<?php
namespace BSR\Db;

class OdbcResultSet implements \Iterator, \ArrayAccess
{
    public $length;

    private $results;
    private $error;
    private $num_fields;
    private $num_rows;
    private $cursor_index;

    public function __construct($odbc_result)
    {
        if ($odbc_result === false) {
            $this->error = odbc_errormsg(Connection::get());
        } else {
            try {
                $this->results = array();
                $this->num_fields = odbc_num_fields($odbc_result);
                $this->num_rows = odbc_num_rows($odbc_result);

                if ($this->num_fields > 0) {
                    while ($row = odbc_fetch_row($odbc_result)) {
                        $data = array();
                        for ($i = 1; $i <= $this->num_fields; ++$i) {
                            $data[odbc_field_name($odbc_result, $i)] = utf8_encode(odbc_result($odbc_result, $i));
                        }
                        $this->results[] = $data;
                    }
                };
            } catch (\Exception $e) {
                print($e->getMessage());
            }

            $this->cursor_index = 0;
            $this->length = count($this->results);
            odbc_free_result($odbc_result);
        }
    }

    public function get_num_rows()
    {
        return $this->num_rows;
    }

    public function is_error()
    {
        return ($this->error ? true : false);
    }

    public function get_error()
    {
        return $this->error;
    }

    public function get_row()
    {
        return $this->current();
    }

    public function to_array()
    {
        return $this->results;
    }

    // ArrayAccess
    /**
     * @param int $offset
     * @return bool
     */
    public function offsetExists($offset)
    {
        return !$this->error && $this->cursor_index < $this->length && $this->cursor_index >= 0;
    }

    /**
     * @param int $offset
     * @return bool|array
     */
    public function offsetGet($offset)
    {
        return $this->offsetExists($offset) ? $this->results[$offset] : false;
    }

    public function offsetSet($offset, $value)
    {
        if($this->offsetExists($offset)) {
            $this->results[$offset] = $value;
        }
    }

    public function offsetUnset($offset)
    {
        throw new \RuntimeException("This makes no sense at all.");
    }

    // Iterator
    /**
     * @return bool|array
     */
    public function current()
    {
        return $this->offsetGet($this->cursor_index);
    }

    /**
     * @return int
     */
    public function key()
    {
        return $this->cursor_index;
    }

    /**
     * @return array|bool
     */
    public function next()
    {
        $current = $this->current();
        ++$this->cursor_index;
        return $current;
    }

    public function rewind()
    {
        $this->cursor_index = 0;
    }

    /**
     * @return bool
     */
    public function valid()
    {
        return $this->offsetExists($this->cursor_index);
    }
}