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

namespace Index\Data\SQLite;

use SQLite3Result;
use InvalidArgumentException;
use Index\AString;
use Index\WString;
use Index\Data\IDbResult;
use Index\IO\Stream;
use Index\IO\TempFileStream;

/**
 * Represents an SQLite result set.
 */
class SQLiteResult implements IDbResult {
    private SQLite3Result $result;
    private array $currentRow = [];

    /**
     * Creates a new instance of SQLiteResult.
     *
     * @param SQLite3Result $result Raw underlying result class.
     * @return SQLiteResult A new SQLiteResult instance.
     */
    public function __construct(SQLite3Result $result) {
        $this->result = $result;
    }

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

    public function next(): bool {
        $result = $this->result->fetchArray(SQLITE3_BOTH);
        if($result === false)
            return false;
        $this->currentRow = $result;
        return true;
    }

    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);
    }

    /**
     * Gets the value from the target index as a Stream.
     * If you're aware that you're using SQLite it may make more sense to use SQLiteConnection::getBlobStream instead.
     */
    public function getStream(int|string $index): ?Stream {
        if($this->isNull($index))
            return null;
        return new TempFileStream($this->getValue($index));
    }

    public function close(): void {}
}