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

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

// gallery页路由
router.get('/', function (req, res, next) {
  (async function () {
    let tag = req.query.category;
    if (!tag) tag = 'latest';

    let user = req.query.author;


    let search = req.query.search;
    if (search) tag = '';

    let filters = (tag == 'latest' || tag == '') ? {} : { tags: tag };
    if (user) {
      let userId = await common.getUserIdByUsername(user);
      if (userId) filters.user = userId;
    }

    let cacheKey = `${CACHE_PREFIX}_${req.originalUrl}`;
    let htmlData = await redis.getAsync(cacheKey);
    htmlData = null;
    if (!htmlData) {
      let query = {
        page: req.query.page,
        length: req.query.length,
        search,
        orderBy: 'publishTime',
        order: 'desc',
        base: { status: 9000 },
        filters,
      }

      // 内容列表
      let result = await getListBuilder(query, models.Art, [{ path: 'user', select: 'username' }]);
      common.organizeData(result.data);


      // 设计师列表
      let userDocs = await models.Art.aggregate([
        // 首先，过滤出 status = 9000 的文档
        { $match: { open: true, status: 9000 } },

        // 首先，根据 user 字段进行分组，并计算每个 user 出现的次数
        { $group: { _id: '$user', count: { $sum: 1 } } },

        // 然后，按照 count 字段进行降序排列
        { $sort: { count: -1 } },

        // 接着，与 users 集合进行连接，以获取用户的详细信息
        {
          $lookup: {
            from: 'users', // 要连接的集合名称
            localField: '_id', // 本地字段（即上一步分组后的 _id 字段）
            foreignField: '_id', // 要连接的集合中的字段
            as: 'userDetails' // 连接后结果存储在新字段 userDetails 中
          }
        },

        // 展开 userDetails 数组，以便将用户信息提升到顶层
        { $unwind: '$userDetails' },

        // 调整输出格式，只保留需要的字段
        { $project: { _id: 1, user: '$_id', count: 1, username: '$userDetails.username', name: '$userDetails.name' } },

        // 限制返回的记录数量
        { $limit: 16 }
      ]);
      for (let doc of userDocs) {
        doc.avatar = `/thumbs/v1/avatar/320/${doc._id}.webp`;
      }

      let data = {
        data: result.data,
        designers: userDocs,
        page: result.page,
        length: result.length,
        recordsFiltered: result.recordsFiltered,
        recordsTotal: result.recordsTotal,
        tag,
        tags: tags.filter(e => e.count && e.count > 0),
        searchTerm: search,
        uri: req.originalUrl,
        pageUri: common.replaceUriParams,
      };

      // 渲染EJS模板到内存中
      res.render('v2/gallery', 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;