<?php

/*

Copyright (c) 2005, Alex Tingle.  $Revision: 287 $

This program is free software; you can redistribute it and/or

modify it under the terms of the GNU General Public License

as published by the Free Software Foundation; either version 2

of the License, or (at your option) any later version.

This program 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 General Public License for more details.

You should have received a copy of the GNU General Public License

along with this program; if not, write to the Free Software

Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

*/

/** Calendar class. Encapsulates all functionality concerning the calendar - 

 *  how many days in each month, leap years, days of the week, locale

 *  names etc. */

class ec3_Date

{

  var $year_num =0;

  var $month_num=0;

  var $day_num  =1;

  var $_unixdate      =0;

  var $_days_in_month =0;

  function ec3_Date($year_num=0,$month_num=0,$day_num=0)

  {

    global $ec3;

    if($year_num>0)

    {

      $this->year_num =$year_num;

      $this->month_num=$month_num;

      $this->day_num  =$day_num;

    }

    if(0==$this->year_num && is_single())

        $this->from_single();

    if(0==$this->year_num && $ec3->is_date_range)

        $this->from_date_range();

    if(0==$this->year_num)

        $this->from_date(); // Falls back to today.

  }

  function from_single()

  {

    global $wp_query;

    if($wp_query->posts && $wp_query->posts[0]->ec3_schedule)

    {

      $this->year_num=

        intval(mysql2date('Y',$wp_query->posts[0]->ec3_schedule[0]->start));

      $this->month_num=

        intval(mysql2date('m',$wp_query->posts[0]->ec3_schedule[0]->start));

    }

  }

  function from_date_range()

  {

    global $wp_query;

    if('' != $wp_query->query_vars['ec3_from'])

    {

      $c=explode('_',$wp_query->query_vars['ec3_from']);

      $this->year_num=intval($c[0]);

      $this->month_num=intval($c[1]);

    }

  }

  /** Utility function. Calculates the value of month/year for the current

   *  page. Code block from wp-includes/template-functions-general.php

   *  (get_calendar function). */

  function from_date()

  {

    global

      $m,

      $monthnum,

      $wpdb,

      $year;

    if (isset($_GET['w'])) {

        $w = ''.intval($_GET['w']);

    }

    // Let's figure out when we are

    if (!empty($monthnum) && !empty($year)) {

        $thismonth = ''.zeroise(intval($monthnum), 2);

        $thisyear = ''.intval($year);

    } elseif (!empty($w)) {

        // We need to get the month from MySQL

        $thisyear = ''.intval(substr($m, 0, 4));

        $d = (($w - 1) * 7) + 6; //it seems MySQL's weeks disagree with PHP's

        $thismonth = $wpdb->get_var("SELECT DATE_FORMAT((DATE_ADD('${thisyear}0101', INTERVAL $d DAY) ), '%m')");

    } elseif (!empty($m)) {

//        $calendar = substr($m, 0, 6);

        $thisyear = ''.intval(substr($m, 0, 4));

        if (strlen($m) < 6) {

            $thismonth = '01';

        } else {

            $thismonth = ''.zeroise(intval(substr($m, 4, 2)), 2);

        }

    } else {

        $thisyear=ec3_strftime("%Y");

        $thismonth=ec3_strftime("%m");

    }

    $this->year_num =intval($thisyear);

    $this->month_num=intval($thismonth);

    $this->day_num  =1;

  }

  /** Month arithmetic. Returns a new date object. */

  function plus_months($month_count)

  {

    $result=new ec3_Date($this->year_num,$this->month_num,$this->day_num);

    $result->month_num += $month_count;

    if($month_count>0)

    {

      while($result->month_num>12)

      {

        $result->month_num -= 12;

        $result->year_num++;

      }

    }

    else

    {

      while($result->month_num<1)

      {

        $result->month_num += 12;

        $result->year_num--;

      }

    }

    return $result;

  }

  /** Convenience function for accessing plus_months(). */

  function prev_month() { return $this->plus_months(-1); }

  function next_month() { return $this->plus_months( 1); }

  /** Modifies the current object to be one day in the future. */

  function increment_day()

  {

    $this->day_num++;

    if($this->day_num > $this->days_in_month())

    {

      $this->day_num=1;

      $this->month_num++;

      if($this->month_num>12)

      {

        $this->month_num=1;

        $this->year_num++;

      }

      $this->_days_in_month=0;

    }

    $this->_unixdate=0;

  }

  function month_id() // e.g. ec3_2005_06

  {

    return 'ec3_' . $this->year_num . '_' . $this->month_num;

  }

  function day_id()  // e.g. ec3_2005_06_25

  {

    $result='ec3_'.$this->year_num.'_'.$this->month_num.'_'.$this->day_num;

    global $ec3_today_id;

    if($result==$ec3_today_id)

      return 'today';

    else

      return $result;

  }

  function day_link()

  {

    global $ec3;

    if($ec3->show_only_events)

    {

      return get_option('home') . '/?m='

       . $this->year_num

       . zeroise($this->month_num, 2)

       . zeroise($this->day_num, 2)

       . "&cat=" . $ec3->event_category;

    }

    else

      return get_day_link($this->year_num,$this->month_num,$this->day_num);

  }

  function month_name() // e.g. June

  {

    global $month;

    return $month[zeroise($this->month_num,2)];

  }

  function month_abbrev() // e.g. Jun

  {

    global $month_abbrev;

    return $month_abbrev[ $this->month_name() ];

  }

  function month_link()

  {

    global $ec3;

    if($ec3->show_only_events)

    {

      return get_option('home') . '/?m='

       . $this->year_num

       . zeroise($this->month_num, 2)

       . "&cat=" . $ec3->event_category;

    }

    else

      return get_month_link($this->year_num,$this->month_num);

  }

  function days_in_month()

  {

    if(0==$this->_days_in_month)

      $this->_days_in_month=intval(date('t', $this->to_unixdate()));

    return $this->_days_in_month;

  }

  function week_day()

  {

    return intval(date('w', $this->to_unixdate()));

  }

  function to_unixdate()

  {

    if(0==intval($this->_unixdate))

    {

      $this->_unixdate =

        mktime(0,0,0, $this->month_num,$this->day_num,$this->year_num);

    }

    return $this->_unixdate;

  }

} // end class ec3_Date

/** Converts a MySQL date object into an EC3 date object. */

function ec3_mysql2date(&$mysqldate)

{

  $as_str=mysql2date('Y,n,j',$mysqldate);

  $as_arr=explode(',',$as_str);

  return new ec3_Date($as_arr[0],$as_arr[1],$as_arr[2]);

}

/** Converts a day or month Id to a PHP date. */

function ec3_dayid2php(&$id)

{

  $parts=explode('_',$id);

  $year =intval($parts[1]);

  $month=intval($parts[2]);

  $day  =(count($parts)>=4? intval($parts[3]): 1);

  return mktime( 0,0,0, $month,$day,$year);

}

?>