<?php

/**
 * Fetches the PLN to EUR conversion rate from the database.
 *
 * @param PDO $db The database connection object.
 * @return float The conversion rate. Defaults to 0.23 if not set or invalid.
 */
function get_pln_to_eur_rate(PDO $db): float {
    static $rate = null;

    if ($rate === null) {
        try {
            $stmt = $db->prepare("SELECT value FROM settings WHERE `key` = 'pln_to_eur_rate'");
            $stmt->execute();
            $result = $stmt->fetch(PDO::FETCH_ASSOC);

            if ($result && is_numeric($result['value']) && $result['value'] > 0) {
                $rate = (float)$result['value'];
            } else {
                $rate = 0.23; // Fallback default
            }
        } catch (PDOException $e) {
            // Log error if possible, for now just use fallback
            error_log('Could not fetch PLN to EUR rate: ' . $e->getMessage());
            $rate = 0.23;
        }
    }

    return $rate;
}

/**
 * Converts a PLN amount to EUR.
 *
 * @param float $pln The amount in PLN.
 * @param float $rate The PLN to EUR conversion rate.
 * @return float The amount in EUR, rounded to 2 decimal places.
 */
function to_eur(float $pln, float $rate): float {
    return round($pln * $rate, 2);
}

/**
 * Formats a money amount based on the language and converts to EUR if necessary.
 *
 * @param float|null $amountPLN The amount in PLN. Can be null.
 * @param string $lang The current language code ('en', 'pl', etc.).
 * @param PDO $db The database connection object.
 * @return string The formatted money string. Returns an empty string or placeholder if amount is null.
 */
function format_money(?float $amountPLN, string $lang, PDO $db): string {
    if ($amountPLN === null) {
        return '-'; // Or some other placeholder for null values
    }

    if ($lang === 'en') {
        $rate = get_pln_to_eur_rate($db);
        $eur = to_eur($amountPLN, $rate);
        return '€' . number_format($eur, 2, '.', ',');
    } else {
        // Default to Polish PLN format
        return number_format($amountPLN, 2, ',', ' ') . ' zł';
    }
}