<?php
declare(strict_types=1);
namespace App\Tests;
use App\Security\Hmac;
use PHPUnit\Framework\TestCase;

final class HmacTest extends TestCase
{
    public function testSignMatchesPythonEdgeContract(): void
    {
        // P1-A edge/alert.py::sign = HMAC-SHA256(nonce+ts+body, secret) hex
        $sig = Hmac::sign('secret', 'n1', '1000.0', '{"a":1}');
        $expected = hash_hmac('sha256', 'n1' . '1000.0' . '{"a":1}', 'secret');
        $this->assertSame($expected, $sig);
        $this->assertSame(64, strlen($sig));
    }

    public function testVerifyTrueOnMatchFalseOnTamper(): void
    {
        $sig = Hmac::sign('secret', 'n1', '1000.0', 'body');
        $this->assertTrue(Hmac::verify('secret', 'n1', '1000.0', 'body', $sig));
        $this->assertFalse(Hmac::verify('secret', 'n1', '1000.0', 'body-TAMPERED', $sig));
        $this->assertFalse(Hmac::verify('wrong', 'n1', '1000.0', 'body', $sig));
    }

    public function testMatchesGoldenVectorsFromPythonEdgeSigner(): void
    {
        // Golden hex produced by running P1-A edge/alert.py::sign — proves cross-language byte-for-byte interop.
        $this->assertSame(
            'a151bb402f070c3678056776b1bcc5638bd150dec1e516aaa07cac1a089f63b9',
            Hmac::sign('secret', 'n1', '1000.0', '{"a":1}')
        );
        $this->assertSame(
            '71865248fe94517dc0305a5c233e2b6c97db95fc9e38815e7c20580d2aa784c9',
            Hmac::sign('sekret', 'abc123', '1700000000.5', '{"device_id":"pi-1","event_type":"fall"}')
        );
    }
}