<?php
/* -*- tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
# ***** BEGIN LICENSE BLOCK *****
# This file is part of Plume Framework, a simple PHP Application Framework.
# Copyright (C) 2001-2007 Loic d'Anterroches and contributors.
#
# Plume Framework is free software; you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
#
# Plume Framework 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#
# ***** END LICENSE BLOCK ***** */


class Pluf_Date
{
    /**
     * Get a GM Date in the format YYYY-MM-DD HH:MM:SS and returns a
     * string with the given format in the current timezone.
     *
     * @param string GMDate
     * @param string Format to be given to strftime ('%Y-%m-%d %H:%M:%S')
     * @return string Formated GMDate into the local time
     */
     public static function gmDateToString($gmdate, $format='%Y-%m-%d %H:%M:%S')
     {
         $time = strtotime($gmdate.'Z');
         return strftime($format, $time);
     }

    /**
     * Get a GM Date in the format YYYY-MM-DD HH:MM:SS and returns a
     * string with the given format in GMT.
     *
     * @param string GMDate
     * @param string Format to be given to date ('c')
     * @return string Formated GMDate into GMT
     */
     public static function gmDateToGmString($gmdate, $format='c')
     {
         $time = strtotime($gmdate.'Z');
         return date($format, $time);
     }

     /**
      * Day compare.
      *
      * Compare if the first date is before or after the second date.
      * Returns:
      *    0 if the days are the same.
      *    1 if the first date is before the second.
      *   -1 if the first date is after the second.
      *
      * @param string YYYY-MM-DD date.
      * @param string YYYY-MM-DD date (today local time).
      * @return int
      */
     public static function dayCompare($date1, $date2=null)
     {
         $date2 = (is_null($date2)) ? date('Y-m-d') : $date2;
         if ($date2 == $date1) return 0;
         if ($date1 > $date2) return -1;
         return 1;
     }
}

/**
 * Set of functions to manage dates.
 */

/**
 * Compare two date and returns the number of seconds between the
 * first and the second. If only the date is given without time, the
 * end of the day is used (23:59:59).
 *
 * @param string Date to compare for ex: '2006-09-17 18:42:00'
 * @param string Second date to compare if null use now (null)
 * @return int Number of seconds between the two dates. Negative 
 *             value if the second date is before the first. 
 */
function Pluf_Date_Compare($date1, $date2=null)
{
    if (strlen($date1) == 10) {
        $date1 .= ' 23:59:59';
    }
    if (is_null($date2)) {
        $date2 = time();
    } else {
        if (strlen($date2) == 10) {
            $date2 .= ' 23:59:59';
        }
        $date2 = strtotime(str_replace('-', '/', $date2));
    }
    $date1 = strtotime(str_replace('-', '/', $date1));
    return $date2 - $date1;
}

/**
 * Display a date in the format:
 * X days Y hours ago
 * X hours Y minutes ago
 * X hours Y minutes left
 *
 * "resolution" is year, month, day, hour, minute.
 *
 * If not time is given, only the day, the end of the day is
 * used: 23:59:59.
 *
 * @param string Date to compare with ex: '2006-09-17 18:42:00'
 * @param string Reference date to compare with by default now (null)
 * @param int Maximum number of elements to show (2)
 * @param string If no delay between the two dates display ('now')
 * @param bool Show ago/left suffix
 * @return string Formatted date
 */
function Pluf_Date_Easy($date, $ref=null, $blocks=2, $notime='now', $show=true)
{
    if (strlen($date) == 10) {
        $date .= ' 23:59:59';
    }
    if (is_null($ref)) {
        $ref = date('Y-m-d H:i:s'); 
        $tref = time();
    } else {
        if (strlen($ref) == 10) {
            $ref .= ' 23:59:59';
        }
        $tref = strtotime(str_replace('-', '/', $ref));
    }
    $tdate = strtotime(str_replace('-', '/', $date));
    $past = true;
    if ($tref < $tdate) {
        // date in the past
        $past = false;
        $_tmp = $ref;
        $ref = $date;
        $date = $_tmp;
    }
    $ref = str_replace(array(' ', ':'), '-', $ref);
    $date = str_replace(array(' ', ':'), '-', $date);
    $refs = split('-', $ref);
    $dates = split('-', $date);
    // Modulo on the month is dynamically calculated after
    $modulos = array(365, 12, 31, 24, 60, 60);
    // day in month 
    $month = $refs[1] - 1;
    $modulos[2] = date('t', mktime(0, 0, 0, $month, 1, $refs[0]));
    $diffs = array();
    for ($i=0; $i<6; $i++) {
        $diffs[$i] = $refs[$i] - $dates[$i];
    }
    $retain = 0;
    for ($i=5; $i>-1; $i--) {
        $diffs[$i] = $diffs[$i] - $retain;
        $retain = 0;
        if ($diffs[$i] < 0) {
            $diffs[$i] = $modulos[$i] + $diffs[$i];
            $retain = 1;
        }
    }
    $res = '';
    $total = 0;
    for ($i=0; $i<5; $i++) {
        if ($diffs[$i] > 0) {
            $total++;
            $res .= $diffs[$i].' ';
            switch ($i) {
            case 0: 
                $res .= _n('year', 'years', $diffs[$i]);
            	break;
            case 1: 
                $res .= _n('month', 'months', $diffs[$i]);
            	break;
            case 2: 
                $res .= _n('day', 'days', $diffs[$i]);
            	break;
            case 3: 
                $res .= _n('hour', 'hours', $diffs[$i]);
            	break;
            case 4: 
                $res .= _n('minute', 'minutes', $diffs[$i]);
            	break;
            case 5: 
                $res .= _n('second', 'seconds', $diffs[$i]);
            	break;
            }
            $res .= ' ';
        }
        if ($total >= $blocks) break;
    }
    if (strlen($res) == 0) {
        return $notime;
    }
    if ($show) {
        if ($past) {
            $res = sprintf(__('%s ago'), $res);
        } else {
            $res = sprintf(__('%s left'), $res);
        }
    }
    return $res;
}