<?php
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP
 *
 * This content is released under the MIT License (MIT)
 *
 * Copyright (c) 2014 - 2016, British Columbia Institute of Technology
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *_version
 * @copyright	Copyright (c) 2014 - 2016, British Columbia Institute of Technology (http://bcit.ca/)
 * @license	http://opensource.org/licenses/MIT	MIT License
 * @link	https://codeigniter.com
 * @since	Version 1.0.0
 * @filesource
 */

/**
 * Database Result Class
 *
 * This is the platform-independent result class.
 * This class will not be called directly. Rather, the adapter
 * class for the specific database will extend and instantiate it.
 *
 * @category	Database
 * @author		EllisLab Dev Team
 * @link		https://codeigniter.com/user_guide/database/
 */
class ResultQuery {

    /**
     * Connection ID
     *
     * @var	resource|object
     */
    public $conn_id;

    /**
     * Result ID
     *
     * @var	resource|object
     */
    public $result_id;

    /**
     * Result Array
     *
     * @var	array[]
     */
    public $result_array			= array();

    /**
     * Result Object
     *
     * @var	object[]
     */
    public $result_object			= array();

    /**
     * Custom Result Object
     *
     * @var	object[]
     */
    public $custom_result_object		= array();

    /**
     * Current Row index
     *
     * @var	int
     */
    public $current_row			= 0;

    /**
     * Number of rows
     *
     * @var	int
     */
    public $num_rows;

    /**
     * Row data
     *
     * @var	array
     */
    public $row_data;

    // --------------------------------------------------------------------

    /**
     * Constructor
     *
     * @param	object	$driver_object
     * @return	void
     */
    public function __construct(&$driver_object)
    {
        $this->conn_id = $driver_object->conn_id;
        $this->result_id = $driver_object->result_id;
    }

    // --------------------------------------------------------------------

    /**
     * Number of rows in the result set
     *
     * @return	int
     */
    public function num_rows()
    {
        return is_int($this->num_rows)
            ? $this->num_rows
            : $this->num_rows = mssql_num_rows($this->result_id);
    }

    // --------------------------------------------------------------------

    /**
     * Query result. Acts as a wrapper function for the following functions.
     *
     * @param	string	$type	'object', 'array' or a custom class name
     * @return	array
     */
    public function result($type = 'object')
    {
        if ($type === 'array')
        {
            return $this->result_array();
        }
        elseif ($type === 'object')
        {
            return $this->result_object();
        }
        else
        {
            return $this->custom_result_object($type);
        }
    }

    // --------------------------------------------------------------------

    /**
     * Custom query result.
     *
     * @param	string	$class_name
     * @return	array
     */
    public function custom_result_object($class_name)
    {
        if (isset($this->custom_result_object[$class_name]))
        {
            return $this->custom_result_object[$class_name];
        }
        elseif ( ! $this->result_id OR $this->num_rows === 0)
        {
            return array();
        }

        // Don't fetch the result set again if we already have it
        $_data = NULL;
        if (($c = count($this->result_array)) > 0)
        {
            $_data = 'result_array';
        }
        elseif (($c = count($this->result_object)) > 0)
        {
            $_data = 'result_object';
        }

        if ($_data !== NULL)
        {
            for ($i = 0; $i < $c; $i++)
            {
                $this->custom_result_object[$class_name][$i] = new $class_name();

                foreach ($this->{$_data}[$i] as $key => $value)
                {
                    $this->custom_result_object[$class_name][$i]->$key = $value;
                }
            }

            return $this->custom_result_object[$class_name];
        }

        is_null($this->row_data) OR $this->data_seek(0);
        $this->custom_result_object[$class_name] = array();

        while ($row = $this->_fetch_object($class_name))
        {
            $this->custom_result_object[$class_name][] = $row;
        }

        return $this->custom_result_object[$class_name];
    }

    // --------------------------------------------------------------------

    /**
     * Query result. "object" version.
     *
     * @return	array
     */
    public function result_object()
    {
        if (count($this->result_object) > 0)
        {
            return $this->result_object;
        }

        // In the event that query caching is on, the result_id variable
        // will not be a valid resource so we'll simply return an empty
        // array.
        if ( ! $this->result_id OR $this->num_rows === 0)
        {
            return array();
        }

        if (($c = count($this->result_array)) > 0)
        {
            for ($i = 0; $i < $c; $i++)
            {
                $this->result_object[$i] = (object) $this->result_array[$i];
            }

            return $this->result_object;
        }

        is_null($this->row_data) OR $this->data_seek(0);
        while ($row = $this->_fetch_object())
        {
            $this->result_object[] = $row;
        }

        return $this->result_object;
    }

    // --------------------------------------------------------------------

    /**
     * Query result. "array" version.
     *
     * @return	array
     */
    public function result_array()
    {
        if (count($this->result_array) > 0)
        {
            return $this->result_array;
        }

        // In the event that query caching is on, the result_id variable
        // will not be a valid resource so we'll simply return an empty
        // array.
        if ( ! $this->result_id OR $this->num_rows === 0)
        {
            return array();
        }

        if (($c = count($this->result_object)) > 0)
        {
            for ($i = 0; $i < $c; $i++)
            {
                $this->result_array[$i] = (array) $this->result_object[$i];
            }

            return $this->result_array;
        }

        is_null($this->row_data) OR $this->data_seek(0);
        while ($row = $this->_fetch_assoc())
        {
            $this->result_array[] = $row;
        }

        return $this->result_array;
    }

    // --------------------------------------------------------------------

    /**
     * Row
     *
     * A wrapper method.
     *
     * @param	mixed	$n
     * @param	string	$type	'object' or 'array'
     * @return	mixed
     */
    public function row($n = 0, $type = 'object')
    {
        if ( ! is_numeric($n))
        {
            // We cache the row data for subsequent uses
            is_array($this->row_data) OR $this->row_data = $this->row_array(0);

            // array_key_exists() instead of isset() to allow for NULL values
            if (empty($this->row_data) OR ! array_key_exists($n, $this->row_data))
            {
                return NULL;
            }

            return $this->row_data[$n];
        }

        if ($type === 'object') return $this->row_object($n);
        elseif ($type === 'array') return $this->row_array($n);
        else return $this->custom_row_object($n, $type);
    }

    // --------------------------------------------------------------------

    /**
     * Assigns an item into a particular column slot
     *
     * @param	mixed	$key
     * @param	mixed	$value
     * @return	void
     */
    public function set_row($key, $value = NULL)
    {
        // We cache the row data for subsequent uses
        if ( ! is_array($this->row_data))
        {
            $this->row_data = $this->row_array(0);
        }

        if (is_array($key))
        {
            foreach ($key as $k => $v)
            {
                $this->row_data[$k] = $v;
            }
            return;
        }

        if ($key !== '' && $value !== NULL)
        {
            $this->row_data[$key] = $value;
        }
    }

    // --------------------------------------------------------------------

    /**
     * Returns a single result row - custom object version
     *
     * @param	int	$n
     * @param	string	$type
     * @return	object
     */
    public function custom_row_object($n, $type)
    {
        isset($this->custom_result_object[$type]) OR $this->custom_result_object($type);

        if (count($this->custom_result_object[$type]) === 0)
        {
            return NULL;
        }

        if ($n !== $this->current_row && isset($this->custom_result_object[$type][$n]))
        {
            $this->current_row = $n;
        }

        return $this->custom_result_object[$type][$this->current_row];
    }

    // --------------------------------------------------------------------

    /**
     * Returns a single result row - object version
     *
     * @param	int	$n
     * @return	object
     */
    public function row_object($n = 0)
    {
        $result = $this->result_object();
        if (count($result) === 0)
        {
            return NULL;
        }

        if ($n !== $this->current_row && isset($result[$n]))
        {
            $this->current_row = $n;
        }

        return $result[$this->current_row];
    }

    // --------------------------------------------------------------------

    /**
     * Returns a single result row - array version
     *
     * @param	int	$n
     * @return	array
     */
    public function row_array($n = 0)
    {
        $result = $this->result_array();
        if (count($result) === 0)
        {
            return NULL;
        }

        if ($n !== $this->current_row && isset($result[$n]))
        {
            $this->current_row = $n;
        }

        return $result[$this->current_row];
    }

    // --------------------------------------------------------------------

    /**
     * Returns the "first" row
     *
     * @param	string	$type
     * @return	mixed
     */
    public function first_row($type = 'object')
    {
        $result = $this->result($type);
        return (count($result) === 0) ? NULL : $result[0];
    }

    // --------------------------------------------------------------------

    /**
     * Returns the "last" row
     *
     * @param	string	$type
     * @return	mixed
     */
    public function last_row($type = 'object')
    {
        $result = $this->result($type);
        return (count($result) === 0) ? NULL : $result[count($result) - 1];
    }

    // --------------------------------------------------------------------

    /**
     * Returns the "next" row
     *
     * @param	string	$type
     * @return	mixed
     */
    public function next_row($type = 'object')
    {
        $result = $this->result($type);
        if (count($result) === 0)
        {
            return NULL;
        }

        return isset($result[$this->current_row + 1])
            ? $result[++$this->current_row]
            : NULL;
    }

    // --------------------------------------------------------------------

    /**
     * Returns the "previous" row
     *
     * @param	string	$type
     * @return	mixed
     */
    public function previous_row($type = 'object')
    {
        $result = $this->result($type);
        if (count($result) === 0)
        {
            return NULL;
        }

        if (isset($result[$this->current_row - 1]))
        {
            --$this->current_row;
        }
        return $result[$this->current_row];
    }

    // --------------------------------------------------------------------

    /**
     * Returns an unbuffered row and move pointer to next row
     *
     * @param	string	$type	'array', 'object' or a custom class name
     * @return	mixed
     */
    public function unbuffered_row($type = 'object')
    {
        if ($type === 'array')
        {
            return $this->_fetch_assoc();
        }
        elseif ($type === 'object')
        {
            return $this->_fetch_object();
        }

        return $this->_fetch_object($type);
    }

    // --------------------------------------------------------------------

    /**
     * The following methods are normally overloaded by the identically named
     * methods in the platform-specific driver -- except when query caching
     * is used. When caching is enabled we do not load the other driver.
     * These functions are primarily here to prevent undefined function errors
     * when a cached result object is in use. They are not otherwise fully
     * operational due to the unavailability of the database resource IDs with
     * cached results.
     */

    // --------------------------------------------------------------------

    /**
     * Number of fields in the result set
     *
     * @return	int
     */
    public function num_fields()
    {
        return mssql_num_fields($this->result_id);
    }

    // --------------------------------------------------------------------

    /**
     * Fetch Field Names
     *
     * Generates an array of column names
     *
     * @return	array
     */
    public function list_fields()
    {
        $field_names = array();
        mssql_field_seek($this->result_id, 0);
        while ($field = mssql_fetch_field($this->result_id))
        {
            $field_names[] = $field->name;
        }

        return $field_names;
    }

    // --------------------------------------------------------------------

    /**
     * Field data
     *
     * Generates an array of objects containing field meta-data
     *
     * @return	array
     */
    public function field_data()
    {
        $retval = array();
        for ($i = 0, $c = $this->num_fields(); $i < $c; $i++)
        {
            $field = mssql_fetch_field($this->result_id, $i);

            $retval[$i]		= new stdClass();
            $retval[$i]->name	= $field->name;
            $retval[$i]->type	= $field->type;
            $retval[$i]->max_length	= $field->max_length;
        }

        return $retval;
    }

    // --------------------------------------------------------------------

    /**
     * Free the result
     *
     * @return	void
     */
    public function free_result()
    {
        if (is_resource($this->result_id))
        {
            mssql_free_result($this->result_id);
            $this->result_id = FALSE;
        }
    }

    // --------------------------------------------------------------------

    /**
     * Data Seek
     *
     * Moves the internal pointer to the desired offset. We call
     * this internally before fetching results to make sure the
     * result set starts at zero.
     *
     * @param	int	$n
     * @return	bool
     */
    public function data_seek($n = 0)
    {
        return mssql_data_seek($this->result_id, $n);
    }

    // --------------------------------------------------------------------

    /**
     * Result - associative array
     *
     * Returns the result set as an array
     *
     * @return	array
     */
    protected function _fetch_assoc()
    {
        return mssql_fetch_assoc($this->result_id);
    }

    // --------------------------------------------------------------------
    
    /**
     * Result - object
     *
     * Returns the result set as an object
     *
     * @param	string	$class_name
     * @return	object
     */
    protected function _fetch_object($class_name = 'stdClass')
    {
        $row = mssql_fetch_object($this->result_id);

        if ($class_name === 'stdClass' OR ! $row)
        {
            return $row;
        }

        $class_name = new $class_name();
        foreach ($row as $key => $value)
        {
            $class_name->$key = $value;
        }

        return $class_name;
    }
}
