<?php
/* $Id$ */
namespace Mammut\DB\PDO;

(defined('MAMMUT') && (basename(__FILE__) != basename($_SERVER['PHP_SELF']))) or die('ACCESS DENIED');

use InvalidArgumentException;
use Mammut\Exception\ImplementationException;
use Mammut\DB\SQLException;
use Mammut\DB\DBException;
use Mammut\DB\Model\TableInfo;
use Mammut\Cache\iCache;
use Mammut\DB\Sql\Expression\SQLFunction;

/*
	today (may 2010), PDO allows access to the folloing databases:
	* DB2 (PDO) - IBM DB2 functions
	* MS SQL Server (PDO) - Microsoft SQL Server (sqlsrv, windows-only)
	+ MySQL (PDO) - MySQL functions (testing)
	* Oracle (PDO) - Oracle functions
	* PostgreSQL (PDO) - PostgreSQL functions (testing)
	* SQLite3 (PDO) - SQLite functions
	
	databases prefixes: 
	+ testet do work with Mammut
	* could work (will work some day)
*/
/**
 * Database connector which uses the PDO abstraction class
 *
 * @author Stefan Daurer <s.daurer@q-spot.org>
 * @package Mammut\DB\Adapter\PDO
 */
class PDO extends \Mammut\DB\DB {
	const _VERSION_ = '1.1.0.0';
	
	/**
	 *
	 * @var \PDO
	 */
	private $db = false;
	private $type = false;
	private $affected = 0;
	private $supported = ['db2','sqlsrv','mysql','oracle','pgsql','sqlite'];
	private $driverVariant = NULL;
	private $utilClass;
	private $tableClass;

	public function __construct($cstring, $user, $password, array $options = array(), iCache $cache = NULL) {
		list($type, $dest) = explode(':', $cstring, 2);
		if(!in_array(strtolower($type), $this->supported))
			throw new InvalidArgumentException('db type not supported:' . $type);
		
		$this->type = strtolower($type);
		
		$pdo_opt = array();
		if(array_search(self::OPT_PERSISTENT, $options) !== false)
			$pdo_opt[PDO::ATTR_PERSISTENT] = true;
		$this->logDebug('connecting via pdo: ' . $cstring);
		try {
			$this->db = new \PDO($cstring, $user, $password, $pdo_opt);
			$this->db->setAttribute(\PDO::ATTR_ERRMODE, \PDO::ERRMODE_EXCEPTION);
		}
		catch(\PDOException $pdoex) {
			throw new \Mammut\DB\DBException($pdoex->getMessage());
		}
		
		switch($this->type) {
			case 'mssql':
			case 'sqlsrv':
				$this->db->query('SET DATEFORMAT ymd');
				$this->db->query('SET IMPLICIT_TRANSACTIONS OFF');
				$this->utilClass = '\\Mammut\\DB\\MSSQL\\MSSQLUtil';
				$this->tableClass = '\\Mammut\\DB\\MSSQL\\Table';
				$this->dialect = new \Mammut\DB\Sql\Dialect\SqlServer($this->db);
			break;
			case 'mysql':
				$this->db->query('SET SESSION sql_mode = \'ANSI\'');
				$this->utilClass = '\\Mammut\\DB\\MySQLi\\MySQLUtil';
				$this->tableClass = '\\Mammut\\DB\\MySQLi\\Table';
				$this->dialect = new \Mammut\DB\Sql\Dialect\Mysql($this->db);
			break;
			case 'pgsql':
				$this->utilClass = '\\Mammut\\DB\\PostGre\\PostGreUtil';
				$this->tableClass = '\\Mammut\\DB\\PostGre\\Table';
				$this->dialect = new \Mammut\DB\Sql\Dialect\Postgresql($this->db);
			break;
		}
		// TODO: add select database
	}

	public function setDatabase($name) {
		try {
			$name = $this->escapeValue($name);
			// todo: add return type support
			switch($this->type) {
				case 'sqlsrv':
				// TODO: implement
				break;
				case 'mysql':
					$this->query("USE DATABASE `{$name}`");
				break;
				case 'pgsql':
					$result = $this->query('\connect ' . $name);
				break;
			}
		}
		catch(\PDOException $e) {
			throw new \Mammut\DB\DBException($e->getMessage);
		}
	}

	public function getDatabase() {
		try {
			switch($this->type) {
				case 'sqlsrv':
					$row = $this->getRow('SELECT db_name()');
					if(is_array($row))
						return $row[0];
					else
						return false;
				break;
				case 'mysql':
					$row = $this->getRow("SELECT DATABASE()");
					if(is_array($row))
						return $row[0];
					else
						return false;
				break;
				case 'pgsql':
					$row = $this->getRow('SELECT current_database() AS db');
					if(is_array($row))
						return $row[0];
					else
						return false;
				break;
			}
		}
		catch(\PDOException $e) {
			throw new \Mammut\DB\DBException($e->getMessage());
		}
	}

	public function getSchema() {
		if($this->type == 'pgsql') {
			$result = $this->getObject("SELECT current_schema() AS s");
			return $result->s;
		}
		return false;
	}

	public function query($query, $limit = -1, $skip = 0) {
		$query = $this->checkQuery($query);
		$limit = intval($limit);
		$skip = intval($skip);
		if($skip < 0)
			$skip = 0;
		
		if($this->type == 'mysql') {
			if($limit >= 0) {
				if($skip > 0)
					$query .= ' LIMIT ' . $skip . ',' . $limit;
				else
					$query .= ' LIMIT ' . $limit;
			}
			elseif($skip > 0) // workaround, mysql dosen't support skip alone 
				$query .= ' LIMIT 99999999999999,' . $skip;
		}
		elseif(($this->type == 'sqlsrv') && ($limit > 0)) {
			$query = preg_replace('#^\s*(SELECT)(\s*)#is', '\\1 TOP ' . ($limit + $skip) . '\\2', $query, 1);
		}
		elseif($this->type == 'pgsql') {
			if($limit >= 0)
				$query .= ' LIMIT ' . $limit;
			if($skip > 0)
				$query .= ' OFFSET ' . $skip;
		}
		
		$this->logTrace('sending new query: ' . $query);
		
		$this->affected = 0;
		$result = false;
		try {
			if(preg_match('/^\s*(SELECT|SHOW|DESCRIBE|\\d[tT])\s+/is', $query)) { // pgsql uses \d[a-Z] commands to fetch meta infos
				$result = $this->db->query($query);
				$this->qcount++;
				if(is_object($result)) {
					if(($this->type == 'sqlsrv') && ($skip > 0)) {
						for($i = 0; $i < $skip; $i++) // sqlsrv emulation of 'skip'
							$result->fetch(PDO::FETCH_NUM);
					}
					$this->affected = $result->rowCount() - $skip;
					return new Result($result, $this->dialect);
				}
				else
					return $result;
			}
			else {
				$this->affected = $this->db->exec($query);
				$this->qcount++;
				return $this->affected;
			}
		}
		catch(\PDOException $e) {
			throw new SQLException($e->getMessage(), $query);
		}
	}

	public function setAutocommit($doAutoCommit) {
		if($this->type == 'pgsql') {
			// not shure if there should be some code in here
		}
		elseif($this->type == 'sqlsrv') {
			if ($doAutoCommit)
				$this->query('SET IMPLICIT_TRANSACTIONS OFF');
			else
				$this->query('SET IMPLICIT_TRANSACTIONS ON');
		}
		else
			$this->db->setAttribute(\PDO::ATTR_AUTOCOMMIT, $doAutoCommit);
	}

	/**
	 * creates a new statement which can be executed later
	 *
	 * @param string $query        	
	 * @return \Mammut\DB\Statement
	 */
	public function prepareStatement($query, $limit = -1, $skip = 0) {
		$query = $this->checkQuery($query);
		try {
			$stmt = new Statement($this, $this->db->prepare($query), $this->dialect);
		}
		catch(\PDOException $e) {
			throw new SQLException($e->getMessage(), $query);
		}
		return $stmt;
	}

	public function getRow($sql) {
		$sql = $this->checkQuery($sql);
		$result = $this->db->query($sql);
		$this->qcount++;
		return $result->fetch(\PDO::FETCH_NUM);
	}

	public function getArray($sql) {
		$sql = $this->checkQuery($sql);
		$result = $this->db->query($sql);
		$this->qcount++;
		return $result->fetch(\PDO::FETCH_ASSOC);
	}

	public function getObject($sql, $class = false, $param = array()) {
		$sql = $this->checkQuery($sql);
		try {
			$result = $this->db->query($sql);
			$this->qcount++;
			if($class)
				return $result->fetchObject($class, $param);
			else
				return $result->fetchObject();
		}
		catch(\PDOException $e) {
			throw new SQLException($e->getMessage(), $sql);
		}
	}

	public function getInsertId() {
		switch($this->type) {
			case 'sqlsrv':
				$this->qcount++;
				return (int) $this->getObject("SELECT @@IDENTITY AS 'identity'")->identity;
			break;
			default:
				return $this->db->lastInsertId();
		}
	}

	/**
	 *
	 * @return int number of rows affected by the last query
	 */
	public function getAffectedRowCount() {
		return $this->affected;
	}

	public function tableList($removePrefix = true) {
		$result = false;
		if(!empty($this->tables))
			return $this->tables;
		$this->qcount++;
		switch($this->type) {
			case 'sqlsrv':
				$result = $this->db->query('SELECT Table_name AS "Table name" FROM Information_schema.Tables  WHERE Table_type = \'BASE TABLE\' AND (Objectproperty (Object_id(Table_name), \'IsMsShipped\') = 0 OR Objectproperty (Object_id(Table_name), \'IsMsShipped\') IS NULL)');
				break;
			case 'mysql':
				$result = $this->db->query("SHOW TABLES");
				break;
			case 'oracle':
				$result = $this->db->query("SELECT table_name FROM user_tables");
				break;
			case 'pgsql':
				$result = $this->db->query("SELECT table_name FROM information_schema.tables WHERE table_schema = 'public'");
				break;
			default:
				throw new \InvalidArgumentException('unsupported type');
		}
		if(is_object($result)) {
			$tables = array();
			while($next = $result->fetch())
				$tables[] = strtolower($next[0]);
			$this->tables = $tables;
			return $tables;
		}
		else
			return false;
	}
	
	public function table($table) {
		if($table instanceof \Mammut\DB\Model\TableInfo)
			$table = $table->getName();
		if(array_search(strtolower($table), $this->tableList()) === false)
			throw new DBException('table "' . $table . '" dosen\'t exist');
		$class = $this->tableClass;
		return new $class($this, $table);
	}

// 	public function getTableInfo($tablename) {
// 		return call_user_func(array($this->utilClass,'getTableInfo'), $this, $tablename);
// 	}

	/**
	 * converts a datetime column value to a unix timestap
	 */
	public function dateCol2uts($date) {
		switch($this->type) {
			default:
				if(preg_match('#([0-9]{1,4})[./-]([0-9]{1,2})[./-]([0-9]{1,2})#', $date, $match)) {
					$t = mktime(0, 0, 0, $match[2], $match[3], $match[1]);
					return $t;
				}
				else
					return false;
			break;
		}
	}

	/**
	 * converts a uts integer to the datetime format of this database
	 */
	public function uts2dateCol($uts) {
		if(!is_numeric($uts))
			throw new \InvalidArgumentException(gettype($uts) . ' is an invalid timestamp type');
		switch($this->type) {
			default:
				return date('Y-m-d', $uts);
		}
	}

	/**
	 * converts a datetime column
	 */
	public function datetimeCol2uts($datetime) {
		switch($this->type) {
			default:
				if(preg_match('#([0-9]{1,4})[./-]([0-9]{1,4})[./-]([0-9]{1,4})\s+([0-9]{1,2})[:.]([0-9]{1,2})[:.]([0-9]{1,2})#', $datetime, $match)) {
					$t = mktime($match[4], $match[5], $match[6], $match[2], $match[3], $match[1]);
					return $t;
				}
				else
					return false;
			break;
		}
	}

	/**
	 * converts a uts integer to the datetime format of this database
	 */
	public function uts2datetimeCol($uts) {
		switch($this->type) {
			default:
				return date('Y-m-d H:i:s', $uts);
		}
	}

	/**
	 * escapes a string to be used as a text value.
	 * that means escaping all special chars and quoting the content
	 *
	 * @param string $name
	 *        	name of the table
	 * @return string escaped and quoted name
	 */
	public function escapeValue($value, $addQuotes = true) {
		if(is_null($value))
			return 'NULL';
		if(is_bool($value)) {
			switch($this->type) {
				case 'sqlsrv':
					return $value ? '1' : '0';
				default:
					return $value ? 'TRUE' : 'FALSE';
			}
		}
		if(is_int($value) || is_long($value))
			return (int) $value;
		if($value instanceof SQLFunction)
			return $this->getDialect()->getFunctionSQL($value);
		$q = $addQuotes ? '\'' : '';
		if($value instanceof \DateTime)
			return $q . $value->format('Y-m-d H:i:s') . $q;
		if($value instanceof \Mammut\IO\File) {
			$filename = $value->getPath();
			$content = file_get_contents($filename);
			return $q . $this->db->quote($content) . $q;
		}
		if(is_int($value) || is_long($value) || is_float($value) || is_double($value))
			return $value;
		return $addQuotes ? $this->db->quote($value) : $value; // ansi syntax
	}
	
}