<?php
/**
 * Routines for sorting Program objects
 *
 * @license     GPL
 *
 * @package     MythWeb
 *
 **/

// A global variable to track the last-used session;
    global $last_sort_session;

/**
 * Returns a formatted link to the specified sort field
 **/
    function get_sort_link($field, $string) {
    // Get the URL
        $url = substr($_SERVER['PATH_INFO'], 1);
        if (empty($url))
            $url = str_replace('mythweb.php/', '', $_SERVER['PHP_SELF']);
        else
            $url = str_replace('//', '/', "$url");
    // Build the link
        $link = '<a href="'.$url.'?sortby='.urlencode($field).'">'
                .$string;
        switch (sort_status($field)) {
            case 1:
                $link .= ' <span class="large">&darr;</span>';
                break;
            case -1:
                $link .= ' <span class="large">&uarr;</span>';
                break;
        }
        return $link.'</a>';
    }

/**
 * Returns the sort status of
 **/
    function sort_status($field, $session = NULL) {
    // Null session means to load the last sorted session
        if (!$session)
            $session = $GLOBALS['last_sort_session'];
    // Make sure this is an array
        if (!is_array($_SESSION[$session]))
            $_SESSION[$session] = array();
    // Make sure the field is lower case
        $field = strtolower($field);
    // No sort function for this variable
        if (!function_exists("by_$field"))
            return NULL;
    // Scan the sort array for any entries matching the current choice, and remove them
        $depth = 0;
        foreach ($_SESSION[$session] as $key => $sort) {
            $depth++;
        // No match, continue looking
            if ($sort['field'] != $field)
                continue;
        // What to do now...
            return ($sort['reverse'] ? 0 - $depth : $depth);
        }
    // No match found
        return false;
    }

/**
 * Sorts a list of programs by the user's session preferences
 **/
    function sort_programs(&$programs, $session) {
        $GLOBALS['last_sort_session'] = $session;
    // First, check for a sort variable passed in by the user
        isset($_GET['reverse']) or $_GET['reverse'] = $_POST['reverse'];
        isset($_GET['sortby'])  or $_GET['sortby']  = $_POST['sortby'];
    // Now we build an array the user's sort preferences
        if (!is_array($_SESSION[$session]) || !count($_SESSION[$session]))
            $_SESSION[$session] = array(array('field' => 'airdate',
                                              'reverse' => false),
                                        array('field' => 'title',
                                              'reverse' => false));
    // If we were given a sort parameter, let's put it into the sort preferences
        if ($_GET['sortby']) {
            $_GET['sortby'] = strtolower($_GET['sortby']);
            if (!function_exists('by_'.$_GET['sortby']))
                $_GET['sortby'] = 'title';
        // This sortby method is the first element in the sort array, let's reverse it (unless told otherwise)
            if ($_SESSION[$session][0]['field'] == $_GET['sortby']) {
                if (isset($_GET['reverse']))
                    $_SESSION[$session][0]['reverse'] = ($_GET['reverse'] > 0 || preg_match('/^y/i', $_GET['reverse'])) ? true : false;
                else
                    $_SESSION[$session][0]['reverse'] = $_SESSION[$session][0]['reverse'] ? false : true;
            }
        // Otherwise, we need to parse the array, and add the current choice to the top
            else {
            // Scan the sort array for any entries matching the current choice, and remove them
                foreach ($_SESSION[$session] as $key => $sort) {
                // Found a match, or an old/accidental sort method - remove the sort entry
                    if ($sort['field'] == $_GET['sortby'] || !function_exists('by_'.$sort['field']))
                        unset($_SESSION[$session][$key]);
                }
            // Add this choice to the top of the list
                array_unshift($_SESSION[$session], array('field'   => $_GET['sortby'],
                                                         'reverse' => $_GET['reverse'] ? true : false));
            }
        }
    // No sortby, but requested a reversal of the main field
        elseif ($_GET['reverse'])
            $_SESSION[$session][0]['reverse'] = $_SESSION[$session][0]['reverse'] ? false : true;
    // Once we've processed the information, we should make sure that we're actually sorting an array
        if (!count($programs))
            return;
    // Now we just need to sort the array
        $GLOBALS['user_sort_choice'] = &$_SESSION[$session];
        usort($programs, 'by_user_choice');
        unset($GLOBALS['user_sort_choice']);
    }


    function by_user_choice(&$a, &$b) {
        foreach ($GLOBALS['user_sort_choice'] as $sort) {
            $function = 'by_'.$sort['field'];
            $response = $function($a, $b);
        // Identical response, go on to the next sort choice
            if (!$response)
                continue;
        // Return the result
            return $sort['reverse'] ? -$response : $response;
        }
    }

/**
 * Sort strings but ignore definite articles.
 **/
    function by_no_articles(&$a, &$b) {
        return strcasecmp(preg_replace('/^(?:'.t('regex: articles').')\s+/i', '', $a),
                          preg_replace('/^(?:'.t('regex: articles').')\s+/i', '', $b)
                         );
    }

    function by_title(&$a, &$b) {
        return by_no_articles($a->title, $b->title);
    }

    function by_subtitle(&$a, &$b) {
        return by_no_articles($a->subtitle, $b->subtitle);
    }

    function by_season(&$a, &$b) {
        $asep = sprintf("%04dx%04d", $a->season, $a->episode);
        $bsep = sprintf("%04dx%04d", $b->season, $b->episode);
        return strcasecmp($asep, $bsep);
    }

    function by_type(&$a, &$b) {
        return strcasecmp($a->texttype, $b->texttype);
    }

    function by_description(&$a, &$b) {
        return strcasecmp($a->description, $b->description);
    }

    function by_channum(&$a, &$b) {
        return strnatcasecmp($a->channel->channum, $b->channel->channum);
    }

    function by_originalairdate(&$a, &$b) {
        return strnatcasecmp($a->airdate, $b->airdate);
    }

    function by_episodenumber(&$a, &$b) {
        return strnatcasecmp($a->syndicatedepisodenumber, $b->syndicatedepisodenumber);
    }

    function by_airdate(&$a, &$b) {
        if ($a->starttime == $b->starttime) return 0;
        return ($a->starttime > $b->starttime) ? 1 : -1;
    }

    function by_recdate(&$a, &$b) {
        if ($a->recstartts == $b->recstartts) return 0;
        return ($a->recstartts > $b->recstartts) ? 1 : -1;
    }

    function by_recgroup(&$a, &$b) {
        if ($a->recgroup == $b->recgroup) return 0;
        return ($a->recgroup > $b->recgroup) ? 1 : -1;
    }

    function by_length(&$a, &$b) {
        if ($a->length == $b->length) return 0;
        return ($a->length > $b->length) ? 1 : -1;
    }

    function by_file_size(&$a, &$b) {
        if (function_exists('gmp_cmp')) {
            return gmp_cmp($a->filesize, $b->filesize);
        }
        if ($a->filesize == $b->filesize) return 0;
        return ($a->filesize > $b->filesize) ? 1 : -1;
    }

    function by_director(&$a, &$b) {
        return strcasecmp($a->director, $b->director);
    }

    function by_category(&$a, &$b) {
        if ($a->category == $b->category) return 0;
        return ($a->category > $b->category) ? 1 : -1;
    }

    function by_userrating(&$a, &$b) {
        return strcasecmp($a->userrating, $b->userrating);
    }

    function by_year(&$a, &$b) {
        return strcasecmp($a->year, $b->year);
    }

    function by_recpriority(&$a, &$b) {
        // reverse sort so that high priority is listed first
        if ($a->recpriority == $b->recpriority) return 0;
        return ($a->recpriority > $b->recpriority) ? -1 : 1;
    }

    function by_profile(&$a, &$b) {
        if ($a->profile == $b->profile) return 0;
        return ($a->profile > $b->profile) ? 1 : -1;
    }

    function by_programid(&$a, &$b) {
        return strcasecmp($a->programid, $b->programid);
    }

    function by_transcoder(&$a, &$b) {
        if ($a->transcoder == $b->transcoder) return 0;
        return ($a->transcoder > $b->transcoder) ? 1 : -1;
    }
