<?php
// MariaDBResult.php
// Created: 2021-05-02
// Updated: 2023-01-01

namespace Index\Data\MariaDB;

use mysqli_result;
use mysqli_stmt;
use InvalidArgumentException;
use Index\AString;
use Index\WString;
use Index\Data\IDbResult;
use Index\IO\Stream;
use Index\IO\TempFileStream;

/**
 * Represents a MariaDB/MySQL database result.
 */
abstract class MariaDBResult implements IDbResult {
    protected mysqli_stmt|mysqli_result $result;
    protected array $currentRow = [];

    /**
     * Creates a new MariaDBResult instance.
     *
     * @param mysqli_stmt|mysqli_result $result A result to work with.
     * @return MariaDBResult A result instance.
     */
    public function __construct(mysqli_stmt|mysqli_result $result) {
        $this->result = $result;
    }

    /**
     * Gets the number of available rows in this result.
     *
     * @return int|string Number of available rows.
     */
    public function getRowCount(): int|string {
        return $this->result->num_rows;
    }

    /**
     * Gets the number of fields in the result per row.
     *
     * @return int Number of fields.
     */
    public function getFieldCount(): int {
        return $this->result->field_count;
    }

    /**
     * Seek to a specific row.
     *
     * @param int $offset Offset of the row.
     */
    public function seekRow(int $offset): void {
        if(!$this->result->data_seek($offset))
            throw new InvalidArgumentException('$offset is not a valid row offset.');
    }

    abstract public function next(): bool;

    public function isNull(int|string $index): bool {
        return array_key_exists($index, $this->currentRow) && $this->currentRow[$index] === null;
    }

    public function getValue(int|string $index): mixed {
        return $this->currentRow[$index] ?? null;
    }

    public function getString(int|string $index): string {
        return (string)$this->getValue($index);
    }

    public function getAString(int|string $index): AString {
        return new AString($this->getString($index));
    }

    public function getWString(int|string $index, string $encoding): WString {
        return new WString($this->getString($index), $encoding);
    }

    public function getInteger(int|string $index): int {
        return (int)$this->getValue($index);
    }

    public function getFloat(int|string $index): float {
        return (float)$this->getValue($index);
    }

    public function getStream(int|string $index): ?Stream {
        if($this->isNull($index))
            return null;
        return new TempFileStream($this->getValue($index));
    }

    abstract function close(): void;

    public function __destruct() {
        $this->close();
    }
}