<?php

declare(strict_types=1);

require_once __DIR__ . '/../../vendor/autoload.php';

use App\Framework\QrCode\ErrorCorrection\ReedSolomonEncoder;

echo "=== Reed-Solomon Decode Test ===\n\n";

// Test: Create a simple Reed-Solomon code and verify it can correct errors
// For RS(26, 16), we can correct up to 5 errors

$dataCodewords = [64, 180, 132, 84, 196, 196, 242, 5, 116, 245, 36, 196, 64, 236, 17, 236];
echo "Data codewords: " . implode(', ', $dataCodewords) . "\n\n";

// Encode
$reedSolomon = new ReedSolomonEncoder();
$ecCodewords = $reedSolomon->encode($dataCodewords, 10);

echo "EC codewords: " . implode(', ', $ecCodewords) . "\n\n";

// Create full codeword sequence
$allCodewords = array_merge($dataCodewords, $ecCodewords);
echo "Full codeword sequence (26): " . implode(', ', $allCodewords) . "\n\n";

// Verify: For Reed-Solomon, if we evaluate the message polynomial at the roots of the generator,
// we should get zero. This is a basic sanity check.

echo "=== Reed-Solomon Verification ===\n";
echo "Note: Full verification requires evaluating the polynomial at generator roots.\n";
echo "For now, we verify the structure:\n";
echo "  - Generator polynomial: degree 10\n";
echo "  - Data codewords: 16\n";
echo "  - EC codewords: 10\n";
echo "  - Total: 26 codewords\n\n";

// Test with a known working QR code library result
// From qrcode.js library, for "HELLO WORLD" V1 M:
// Expected EC codewords might be different

echo "=== Comparison with Known Values ===\n";
echo "Note: Different QR code implementations may use different mask patterns,\n";
echo "which affects which EC codewords are generated.\n\n";

// The key test: Can we decode our own encoded data?
// We need to verify that the EC codewords are correct by checking if
// they can be used to reconstruct the original data

echo "=== Reed-Solomon Structure Check ===\n";
echo "For RS(26, 16) with generator polynomial g(x):\n";
echo "  - Message polynomial: m(x) = data + zeros\n";
echo "  - Encoded: c(x) = m(x) * x^10 + (m(x) * x^10) mod g(x)\n";
echo "  - EC codewords = remainder of (m(x) * x^10) / g(x)\n\n";

// Verify generator polynomial
$reflection = new ReflectionClass($reedSolomon);
$getGeneratorMethod = $reflection->getMethod('getGeneratorPolynomial');
$getGeneratorMethod->setAccessible(true);
$generator = $getGeneratorMethod->invoke($reedSolomon, 10);

echo "Generator polynomial coefficients: " . implode(', ', $generator) . "\n";
echo "Degree: " . (count($generator) - 1) . " (expected: 10)\n\n";

// Check if EC codewords match expected pattern
// For RS codes, the EC codewords should have certain properties
echo "EC codewords check:\n";
echo "  - All EC codewords are bytes (0-255): ";
$allValid = true;
foreach ($ecCodewords as $ec) {
    if ($ec < 0 || $ec > 255) {
        $allValid = false;
        break;
    }
}
echo ($allValid ? "✅" : "❌") . "\n";

echo "  - EC codeword count: " . count($ecCodewords) . " (expected: 10) ";
echo (count($ecCodewords) === 10 ? "✅" : "❌") . "\n\n";

echo "If the QR code doesn't scan, the issue might be:\n";
echo "1. EC codewords are incorrect (most likely)\n";
echo "2. Data codewords are incorrect (but we can decode them, so unlikely)\n";
echo "3. Mask pattern selection is wrong\n";
echo "4. Format information is wrong (but we verified it's correct)\n";