<?php
/*
 *  Copyright 2008 Blandware (http://www.blandware.com)
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

/**
 * This file contains functions which allow to work with dates and time.
 *
 * @package     AtleapLite
 * @author      Roman Puchkovskiy
 * @license     http://www.apache.org/licenses/LICENSE-2.0  Apache License, Version 2.0
 */

/**
 * Makes a timestamp from a string.
 *
 * @param string $string    string that represents some date/time
 */
function makeTimestamp($string)
{
    if(empty($string)) {
        $string = "now";
    }
    $time = strtotime($string);
    if (is_numeric($time) && $time != -1)
        return $time;

    // is mysql timestamp format of YYYYMMDDHHMMSS?
    if (preg_match('/^\d{14}$/', $string)) {
        $time = mktime(substr($string,8,2),substr($string,10,2),substr($string,12,2),
               substr($string,4,2),substr($string,6,2),substr($string,0,4));

        return $time;
    }

    // couldn't recognize it, try to return a time
    $time = (int) $string;
    if ($time > 0)
        return $time;
    else
        return time();
}

/**
 * Formats a date according to a given format.
 *
 * @param int $value        timestamp to format
 * @param string $pattern   pattern to use when formatting (as date()
 * understands)
 * @return string formatted date
 */
function formatDate($value, $pattern) {
    return date($pattern, $value);
}

/**
 * Parses a date from a string.
 *
 * @param string $value     string to parse
 * @param strig $pattern    pattern
 * @return int timestamp
 * @todo this implementation is extremely stupid :( need to parse it correctly
 */
function parseDate($value, $pattern) {
    if ($pattern == "d.m.Y") {
        list($d, $m, $y) = explode('.', $value);
    } else {
        list($y, $m, $d) = explode('-', $value);
    }
    return mktime(0, 0, 0, $m, $d, $y);
}

/**
 * Converts a date to format understandable by DB.
 *
 * @param string $value string representing date
 * @return string converted date
 */
function dateToDbFormat($value) {
    $value = parseDate($value, DATE_PATTERN);
    return formatDate($value, "Y-m-d");
}

/**
 * Converts a date from format understandable by DB.
 *
 * @param string $value string representing date in DB format
 * @return string converted date
 */
function dateFromDbFormat($value) {
    $value = parseDate($value, "Y-m-d");
    return formatDate($value, DATE_PATTERN);
}

/**
 * Returns the current date formatted for database.
 *
 * @return string formatted date
 */
function getNowDate() {
    return date('Y-m-d H:i:s');
}

/**
 * Determines whether the current date/time is between two dates which are
 * given using the database representation.
 *
 * @param string $begin begin date
 * @param string $end   end date
 * @return true if between (inclusive)
 */
function isNowBetween($begin, $end) {
    $begin = strtotime($begin);
    $end = strtotime($end);
    $now = time();
    return $now >= $begin && $now <= $end;
}

?>