<?php

/*
Plugin Name: Better Category Lists
Plugin URI: http://laughingmeme.org
Description: Better Category Lists
Version: 0.1
Author: Kellan
Author URI: http://laughingmeme.org
*/

/**
wp_list_popular_categories - wp_list_cats but only categoreries with $cat_threshold posts
*/

function wp_list_popular_categories($args) {
    add_filter('list_cats_exclusions', 'filter_popular_cats_only');

    parse_str($args, $r);

    $GLOBALS['__better_cat_lists_threshold'] = intval($r['cat_threshold']);
    wp_list_cats($args);

    remove_filter('list_cats_exclusions', 'filter_popular_cats_only');          
}

function filter_popular_cats_only($exclusion_str) {
    global $wpdb;

    $threshold = $GLOBALS['__better_cat_lists_threshold'];

    $cats = $wpdb->get_results("SELECT cat_ID FROM $wpdb->categories WHERE category_count >= $threshold");

    $cat_ids = array();

    foreach ($cats as $cat) {
        if ($count < $threshold ) {
            $cat_ids[] = $cat->cat_ID;
        }
    }

    if (count($cat_ids)) {
        $exclusion_str .= " AND cat_ID IN (" . join(',', $cat_ids) . ") ";
    }

    return $exclusion_str;
}

/**
wp_list_popular_categories - categories of posts more recent then $days_ago days
*/

function wp_list_recent_categories($args) {
    add_filter('list_cats_exclusions', 'filter_recent_cats_only');

    parse_str($args, $r);                                                                                                                                          
    $GLOBALS['__better_cat_lists_ago'] = intval($r['days_ago']);
    $GLOBALS['__better_cat_lists_limit'] = intval($r['cat_limit']);                                                                                        

    wp_list_cats($args);                                           

    remove_filter('list_cats_exclusions', 'filter_recent_cats_only');          
}

function filter_recent_cats_only($exclusion_str ='') {
    global $wpdb;

    $ago = date("Y-m-d H:i:s", time() - (60*60*24*$GLOBALS['__better_cat_lists_ago'] ));


    $limit = $GLOBALS['__better_cat_lists_limit'];	

    $sql = "SELECT wp_post2cat.category_id FROM wp_posts, wp_post2cat " .
        "WHERE wp_posts.ID = wp_post2cat.post_id AND post_date > '$ago' " .
        "ORDER BY post_date desc";

    $cats = $wpdb->get_results($sql);

    $cat_ids = array();

    foreach ($cats as $cat) {                                                    
        $cat_ids[] = $cat->category_id;
    }

    if($limit) {
        $cat_ids = array_splice($cat_ids, 0, $limit);
    }

    if (count($cat_ids)) {
        $exclusion_str .= " AND cat_ID IN (" . join(',', $cat_ids) . ") ";
    }

    return $exclusion_str;   
}

?>