<?php
namespace Bsr\Db;

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

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

    public function __construct($resultset)
    {
        $this->results = $resultset;
        $this->num_fields = is_array(current($resultset)) ? count(current($resultset)) : count($resultset);
        $this->num_rows = count($this->results);
        $this->length = $this->num_rows;
        $this->cursor_index = 0;
    }

    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;
    }

    // Implementing Countable
    public function count(): int {
        return $this->get_num_rows();
    }

    // Implementing ArrayAccess
    public function offsetExists(mixed $offset): bool
    {
        return !$this->error && $offset < $this->length && $offset >= 0;
    }

    public function offsetGet(mixed $offset): mixed
    {
        return $this->offsetExists($offset) ? $this->results[$offset] : false;
    }

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

    public function offsetUnset(mixed $offset): void
    {
        throw new \RuntimeException("Unsetting elements is not supported.");
    }

    // Implementing Iterator
    public function current(): mixed
    {
        return $this->offsetGet($this->cursor_index);
    }

    public function key(): mixed
    {
        return $this->cursor_index;
    }

    public function next(): void
    {
        ++$this->cursor_index;
    }

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

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