<?php

/**
 * Class to represent a database connection
 *
 * $Id: Connection.php,v 1.15 2008/02/18 21:42:47 ioguix Exp $
 */

include_once('./classes/database/ADODB_base.php');

class Connection {

	var $conn;
	
	// The backend platform.  Set to UNKNOWN by default.
	var $platform = 'UNKNOWN';
	
	/**
	 * Creates a new connection.  Will actually make a database connection.
	 * @param $fetchMode Defaults to associative.  Override for different behaviour
	 */
	function Connection($host, $port, $sslmode, $user, $password, $database, $fetchMode = ADODB_FETCH_ASSOC) {
		$this->conn = &ADONewConnection('postgres7');
		$this->conn->setFetchMode($fetchMode);

		// Ignore host if null
		if ($host === null || $host == '')
			if ($port !== null && $port != '')
				$pghost = ':'.$port;
			else
				$pghost = '';
		else
			$pghost = "{$host}:{$port}";

		// Add sslmode to $pghost as needed
                if (($sslmode == 'disable') || ($sslmode == 'allow') || ($sslmode == 'prefer') || ($sslmode == 'require')) {
                        $pghost .= ':'.$sslmode;
                } elseif ($sslmode == 'legacy') {
                        $pghost .= ' requiressl=1';
                }

		$this->conn->connect($pghost, $user, $password, $database);
	}

	/**
	 * Gets the name of the correct database driver to use.  As a side effect,
	 * sets the platform.
	 * @param (return-by-ref) $description A description of the database and version
	 * @return The class name of the driver eg. Postgres84
	 * @return null if version is < 7.4
	 * @return -3 Database-specific failure
	 */
	function getDriver(&$description) {
		// If we're on a recent enough PHP 5, and against PostgreSQL 7.4 or
		// higher, we don't need to query for the version.  This gives a great
		// speed up.				
		if (function_exists('pg_version')) {
			$v = pg_version($this->conn->_connectionID);
			if (isset($v['server'])) $version = $v['server'];			
		}
		
		// If we didn't manage to get the version without a query, query...
		if (!isset($version)) {
			$adodb = new ADODB_base($this->conn);
	
			$sql = "SELECT VERSION() AS version";
			$field = $adodb->selectField($sql, 'version');
	
			// Check the platform, if it's mingw, set it
			if (preg_match('/ mingw /i', $field))
				$this->platform = 'MINGW';
	
			$params = explode(' ', $field);
			if (!isset($params[1])) return -3;
	
			$version = $params[1]; // eg. 8.4.4
		}
		
		$description = "PostgreSQL {$version}";

		// Detect version and choose appropriate database driver
		switch (substr($version,0,3)) {
			case '8.4': return 'Postgres'; break;
			case '8.3': return 'Postgres83'; break;
			case '8.2': return 'Postgres82'; break;
			case '8.1': return 'Postgres81'; break;
			case '8.0':
			case '7.5': return 'Postgres80'; break;
			case '7.4': return 'Postgres74'; break;
		}

		/* All <7.4 versions are not supported */
		// if major version is 7 or less and wasn't catch in the
		// switch/case block, we have an unsupported version.
		if ((int)substr($version, 0, 1) < 8)
			return null;

		// If unknown version, then default to latest driver
		return 'Postgres';

	}

	/** 
	 * Get the last error in the connection
	 * @return Error string
	 */
	function getLastError() {		
		if (function_exists('pg_errormessage'))
			return pg_errormessage($this->conn->_connectionID);
		else
			return pg_last_error($this->conn->_connectionID);
	}
}

?>