/*
 * Possible strategies for updating the topic:
 *
 * o Set the topic unconditionally when the feed changes. This makes
 *   it possible for users to change the topic and it won't be
 *   overridden until the feed changes.
 *
 * o Set the topic on any topic change (making the feed control the
 *   entire topic)
 *
 * o Support a delimiter so it can control only a part of the topic,
 *   like "<>". Example
 *
 *   Next meeting, sat 1900 <> DATA FROM FEED.
 *
 *   A regexp selecting the are to be updated might conver it.
 *
 * o If the bot changed the topic the last time, it's probably safe to
 *   just update it.
 */

var node_irc = require('../node_modules/node-irc/IRC.js')
  , cron = require('cron').CronJob
  , parser = require('blindparser')
  , events = require('events')
  , _ = require('underscore');

var parserOptions = {};

var config;
var cronJobs = [];

var state = {
  channelTopic: undefined,
  irc: undefined,
  updatingFeed: false,
  feeds: [],
  newest: {
    timestamp: 0,
    text: undefined
  }
};
module.exports.state = state;

var eventEmitter = new events.EventEmitter;

function startIrc() {
  irc = new node_irc.IRC(config.host, config.port);
  irc.on('raw', function(data) { console.log(data) });
  irc.on('connected', function(server) {
    console.log('Connected to ' + server);
    irc.join(config.channel, function(error) {
      irc.notice(config.channel, 'well hello yall');
    });
  });
  irc.topic = function(channel, topic) {
    irc._socket.write('topic ' + channel + ' :' + topic + '\r\n');
  };

  irc.on('topic', function(channel, topic) {
    console.log("new topic: " + topic);
    /* If we're not storing this, it is possible for people to set
     * the topic after the bot has set it and it will persist (until
     * next update from the feed).
    topic = t;
     */

    state.channelTopic = topic;
  });
}

function updateFeed(feedState) {
  console.log("Fetching " + feedState.url);
  if(feedState.updatingFeed)
    console.log("Already working");
  feedState.updatingFeed = true;

  parser.parseURL(feedState.url, parserOptions, function(err, feed) {
//    console.log("Fetched " + feedState.url + ", status=" + (err ? "failure" : "success"));
    if(err) {
      console.log(err);
      return;
    }
    var newest = processFeed(feed);
    if(typeof newest == "object") {
      eventEmitter.emit("feedChanged", feedState.url, newest);
    }
    feedState.updatingFeed = false;
  });
}

function processFeed(feed) {
  // Extracts the username from the feed.
  // TODO: Use something better than blindparser to parse atom so that
  // each entry has an author too to get the full name.
  if(typeof feed.items[0] == "undefined") {
    console.log("feed does not contain any items", feed);
    return undefined;
  }
  var match = /^http:\/\/twitter.com\/([a-zA-Z0-9_]+)\/.*$/.exec(feed.items[0].link)
  if(match.length != 2) {
    return undefined;
  }
  return {
    text: feed.items[0].title,
    author: match[1],
    timestamp: feed.items[0].date
  };
}
module.exports.processFeed = processFeed;

eventEmitter.on("feedChanged", function(url, newest) {
  state.feeds[url] = newest;

  if(state.newest.timestamp >= newest.timestamp) {
//    console.log("oold: " + newest.text);
    return;
  }

  var text = newest.author + ": " + newest.text;
  console.log("New topic", newest.timestamp, url, text);
  state.newest = newest;
  if(config.connect && state.topic != text) {
    irc.topic(config.channel, text);
  }
});

eventEmitter.on("configUpdated", function(c) {
  setup();
});

function setup() {
  console.log("Stopping " + cronJobs.length + " cron jobs");
  _.each(cronJobs, function(job) { job.stop(); });
  cronJobs = [];
  _.each(config.feeds, function(feed) {
    var state = {
      url: feed,
      updatingFeed: false,
      last: undefined
    };
    var job = new cron("*/10 * * * *", function() {
      updateFeed(state);
    }, function() {}, true);
    cronJobs.push(job);
  });
}

function start(c) {
  config = c;
  startIrc();
  setup();
  if(config.connect) {
    console.log('Connecting to ' + config.host + ':' + config.port);
    irc.connect(config.nick);
  } else {
    console.log('Not connecting to IRC');
  }
}

module.exports.start = start;

module.exports.emit = function(config) {
  eventEmitter.emit("configUpdated", config);
}