<?php

    /**
     * @class DBMSSQL
     * @author NHN (developers@xpressengine.com)
     * @brief Modified to use MSSQL driver by sol (sol@ngleader.com)
     * @version 0.1
     **/

    class DBMssql extends DB {

        /**
         * information to connect to DB
         **/
        var $prefix		= 'xe'; // / <prefix of XE tables(One more XE can be installed on a single DB)
        var $param		= array();
        var $comment_syntax = '/* %s */';

        /**
         * @brief column type used in mssql
         *
         * column_type should be replaced for each DBMS's type
         * becasue it uses commonly defined type in the schema/query xml
         **/
        var $column_type = array(
            'bignumber' => 'bigint',
            'number' => 'int',
            'varchar' => 'varchar',
            'char' => 'char',
            'text' => 'text',
            'bigtext' => 'text',
            'date' => 'varchar(14)',
            'float' => 'float',
        );

        /**
         * @brief constructor
         **/
        function DBMssql() {
            $this->_setDBInfo();
            $this->_connect();
        }

		/**
		 * @brief create an instance of this class
		 */
		function create()
		{
			return new DBMssql;
		}

        /**
         * @brief Return if installable
         **/
        function isSupported() {
            if (!extension_loaded("sqlsrv")) return false;
            return true;
        }

        /**
         * @brief DB Connection
         **/
        function __connect($connection) {
            //sqlsrv_configure( 'WarningsReturnAsErrors', 0 );
            //sqlsrv_configure( 'LogSeverity', SQLSRV_LOG_SEVERITY_ALL );
            //sqlsrv_configure( 'LogSubsystems', SQLSRV_LOG_SYSTEM_ALL );
            $result = @sqlsrv_connect($connection["db_hostname"], array('Database' => $connection["db_database"], 'UID' => $connection["db_userid"], 'PWD' => $connection["db_password"]));

            if(!$result)
            {
                $errors = print_r(sqlsrv_errors(), true);
                $this->setError (-1, 'database connect fail' . PHP_EOL . $errors);
		return;
            }
            return $result;
        }

        /**
         * @brief DB disconnect
         **/
        function _close($connection) {
            $this->commit();
            sqlsrv_close($connection);
        }

        /**
         * @brief handles quatation of the string variables from the query
         **/
        // TODO See what to do about this
        function addQuotes($string) {
            if(version_compare(PHP_VERSION, "5.9.0", "<") && get_magic_quotes_gpc()) $string = stripslashes(str_replace("\\","\\\\",$string));
            //if(!is_numeric($string)) $string = str_replace("'","''",$string);

            return $string;
        }

        /**
         * @brief Begin transaction
         **/
        function _begin() {
            $connection = $this->_getConnection('master');
            if(sqlsrv_begin_transaction($connection) === false) return;
            return true;
        }

        /**
         * @brief Rollback
         **/
        function _rollback() {
            $connection = $this->_getConnection('master');
            sqlsrv_rollback($connection);
            return true;
        }

        /**
         * @brief Commit
         **/
        function _commit() {
            $connection = $this->_getConnection('master');
            sqlsrv_commit($connection);
            return true;
        }

        /**
         * @brief : executing the query and fetching the result
         *
         * query: run a query and return the result\n
         * fetch: NULL if no value returned \n
         *        array object if rows returned \n
         *        object if a row returned \n
         *        return\n
         **/
        function __query($query, $connection) {
            $_param = array();

            if(count($this->param)){
                    foreach($this->param as $k => $o){
						if($o->isColumnName()) continue;
						if($o->getType() == 'number'){
								$value = $o->getUnescapedValue();
								if(is_array($value)) $_param = array_merge($_param, $value);
								else $_param[] = $o->getUnescapedValue();
						}else{
								$value = $o->getUnescapedValue();
								if(is_array($value)) {
									foreach($value as $v)
										$_param[] = array($v, SQLSRV_PARAM_IN, SQLSRV_PHPTYPE_STRING('utf-8'));
								}
								else $_param[] = array($value, SQLSRV_PARAM_IN, SQLSRV_PHPTYPE_STRING('utf-8'));
						}
                    }
            }

            // Run the query statement
			$result = false;
			if(count($_param)){		
				$args = $this->_getParametersByReference($_param);
				$stmt = sqlsrv_prepare($connection, $query, $args);
			}else{
				$stmt = sqlsrv_prepare($connection, $query);
			}
			
			if(!$stmt) 
			{
				$result = false;
			}
			else 
			{
				$result = sqlsrv_execute($stmt);
			}
			
            // Error Check
			if(!$result) 
				$this->setError(print_r(sqlsrv_errors(),true));

            $this->param = array();

            return $stmt;
        }
		
		/**
		 * Parameters to sqlsrv_prepare need to be references, and not literals
		 * Parameters are sent as an array, where each parameter can be:
		 *	- a PHP variable (by reference)
		 *	- a PHP array (containng param value, type and direction) -> also needs to be sent by reference
		 */
		function _getParametersByReference($_param) 
		{
			$copy = array(); $args = array(); $i = 0;
			foreach($_param as $key => $value) {
				if(is_array($value))
				{
					$value_copy = $value;
					$value_arg = array();
					$value_arg[] = &$value_copy[0];
					$value_arg[] = $value_copy[1];
					$value_arg[] = $value_copy[2];
				}
				else 
				{
					$value_arg = $value;
				}
				$copy[$key] = $value_arg;
				$args[$i++] = &$copy[$key];
			}
			return $args;
		}

        /**
         * @brief Fetch results
         **/
        function _fetch($result, $arrayIndexEndValue = NULL) {
			$output = array();
			if(!$this->isConnected() || $this->isError() || !$result) return $output;

			$c = sqlsrv_num_fields($result);
			$m = null;

			while(sqlsrv_fetch($result)){
				if(!$m) $m = sqlsrv_field_metadata($result);
				unset($row);
				for($i=0;$i<$c;$i++){
					$row->{$m[$i]['Name']} = sqlsrv_get_field( $result, $i, SQLSRV_PHPTYPE_STRING( 'utf-8' ));
				}
				if($arrayIndexEndValue) $output[$arrayIndexEndValue--] = $row;
				else $output[] = $row;
			}

            if(count($output)==1) {
            	if(isset($arrayIndexEndValue)) return $output;
            	else return $output[0];
            }
            return $output;

        }

        /**
         * @brief Return sequence value incremented by 1(auto_increment is usd in the sequence table only)
         **/
        function getNextSequence() {
            $query = sprintf("insert into %ssequence (seq) values (ident_incr('%ssequence'))", $this->prefix, $this->prefix);
			$this->_query($query);

            $query = sprintf("select ident_current('%ssequence')+1 as sequence", $this->prefix);
            $result = $this->_query($query);
            $tmp = $this->_fetch($result);


            return $tmp->sequence;
        }

        /**
         * @brief Return if a table already exists
         **/
        function isTableExists($target_name) {
            $query = sprintf("select name from sysobjects where name = '%s%s' and xtype='U'", $this->prefix, $this->addQuotes($target_name));
            $result = $this->_query($query);
            $tmp = $this->_fetch($result);

            if(!$tmp) return false;
            return true;
        }

        /**
         * @brief Add a column to a table
         **/
        function addColumn($table_name, $column_name, $type='number', $size='', $default = '', $notnull=false) {
			if($this->isColumnExists($table_name, $column_name)) return;
            $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 ";

            $this->_query($query);
        }

        /**
         * @brief Delete a column from a table
         **/
        function dropColumn($table_name, $column_name) {
			if(!$this->isColumnExists($table_name, $column_name)) return;
            $query = sprintf("alter table %s%s drop %s ", $this->prefix, $table_name, $column_name);
            $this->_query($query);
        }

        /**
         * @brief Return column information of a table
         **/
        function isColumnExists($table_name, $column_name) {
            $query = sprintf("select syscolumns.name as name from syscolumns, sysobjects where sysobjects.name = '%s%s' and sysobjects.id = syscolumns.id and syscolumns.name = '%s'", $this->prefix, $table_name, $column_name);
            $result = $this->_query($query);
            if($this->isError()) return;
            $tmp = $this->_fetch($result);
            if(!$tmp->name) return false;
            return true;
        }

        /**
         * @brief Add an index to a table
         * $target_columns = array(col1, col2)
         * $is_unique? unique : none
         **/
        function addIndex($table_name, $index_name, $target_columns, $is_unique = false) {
			if($this->isIndexExists($table_name, $index_name)) return;
            if(!is_array($target_columns)) $target_columns = array($target_columns);

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

        /**
         * @brief Drop an index from a table
         **/
        function dropIndex($table_name, $index_name, $is_unique = false) {
			if(!$this->isIndexExists($table_name, $index_name)) return;
            $query = sprintf("drop index %s%s.%s", $this->prefix, $table_name, $index_name);
            $this->_query($query);
        }

        /**
         * @brief Return index information of a table
         **/
        function isIndexExists($table_name, $index_name) {
            $query = sprintf("select sysindexes.name as name from sysindexes, sysobjects where sysobjects.name = '%s%s' and sysobjects.id = sysindexes.id and sysindexes.name = '%s'", $this->prefix, $table_name, $index_name);

            $result = $this->_query($query);
            if($this->isError()) return;
            $tmp = $this->_fetch($result);

            if(!$tmp->name) return false;
            return true;
        }

        /**
         * @brief Create a table by using xml file
         **/
        function createTableByXml($xml_doc) {
            return $this->_createTable($xml_doc);
        }

        /**
         * @brief Create a table by using xml file
         **/
        function createTableByXmlFile($file_name) {
            if(!file_exists($file_name)) return;
            // read xml file
            $buff = FileHandler::readFile($file_name);
            return $this->_createTable($buff);
        }

        /**
         * @brief generate a query statement to create a table by using schema xml
         *
         * type : number, varchar, text, char, date, \n
         * opt : notnull, default, size\n
         * index : primary key, index, unique\n
         **/
        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;

            if($table_name == 'sequence') {
                $table_name = $this->prefix.$table_name;
                $query = sprintf('create table %s ( sequence int identity(1,1), seq int )', $table_name);
                return $this->_query($query);
            } else {
                $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],
                    !in_array($type,array('number','text'))&&$size?'('.$size.')':'',
                    isset($default)?"default '".$default."'":'',
                    $notnull?'not null':'null',
                    $auto_increment?'identity(1,1)':''
                    );

					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,'","').'"');
				}				
				
                $schema = sprintf('create table [%s] (%s%s)', $this->addQuotes($table_name), "\n", implode($column_schema,",\n"));
                $output = $this->_query($schema);
                if(!$output) return false;

                if(count($unique_list)) {
                    foreach($unique_list as $key => $val) {
                        $query = sprintf("create unique index %s on %s (%s);", $key, $table_name, '['.implode('],[',$val).']');
                        $this->_query($query);
                    }
                }

                if(count($index_list)) {
                    foreach($index_list as $key => $val) {
                        $query = sprintf("create index %s on %s (%s);", $key, $table_name, '['.implode('],[',$val).']');
                        $this->_query($query);
                    }
                }
				return true;
            }
        }


        /**
         * @brief Handle the insertAct
         **/
        // TODO Lookup _filterNumber against sql injection - see if it is still needed and how to integrate
        function _executeInsertAct($queryObject) {
        	$query = $this->getInsertSql($queryObject, false);
        	$this->param = $queryObject->getArguments();
            return $this->_query($query);
        }

        /**
         * @brief Handle updateAct
         **/
        function _executeUpdateAct($queryObject) {
        	$query = $this->getUpdateSql($queryObject, false);
        	$this->param = $queryObject->getArguments();
            return $this->_query($query);
        }

    	function getUpdateSql($query, $with_values = true, $with_priority = false){
			$columnsList = $query->getUpdateString($with_values);
			if($columnsList == '') return new Object(-1, "Invalid query");

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

			$tables = $query->getTables();
			$alias_list = '';
			foreach($tables as $table)
				$alias_list .= $table->getAlias();
			implode(',', explode(' ', $alias_list));
			
			$where = $query->getWhereString($with_values);
			if($where != '') $where = ' WHERE ' . $where;

			$priority = $with_priority?$query->getPriority():'';

			return "UPDATE $priority $alias_list SET $columnsList FROM ".$from.$where;
		}		
		
        /**
         * @brief Handle deleteAct
         **/
        function _executeDeleteAct($queryObject) {
        	$query = $this->getDeleteSql($queryObject, false);
        	$this->param = $queryObject->getArguments();
            return $this->_query($query);
        }

        function getSelectSql($query, $with_values = TRUE){
       		$with_values = false;

       		//$limitOffset = $query->getLimit()->getOffset();
       		//if($limitOffset)
       			// TODO Implement Limit with offset with subquery
		 	$limit = '';$limitCount = '';
                        $limitQueryPart = $query->getLimit();
		 	if($limitQueryPart)
       			$limitCount = $limitQueryPart->getLimit();
		 	if($limitCount != '') $limit = 'SELECT TOP ' . $limitCount;

			$select = $query->getSelectString($with_values);
			if($select == '') return new Object(-1, "Invalid query");
			if($limit != '')
				$select = $limit.' '.$select;
			else
				$select = 'SELECT ' .$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;


		 	return $select . ' ' . $from . ' ' . $where . ' ' . $groupBy . ' ' . $orderBy;
        }

        /**
         * @brief Handle selectAct
         *
         * In order to get a list of pages easily when selecting \n
         * it supports a method as navigation
         **/
        function _executeSelectAct($queryObject, $connection = null) {
			$query = $this->getSelectSql($queryObject);

			if(strpos($query, "substr")) $query = str_replace ("substr", "substring", $query);

			// TODO Decide if we continue to pass parameters like this
			$this->param = $queryObject->getArguments();

			$query .= (__DEBUG_QUERY__&1 && $output->query_id)?sprintf(' '.$this->comment_syntax,$this->query_id):'';
			$result = $this->_query($query, $connection);

			if ($this->isError ()) return $this->queryError($queryObject);
			else return $this->queryPageLimit($queryObject, $result, $connection);
        }

        function &getParser($force = FALSE){
		$dbParser = new DBParser("[", "]", $this->prefix);
        	return $dbParser;
        }

    	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;
		}

		function queryPageLimit($queryObject, $result, $connection) {
			$limit = $queryObject->getLimit();
			if ($limit && $limit->isPageHandler()) {
				// Total count
				$temp_where = $queryObject->getWhereString(true, false);
				$count_query = sprintf('select count(*) as "count" %s %s', 'FROM ' . $queryObject->getFromString(), ($temp_where === '' ? '' : ' WHERE ' . $temp_where));

                // Check for distinct query and if found update count query structure
                $temp_select = $queryObject->getSelectString(true);
                $uses_distinct = strpos(strtolower($temp_select), "distinct") !== false;
                $uses_groupby = $queryObject->getGroupByString() != '';
                if($uses_distinct || $uses_groupby) {
                    $count_query = sprintf('select %s %s %s %s'
                        , $temp_select
                        , 'FROM ' . $queryObject->getFromString(true)
                        , ($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, $this->query_id) : '';
				$this->param = $queryObject->getArguments();
				$result_count = $this->_query($count_query, $connection);
				$count_output = $this->_fetch($result_count);
				$total_count = (int) $count_output->count;

				$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;
				$this->param = $queryObject->getArguments();
				$virtual_no = $total_count - $start_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);
			}else {
				$data = $this->_fetch($result);
				$buff = new Object ();
				$buff->data = $data;
			}
			return $buff;
		}

    }

return new DBMssql;
?>