michaelschiemer/tests/debug/test-bit-order-fix.php

<?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 "=== Testing Bit Order Fix ===\n\n";

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

// Manually encode to see what bits we expect
echo "Manual encoding:\n";
echo "Mode indicator (Byte): 0100\n";
echo "Character count (11): " . str_pad(decbin(11), 8, '0', STR_PAD_LEFT) . "\n";
echo "Data 'H': " . str_pad(decbin(ord('H')), 8, '0', STR_PAD_LEFT) . "\n";
echo "Data 'E': " . str_pad(decbin(ord('E')), 8, '0', STR_PAD_LEFT) . "\n\n";

$expectedFirstBits = "0100" . str_pad(decbin(11), 8, '0', STR_PAD_LEFT) . str_pad(decbin(ord('H')), 8, '0', STR_PAD_LEFT);
echo "Expected first 20 bits: {$expectedFirstBits}\n\n";

// Generate matrix
$matrix = QrCodeGenerator::generate($testData, $config);
$size = $matrix->getSize();

// Extract format info to get mask pattern
$formatCols = [0, 1, 2, 3, 4, 5, 7, 8, $size - 1, $size - 2, $size - 3, $size - 4, $size - 5, $size - 6, $size - 7];
$formatH = '';
foreach ($formatCols as $col) {
    $formatH .= $matrix->getModuleAt(8, $col)->isDark() ? '1' : '0';
}

$xorMask = "101010000010010";
$unmasked = '';
for ($i = 0; $i < 15; $i++) {
    $unmasked .= (int)$formatH[$i] ^ (int)$xorMask[$i];
}

$maskBits = substr($unmasked, 2, 3);
$maskPattern = bindec($maskBits);

echo "Detected mask pattern: {$maskPattern}\n\n";

// Read actual bits
use App\Framework\QrCode\Masking\MaskPattern as MaskPatternEnum;

$mask = match($maskPattern) {
    0 => MaskPatternEnum::PATTERN_0,
    1 => MaskPatternEnum::PATTERN_1,
    2 => MaskPatternEnum::PATTERN_2,
    3 => MaskPatternEnum::PATTERN_3,
    4 => MaskPatternEnum::PATTERN_4,
    5 => MaskPatternEnum::PATTERN_5,
    6 => MaskPatternEnum::PATTERN_6,
    7 => MaskPatternEnum::PATTERN_7,
};

$actualBits = '';
$bitCount = 0;

for ($col = $size - 1; $col >= 1 && $bitCount < 20; $col -= 2) {
    if ($col === 6) {
        $col--;
    }
    
    $upward = ((int) (($size - 1 - $col) / 2) % 2) === 0;
    
    for ($i = 0; $i < $size && $bitCount < 20; $i++) {
        $row = $upward ? ($size - 1 - $i) : $i;
        
        // Read in same order as placement: right column first, then left
        for ($c = 0; $c < 2 && $bitCount < 20; $c++) {
            $currentCol = $col - $c;
            
            // Skip function patterns
            if (($row <= 8 && $currentCol <= 8) ||
                ($row <= 7 && $currentCol >= $size - 8) ||
                ($row >= $size - 8 && $currentCol <= 7) ||
                $row === 6 || $currentCol === 6 ||
                ($row === 8 && (($currentCol >= 0 && $currentCol <= 5) || $currentCol === 7 || $currentCol === 8 || $currentCol >= $size - 8)) ||
                ($currentCol === 8 && (($row >= 0 && $row <= 5) || $row === 7 || $row === 8 || $row >= $size - 7)) ||
                ($row === 13 && $currentCol === 8)) {
                continue;
            }
            
            // Read and unmask
            $maskedBit = $matrix->getModuleAt($row, $currentCol)->isDark() ? 1 : 0;
            $unmaskedBit = $mask->shouldInvert($row, $currentCol) ? (1 - $maskedBit) : $maskedBit;
            $actualBits .= (string)$unmaskedBit;
            $bitCount++;
        }
    }
}

echo "Actual first 20 bits:   {$actualBits}\n\n";

// Compare
$matches = 0;
for ($i = 0; $i < 20; $i++) {
    if ($expectedFirstBits[$i] === $actualBits[$i]) {
        $matches++;
    } else {
        echo "Bit {$i}: expected {$expectedFirstBits[$i]}, got {$actualBits[$i]}\n";
    }
}

echo "\nMatch: {$matches}/20 bits\n";

if ($matches === 20) {
    echo "✅ CORRECT!\n";
} else {
    echo "❌ Still wrong\n";
}