<?php

declare(strict_types=1);

namespace paygw_moneta\local\protocol;

use InvalidArgumentException;
use paygw_moneta\local\Money;

/**
 * @package paygw_moneta
 * @copyright 2026 Moneta Labs {@link https://moneta.ru/}
 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
final class CallbackNotification
{
    private const ACCOUNT_ID_MAX_LENGTH = 20;
    private const TRANSACTION_ID_MAX_LENGTH = 255;
    private const OPERATION_ID_MAX_LENGTH = 255;
    private const SUBSCRIBER_ID_MAX_LENGTH = 255;

    private readonly string $command;
    private readonly string $accountId;
    private readonly string $transactionId;
    private readonly string $operationId;
    private readonly string $rawAmount;
    private readonly ?Money $amount;
    private readonly string $currency;
    private readonly string $subscriberId;
    private readonly string $rawTestMode;
    private readonly string $signature;

    /**
     * @param array<string, mixed> $fields
     */
    public function __construct(array $fields)
    {
        $this->command = self::optional($fields, 'MNT_COMMAND');
        if (!in_array($this->command, ['', AssistantProtocol::COMMAND_CHECK], true)) {
            throw new InvalidArgumentException('Неизвестная команда уведомления.');
        }
        $this->accountId = self::required($fields, 'MNT_ID', self::ACCOUNT_ID_MAX_LENGTH);
        $this->transactionId = self::required($fields, 'MNT_TRANSACTION_ID', self::TRANSACTION_ID_MAX_LENGTH);
        $this->operationId = self::optional($fields, 'MNT_OPERATION_ID', self::OPERATION_ID_MAX_LENGTH);
        $this->rawAmount = self::optional($fields, 'MNT_AMOUNT');
        $this->amount = $this->rawAmount === '' ? null : Money::fromDecimal($this->rawAmount);
        $this->currency = self::required($fields, 'MNT_CURRENCY_CODE', 3);
        $this->subscriberId = self::optional($fields, 'MNT_SUBSCRIBER_ID', self::SUBSCRIBER_ID_MAX_LENGTH);
        $this->rawTestMode = self::required($fields, 'MNT_TEST_MODE', 1);
        if (!in_array($this->rawTestMode, ['0', '1'], true)) {
            throw new InvalidArgumentException('Недопустимое значение MNT_TEST_MODE.');
        }
        $this->signature = self::required($fields, 'MNT_SIGNATURE', 32);
        if (($this->amount === null || $this->operationId === '') && !$this->isCheck()) {
            throw new InvalidArgumentException('Уведомлению об оплате нужны сумма и номер операции.');
        }
    }

    public function isCheck(): bool
    {
        return $this->command === AssistantProtocol::COMMAND_CHECK;
    }

    public function getCommand(): string
    {
        return $this->command;
    }

    public function getAccountId(): string
    {
        return $this->accountId;
    }

    public function getTransactionId(): string
    {
        return $this->transactionId;
    }

    public function getOperationId(): string
    {
        return $this->operationId;
    }

    public function getRawAmount(): string
    {
        return $this->rawAmount;
    }

    public function getAmount(): ?Money
    {
        return $this->amount;
    }

    public function getCurrency(): string
    {
        return $this->currency;
    }

    public function getSubscriberId(): string
    {
        return $this->subscriberId;
    }

    public function getRawTestMode(): string
    {
        return $this->rawTestMode;
    }

    public function isTestMode(): bool
    {
        return $this->rawTestMode === '1';
    }

    public function isSignedBy(Signature $signature): bool
    {
        return Signature::equals($signature->forNotification($this), $this->signature);
    }

    /**
     * @param array<string, mixed> $fields
     */
    private static function required(array $fields, string $name, int $maxLength): string
    {
        $value = self::optional($fields, $name, $maxLength);
        if ($value === '') {
            throw new InvalidArgumentException("Не передано поле {$name}.");
        }

        return $value;
    }

    /**
     * @param array<string, mixed> $fields
     */
    private static function optional(array $fields, string $name, int $maxLength = 255): string
    {
        if (!array_key_exists($name, $fields)) {
            return '';
        }

        $value = $fields[$name];
        if (!is_string($value)) {
            throw new InvalidArgumentException("Поле {$name} должно быть строкой.");
        }
        if (strlen($value) > $maxLength) {
            throw new InvalidArgumentException("Поле {$name} длиннее допустимого.");
        }

        return $value;
    }
}