var express = require('express');
var router = express.Router();
const models = require('../../models');
const common = require('./common');
const redis = require('../../libs/redis');
const { coloringData } = require('./config');
const { getListBuilder } = require('../../libs/pager');

const CACHE_PREFIX = "art_v2";
// const CACHE_EXPIRES = 60; // 60s刷新一次
const CACHE_EXPIRES = 600;

router.get('/', process());


function process() {
  return (req, res, next) => {
    (async function () {
      let uri = req.baseUrl.substring(1);
      let cacheKey = `${CACHE_PREFIX}_${uri}`;
      let htmlData = await redis.getAsync(cacheKey);
      // htmlData = null;
      if (!htmlData) {
        if (!coloringData[uri].data) {
          let query = {
            orderBy: 'publishTime',
            order: 'desc',
            base: { status: 9000 },
            filters: { _id: coloringData[uri].list },
          }
          let result = await getListBuilder(query, models.Art, [{ path: 'user', select: 'username' }]);
          common.organizeData(result.data);
          coloringData[uri].data = result.data;
        }
        const comments = await models.Comment.find({ approved: true, page: coloringData[uri].title }).sort({ createdAt: -1 });
        let data = {
          uri: req.originalUrl,
          data: coloringData[uri],
          pageId: coloringData[uri].title,
          comments,
          dateFormat: common.dateFormat,
        };
        // 渲染EJS模板到内存中
        res.render('v2/coloring-page-collection', data, async (err, html) => {
          if (err) {
            // 如果渲染出错，调用next()传递错误
            return next(err);
          }

          // 渲染成功，存redis, 发送数据到客户端
          htmlData = html;
          try {
            await redis.set(cacheKey, htmlData, 'EX', CACHE_EXPIRES);
          } catch (e) {
            console.error(e);
          }

          res.send(htmlData);
        });
      } else {
        // 缓存命中， 直接发送缓存数据
        res.set({ 'X-From-Cache': 'true' });
        res.send(htmlData);
      }

    })().catch(next);
  }
}


module.exports = router;