<?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.
   */
  
  /**
   * small wrapper around \Doctrine\DBAL\Driver\Statement to make it behave, more like an MDB2 Statement
   */
  class OC_DB_StatementWrapper {
  	/**
  	 * @var \Doctrine\DBAL\Driver\Statement
  	 */
  	private $statement = null;
  	private $isManipulation = false;
  	private $lastArguments = array();
  
  	public function __construct($statement, $isManipulation) {
  		$this->statement = $statement;
  		$this->isManipulation = $isManipulation;
  	}
  
  	/**
  	 * pass all other function directly to the \Doctrine\DBAL\Driver\Statement
  	 */
  	public function __call($name,$arguments) {
  		return call_user_func_array(array($this->statement,$name), $arguments);
  	}
  
  	/**
  	 * provide numRows
  	 */
  	public function numRows() {
  		$type = OC_Config::getValue( "dbtype", "sqlite" );
  		if ($type == 'oci') {
  			// OCI doesn't have a queryString, just do a rowCount for now
  			return $this->statement->rowCount();
  		}
  		$regex = '/^SELECT\s+(?:ALL\s+|DISTINCT\s+)?(?:.*?)\s+FROM\s+(.*)$/i';
  		$queryString = $this->statement->getWrappedStatement()->queryString;
  		if (preg_match($regex, $queryString, $output) > 0) {
  			$query = OC_DB::prepare("SELECT COUNT(*) FROM {$output[1]}");
  			return $query->execute($this->lastArguments)->fetchColumn();
  		}else{
  			return $this->statement->rowCount();
  		}
  	}
  
  	/**
  	 * make execute return the result instead of a bool
  	 */
  	public function execute($input=array()) {
  		if(OC_Config::getValue( "log_query", false)) {
  			$params_str = str_replace("
  ", " ", var_export($input, true));
  			OC_Log::write('core', 'DB execute with arguments : '.$params_str, OC_Log::DEBUG);
  		}
  		$this->lastArguments = $input;
  		if (count($input) > 0) {
  
  			if (!isset($type)) {
  				$type = OC_Config::getValue( "dbtype", "sqlite" );
  			}
  
  			if ($type == 'mssql') {
  				$input = $this->tryFixSubstringLastArgumentDataForMSSQL($input);
  			}
  
  			$result = $this->statement->execute($input);
  		} else {
  			$result = $this->statement->execute();
  		}
  		
  		if ($result === false) {
  			return false;
  		}
  		if ($this->isManipulation) {
  			return $this->statement->rowCount();
  		} else {
  			return $this;
  		}
  	}
  
  	private function tryFixSubstringLastArgumentDataForMSSQL($input) {
  		$query = $this->statement->getWrappedStatement()->queryString;
  		$pos = stripos ($query, 'SUBSTRING');
  
  		if ( $pos === false) {
  			return $input;
  		}
  
  		try {
  			$newQuery = '';
  
  			$cArg = 0;
  
  			$inSubstring = false;
  
  			// Create new query
  			for ($i = 0; $i < strlen ($query); $i++) {
  				if ($inSubstring == false) {
  					// Defines when we should start inserting values
  					if (substr ($query, $i, 9) == 'SUBSTRING') {
  						$inSubstring = true;
  					}
  				} else {
  					// Defines when we should stop inserting values
  					if (substr ($query, $i, 1) == ')') {
  						$inSubstring = false;
  					}
  				}
  
  				if (substr ($query, $i, 1) == '?') {
  					// We found a question mark
  					if ($inSubstring) {
  						$newQuery .= $input[$cArg];
  
  						//
  						// Remove from input array
  						//
  						array_splice ($input, $cArg, 1);
  					} else {
  						$newQuery .= substr ($query, $i, 1);
  						$cArg++;
  					}
  				} else {
  					$newQuery .= substr ($query, $i, 1);
  				}
  			}
  
  			// The global data we need
  			$name = OC_Config::getValue( "dbname", "owncloud" );
  			$host = OC_Config::getValue( "dbhost", "" );
  			$user = OC_Config::getValue( "dbuser", "" );
  			$pass = OC_Config::getValue( "dbpassword", "" );
  			if (strpos($host, ':')) {
  				list($host, $port) = explode(':', $host, 2);
  			} else {
  				$port = false;
  			}
  			$opts = array();
  
  			if ($port) {
  				$dsn = 'sqlsrv:Server='.$host.','.$port.';Database='.$name;
  			} else {
  				$dsn = 'sqlsrv:Server='.$host.';Database='.$name;
  			}
  
  			$PDO = new PDO($dsn, $user, $pass, $opts);
  			$PDO->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
  			$PDO->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
  
  			$this->statement = $PDO->prepare($newQuery);
  
  			$this->lastArguments = $input;
  
  			return $input;
  		} catch (PDOException $e){
  			$entry = 'PDO DB Error: "'.$e->getMessage().'"<br />';
  			$entry .= 'Offending command was: '.$this->statement->queryString .'<br />';
  			$entry .= 'Input parameters: ' .print_r($input, true).'<br />';
  			$entry .= 'Stack trace: ' .$e->getTraceAsString().'<br />';
  			OC_Log::write('core', $entry, OC_Log::FATAL);
  			OC_User::setUserId(null);
  
  			// send http status 503
  			header('HTTP/1.1 503 Service Temporarily Unavailable');
  			header('Status: 503 Service Temporarily Unavailable');
  			OC_Template::printErrorPage('Failed to connect to database');
  			die ($entry);
  		}
  	}
      
  	/**
  	 * provide an alias for fetch
  	 */
  	public function fetchRow() {
  		return $this->statement->fetch();
  	}
  
  	/**
  	 * Provide a simple fetchOne.
  	 * fetch single column from the next row
  	 * @param int $colnum the column number to fetch
  	 * @return string
  	 */
  	public function fetchOne($colnum = 0) {
  		return $this->statement->fetchColumn($colnum);
  	}
  }