设备代码不存在或已过期",
      });
    }

    // 设备代码存在但令牌未绑定
    return res.json({
      status: "pending",
      message: "等待用户授权",
      expires_in: Math.floor((status.expiresAt - Date.now()) / 1000),
    });
  })
);

/**
 * GET /device/status
 * 查询设备代码状态（仅用于调试）
 *
 * Query Parameters:
 * - device_code: 设备代码
 *
 * Response:
 * {
 *   "device_code": "1234-ABCD",
 *   "exists": true,
 *   "has_token": false,
 *   "expires_in": 850 (秒)
 * }
 */
router.get(
  "/device/status",
  errors.catchAsync(async (req, res, next) => {
    const { device_code } = req.query;

    if (!device_code) {
      return next(errors.createError(400, "请提供 device_code"));
    }

    const status = deviceCodeStore.getStatus(device_code);

    if (!status) {
      return res.json({
        device_code,
        exists: false,
        message: "设备代码不存在或已过期",
      });
    }

    return res.json({
      device_code,
      exists: true,
      has_token: status.hasToken,
      expires_in: Math.floor((status.expiresAt - Date.now()) / 1000),
      created_at: status.createdAt,
    });
  })
);

export default router;