<?php // vim:ts=4:sw=4:noet

require_once(dirname(__FILE__) . '/KjwSql.php');

// FIXME: acquireLock/release moet hier in execute()
// FIXME: wel columns accepteren in SELECT
// FIXME: WHERE-clause ;)
// FIXME: DELETE/UPDATE

/**
 * KjwFakeSql is an abstract class to alleviate the construction
 * of fake sql supporting classes.
 * It's supposed to be a temporary solution for tiny database needs.
 */
class KjwFakeSql extends KjwSql {
	var $_lockName = null;
	var $_lockHandle = null;
	var $_locked = null;

	/**
	 * Construct a KjwFakeSql object.
     *
	 * @param $sqltype SQL type name (e.g.\ 'xmlsql').
	 * @param $unused_host Server name (possibly unused).
	 * @param $unused_port Port number (possibly unused).
	 * @param $unused_user User name (possibly unused).
	 * @param $unused_pass Password (possibly unused).
	 * @param $lockpath Lockfile name. Optional if you do your own locking. (Override _acquireLock/_releaseLock.)
	 */
	function KjwFakeSql($sqltype, $unused_host, $unused_port, $unused_user, $unused_pass, $lockpath = null) {
		parent::KjwSql($sqltype, $unused_host, $unused_port, $unused_user, $unused_pass, $lockpath);
		$this->_lockName = $lockpath;
	}

	/* [INHERITED DOCS] */
	function destroy() {
		parent::destroy();
		$this->disconnect();
	}

	/* [INHERITED DOCS] */
	function connect() {
		global $kjw_suppressed_error;
		if ($this->_lockHandle)
			return true;
		if ($this->_lockHandle === null)
			if (($this->_lockHandle = @fopen($this->_lockName, 'a')) === false)
				$this->croak('Database Data Transfer Failure',
						'Can\'t open lockfile "' . $this->_lockName . '": ' . $kjw_suppressed_error);
		return true;
	}

	/* [INHERITED DOCS] */
	function disconnect() {
		if ($this->_locked)
			$this->_releaseLock();
		if ($this->_lockHandle && fclose($this->_lockHandle))
			$this->_lockHandle = null;
		return $this->_locked === null && !$this->_lockHandle;
	}

	function _acquireLock($type = 'RW', $retryCount = 3, $waitMs = 64) {
		$this->trace("_acquireLock: $type, $retryCount, $waitMs");
		switch ($type) {
		case 'R':	$flocktype = LOCK_SH /*| LOCK_NB*/; break;
		case 'RW':	$flocktype = LOCK_EX /*| LOCK_NB*/; break;
		default:	return false;
		}

		if ($this->_lockHandle === null)
			$this->connect();
		if (!$this->_lockHandle)
			return false;
		if (flock($this->_lockHandle, $flocktype)) {
			$this->_locked = $type;
			return true;
		} elseif ($retryCount > 1) {
			//usleep($waitMs * 1000); for LOCK_NB
			return $this->_acquireLock($type, $retryCount - 1, $waitMs << 1);
		}	
		return false;
	}

	function _releaseLock() {
		if ($this->_locked && flock($this->_lockHandle, LOCK_UN))
			$this->_locked = null;
	}

	/* [INHERITED DOCS] */
	function execute($query) {
		$this->_last_query = $query;
		//
		// MATCH SELECT
		// select * from mytable order by a desc, b, c asc limit 2, 3
		//
		if (preg_match('/^\s*
				select\s+(\*)\s+
				from\s+([0-9A-Za-z%_-]+)
				(\s+order\s+by\s+([0-9A-Za-z%_-]+(\s+asc|\s+desc)?(\s*,\s[0-9A-Za-z%_-]+(\s+asc|\s+desc))?))?
				(\s+limit\s+([0-9]+)(\s*,\s*([0-9]+))?)?
		\s*$/ix', $query, $m)) {
			$columns = $m[1];
			$table = $this->_nameUnquote($m[2]);
			$order = array();
			if (isset($m[4])) {
				foreach (preg_split('/\s*,\s*/', $m[4]) as $v) {
					$tmp = preg_split('/\s+/', $v);
					if (sizeof($tmp) == 1)
						array_push($order, "+" . $this->_nameUnquote($v));
					else
						array_push($order, ($tmp[1] == 'asc' ? '+' : '-') . $this->_nameUnquote($tmp[0]));
				}
			}
			if (isset($m[11])) {
				$skip = (int)$m[9];
				$max = (int)$m[11];
			} else {
				$skip = 0;
				$max = isset($m[9]) ? (int)$m[9] : -1;
			}
			return $this->_simpleSelect($table, $columns, $order, $skip, $max);
		} elseif (preg_match('/^\s*
				insert\s+into\s+([0-9A-Za-z%_-]+)\s*
				(\(([\s,0-9A-Za-z%_-]+)\))?
				\s*values\s*
				\(\s*(.*?)\s*\)
		\s*$/ix', $query, $m)) {
			$table = $m[1];
			$columns = $m[3] != '' ? $this->_splitColumns($m[3]) : null;
			$values = $this->_splitValues($m[4]);
			if ($columns === null)
				return $this->_simpleInsert($table, $values);
			if (sizeof($columns) != sizeof($values))
				$this->croak('Database Data Transfer Failure', 'Column and value count differ.');
			$args = array();
			reset($values);
			foreach ($columns as $key) {
				$value = each($values);
				$args[$key] = $value['value'];
			}
			return $this->_simpleInsert($table, $args);
		}
		echo $query;

		$this->croak('Database Data Transfer Failure',
				'Unknown or unsupported SQL command.' . (KJW_DEBUG ? " Query was: $query" : ''));
	}

	/* [INHERITED DOCS] */
	function nameQuote($name) {
		/* This way we know that we won't have to look for quotes and escaped quotes */
		return urlencode($name);
	}

	/**
	 * [PRIVATE] Undo what nameQuote does.
	 */
	function _nameUnquote($quoted) {
		return urldecode($quoted);
	}

	/* [INHERITED DOCS] */
	function safeQuote($mixed) {
		if (is_string($mixed))
			return "'" . str_replace("'", "''", str_replace("\x00", '', $mixed)) . "'";
		return parent::safeQuote($mixed);
	}

	function _safeUnquote($quoted) {
		if (strcasecmp($quoted, 'null') == 0)
			return null;
		if ($quoted[0] == "'")
			return str_replace("''", "'", substr($quoted, 1, -1));
		if (!is_numeric($quoted))
			$this->croak('Database Data Transfer Failure', 'Non-numeric literal found.');
		if (strpos($quoted, '.') === false)
			return (int)$quoted;
		return (float)$quoted;
	}

	function _splitColumns($string) {
		return array_map(array($this, '_nameUnquote'), preg_split('/\s*,\s*/', $string));
	}

	function _splitValues($string) {
		if (preg_match_all('/\s*([^\',\s]+|\'(\'\'|[^\'])*\')(\s*,\s*|\s*$)/', $string, $m) !== false)
			return array_map(array($this, '_safeUnquote'), $m[1]);
		$this->croak('Database Data Transfer Failure', 'Unable to parse value list.');
	}
}

?>