<?php

class App_ECommerce_Order_Garbage_Obj extends App_ECommerce_Order_Abstract_Obj
{
    protected $_tableAlias = 'Transaction';
    const GARBAGE_DAY_PERIOD = 30;

    public function removeGarbage()
    {
        $this->_removeCartGarbage();
        $this->_removeTransactionGarbage();
        return $this;
    }

    protected function _removeCartGarbage()
    {
        $select = $this->_db->select();
        $select->from($this->_getPair('Cart'), array());
        $select->where('DATE_ADD(`Cart`.`changed`, INTERVAL ' . self::GARBAGE_DAY_PERIOD . ' DAY) <= NOW()');
        $select->where('`Cart`.`transactionId` IS NULL');
        $this->_deleteFromSelect($select);
        return $this;
    }

    protected function _removeTransactionGarbage()
    {
        $select = $this->_db->select()->reset();
        $select->from($this->_getPair(), array());
        $select->joinLeft(
            $this->_getPair('Cart'),
            '`Cart`.`transactionId` = `' . $this->_tableAlias . '`.`id`',
            array()
        );
        $select->where('DATE_ADD(`' . $this->_tableAlias . '`.`changed`,
            INTERVAL ' . self::GARBAGE_DAY_PERIOD . ' DAY) <= NOW()');
        $select->where('`Cart`.`id` IS NULL');
        $this->_deleteFromSelect($select);
        return $this;
    }

    /**
     * Create delete query from select object
     *
     * @param Zend_Db_Select $select
     * @return App_ECommerce_Order_Garbage_Obj
     */
    protected function _deleteFromSelect(Zend_Db_Select $select)
    {
        $sql = 'DELETE';
        $sqlParts = '';
        foreach ($select->getPart(Zend_Db_Select::FROM) as $partName => $part) {
            if ($part['joinCondition'] == Zend_Db_Select::FROM) {
                continue;
            }
            $sqlParts .= ' ' . strtoupper($part['joinType']) . ' ' . $part['tableName'] . ' AS ' . $partName
                . (!empty($part['joinCondition']) ? (strstr($part['joinType'], 'join') ? ' ON' : '')
                .  ' ' . $part['joinCondition'] : '') . ' ';
        }
        $sql .= ' ' .implode(', ', array_keys($select->getPart(Zend_Db_Select::FROM)));
        $sql .= $sqlParts;
        if ($select->getPart(Zend_Db_Select::WHERE)) {
            $sql .= 'WHERE';
            foreach ($select->getPart(Zend_Db_Select::WHERE) as $wherePart) {
                $sql .= ' ' . $wherePart . ' ';
            }
        }
        $this->_db->exec($sql);
        return $this;
    }
}