<?php
/**
 * Class to use MySQL DBMS
 * mysql handling class
 *
 * Does not use prepared statements, since mysql driver does not support them
 *
 * @author NHN (developers@xpressengine.com)
 * @package /classes/db
 * @version 0.1
 */
class DBMysql extends DB {

    /**
	 * prefix of a tablename (One or more XEs can be installed in a single DB)
	 * @var string
     */
    var $prefix   = 'xe_'; // / <
    var $comment_syntax = '/* %s */';

    /**
     * Column type used in MySQL
     *
     * Becasue a common column type in schema/query xml is used for colum_type,
     * it should be replaced properly for each DBMS
	 * @var array
     */
    var $column_type = array(
        'bignumber' => 'bigint',
        'number' => 'bigint',
        'varchar' => 'varchar',
        'char' => 'char',
        'text' => 'text',
        'bigtext' => 'longtext',
        'date' => 'varchar(14)',
        'float' => 'float',
    );

    /**
     * Constructor
	 * @return void
     */
    function DBMysql() {
        $this->_setDBInfo();
        $this->_connect();
    }

	/**
	 * Create an instance of this class
	 * @return DBMysql return DBMysql object instance
	 */
    function create() {
        return new DBMysql;
    }

	/**
	 * Return if supportable
	 * Check 'mysql_connect' function exists.
	 * @return boolean
	 */
    function isSupported() {
        if(!function_exists('mysql_connect')) return false;
        return true;
    }

	/**
	 * DB Connect
	 * this method is private
	 * @param array $connection connection's value is db_hostname, db_port, db_database, db_userid, db_password
	 * @return resource
	 */
    function __connect($connection) {
        // Ignore if no DB information exists
        if (strpos($connection["db_hostname"], ':') === false && $connection["db_port"])
            $connection["db_hostname"] .= ':' . $connection["db_port"];

        // Attempt to connect
        $result = @mysql_connect($connection["db_hostname"], $connection["db_userid"], $connection["db_password"]);

        if(mysql_error()) {
            $this->setError(mysql_errno(), mysql_error());
            return;
        }
        // Error appears if the version is lower than 4.1
        if(mysql_get_server_info($result)<"4.1") {
            $this->setError(-1, "XE cannot be installed under the version of mysql 4.1. Current mysql version is ".mysql_get_server_info());
            return;
        }
        // select db
        @mysql_select_db($connection["db_database"], $result);
        if(mysql_error()) {
            $this->setError(mysql_errno(), mysql_error());
            return;
        }

        return $result;
    }

	/**
	 * If have a task after connection, add a taks in this method
	 * this method is private
	 * @param resource $connection
	 * @return void
	 */
    function _afterConnect($connection){
        // Set utf8 if a database is MySQL
        $this->_query("set names 'utf8'", $connection);
    }

	/**
	 * DB disconnection
	 * this method is private
	 * @param resource $connection
	 * @return void
	 */
    function _close($connection) {
        @mysql_close($connection);
    }

	/**
	 * Handles quatation of the string variables from the query
	 * @param string $string
	 * @return string
	 */
    function addQuotes($string) {
        if(version_compare(PHP_VERSION, "5.9.0", "<") && get_magic_quotes_gpc()) $string = stripslashes(str_replace("\\","\\\\",$string));
        if(!is_numeric($string)) $string = @mysql_real_escape_string($string);
        return $string;
    }

	/**
	 * DB transaction start
	 * this method is private
	 * @return boolean
	 */
    function _begin() {
        return true;
    }

	/**
	 * DB transaction rollback
	 * this method is private
	 * @return boolean
	 */
    function _rollback() {
        return true;
    }

	/**
	 * DB transaction commit
	 * this method is private
	 * @return boolean
	 */
    function _commit() {
        return true;
    }

	/**
	 * Execute the query
	 * this method is private
	 * @param string $query
	 * @param resource $connection
	 * @return resource
	 */
    function __query($query, $connection) {
        // Run the query statement
        $result = mysql_query($query, $connection);
        // Error Check
        if(mysql_error($connection)) $this->setError(mysql_errno($connection), mysql_error($connection));
        // Return result
        return $result;
    }

	/**
	 * Fetch the result
	 * @param resource $result
	 * @param int|NULL $arrayIndexEndValue
	 * @return array
	 */
    function _fetch($result, $arrayIndexEndValue = NULL) {
        $output = array();
        if(!$this->isConnected() || $this->isError() || !$result) return $output;
        while($tmp = $this->db_fetch_object($result)) {
            if($arrayIndexEndValue) $output[$arrayIndexEndValue--] = $tmp;
            else $output[] = $tmp;
        }
        if(count($output)==1){
            if(isset($arrayIndexEndValue)) return $output;
            else return $output[0];
        }
        $this->db_free_result($result);
        return $output;
    }

	/**
	 * Return the sequence value incremented by 1
	 * Auto_increment column only used in the sequence table
	 * @return int
	 */
    function getNextSequence() {
        $query = sprintf("insert into `%ssequence` (seq) values ('0')", $this->prefix);
        $this->_query($query);
        $sequence = $this->db_insert_id();
        if($sequence % 10000 == 0) {
            $query = sprintf("delete from  `%ssequence` where seq < %d", $this->prefix, $sequence);
            $this->_query($query);
        }

        return $sequence;
    }

	/**
	 * Function to obtain mysql old password(mysql only)
	 * @param string $password input password
	 * @param string $saved_password saved password in DBMS
	 * @return boolean
	 */
    function isValidOldPassword($password, $saved_password) {
        $query = sprintf("select password('%s') as password, old_password('%s') as old_password", $this->addQuotes($password), $this->addQuotes($password));
        $result = $this->_query($query);
        $tmp = $this->_fetch($result);
        if($tmp->password == $saved_password || $tmp->old_password == $saved_password) return true;
        return false;
    }

	/**
	 * Check a table exists status
	 * @param string $target_name
	 * @return boolean
	 */
    function isTableExists($target_name) {
        $query = sprintf("show tables like '%s%s'", $this->prefix, $this->addQuotes($target_name));
        $result = $this->_query($query);
        $tmp = $this->_fetch($result);
        if(!$tmp) return false;
        return true;
    }

	/**
	 * Add a column to the table
	 * @param string $table_name table name
	 * @param string $column_name column name
	 * @param string $type column type, default value is 'number'
	 * @param int $size column size
	 * @param string|int $default default value
	 * @param boolean $notnull not null status, default value is false
	 * @return void
	 */
    function addColumn($table_name, $column_name, $type='number', $size='', $default = '', $notnull=false) {
        $type = $this->column_type[$type];
        if(strtoupper($type)=='INTEGER') $size = '';

        $query = sprintf("alter table `%s%s` add `%s` ", $this->prefix, $table_name, $column_name);
        if($size) $query .= sprintf(" %s(%s) ", $type, $size);
        else $query .= sprintf(" %s ", $type);
        if($default) $query .= sprintf(" default '%s' ", $default);
        if($notnull) $query .= " not null ";

        return $this->_query($query);
    }

	/**
	 * Drop a column from the table
	 * @param string $table_name table name
	 * @param string $column_name column name
	 * @return void
	 */
    function dropColumn($table_name, $column_name) {
        $query = sprintf("alter table `%s%s` drop `%s` ", $this->prefix, $table_name, $column_name);
        $this->_query($query);
    }

	/**
	 * Check column exist status of the table
	 * @param string $table_name table name
	 * @param string $column_name column name
	 * @return boolean
	 */
    function isColumnExists($table_name, $column_name) {
        $query = sprintf("show fields from `%s%s`", $this->prefix, $table_name);
        $result = $this->_query($query);
        if($this->isError()) return;
        $output = $this->_fetch($result);
        if($output) {
            $column_name = strtolower($column_name);
            foreach($output as $key => $val) {
                $name = strtolower($val->Field);
                if($column_name == $name) return true;
            }
        }
        return false;
    }

	/**
	 * Add an index to the table
	 * $target_columns = array(col1, col2)
	 * $is_unique? unique : none
	 * @param string $table_name table name
	 * @param string $index_name index name
	 * @param string|array $target_columns target column or columns
	 * @param boolean $is_unique
	 * @return void
	 */
    function addIndex($table_name, $index_name, $target_columns, $is_unique = false) {
        if(!is_array($target_columns)) $target_columns = array($target_columns);

        $query = sprintf("alter table `%s%s` add %s index `%s` (%s);", $this->prefix, $table_name, $is_unique?'unique':'', $index_name, implode(',',$target_columns));
        $this->_query($query);
    }

	/**
	 * Drop an index from the table
	 * @param string $table_name table name
	 * @param string $index_name index name
	 * @param boolean $is_unique
	 * @return void
	 */
    function dropIndex($table_name, $index_name, $is_unique = false) {
        $query = sprintf("alter table `%s%s` drop index `%s`", $this->prefix, $table_name, $index_name);
        $this->_query($query);
    }


	/**
	 * Check index status of the table
	 * @param string $table_name table name
	 * @param string $index_name index name
	 * @return boolean
	 */
    function isIndexExists($table_name, $index_name) {
        //$query = sprintf("show indexes from %s%s where key_name = '%s' ", $this->prefix, $table_name, $index_name);
        $query = sprintf("show indexes from `%s%s`", $this->prefix, $table_name);
        $result = $this->_query($query);
        if($this->isError()) return;
        $output = $this->_fetch($result);
        if(!$output) return;
        if(!is_array($output)) $output = array($output);

        for($i=0;$i<count($output);$i++) {
            if($output[$i]->Key_name == $index_name) return true;
        }
        return false;
    }

	/**
	 * Creates a table by using xml contents
	 * @param string $xml_doc xml schema contents
	 * @return void|object
	 */
    function createTableByXml($xml_doc) {
        return $this->_createTable($xml_doc);
    }

	/**
	 * Creates a table by using xml file path
	 * @param string $file_name xml schema file path
	 * @return void|object
	 */
    function createTableByXmlFile($file_name) {
        if(!file_exists($file_name)) return;
        // read xml file
        $buff = FileHandler::readFile($file_name);
        return $this->_createTable($buff);
    }

	/**
	 * Create table by using the schema xml
	 *
	 * type : number, varchar, tinytext, text, bigtext, char, date, \n
	 * opt : notnull, default, size\n
	 * index : primary key, index, unique\n
	 * @param string $xml_doc xml schema contents
	 * @return void|object
	 */
    function _createTable($xml_doc) {
        // xml parsing
        $oXml = new XmlParser();
        $xml_obj = $oXml->parse($xml_doc);
        // Create a table schema
        $table_name = $xml_obj->table->attrs->name;
        if($this->isTableExists($table_name)) return;
        $table_name = $this->prefix.$table_name;

        if(!is_array($xml_obj->table->column)) $columns[] = $xml_obj->table->column;
        else $columns = $xml_obj->table->column;

        $primary_list = array();
        $unique_list = array();
        $index_list = array();

        foreach($columns as $column) {
            $name = $column->attrs->name;
            $type = $column->attrs->type;
            $size = $column->attrs->size;
            $notnull = $column->attrs->notnull;
            $primary_key = $column->attrs->primary_key;
            $index = $column->attrs->index;
            $unique = $column->attrs->unique;
            $default = $column->attrs->default;
            $auto_increment = $column->attrs->auto_increment;

            $column_schema[] = sprintf('`%s` %s%s %s %s %s',
                $name,
                $this->column_type[$type],
                $size?'('.$size.')':'',
                isset($default)?"default '".$default."'":'',
                $notnull?'not null':'',
                $auto_increment?'auto_increment':''
            );

            if($primary_key) $primary_list[] = $name;
            else if($unique) $unique_list[$unique][] = $name;
            else if($index) $index_list[$index][] = $name;
        }

        if(count($primary_list)) {
            $column_schema[] = sprintf("primary key (%s)", '`'.implode($primary_list,'`,`').'`');
        }

        if(count($unique_list)) {
            foreach($unique_list as $key => $val) {
                $column_schema[] = sprintf("unique %s (%s)", $key, '`'.implode($val,'`,`').'`');
            }
        }

        if(count($index_list)) {
            foreach($index_list as $key => $val) {
                $column_schema[] = sprintf("index %s (%s)", $key, '`'.implode($val,'`,`').'`');
            }
        }

        $schema = sprintf('create table `%s` (%s%s) %s;', $this->addQuotes($table_name), "\n", implode($column_schema,",\n"), "ENGINE = MYISAM  CHARACTER SET utf8 COLLATE utf8_general_ci");

        $output = $this->_query($schema);
        if(!$output) return false;
    }

	/**
	 * Handles insertAct
	 * @param Object $queryObject
	 * @param boolean $with_values
	 * @return resource
	 */
    function _executeInsertAct($queryObject, $with_values = true) {
        $query = $this->getInsertSql($queryObject, $with_values, true);
		$query .= (__DEBUG_QUERY__ & 1 && $this->query_id) ? sprintf(' ' . $this->comment_syntax, $this->query_id) : '';
        if(is_a($query, 'Object')) return;
        return $this->_query($query);
    }

	/**
	 * Handles updateAct
	 * @param Object $queryObject
	 * @param boolean $with_values
	 * @return resource
	 */
    function _executeUpdateAct($queryObject, $with_values = true) {
        $query = $this->getUpdateSql($queryObject, $with_values, true);
		$query .= (__DEBUG_QUERY__ & 1 && $this->query_id) ? sprintf(' ' . $this->comment_syntax, $this->query_id) : '';
        if(is_a($query, 'Object')) return;
        return $this->_query($query);
    }

	/**
	 * Handles deleteAct
	 * @param Object $queryObject
	 * @param boolean $with_values
	 * @return resource
	 */
    function _executeDeleteAct($queryObject, $with_values = true) {
        $query = $this->getDeleteSql($queryObject, $with_values, true);
		$query .= (__DEBUG_QUERY__ & 1 && $this->query_id) ? sprintf(' ' . $this->comment_syntax, $this->query_id) : '';
        if(is_a($query, 'Object')) return;
        return $this->_query($query);
    }

	/**
	 * Handle selectAct
	 * In order to get a list of pages easily when selecting \n
	 * it supports a method as navigation
	 * @param Object $queryObject
	 * @param resource $connection
	 * @param boolean $with_values
	 * @return Object
	 */
    function _executeSelectAct($queryObject, $connection = null, $with_values = true) {
        $limit = $queryObject->getLimit();
        $result = NULL;
        if ($limit && $limit->isPageHandler())
            return $this->queryPageLimit($queryObject, $result, $connection, $with_values);
        else {
            $query = $this->getSelectSql($queryObject, $with_values);
            if (is_a($query, 'Object'))
                return;
            $query .= (__DEBUG_QUERY__ & 1 && $queryObject->queryID) ? sprintf(' ' . $this->comment_syntax, $queryObject->queryID) : '';

            $result = $this->_query($query, $connection);
            if ($this->isError())
                return $this->queryError($queryObject);

            $data = $this->_fetch($result);
            $buff = new Object ();
            $buff->data = $data;
            return $buff;
        }
    }

	/**
	 * Get the ID generated in the last query
	 * Return next sequence from sequence table
	 * This method use only mysql
	 * @return int
	 */
    function db_insert_id()
    {
        $connection = $this->_getConnection('master');
        return mysql_insert_id($connection);
    }

	/**
	 * Fetch a result row as an object
	 * @param resource $result
	 * @return object
	 */
    function db_fetch_object(&$result)
    {
        return mysql_fetch_object($result);
    }

	/**
	 * Free result memory
	 * @param resource $result
	 * @return boolean Returns TRUE on success or FALSE on failure.
	 */
    function db_free_result(&$result){
        return mysql_free_result($result);
    }

	/**
	 * Return the DBParser
	 * @param boolean $force
	 * @return DBParser
	 */
    function &getParser($force = FALSE){
        $dbParser = new DBParser('`', '`', $this->prefix);
        return $dbParser;
    }

	/**
	 * If have a error, return error object
	 * @param Object $queryObject
	 * @return Object
	 */
    function queryError($queryObject){
        $limit = $queryObject->getLimit();
        if ($limit && $limit->isPageHandler()){
            $buff = new Object ();
            $buff->total_count = 0;
            $buff->total_page = 0;
            $buff->page = 1;
            $buff->data = array ();
            $buff->page_navigation = new PageHandler (/*$total_count*/0, /*$total_page*/1, /*$page*/1, /*$page_count*/10);//default page handler values
            return $buff;
        }else
            return;
    }

	/**
	 * If select query execute, return page info
	 * @param Object $queryObject
	 * @param resource $result
	 * @param resource $connection
	 * @param boolean $with_values
	 * @return Object Object with page info containing
	 */
    function queryPageLimit($queryObject, $result, $connection, $with_values = true){
        $limit = $queryObject->getLimit();
        // Total count
        $temp_where = $queryObject->getWhereString($with_values, false);
        $count_query = sprintf('select count(*) as "count" %s %s', 'FROM ' . $queryObject->getFromString($with_values), ($temp_where === '' ? '' : ' WHERE '. $temp_where));

        // Check for distinct query and if found update count query structure
        $temp_select = $queryObject->getSelectString($with_values);
        $uses_distinct = strpos(strtolower($temp_select), "distinct") !== false;
        $uses_groupby = $queryObject->getGroupByString() != '';
        if($uses_distinct || $uses_groupby) {
            $count_query = sprintf('select %s %s %s %s'
                , $temp_select == '*' ? '1' : $temp_select
                , 'FROM ' . $queryObject->getFromString($with_values)
                , ($temp_where === '' ? '' : ' WHERE '. $temp_where)
                , ($uses_groupby ? ' GROUP BY ' . $queryObject->getGroupByString() : '')
            );

            // If query uses grouping or distinct, count from original select
            $count_query = sprintf('select count(*) as "count" from (%s) xet', $count_query);
        }

        $count_query .= (__DEBUG_QUERY__&1 && $queryObject->queryID)?sprintf (' '.$this->comment_syntax, $queryObject->queryID):'';
        $result_count = $this->_query($count_query, $connection);
        $count_output = $this->_fetch($result_count);
        $total_count = (int)(isset($count_output->count) ? $count_output->count : NULL);

        $list_count = $limit->list_count->getValue();
        if (!$list_count) $list_count = 20;
        $page_count = $limit->page_count->getValue();
        if (!$page_count) $page_count = 10;
        $page = $limit->page->getValue();
        if (!$page) $page = 1;

        // total pages
        if ($total_count)
            $total_page = (int) (($total_count - 1) / $list_count) + 1;
        else
            $total_page = 1;

        // check the page variables
        if ($page > $total_page) {
            // If requested page is bigger than total number of pages, return empty list
            $buff = new Object ();
            $buff->total_count = $total_count;
            $buff->total_page = $total_page;
            $buff->page = $page;
            $buff->data = array();
            $buff->page_navigation = new PageHandler($total_count, $total_page, $page, $page_count);
            return $buff;
        }
        $start_count = ($page - 1) * $list_count;

        $query = $this->getSelectPageSql($queryObject, $with_values, $start_count, $list_count);

        $query .= (__DEBUG_QUERY__&1 && $queryObject->query_id)?sprintf (' '.$this->comment_syntax, $this->query_id):'';
        $result = $this->_query ($query, $connection);
        if ($this->isError ())
            return $this->queryError($queryObject);

        $virtual_no = $total_count - ($page - 1) * $list_count;
        $data = $this->_fetch($result, $virtual_no);

        $buff = new Object ();
        $buff->total_count = $total_count;
        $buff->total_page = $total_page;
        $buff->page = $page;
        $buff->data = $data;
        $buff->page_navigation = new PageHandler($total_count, $total_page, $page, $page_count);
        return $buff;
    }

	/**
	 * If select query execute, return paging sql
	 * @param object $query
	 * @param boolean $with_values
	 * @param int $start_count
	 * @param int $list_count
	 * @return string select paging sql
	 */
    function getSelectPageSql($query, $with_values = true, $start_count = 0, $list_count = 0) {
        $select = $query->getSelectString($with_values);
        if($select == '') return new Object(-1, "Invalid query");
        $select = 'SELECT ' .$select;

        $from = $query->getFromString($with_values);
        if($from == '') return new Object(-1, "Invalid query");
        $from = ' FROM '.$from;

        $where = $query->getWhereString($with_values);
        if($where != '') $where = ' WHERE ' . $where;

        $groupBy = $query->getGroupByString();
        if($groupBy != '') $groupBy = ' GROUP BY ' . $groupBy;

        $orderBy = $query->getOrderByString();
        if($orderBy != '') $orderBy = ' ORDER BY ' . $orderBy;

        $limit = $query->getLimitString();
        if ($limit != '') $limit = sprintf (' LIMIT %d, %d', $start_count, $list_count);

        return $select . ' ' . $from . ' ' . $where . ' ' . $groupBy . ' ' . $orderBy . ' ' . $limit;
    }
}
?>