/*!
 * nodeclub - controllers/topic.js
 */

/**
 * Module dependencies.
 */

var models = require('../models');
var Topic = models.Topic;
var TopicTag = models.TopicTag;
var TopicCollect = models.TopicCollect;
var Relation = models.Relation;
var sanitize = require('validator').sanitize;
var at_ctrl = require('./at');
var tag_ctrl = require('./tag');
var user_ctrl = require('./user');
var reply_ctrl = require('./reply');
var EventProxy = require('eventproxy');
var Showdown = require('../public/libs/showdown');
var Util = require('../libs/util');

/**
 * Topic page
 *
 * @param  {HttpRequest} req
 * @param  {HttpResponse} res
 * @param  {Function} next
 */
exports.index = function (req, res, next) {
  var topic_id = req.params.tid;
  if (topic_id.length !== 24) {
    return res.render('notify/notify', {
      error: '此话题不存在或已被删除。'
    });
  }
  var events = ['topic', 'other_topics', 'no_reply_topics', 'get_relation', '@user'];
  var ep = EventProxy.create(events, function (topic, other_topics, no_reply_topics, relation) {
    res.render('topic/index', {
      topic: topic,
      author_other_topics: other_topics,
      no_reply_topics: no_reply_topics,
      relation : relation
    });
  });

  ep.fail(next);

  ep.once('topic', function (topic) {
    if (topic.content_is_html) {
      return ep.emit('@user');
    }
    at_ctrl.linkUsers(topic.content, ep.done(function (content) {
      topic.content = Util.xss(Showdown.parse(content));
      ep.emit('@user');
    }));
  });

  getFullTopic(topic_id, ep.done(function (message, topic, tags, author, replies) {
    if (message) {
      ep.unbind();
      return res.render('notify/notify', { error: message });
    }

    topic.visit_count += 1;
    topic.save(ep.done(function () {
      // format date
      topic.friendly_create_at = Util.format_date(topic.create_at, true);
      topic.friendly_update_at = Util.format_date(topic.update_at, true);

      topic.tags = tags;
      topic.author = author;
      topic.replies = replies;

      if (!req.session.user) {
        ep.emit('topic', topic);
      } else {
        var q = { user_id: req.session.user._id, topic_id: topic._id };
        TopicCollect.findOne(q, ep.done(function (doc) {
          topic.in_collection = doc;
          ep.emit('topic', topic);
        }));
      }
    }));

    //get author's relationship
    if (!req.session.user || req.session.user._id) {
      ep.emit('get_relation', null);
    } else {
      Relation.findOne({user_id: req.session.user._id, follow_id: topic.author_id}, ep.done('get_relation'));
    }

    // get author other topics
    var options = { limit: 5, sort: [ [ 'last_reply_at', 'desc' ] ]};
    var query = { author_id: topic.author_id, _id: { '$nin': [ topic._id ] } };
    exports.getTopicsByQuery(query, options, ep.done('other_topics'));

    // get no reply topics
    var options2 = { limit: 5, sort: [ ['create_at', 'desc'] ] };
    exports.getTopicsByQuery({reply_count: 0}, options2, ep.done('no_reply_topics'));
  }));
};

exports.create = function (req, res, next) {
  if (!req.session.user) {
    res.render('notify/notify', {error: '未登入用户不能发布话题。'});
    return;
  }
  // TODO: app.get/app.post
  var method = req.method.toLowerCase();
  if (method === 'get') {
    tag_ctrl.getAllTags(function (err, tags) {
      if (err) {
        return next(err);
      }
      res.render('topic/edit', {tags: tags});
    });
  }

  if (method === 'post') {
    var title = sanitize(req.body.title).trim();
    title = sanitize(title).xss();
    var content = req.body.t_content;
    var topic_tags = [];
    if (req.body.topic_tags !== '') {
      topic_tags = req.body.topic_tags.split(',');
    }

    if (title === '') {
      tag_ctrl.getAllTags(function (err, tags) {
        if (err) {
          return next(err);
        }
        for (var i = 0; i < topic_tags.length; i++) {
          for (var j = 0; j < tags.length; j++) {
            if (topic_tags[i] === tags[j]._id) {
              tags[j].is_selected = true;
            }
          }
        }
        res.render('topic/edit', {tags: tags, edit_error: '标题不能是空的。', content: content});
      });
    } else if (title.length < 10 || title.length > 100) {
      tag_ctrl.getAllTags(function (err, tags) {
        if (err) {
          return next(err);
        }
        for (var i = 0; i < topic_tags.length; i++) {
          for (var j = 0; j < tags.length; j++) {
            if (topic_tags[i] === tags[j]._id) {
              tags[j].is_selected = true;
            }
          }
        }
        res.render('topic/edit', {tags: tags, edit_error: '标题字数太多或太少', title: title, content: content});
      });
    } else {
      var topic = new Topic();
      topic.title = title;
      topic.content = content;
      topic.author_id = req.session.user._id;
      topic.save(function (err) {
        if (err) {
          return next(err);
        }

        var proxy = new EventProxy();
        var render = function () {
          res.redirect('/topic/' + topic._id);
        };

        proxy.assign('tags_saved', 'score_saved', render);
        proxy.fail(next);
        // 话题可以没有标签
        if (topic_tags.length === 0) {
          proxy.emit('tags_saved');
        }
        var tags_saved_done = function () {
          proxy.emit('tags_saved');
        };
        proxy.after('tag_saved', topic_tags.length, tags_saved_done);
        //save topic tags
        topic_tags.forEach(function (tag) {
          var topic_tag = new TopicTag();
          topic_tag.topic_id = topic._id;
          topic_tag.tag_id = tag;
          topic_tag.save(proxy.done('tag_saved'));
          tag_ctrl.getTagById(tag, proxy.done(function (tag) {
            tag.topic_count += 1;
            tag.save();
          }));
        });
        user_ctrl.getUserById(req.session.user._id, proxy.done(function (user) {
          user.score += 5;
          user.topic_count += 1;
          user.save();
          req.session.user.score += 5;
          proxy.emit('score_saved');
        }));

        //发送at消息
        at_ctrl.sendMessageToMentionUsers(content, topic._id, req.session.user._id);
      });
    }
  }
};

exports.edit = function (req, res, next) {
  if (!req.session.user) {
    res.redirect('home');
    return;
  }

  var topic_id = req.params.tid;
  var method = req.method.toLowerCase();
  if (method === 'get') {
    if (topic_id.length !== 24) {
      res.render('notify/notify', {error: '此话题不存在或已被删除。'});
      return;
    }
    exports.getTopicById(topic_id, function (err, topic, tags) {
      if (!topic) {
        res.render('notify/notify', {error: '此话题不存在或已被删除。'});
        return;
      }
      if (topic.author_id === req.session.user._id || req.session.user.is_admin) {
        tag_ctrl.getAllTags(function (err, all_tags) {
          if (err) {
            return next(err);
          }
          for (var i = 0; i < tags.length; i++) {
            for (var j = 0; j < all_tags.length; j++) {
              if (tags[i].id === all_tags[j].id) {
                all_tags[j].is_selected = true;
              }
            }
          }

          res.render('topic/edit', {action: 'edit', topic_id: topic._id, title: topic.title, content: topic.content, tags: all_tags});
        });
      } else {
        res.render('notify/notify', {error: '对不起，你不能编辑此话题。'});
        return;
      }
    });
  }

  if (method === 'post') {
    if (topic_id.length !== 24) {
      res.render('notify/notify', {error: '此话题不存在或已被删除。'});
      return;
    }
    exports.getTopicById(topic_id, function (err, topic) {
      if (!topic) {
        res.render('notify/notify', {error: '此话题不存在或已被删除。'});
        return;
      }
      if (topic.author_id === req.session.user._id || req.session.user.is_admin) {
        var title = sanitize(req.body.title).trim();
        title = sanitize(title).xss();
        var content = req.body.t_content;
        var topic_tags = [];
        if (req.body.topic_tags !== '') {
          topic_tags = req.body.topic_tags.split(',');
        }

        if (title === '') {
          tag_ctrl.getAllTags(function (err, all_tags) {
            if (err) {
              return next(err);
            }
            for (var i = 0; i < topic_tags.length; i++) {
              for (var j = 0; j < all_tags.length; j++) {
                if (topic_tags[i] === all_tags[j]._id) {
                  all_tags[j].is_selected = true;
                }
              }
            }
            res.render('topic/edit', {action: 'edit', edit_error: '标题不能是空的。', topic_id: topic._id, content: content, tags: all_tags});
            return;
          });
        } else {
          //保存话题
          //删除topic_tag，标签topic_count减1
          //保存新topic_tag
          topic.title = title;
          topic.content = content;
          topic.update_at = new Date();
          topic.save(function (err) {
            if (err) {
              return next(err);
            }

            var proxy = new EventProxy();
            var render = function () {
              res.redirect('/topic/' + topic._id);
            };
            proxy.assign('tags_removed_done', 'tags_saved_done', render);
            proxy.fail(next);

            // 删除topic_tag
            var tags_removed_done = function () {
              proxy.emit('tags_removed_done');
            };
            TopicTag.find({topic_id: topic._id}, function (err, docs) {
              if (docs.length === 0) {
                proxy.emit('tags_removed_done');
              } else {
                proxy.after('tag_removed', docs.length, tags_removed_done);
                // delete topic tags
                docs.forEach(function (doc) {
                  doc.remove(proxy.done(function () {
                    tag_ctrl.getTagById(doc.tag_id, proxy.done(function (tag) {
                      proxy.emit('tag_removed');
                      tag.topic_count -= 1;
                      tag.save();
                    }));
                  }));
                });
              }
            });

            // 保存topic_tag
            var tags_saved_done = function () {
              proxy.emit('tags_saved_done');
            };
            //话题可以没有标签
            if (topic_tags.length === 0) {
              proxy.emit('tags_saved_done');
            } else {
              proxy.after('tag_saved', topic_tags.length, tags_saved_done);
              //save topic tags
              topic_tags.forEach(function (tag) {
                var topic_tag = new TopicTag();
                topic_tag.topic_id = topic._id;
                topic_tag.tag_id = tag;
                topic_tag.save(proxy.done('tag_saved'));
                tag_ctrl.getTagById(tag, proxy.done(function (tag) {
                  tag.topic_count += 1;
                  tag.save();
                }));
              });
            }

            //发送at消息
            at_ctrl.sendMessageToMentionUsers(content, topic._id, req.session.user._id);
          });
        }
      } else {
        res.render('notify/notify', {error: '对不起，你不能编辑此话题。'});
        return;
      }
    });
  }
};

exports.delete = function (req, res, next) {
  //删除话题, 话题作者topic_count减1
  //删除回复，回复作者reply_count减1
  //删除topic_tag，标签topic_count减1
  //删除topic_collect，用户collect_topic_count减1
  if (!req.session.user || !req.session.user.is_admin) {
    return res.send({success: false, message: '无权限'});
  }
  var topic_id = req.params.tid;
  if (topic_id.length !== 24) {
    return res.send({ success: false, error: '此话题不存在或已被删除。' });
  }
  exports.getTopicById(topic_id, function (err, topic) {
    if (err) {
      return res.send({ success: false, message: err.message });
    }
    if (!topic) {
      return res.send({ success: false, message: '此话题不存在或已被删除。' });
    }
    topic.remove(function (err) {
      if (err) {
        return res.send({ success: false, message: err.message });
      }
      res.send({ success: true, message: '话题已被删除。' });
    });
  });
};

exports.top = function (req, res, next) {
  if (!req.session.user.is_admin) {
    res.redirect('home');
    return;
  }
  var topic_id = req.params.tid;
  var is_top = req.params.is_top;
  if (topic_id.length !== 24) {
    res.render('notify/notify', {error: '此话题不存在或已被删除。'});
    return;
  }
  exports.getTopicById(topic_id, function (err, topic) {
    if (err) {
      return next(err);
    }
    if (!topic) {
      res.render('notify/notify', {error: '此话题不存在或已被删除。'});
      return;
    }
    topic.top = is_top;
    topic.save(function (err) {
      if (err) {
        return next(err);
      }
      var msg = topic.top ? '此话题已经被置顶。' : '此话题已经被取消置顶。';
      res.render('notify/notify', {success: msg});
    });
  });
};

exports.collect = function (req, res, next) {
  if (!req.session || !req.session.user) {
    res.send('forbidden!');
    return;
  }
  var topic_id = req.body.topic_id;
  Topic.findOne({_id: topic_id}, function (err, topic) {
    if (err) {
      return next(err);
    }
    if (!topic) {
      res.json({status: 'failed'});
    }

    TopicCollect.findOne({user_id: req.session.user._id, topic_id: topic._id}, function (err, doc) {
      if (err) {
        return next(err);
      }
      if (doc) {
        res.json({status: 'success'});
        return;
      }

      var topic_collect = new TopicCollect();
      topic_collect.user_id = req.session.user._id;
      topic_collect.topic_id = topic._id;
      topic_collect.save(function (err) {
        if (err) {
          return next(err);
        }
        res.json({status: 'success'});
      });
      user_ctrl.getUserById(req.session.user._id, function (err, user) {
        if (err) {
          return next(err);
        }
        user.collect_topic_count += 1;
        user.save();
      });

      req.session.user.collect_topic_count += 1;
      topic.collect_count += 1;
      topic.save();
    });
  });
};

exports.de_collect = function (req, res, next) {
  if (!req.session || !req.session.user) {
    res.send('fobidden!');
    return;
  }
  var topic_id = req.body.topic_id;
  Topic.findOne({_id: topic_id}, function (err, topic) {
    if (err) {
      return next(err);
    }
    if (!topic) {
      res.json({status: 'failed'});
    }
    TopicCollect.remove({user_id: req.session.user._id, topic_id: topic._id}, function (err) {
      if (err) {
        return next(err);
      }
      res.json({status: 'success'});
    });

    user_ctrl.getUserById(req.session.user._id, function (err, user) {
      if (err) {
        return next(err);
      }
      user.collect_topic_count -= 1;
      user.save();
    });

    topic.collect_count -= 1;
    topic.save();

    req.session.user.collect_topic_count -= 1;
  });
};

// get topic without replies
exports.getTopicById = function (id, cb) {
  var proxy = new EventProxy();
  var done = function (topic, tags, author, last_reply) {
    return cb(null, topic, tags, author, last_reply);
  };
  proxy.assign('topic', 'tags', 'author', 'last_reply', done);
  proxy.fail(cb);

  Topic.findOne({_id: id}, proxy.done(function (topic) {
    if (!topic) {
      proxy.emit('topic', null);
      proxy.emit('tags', []);
      proxy.emit('author', null);
      proxy.emit('last_reply', null);
      return;
    }
    proxy.emit('topic', topic);

    TopicTag.find({topic_id: topic._id}, proxy.done(function (topic_tags) {
      var tags_id = [];
      for (var i = 0; i < topic_tags.length; i++) {
        tags_id.push(topic_tags[i].tag_id);
      }
      tag_ctrl.getTagsByIds(tags_id, proxy.done('tags'));
    }));

    user_ctrl.getUserById(topic.author_id, proxy.done('author'));

    if (topic.last_reply) {
      reply_ctrl.getReplyById(topic.last_reply, proxy.done(function (last_reply) {
        proxy.emit('last_reply', last_reply || null);
      }));
    } else {
      proxy.emit('last_reply', null);
    }
  }));
}
// get topic with replies
exports.getFullTopic = function (id, cb) {
  var proxy = new EventProxy();
  var done = function (topic, tags, author, replies) {
    return cb(null, '', topic, tags, author, replies);
  };
  proxy.assign('topic', 'tags', 'author', 'replies', done);
  proxy.fail(cb);

  Topic.findOne({_id: id}, proxy.done(function (topic) {
    if (!topic) {
      proxy.unbind();
      return cb(null, '此话题不存在或已被删除。');
    }
    proxy.emit('topic', topic);

    TopicTag.find({topic_id: topic._id}, proxy.done(function (topic_tags) {
      var tags_ids = [];
      for (var i = 0; i < topic_tags.length; i++) {
        tags_ids.push(topic_tags[i].tag_id);
      }
      tag_ctrl.getTagsByIds(tags_ids, proxy.done('tags'));
    }));

    user_ctrl.getUserById(topic.author_id, proxy.done(function (author) {
      if (!author) {
        proxy.unbind();
        return cb(null, '话题的作者丢了。');
      }
      proxy.emit('author', author);
    }));

    reply_ctrl.getRepliesByTopicId(topic._id, proxy.done('replies'));
  }));
}
exports.getTopicsByQuery = function (query, opt, cb) {
  Topic.find(query, ['_id'], opt, function (err, docs) {
    if (err) {
      return cb(err);
    }
    if (docs.length === 0) {
      return cb(null, []);
    }

    var topics_id = [];
    for (var i = 0; i < docs.length; i++) {
      topics_id.push(docs[i]._id);
    }

    var proxy = new EventProxy();
    var topics = [];
    proxy.after('topic_ready', topics_id.length, function () {
      return cb(null, topics);
    });
    proxy.fail(cb);

    topics_id.forEach(function (id, i) {
      exports.getTopicById(id, proxy.done(function (topic, tags, author, last_reply) {
        topic.tags = tags;
        topic.author = author;
        topic.reply = last_reply;
        topic.friendly_create_at = Util.format_date(topic.create_at, true);
        topics[i] = topic;
        proxy.emit('topic_ready');
      }));
    });
  });
};

exports.getCountByQuery = function (query, cb) {
  Topic.count(query, cb);
};