<?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 */
    public $id;
    public $object_type;
    public $object_id;
    public $date;
    public $user;
    public $agent;


    /**
      * 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, $agent='')
    {
        $type = self::validate_type($type);

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

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

    } // insert

    /**
      * get_object_count
     * Get count for an object
     */
    public static function get_object_count($object_type, $object_id)
    {
        $sql = "SELECT COUNT(*) AS `object_cnt` FROM `object_count` WHERE `object_type`= ? AND `object_id` = ?";
        $db_results = Dba::read($sql, array($object_type, $object_id));

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

        return $results['object_cnt'];
    } // get_object_count

    /**
     * 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;

        $sql = "SELECT * FROM `object_count` " .
            "LEFT JOIN `song` ON `song`.`id` = `object_count`.`object_id` " .
            "LEFT JOIN `catalog` ON `catalog`.`id` = `song`.`catalog` " .
            "WHERE `object_count`.`user` = ? AND `object_count`.`object_type`='song' " .
            "AND `catalog`.`enabled` = '1' " .
            "ORDER BY `object_count`.`date` DESC LIMIT 1";
        $db_results = Dba::read($sql, array($user_id));

        $results = Dba::fetch_assoc($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;

        $sql = "SELECT * FROM `object_count` " .
            "LEFT JOIN `song` ON `song`.`id` = `object_count`.`object_id` " .
            "LEFT JOIN `catalog` ON `catalog`.`id` = `song`.`catalog` " .
            "WHERE `object_count`.`user` = ? AND `object_count`.`object_type`='song' AND `object_count`.`date` >= ? " .
            "AND `catalog`.`enabled` = '1' " .
            "ORDER BY `object_count`.`date` DESC";
        $db_results = Dba::read($sql, array($user_id, $time));

        $results = array();

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

        return $results;

    } // get_object_history

    /**
     * get_top_sql
     * This returns the get_top sql
     */
    public static function get_top_sql($type, $threshold = '')
    {
        $type = self::validate_type($type);
        /* If they don't pass one, then use the preference */
        if (!$threshold) {
            $threshold = AmpConfig::get('stats_threshold');
        }
        $date    = time() - (86400*$threshold);

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

    /**
      * get_top
     * This returns the top X for type Y from the
     * last stats_threshold days
     */
    public static function get_top($type,$count='',$threshold = '',$offset='')
    {
        if (!$count) {
            $count = AmpConfig::get('popular_threshold');
        }

        $count    = intval($count);
        if (!$offset) {
            $limit = $count;
        } else {
            $limit = intval($offset) . "," . $count;
        }

        $sql = self::get_top_sql($type, $threshold);
        $sql .= "LIMIT $limit";
        $db_results = Dba::read($sql);

        $results = array();

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

    } // get_top

    /**
     * get_recent_sql
     * This returns the get_recent sql
     */
    public static function get_recent_sql($type)
    {
        $type = self::validate_type($type);

        $sql = "SELECT DISTINCT(`object_id`) as `id`, MAX(`date`) FROM object_count" .
            " WHERE `object_type` = '" . $type ."' AND " . Catalog::get_enable_filter($type, '`object_id`') .
            " GROUP BY `object_id` ORDER BY MAX(`date`) DESC, `id` ";
        return $sql;
    }

    /**
     * get_recent
     * This returns the recent X for type Y from the
     * last stats_threshold days
    */
    public static function get_recent($type, $count='',$threshold = '',$offset='')
    {
        /* If they don't pass one, then use the preference */
        if (!$threshold) {
            $threshold = AmpConfig::get('stats_threshold');
        }

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

        $count = intval($count);
        $type = self::validate_type($type);
        if (!$offset) {
            $limit = $count;
        } else {
            $limit = intval($offset) . "," . $count;
        }

        $sql = self::get_recent_sql($type);
        $sql .= "LIMIT $limit";
        $db_results = Dba::read($sql);

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

        return $results;

    } // get_recent

    /**
      * 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);

        /* If full then don't limit on date */
        if ($full) {
            $date = '0';
        } else {
            $date = time() - (86400*AmpConfig::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 = ? AND date >= ? AND user = ?" .
            " GROUP BY object_id ORDER BY `count` DESC LIMIT $count";
        $db_results = Dba::read($sql, array($type, $date, $user));

        $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_sql
     * This returns the get_newest sql
     */
    public static function get_newest_sql($type, $catalog=0)
    {
        $type = self::validate_type($type);

        $sql = "SELECT DISTINCT(`$type`) as `id`, MIN(`addition_time`) AS `real_atime` FROM `song` ";
        $sql .= "LEFT JOIN `catalog` ON `catalog`.`id` = `song`.`catalog` " .
                "WHERE `catalog`.`enabled` = '1' ";
        if ($catalog > 0) {
            $sql .= "AND `catalog` = '" . scrub_in($catalog) ."' ";
        }
        $sql .= "GROUP BY `$type` ORDER BY `real_atime` DESC ";
        return $sql;
    }

    /**
     * get_newest
     * This returns an array of the newest artists/albums/whatever
     * in this ampache instance
     */
    public static function get_newest($type, $limit='', $offset='', $catalog=0)
    {
        if (!$count) { $count = AmpConfig::get('popular_threshold'); }
        if (!$offset) {
            $limit = $count;
        } else {
            $limit = $offset . ',' . $count;
        }

        $sql = self::get_newest_sql($type, $catalog);
        $sql .= "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