require("dotenv").config();
const Koa = require("koa");
const Router = require("koa-router");
const jwt = require("jsonwebtoken");
const koaJwt = require("koa-jwt");
const fs = require("fs");
const path = require("path");
const bodyParser = require("koa-bodyparser");
const verifyThirdPartyToken = require("./auth/verifyThirdPartyToken");
const app = new Koa();
app.use(bodyParser()); // 添加在路由中间件之前
const router = new Router();

// 自动加载API路由函数
const loadAPIRoutes = (baseDir = 'api', baseRoute = '/api') => {
  const scanDirectory = (dir, routePrefix) => {
    const entries = fs.readdirSync(dir, { withFileTypes: true });

    entries.forEach(entry => {
      const fullPath = path.join(dir, entry.name);
      const relativePath = path.relative(baseDir, dir);
      
      // 构建路由路径：工程目录结构 -> URL路径
      const routePath = path.join(
        routePrefix,
        relativePath,
        entry.name.replace(/\.js$/, '')
      ).replace(/\\/g, '/'); // Windows路径转URL路径

      if (entry.isDirectory()) {
        scanDirectory(fullPath, routePrefix); // 递归扫描子目录
      } else if (
        entry.isFile() && 
        path.extname(entry.name) === '.js' &&
        entry.name !== 'index.js'
      ) {
        registerRoute(fullPath, routePath);
      }
    });
  };

  // 路由注册器（支持扩展其他HTTP方法）
  const registerRoute = (filePath, routePath) => {
    try {
      const handler = require(filePath);
      router.post(routePath, async ctx => await handler(ctx));
      console.log(`[Route] POST ${routePath} -> ${filePath}`);
    } catch (err) {
      console.error(`[Error] Failed to load route ${routePath}:`, err);
    }
  };

  // 初始化扫描
  scanDirectory(path.join(__dirname, baseDir), baseRoute);
};
// 公开路由
router.get("/public", (ctx) => {
  ctx.body = "Public content";
});

// 自定义中间件：解析并验证第三方Token
app.use(async (ctx, next) => {
  const authHeader = ctx.headers.authorization;
  if (authHeader && authHeader.startsWith('Bearer ')) {
    const thirdPartyToken = authHeader.split(' ')[1];
    try {
      // 这里假设第三方Token可以通过某种方式验证并转换为JWT Token
      const decoded = verifyThirdPartyToken(thirdPartyToken); // 假设有一个验证函数
      const jwtToken = jwt.sign(decoded, process.env.JWT_SECRET, { expiresIn: "1h" });
      ctx.state.user = decoded; // 将用户信息存储在ctx.state中
      ctx.headers.authorization = `Bearer ${jwtToken}`; // 替换为JWT Token
    } catch (err) {
      ctx.throw(401, 'Invalid third-party token');
    }
  }
  await next();
});
// JWT中间件（保护下方所有路由）
app.use(
  koaJwt({
    secret: process.env.JWT_SECRET,
  }).unless({
    path: [/^\/public/, /^\/login/],
  })
);

// 加载自动生成的路由
loadAPIRoutes();

// 受保护路由
router.get("/protected", (ctx) => {
  ctx.body = `Protected content for ${ctx.state.user.username}`;
});

app.use(router.routes());
app.use(router.allowedMethods());

app.listen(process.env.PORT || 3000, () => {
  console.log(`Server running on http://localhost:${process.env.PORT || 3000}`);
});