<?php
if (! extension_loaded('mssql')) {
    //Return an associative array. Used on mssql_fetch_array()'s result_type parameter.
    define('MSSQL_ASSOC', '1');
    //Return an array with numeric keys. Used on mssql_fetch_array()'s result_type parameter.
    define('MSSQL_NUM', '2');
    //Return an array with both numeric keys and keys with their field name. This is the default value for mssql_fetch_array()'s result_type parameter.
    define('MSSQL_BOTH', '3');
    //Indicates the 'TEXT' type in MSSQL, used by mssql_bind()'s type parameter.
    define('SQLTEXT', '35');
    //Indicates the 'VARCHAR' type in MSSQL, used by mssql_bind()'s type parameter.
    define('SQLVARCHAR', '39');
    //Indicates the 'CHAR' type in MSSQL, used by mssql_bind()'s type parameter.
    define('SQLCHAR', '47');
    //Represents one byte, with a range of -128 to 127.
    define('SQLINT1', '48');
    //Represents two bytes, with a range of -32768 to 32767.
    define('SQLINT2', '52');
    //Represents four bytes, with a range of -2147483648 to 2147483647.
    define('SQLINT4', '56');
    //Indicates the 'BIT' type in MSSQL, used by mssql_bind()'s type parameter.
    define('SQLBIT', '50');
    //Represents an four byte float.
    define('SQLFLT4', '59');
    //Represents an eight byte float.
    define('SQLFLT8', '62');
    class MSSQL_PDO extends PDO {
        public function __construct($dsn, $username="", $password="", $driver_options=array()) {
            parent::__construct($dsn,$username,$password, $driver_options);
            if (empty($driver_options[PDO::ATTR_STATEMENT_CLASS])) {
                $this->setAttribute(PDO::ATTR_STATEMENT_CLASS, array('MSSQL_PDOStatement', array($this)));
            }
        }
    }
    class MSSQL_PDOStatement extends PDOStatement {
        //public $_all = null;
        public $dbh;
        protected function __construct($dbh) {
            $this->dbh = $dbh;
        }
    }
    function mssql_last_link($link_identifier = null) {
        static $last = null;
        if ($link_identifier) {
            $last = $link_identifier;
        }
        return $last;
    }
    function mssql_bind($stmt, $param_name, &$var, $type, $is_output = false, $is_null = false, $maxlen = -1) {
        $mssql_type_map = array(
                SQLTEXT => PDO::PARAM_LOB,
                SQLVARCHAR => PDO::PARAM_STR,
                SQLCHAR => PDO::PARAM_STR,
                SQLINT1 => PDO::PARAM_INT,
                SQLINT2 => PDO::PARAM_INT,
                SQLINT4 => PDO::PARAM_INT,
                SQLBIT =>  PDO::PARAM_BOOL,
                SQLFLT4 => PDO::PARAM_INT,
                SQLFLT8 => PDO::PARAM_INT,
        );
        $var = $is_null?null:$var;
        $ret = $stmt->bindParam($param_name, $var, $mssql_type_map[$type], $is_output?$maxlen:($maxlen<0?null:$maxlen));
        return $ret;
    }
    #@todo write a mssql_close function
    function mssql_connect($servername, $username, $password, $new_link = false) {
        $pdo = new PDO('sqlsrv:Server='.$servername .';', $username, $password);
        $pdo->setAttribute(PDO::SQLSRV_ENCODING_SYSTEM, 0);
        // cursor scroll is set to allow driver to count rows (mssql_num_rows)
        $pdo->setAttribute(PDO::ATTR_CURSOR, PDO::CURSOR_SCROLL);
        $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        $pdo->setAttribute(PDO::ATTR_STATEMENT_CLASS, array('MSSQL_PDOStatement', array($pdo)));
        mssql_last_link($pdo);
        return $pdo;
    }
    function mssql_pconnect($servername, $username, $password, $new_link = false) {
        $pdo = mssql_connect($servername, $username, $password, $new_link);
        // @todo this may not work except at connection time.
        // this wont work in fast-cgi or pdo_sqlsrv in anycase.
        // left here as a woulda-shoulda-cant
        //$pdo->setAttribute(PDO::ATTR_PERSISTENT, true);
        return $pdo;
    }
    function mssql_execute($stmt, $skip_results = false) {
        return $stmt->execute();
    }


    function mssql_fetch_array($result, $result_type = MSSQL_BOTH) {
        $mssql_result_type = array(
                MSSQL_ASSOC => PDO::FETCH_ASSOC,
                MSSQL_NUM => PDO::FETCH_NUM,
                MSSQL_BOTH => PDO::FETCH_BOTH
        );
        return $result->fetch($mssql_result_type[$result_type]);
    }
    function mssql_fetch_assoc($result) {
        return $result->fetch(PDO::FETCH_ASSOC);
    }
    function mssql_fetch_object($result) {
        return $result->fetch(PDO::FETCH_OBJ);
    }
    function mssql_fetch_row($result) {
        return $result->fetch();
    }
    function mssql_free_result($result) {
        return $stmt->closeCursor();
    }
    function mssql_free_statement($stmt) {
        return $stmt->closeCursor();
    }
    function mssql_get_last_message() {
        $link_identifier = mssql_last_link();
        $errors = $link_identifier->errorInfo();
        return $errors[2];
    }
    function mssql_init($sp_name, $link_identifier = null) {
        if (is_null($link_identifier)) {
            $link_identifier = mssql_last_link();
        }
        return $link_identifier->prepare('exec '.$sp_name);
    }
    function mssql_next_result($result_id) {
        return $result_id->nextRowset();
    }
    function mssql_num_fields($result) {
        return $result->columnCount();
    }
    function mssql_num_rows($result) {
        return $result->rowCount();
    }
    function mssql_query($query, $link_identifier = null, $batch_size = 0) {
        if (is_null($link_identifier)) {
            $link_identifier = mssql_last_link();
        }
        //$driver_options = array(PDO::SQLSRV_ATTR_ENCODING => PDO::SQLSRV_ENCODING_UTF8)
        $driver_options = array(PDO::ATTR_CURSOR => PDO::CURSOR_SCROLL)
        $stmt = $link_identifier->prepare($query, $driver_options);
        $return = $stmt->execute();
        // Match mssql_query behavior
        if ($return) {
            $rows = $stmt->rowCount();
            $link_identifier->lastAffected = $rows;
            if (is_null($rows)) {
                $return = true;
            } else {
                $return = $stmt;
            }
        }
        return $return;
    }
    function mssql_data_seek($result_identifier, $row_number) {
        $row = $result_identifier->fetch(PDO::FETCH_BOTH, PDO::FETCH_ORI_ABS, $row_number);
        // Rewind - CI always does a data_seek(0) as a rewind, but that offsets the cursor,
        // we have to move to -1 so the next fetch will return the first piece of data
        // @todo rather than resetting, it would be better to restore the old position
        // if we can't fetch that data somehow then track the position in the statement class
        $row = $result_identifier->fetch(PDO::FETCH_BOTH, PDO::FETCH_ORI_ABS, -1);
        return $row;
    }
    function mssql_result($resource, $row, $field) {
        $data_row = mssql_data_seek($resource, $row);
        return $data_row[$field];
    }


    function mssql_rows_affected($link_identifier = null) {
        if (is_null($link_identifier)) {
            $link_identifier = mssql_last_link();
        }
        return  $link_identifier->lastAffected;
    }
    // @todo try/catch return false on failure
    function mssql_select_db($database_name, $link_identifier = null) {
        if (is_null($link_identifier)) {
            $link_identifier = mssql_last_link();
        }
        $affected = $link_identifier->exec('USE '.$database_name);
        $link_identifier->lastAffected = $affected;
        return true;
    }
}
?>