<?php
/* vim:set softtabstop=4 shiftwidth=4 expandtab: */
/**
 *
 * LICENSE: GNU General Public License, version 2 (GPLv2)
 * Copyright 2001 - 2013 Ampache.org
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License v2
 * as published by the Free Software Foundation.
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 */

/**
 * Stats Class
 *
 * this class handles the object_count
 * stuff, before this was done in the user class
 * but that's not good, all done through here.
 *
 */
class Stats {

    /* Base vars */
    var $id;
    var $object_type;
    var $object_id;
    var $date;
    var $user;


    /**
      * Constructor
     * This doesn't do anything currently
     */
    public function __construct() {

        return true;

    } // Constructor

    /**
     * clear
     *
     * This clears all stats for _everything_.
     */
    public static function clear() {
        Dba::write('TRUNCATE `object_count`');
        Dba::write('UPDATE `song` SET `played` = 0');
    }

    /**
     * gc
     *
     * This removes stats for things that no longer exist.
     */
    public static function gc() {
        foreach(array('song', 'album', 'artist', 'live_stream', 'video') as $object_type) {
            Dba::write("DELETE FROM `object_count` USING `object_count` LEFT JOIN `$object_type` ON `$object_type`.`id` = `object_count`.`object_id` WHERE `object_type` = '$object_type' AND `$object_type`.`id` IS NULL");
        }
    }

    /**
      * insert
     * This inserts a new record for the specified object
     * with the specified information, amazing!
     */
    public static function insert($type,$oid,$user) {

        $type     = self::validate_type($type);
        $oid    = Dba::escape($oid);
        $user    = Dba::escape($user);
        $date    = time();

        $sql = "INSERT INTO `object_count` (`object_type`,`object_id`,`date`,`user`) " .
            " VALUES ('$type','$oid','$date','$user')";
        $db_results = Dba::write($sql);

        if (!$db_results) {
            debug_event('statistics','Unabled to insert statistics:' . $sql,'3');
        }

    } // insert

    /**
     * get_last_song
     * This returns the full data for the last song that was played, including when it
     * was played, this is used by, among other things, the LastFM plugin to figure out
     * if we should re-submit or if this is a duplicate / if it's too soon. This takes an
     * optional user_id because when streaming we don't have $GLOBALS()
     */
    public static function get_last_song($user_id='') {

        $user_id = $user_id ? $user_id : $GLOBALS['user']->id;

        $user_id = Dba::escape($user_id);

        $sql = "SELECT * FROM `object_count` WHERE `user`='$user_id' AND `object_type`='song' ORDER BY `date` DESC LIMIT 1";
        $db_results = Dba::read($sql);

        $results = Dba::fetch_assoc($db_results);

        return $results;

    } // get_last_song

    /**
      * get_object_history
     * This returns the objects that have happened for $user_id sometime after $time
     * used primarly by the democratic cooldown code
     */
    public static function get_object_history($user_id='',$time) {

        $user_id = $user_id ? $user_id : $GLOBALS['user']->id;

        $user_id = Dba::escape($user_id);

        $time = Dba::escape($time);

        $sql = "SELECT * FROM `object_count` WHERE `user`='$user_id' AND `object_type`='song' AND `date`>='$time' " .
            "ORDER BY `date` DESC";
        $db_results = Dba::read($sql);

        $results = array();

        while ($row = Dba::fetch_assoc($db_results)) {
            $results[] = $row['object_id'];
        }

        return $results;

    } // get_object_history

    /**
      * get_top
     * This returns the top X for type Y from the
     * last stats_threshold days
     */
    public static function get_top($type,$count='',$threshold = '') {

        /* If they don't pass one, then use the preference */
        if (!$threshold) {
            $threshold = Config::get('stats_threshold');
        }

        if (!$count) {
            $count = Config::get('popular_threshold');
        }

        $count    = intval($count);
        $type    = self::validate_type($type);
        $date    = time() - (86400*$threshold);

        /* Select Top objects counting by # of rows */
        $sql = "SELECT object_id,COUNT(id) AS `count` FROM object_count" .
            " WHERE object_type='$type' AND date >= '$date'" .
            " GROUP BY object_id ORDER BY `count` DESC LIMIT $count";
        $db_results = Dba::read($sql);

        $results = array();

        while ($row = Dba::fetch_assoc($db_results)) {
            $results[] = $row['object_id'];
        }

        return $results;

    } // get_top

    /**
      * get_user
     * This gets all stats for atype based on user with thresholds and all
     * If full is passed, doesn't limit based on date
     */
    public static function get_user($count,$type,$user,$full='') {

        $count     = intval($count);
        $type    = self::validate_type($type);
        $user    = Dba::escape($user);

        /* If full then don't limit on date */
        if ($full) {
            $date = '0';
        }
        else {
            $date = time() - (86400*Config::get('stats_threshold'));
        }

        /* Select Objects based on user */
        //FIXME:: Requires table scan, look at improving
        $sql = "SELECT object_id,COUNT(id) AS `count` FROM object_count" .
            " WHERE object_type='$type' AND date >= '$date' AND user = '$user'" .
            " GROUP BY object_id ORDER BY `count` DESC LIMIT $count";
        $db_results = Dba::read($sql);

        $results = array();

        while ($r = Dba::fetch_assoc($db_results)) {
            $results[] = $r;
        }

        return $results;

    } // get_user

    /**
     * validate_type
     * This function takes a type and returns only those
     * which are allowed, ensures good data gets put into the db
     */
    public static function validate_type($type) {

        switch ($type) {
            case 'artist':
            case 'album':
            case 'genre':
            case 'song':
            case 'video':
                return $type;
            default:
                return 'song';
            break;
        } // end switch

    } // validate_type

    /**
     * get_newest
     * This returns an array of the newest artists/albums/whatever
     * in this ampache instance
     */
    public static function get_newest($type,$limit='') {

        if (!$limit) { $limit = Config::get('popular_threshold'); }

        $type = self::validate_type($type);
        $object_name = ucfirst($type);

        $sql = "SELECT DISTINCT(`$type`), MIN(`addition_time`) AS `real_atime` FROM `song` GROUP BY `$type` ORDER BY `real_atime` DESC " .
            "LIMIT $limit";
        $db_results = Dba::read($sql);

        $items = array();

        while ($row = Dba::fetch_row($db_results)) {
            $items[] = $row['0'];
        } // end while results

        return $items;

    } // get_newest

} // Stats class
?>
