<?php
declare(strict_types=1);

namespace Esun\Oceanpayment\Model;

class Signature
{
    private const CALLBACK_FIELDS = [
        'account',
        'terminal',
        'order_number',
        'order_currency',
        'order_amount',
        'order_notes',
        'card_number',
        'payment_id',
        'payment_authType',
        'payment_status',
        'payment_details',
        'payment_risk',
    ];

    private const CREATE_RESPONSE_FIELDS = [
        'account',
        'terminal',
        'order_number',
        'order_currency',
        'order_amount',
        'order_notes',
        'payment_id',
        'pay_url',
        'pay_results',
        'pay_details',
    ];

    public function sanitize(string $value): string
    {
        return str_replace(['<', '>', "'", '"'], ' ', trim($value));
    }

    public function createRequest(array $data, string $secureCode): string
    {
        $plain = (string)($data['account'] ?? '')
            . (string)($data['terminal'] ?? '')
            . (string)($data['backUrl'] ?? '')
            . (string)($data['order_number'] ?? '')
            . (string)($data['order_currency'] ?? '')
            . (string)($data['order_amount'] ?? '')
            . (string)($data['billing_firstName'] ?? '')
            . (string)($data['billing_lastName'] ?? '')
            . (string)($data['billing_email'] ?? '')
            . $secureCode;

        return hash('sha256', $plain);
    }

    public function createEmbeddedRequest(array $data, string $secureCode): string
    {
        $plain = (string)($data['account'] ?? '')
            . (string)($data['terminal'] ?? '')
            . (string)($data['order_number'] ?? '')
            . (string)($data['order_currency'] ?? '')
            . (string)($data['order_amount'] ?? '')
            . (string)($data['billing_firstName'] ?? '')
            . (string)($data['billing_lastName'] ?? '')
            . (string)($data['billing_email'] ?? '')
            . $secureCode;

        return hash('sha256', $plain);
    }

    public function verifyCreateResponse(array $data, string $secureCode): bool
    {
        return $this->verifyFields($data, self::CREATE_RESPONSE_FIELDS, $secureCode);
    }

    public function verifyCallback(array $data, string $secureCode): bool
    {
        $provided = strtolower(trim((string)($data['signValue'] ?? '')));
        if (!preg_match('/^[a-f0-9]{64}$/', $provided)) {
            return false;
        }

        return hash_equals($this->createCallback($data, $secureCode), $provided);
    }

    public function createCallback(array $data, string $secureCode): string
    {
        return $this->createFields($data, self::CALLBACK_FIELDS, $secureCode);
    }

    private function verifyFields(array $data, array $fields, string $secureCode): bool
    {
        $provided = strtolower(trim((string)($data['signValue'] ?? '')));
        if (!preg_match('/^[a-f0-9]{64}$/', $provided)) {
            return false;
        }

        return hash_equals($this->createFields($data, $fields, $secureCode), $provided);
    }

    private function createFields(array $data, array $fields, string $secureCode): string
    {
        $plain = '';
        foreach ($fields as $field) {
            $plain .= (string)($data[$field] ?? '');
        }

        return hash('sha256', $plain . $secureCode);
    }
}