/*!
 * nodeclub - site index controller.
 * Copyright(c) 2012 fengmk2 <fengmk2@gmail.com>
 * Copyright(c) 2012 muyuan
 * MIT Licensed
 */

/**
 * Module dependencies.
 */

var User = require('../proxy').User;
var Topic = require('../proxy').Topic;
var config = require('../config');
var EventProxy = require('eventproxy');
var mcache = require('memory-cache');

// 主页的缓存工作。主页是需要主动缓存的
setInterval(function () {
  var limit = config.list_topic_count;
  // 只缓存第一页, page = 1
  var options = { skip: (1 - 1) * limit, limit: limit, sort: [
    ['top', 'desc' ],
    [ 'last_reply_at', 'desc' ]
  ] };
  // 为所有版块（tab）做缓存
  ['', '全部'].concat(config.tabs).forEach(function (pair) {
    var tabValue = pair[0];
    var query = {};
    if (tabValue) {
      query.tab = tabValue;
    }
    var optionsStr = JSON.stringify(query) + JSON.stringify(options);
    Topic.getTopicsByQuery({}, options, function (err, topics) {
      mcache.put(optionsStr, topics);
      return topics;
    });
  });
}, 1000 * 5); // 五秒更新一次
// END 主页的缓存工作

exports.index = function (req, res, next) {
  var page = parseInt(req.query.page, 10) || 1;
  page = page > 0 ? page : 1;
  var tab = req.query.tab || req.session.tab || '';
  req.session.tab = tab;
  var limit = config.list_topic_count;

  var proxy = EventProxy.create('topics', 'tops', 'no_reply_topics', 'pages',
    function (topics, tops, no_reply_topics, pages) {
      res.render('index', {
        topics: topics,
        current_page: page,
        list_topic_count: limit,
        tops: tops,
        no_reply_topics: no_reply_topics,
        pages: pages,
        site_links: config.site_links,
        tabs: config.tabs,
        tab: tab,
      });
    });
  proxy.fail(next);

  // 取主题
  var query = {};
  if (tab && tab !== 'all') {
    query.tab = tab;
  }
  var options = { skip: (page - 1) * limit, limit: limit, sort: [
    ['top', 'desc' ],
    [ 'last_reply_at', 'desc' ]
  ] };
  var optionsStr = JSON.stringify(query) + JSON.stringify(options);
  if (mcache.get(optionsStr)) {
    proxy.emit('topics', mcache.get(optionsStr));
  } else {
    Topic.getTopicsByQuery(query, options, proxy.done('topics', function (topics) {
      return topics;
    }));
  }
  // END 取主题

  // 取排行榜上的用户
  if (mcache.get('tops')) {
    proxy.emit('tops', mcache.get('tops'));
  } else {
    User.getUsersByQuery(
      {'$or': [
        {is_block: {'$exists': false}},
        {is_block: false}
      ]},
      { limit: 10, sort: [
        [ 'score', 'desc' ]
      ] },
      proxy.done('tops', function (tops) {
        mcache.put('tops', tops, 1000 * 60 * 1);
        return tops;
      })
    );
  }
  // 取0回复的主题
  if (mcache.get('no_reply_topics')) {
    proxy.emit('no_reply_topics', mcache.get('no_reply_topics'));
  } else {
    Topic.getTopicsByQuery(
      { reply_count: 0 },
      { limit: 5, sort: [
        [ 'create_at', 'desc' ]
      ] },
      proxy.done('no_reply_topics', function (no_reply_topics) {
        mcache.put('no_reply_topics', no_reply_topics, 1000 * 60 * 1);
        return no_reply_topics;
      }));
  }
  // 取分页数据
  if (mcache.get('pages')) {
    proxy.emit('pages', mcache.get('pages'));
  } else {
    Topic.getCountByQuery(query, proxy.done(function (all_topics_count) {
      var pages = Math.ceil(all_topics_count / limit);
      mcache.put(JSON.stringify(query) + 'pages', pages, 1000 * 60 * 1);
      proxy.emit('pages', pages);
    }));
  }
};