/*
 *  rhwebimport
 *
 *  Copyright (C) 2014-2015 Christian Pointner <equinox@helsinki.at>
 *
 *  This file is part of rhwebimport.
 *
 *  rhwebimport is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  any later version.
 *
 *  rhwebimport is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with rhwebimport. If not, see <http://www.gnu.org/licenses/>.
 */

alertbox = function() {}
alertbox.warning = function (dest, heading, message) {
  $('#' + dest + ' .alertbox').html('<div class="alert"><a class="close" data-dismiss="alert" href="#">&times;</a><h4 class="alert-heading">' + heading + '</h4>' + message + '</div>');
}
alertbox.error = function (dest, heading, message) {
  $('#' + dest + ' .alertbox').html('<div class="alert alert-error"><a class="close" data-dismiss="alert" href="#">&times;</a><h4 class="alert-heading">' + heading + '</h4>' + message + '</div>');
}
alertbox.info = function (dest, heading, message) {
  $('#' + dest + ' .alertbox').html('<div class="alert alert-info"><a class="close" data-dismiss="alert" href="#">&times;</a><h4 class="alert-heading">' + heading + '</h4>' + message + '</div>');
}

Number.prototype.pad = function(size) {
  var s = String(this);
  while (s.length < (size || 2)) {s = "0" + s;}
  return s;
}

var weekday = new Array(7);
weekday[0] = "Sonntag";
weekday[1] = "Montag";
weekday[2] = "Dienstag";
weekday[3] = "Mittwoch";
weekday[4] = "Donnerstag";
weekday[5] = "Freitag";
weekday[6] = "Samstag";

function format_datetime(d) {
  if(Object.prototype.toString.call(d) === "[object Date]") {
    var daynames = new Array('So', 'Mo', 'Di', 'Mi', 'Do', 'Fr', 'Sa');
    var datetimestr = daynames[d.getDay()];
    datetimestr += ' ' + Number(d.getDate()).pad(2);
    datetimestr += '.' + Number(d.getMonth() + 1).pad(2);
    datetimestr += '.' + d.getFullYear();
    datetimestr += ' ' + Number(d.getHours()).pad(2);
    datetimestr += ':' + Number(d.getMinutes()).pad(2);
    datetimestr += ':' + Number(d.getSeconds()).pad(2);
    return datetimestr;
  }
  return d;
}

function msToTimeString(time) {
  if(time == '-') return time;

  var h = Number(Math.floor(time / 3600000));
  time %= 3600000;
  var m = Number(Math.floor(time / 60000));
  time %= 60000;
  var s = Number(Math.floor(time / 1000));
  var hs = Number(Math.floor((time % 1000)/100));

  return h + ':' + m.pad(2) + ':' + s.pad(2) + '.' + hs;
}

function get_tz_offset(today) {
  //
  // This computes the timezone offset for Europe/Vienna
  // in seconds. This is either 3600 or 7200 depending on
  // daylight savings time...
  // For Europe/Vienna daylight saving starts on the last
  // Sunday in March and ends on the last Sunday in October
  //
  var m = today.getMonth();
  if (m < 2 || m > 9) return 3600;
  if (m > 2 || m < 9) return 7200;
  var lsdm = today.getDate() - today.getDay(); // day of month of the last sunday
  if(m == 2) {
    if(lsdm < 25) return 3600; // last sunday was not the last sunday of the month
    if(today.getDay() == 0 && today.getHours() >= 2) return 7200; // this is the last sunday
    if(lsdm < today.getDate()) return 7200; // we are after the last sunday
  }
  if(m == 9) {
    if(lsdm < 25) return 7200; // last sunday was not the last sunday of the month
    if(today.getDay() == 0 && today.getHours() < 3) return 7200; // this is the last sunday
  }
  return 3600;
}

function get_rd_week() {
  //
  // This computes the current Rivendell Week based on the number
  // of weeks since epoch.
  //
  // Explanation:
  //  epoch was at 01.01.1970 which was a Thursday.
  //  Monday in that week is (s-from-epoch + 3*24*60*60) seconds ago.
  //  This needs to be adjusted by the timezone offset for Europe/Vienna
  //  which is of course not constant (damn you daylight savings time)
  //  Divide this by (7*24*60*60) and you get the number of
  //  weeks since the Monday in the week of epoch adjusted for timezone offsets.
  //  This week had week number 3 so add an offset of 2 and
  //  get the modulo of 4. This rounded down gives you the current week
  //  with 0 meaning Week 1. So add 1 to that number and you will get
  //  the current RD week.
  //
  var today = new Date();
  var sEpoch = ((+today) / 1000) + get_tz_offset(today);
  var week = Math.floor((((sEpoch + 259200)/604800) + 2) % 4) + 1;
  return week;
}

function Clock(draw_callback) {
  this.draw_callback = draw_callback;
  this.daynames = new Array('So', 'Mo', 'Di', 'Mi', 'Do', 'Fr', 'Sa');

  this.last_message = { t1: 0, t2: 0, t3: 0, t4: 0, tz_offset: 3600, week: 3 };
  this.clock_offset = 0;
  this.clock_rtt = 0;

  this.redraw = function() {
    var rdtime_ms = (+new Date()) + (this.last_message.tz_offset * 1000) + this.clock_offset;

    var rdtime = new Date(rdtime_ms);
    var date_str = this.daynames[rdtime.getUTCDay()]  + ', ';
    date_str += rdtime.getUTCDate() + '.' + (rdtime.getUTCMonth() + 1) + '.' + rdtime.getUTCFullYear();

    var time_str = (rdtime.getUTCHours() > 9 ? ' ' : ' 0') + rdtime.getUTCHours();
    time_str += (rdtime.getUTCMinutes() > 9 ? ':' : ':0') + rdtime.getUTCMinutes();
    time_str += (rdtime.getUTCSeconds() > 9 ? ':' : ':0') + rdtime.getUTCSeconds();

    this.draw_callback(date_str, time_str, this.last_message.week);
  }

  this.ntp_update = function(event) {
    var t4 = (+new Date());

    var msg = JSON.parse(event.data);
    msg.t4 = t4;
    this.last_message = msg;
    this.clock_offset = ((msg.t2 - msg.t1) + (msg.t3 - msg.t4)) / 2;
    this.clock_rtt = (msg.t4 - msg.t1) - (msg.t3 - msg.t2);
    console.log("got new ntp message from rhrdtime (rtt=" + this.clock_rtt + " ms): new offset = " + this.clock_offset + " ms");
  }

  this.ntp_request = function() {
    this.sock.send(JSON.stringify({ t1: (+new Date()), t2: 0, t3: 0, t4: 0, tz_offset: 0, week: 0 }));
  }

  this.sock_onopen = function() {
    this.ntp_request();
    this.interval_request = setInterval(this.ntp_request.bind(this), 5000);
  }

  this.start = function() {
    this.sock = new WebSocket("wss://" + window.location.host + "/ntp");
    this.sock.onmessage = this.ntp_update.bind(this);
    this.sock.onopen = this.sock_onopen.bind(this);
    this.interval_redraw = setInterval(this.redraw.bind(this), 200);
  }
  this.stop = function() {
    clearInterval(this.interval_redraw);
    delete this.interval_redraw;
    clearInterval(this.interval_request);
    delete this.interval_request;
    this.sock.close();
  }
}