<?php

/**
 * Класс модели данных
 *
 * @copyright NetMonsters <team@netmonsters.ru>
 * @link http://netmonsters.ru
 * @package Majestic
 * @subpackage Model
 * @since 2010-02-16
 * @version SVN: $Id$
 * @filesource $URL$
 */

abstract class Model
{

    /**
     * DbDriver instance
     *
     * @var DbDriver
     */
    protected $db;

    /**
     * Cache instance
     *
     * @var Cache
     */
    protected $cache;
    
    /**
     * Custom expiration time for keys
     * 
     * @var mixed
     */
    protected $cache_keys  = array();
    
    /**
     * Caches to clean.
     * 
     * @var mixed
     */
    protected $caches_clean = array();

    protected $table;

    protected $key          = 'id';
    

    public function __construct($connection = 'default')
    {
        $this->db = Db::connect($connection);
    }

    /**
     * @return int
     */
    public function getInsertId()
    {
        return $this->db->getInsertId($this->table(), $this->key);
    }

    /**
     * @param string $ident
     * @return string Quoted identifier.
     */
    public function identify($ident)
    {
        return $this->db->quoteIdentifier($ident);
    }

    /**
     * @param mixed $value
     * @return string Quoted value.
     */
    public function quote($value)
    {
        return $this->db->quote($value);
    }

    /**
     * @param int $id
     * @return object
     */
    public function get($id)
    {
        $sql = 'SELECT * FROM :table WHERE :pk=?';
        return $this->fetch($sql, $id);
    }

    /**
     * @param array $data
     * @param array $on_duplicate
     * @return int Id of inserted row
     */
    public function insert($data, $on_duplicate = array())
    {
        $affected = $this->db->insert($this->table(), $data, $on_duplicate);
        return ($this->getInsertId()) ? $this->getInsertId() : $affected;
    }

    /**
     * @param array $data
     * @param mixed $where
     * @return int Number of affected rows
     */
    public function update($data, $where)
    {
        if (is_int($where) || $where === (string) (int) $where) {
            $where = $this->identify($this->key) . '=' . (int) $where;
        }
        return $this->db->update($this->table(), $data, $where);
    }

    /**
     * @param int $id Int id
     * @return int Number of affected rows
     */
    public function delete($id)
    {
        $where = $this->identify($this->key) . '=' . (int) $id;
        return $this->db->delete($this->table(), $where);
    }
    
    /**
     * @return string
     */
    protected function table()
    {
        if (!$this->table) {
            $this->table = substr(strtolower(get_class($this)), 0, -5/*strlen('Model')*/);
        }
        return $this->table;
    }
    
    /**
     * Creates order sql string
     * 
     * @param array $params
     * @param array $sortable
     * @return string
     */
    protected function order($params, $sortable = array('id'))
    {
        $sql = '';
        if (isset($params['sort'])) {
            $order = (isset($params['order']) && $params['order'] == 'desc') ? 'DESC' : 'ASC';
            if (in_array($params['sort'], $sortable)) {
                $sql = ' ORDER BY ' . $this->identify($params['sort']) .  ' ' . $order;
            }
        }
        return $sql;
    }
    
    /**
     * Searches using like
     * 
     * @param array $params
     * @param array $searchable
     * @param string $table_prefix
     * @return string
     */
    protected function search($params, $searchable = array('id'), $table_prefix = '')
    {
        $sql = '';
        if (isset($params['q']) && isset($params['qt']) && in_array($params['qt'], $searchable)) {
            if ($table_prefix) {
                $sql = $table_prefix . '.';
            }
            $sql .= $this->identify($params['qt']) .  ' LIKE ' . $this->quote('%' . $params['q'] . '%');
        }
        return $sql;
    }

    /**
     * This method appends to params table and primary key.
     * So they can be accessed thru `:table` and `:pk` placeholders.
     * 
     * @return DbStatement
     */
    protected function query($sql, $params = array()) 
    {
        if (!is_array($params)) {
            $params = array($params);
        }
        $params = array(
            'table' => new DbExpr($this->identify($this->table())),
            'pk' => new DbExpr($this->identify($this->key)),
        ) + $params;
        return $this->db->query($sql, $params);
    }

    /**
     * @param string $sql
     * @param array $params
     * @param string $field
     * @param CacheKey $cache_key
     */
    protected function fetchField($sql, $params = array(), $field, $cache_key = null)
    {
        if (!$cache_key || !$result = $cache_key->get()) {
            $result = $this->query($sql, $params)->fetchField($field);
            if ($cache_key) {
                $cache_key->set($result);
            }
        }
        return $result;
    }
    
    /**
     * @param string $sql
     * @param array $params
     * @param CacheKey $cache_key
     */
    protected function fetch($sql, $params = array(), $cache_key = null)
    {
        if (!$cache_key || !$result = $cache_key->get()) {
            $result = $this->query($sql, $params)->fetch();
            if ($cache_key) {
                $cache_key->set($result);
            }
        }


       // $debug = __CLASS__;
        $debug = get_class($this->query($sql, $params));


       // $debug = get_class_methods($this->query($sql, $params));

        //$result = print_r($debug, true);


        return $result;
    }
    
    /**
     * @param string $sql
     * @param array $params
     * @param CacheKey $cache_key
     */
    protected function fetchAll($sql, $params = array(), $cache_key = null)
    {
        if (!$cache_key || !$result = $cache_key->get()) {
            $result = $this->query($sql, $params)->fetchAll();
            if ($cache_key) {
                $cache_key->set($result);
            }
        }
        return $result;
    }
    
    /* Cache workaround */
    
    /**
     * @return Cache
     */
    public function getCache()
    {
        if (!$this->cache) {
            $this->cache = Cacher::get(Config::get(__CLASS__, 'MemcacheCache'));
        }
        return $this->cache;
    }
    
    /**
     * @param string $name
     * @param array $params
     * @return CacheKey
     */
    protected function cacheKey($name, $params = array())
    {
        $expire = (isset($this->cache_keys[$name])) ? ($this->cache_keys[$name] * 60) : 0;
        return new CacheKey($this->getCache(), $name, $params, $expire);
    }
    
    /**
     * @param CacheKey $cache
     */
    protected function addCleanCache($cache)
    {
        $this->caches_clean[] = $cache;
    }
    
    protected function cleanCaches()
    {
        // cleaning caches
        foreach ($this->caches_clean as $cache) {
            $cache->del();
        }
        $this->caches_clean = array();
    }
}