<?php
/**
 * Common direct db actions
 *
 * @author Christian Winther <cwin@mocsystems.com>
 * @since 08.04.2010
 */
class MOC_DB {

    /**
      * Table field cache
     *
     * @var array
     */
    protected static $tableCache = array();

    protected static $tableInformation = array();

    /**
     * Get a list of fields in a table
     *
     * @return array
     */
    public static function tableFields($table) {
        if (!array_key_exists($table, self::$tableCache)) {
            self::$tableCache[$table] = $GLOBALS['TYPO3_DB']->admin_get_fields($table);
        }
        return self::$tableCache[$table];
    }

    public static function saveFields($table, $data) {
        $fields = self::tableFields($table);
        return array_intersect_key($data, $fields);
    }

    public static function beginTransaction() {
        $GLOBALS['TYPO3_DB']->sql_query('BEGIN');
    }

    public static function rollbackTransaction() {
        $GLOBALS['TYPO3_DB']->sql_query('ROLLBACK');
    }

    public static function commitTransaction() {
        $GLOBALS['TYPO3_DB']->sql_query('COMMIT');
    }

    public static function checkTransactionSupportForTable($names) {
        if (!is_array($names)) {
            $names = array($names);
        }

        self::loadTableInformation();

        foreach ($names as $name) {
            if (!array_key_exists($name, self::$tableInformation)) {
                throw new MOC_DB_Exception(sprintf('Cant check table %s for transaction support, its not present in self::$tableInformation. (Maybe the table doesnt exist)', $name));
            }

            if (self::$tableInformation[$name]['Engine'] !== 'InnoDB') {
                throw new MOC_DB_Exception(sprintf('Table %s does not have transaction support, its not an InnoDB table. Table type %s does not support transactions', $name, self::$tableInformation[$name]['Engine']));
            }
        }
    }

    protected static function loadTableInformation() {
        if (!empty(self::$tableInformation)) {
            return;
        }

        $resource = $GLOBALS['TYPO3_DB']->sql_query('SHOW TABLE STATUS');
        while ($record = mysql_fetch_array($resource)) {
            self::$tableInformation[$record['Name']] = $record;
        }
    }

    public static function error() {
        $error = $GLOBALS['TYPO3_DB']->sql_error();
        if (empty($error)) {
            return false;
        }
        return $error;
    }

    public static function insertId() {
        return $GLOBALS['TYPO3_DB']->sql_insert_id();
    }

    public static function affectedRows() {
        return $GLOBALS['TYPO3_DB']->sql_affected_rows();
    }

    public static function suppressHTMLErrors() {
        $GLOBALS['TYPO3_DB']->debugOutput = 0;
    }
}