<?php

declare(strict_types=1);

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

use App\Framework\QrCode\QrCodeGenerator;
use App\Framework\QrCode\ValueObjects\ErrorCorrectionLevel;
use App\Framework\QrCode\ValueObjects\QrCodeConfig;
use App\Framework\QrCode\ValueObjects\QrCodeVersion;
use App\Framework\QrCode\ValueObjects\EncodingMode;

echo "=== Format Information Decode Test ===\n\n";

$config = new QrCodeConfig(
    version: QrCodeVersion::fromNumber(1),
    errorCorrectionLevel: ErrorCorrectionLevel::M,
    encodingMode: EncodingMode::BYTE
);

$matrix = QrCodeGenerator::generate('HELLO WORLD', $config);

// Read format information
$formatCols = [0, 1, 2, 3, 4, 5, 7, 8, 20, 19, 18, 17, 16, 15, 14];
$formatH = '';
foreach ($formatCols as $col) {
    $formatH .= $matrix->getModuleAt(8, $col)->isDark() ? '1' : '0';
}

echo "Format Info (Horizontal): {$formatH}\n";

// XOR mask: 101010000010010
$xorMask = '101010000010010';
echo "XOR Mask:                {$xorMask}\n";

$unmasked = '';
for ($i = 0; $i < 15; $i++) {
    $unmasked .= (int)$formatH[$i] ^ (int)$xorMask[$i];
}
echo "Unmasked:               {$unmasked}\n\n";

// Decode format information
// Format: [EC Level (2 bits)] [Mask Pattern (3 bits)] [Error Correction (10 bits)]
$ecBits = substr($unmasked, 0, 2);
$maskBits = substr($unmasked, 2, 3);  // Only 3 bits for mask pattern!
$errorCorrectionBits = substr($unmasked, 5, 10); // BCH error correction

echo "EC Level (bits 0-1):     {$ecBits}\n";
echo "Mask Pattern (bits 2-4): {$maskBits}\n";
echo "Error Correction:       {$errorCorrectionBits}\n\n";

$ecLevel = match($ecBits) {
    '01' => 'L',
    '00' => 'M',
    '11' => 'Q',
    '10' => 'H',
    default => 'UNKNOWN'
};

$maskPattern = bindec($maskBits);

echo "Decoded:\n";
echo "  EC Level: {$ecLevel}\n";
echo "  Mask Pattern: {$maskPattern}\n\n";

if ($maskPattern > 7) {
    echo "❌ ERROR: Mask Pattern {$maskPattern} is invalid! (should be 0-7)\n";
    echo "This means the format information is corrupted or incorrect!\n\n";
    
    // Check what mask pattern was actually used
    echo "Checking what mask pattern was actually applied...\n";
    
    // We can check by looking at the data area and trying to unmask
    // But first, let's check if the format info itself is correct
    
    // Expected format info for Level M, Mask 0-7
    $expectedFormats = [
        '101010000010010',  // M, Mask 0
        '101000100100101',  // M, Mask 1
        '101111001111100',  // M, Mask 2
        '101101101001011',  // M, Mask 3
        '100010111111001',  // M, Mask 4
        '100000011001110',  // M, Mask 5
        '100111110010111',  // M, Mask 6
        '100101010100000',  // M, Mask 7
    ];
    
    echo "\nExpected format info for Level M:\n";
    foreach ($expectedFormats as $mask => $expected) {
        $masked = '';
        for ($i = 0; $i < 15; $i++) {
            $masked .= (int)$expected[$i] ^ (int)$xorMask[$i];
        }
        echo "  Mask {$mask}: {$masked} (unmasked: {$expected})\n";
        
        if ($masked === $formatH) {
            echo "    ✅ This matches our format info!\n";
            echo "    So mask pattern {$mask} was used.\n";
        }
    }
} else {
    echo "✅ Mask Pattern is valid\n";
}