<?php
  /**
   * Copyright (c) 2013 Bart Visscher <bartv@thisnet.nl>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */
  
  namespace OC\DB;
  
  /**
   * This handles the way we use to write queries, into something that can be
   * handled by the database abstraction layer.
   */
  class Adapter {
  
  	/**
  	 * @var \OC\DB\Connection $conn
  	 */
  	protected $conn;
  
  	public function __construct($conn) {
  		$this->conn = $conn;
  	}
  
  	/**
  	 * @param string $table name
  	 * @return int id of last insert statement
  	 */
  	public function lastInsertId($table) {
  		return $this->conn->realLastInsertId($table);
  	}
  
  	/**
  	 * @param string $statement that needs to be changed so the db can handle it
  	 * @return string changed statement
  	 */
  	public function fixupStatement($statement) {
  		return $statement;
  	}
  
  	/**
  	 * @brief insert the @input values when they do not exist yet
  	 * @param string $table name
  	 * @param array $input key->value pairs
  	 * @return int count of inserted rows
  	 */
  	public function insertIfNotExist($table, $input) {
  		$query = 'INSERT INTO `' .$table . '` (`'
  			. implode('`,`', array_keys($input)) . '`) SELECT '
  			. str_repeat('?,', count($input)-1).'? ' // Is there a prettier alternative?
  			. 'FROM `' . $table . '` WHERE ';
  
  		foreach($input as $key => $value) {
  			$query .= '`' . $key . '` = ? AND ';
  		}
  		$query = substr($query, 0, strlen($query) - 5);
  		$query .= ' HAVING COUNT(*) = 0';
  		$inserts = array_values($input);
  		$inserts = array_merge($inserts, $inserts);
  
  		try {
  			return $this->conn->executeUpdate($query, $inserts);
  		} catch(\Doctrine\DBAL\DBALException $e) {
  			$entry = 'DB Error: "'.$e->getMessage() . '"<br />';
  			$entry .= 'Offending command was: ' . $query.'<br />';
  			\OC_Log::write('core', $entry, \OC_Log::FATAL);
  			error_log('DB error: ' . $entry);
  			\OC_Template::printErrorPage( $entry );
  		}
  	}
  }