<?php

declare(strict_types=1);

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

use App\Framework\QrCode\QrCodeGenerator;
use App\Framework\QrCode\ErrorCorrection\ReedSolomonEncoder;
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 "=== Step-by-Step Encoding Test ===\n\n";

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

echo "Test data: '{$testData}'\n";
echo "Length: " . strlen($testData) . " bytes\n\n";

// Step 1: Mode indicator
$modeBits = $config->encodingMode->getModeBits();
echo "1. Mode indicator: {$modeBits} (Byte mode)\n";

// Step 2: Character count
$charCountBits = $config->encodingMode->getCharacterCountBits($config->version);
$dataLength = strlen($testData);
$countBits = str_pad(decbin($dataLength), $charCountBits, '0', STR_PAD_LEFT);
echo "2. Character count ({$charCountBits} bits): {$countBits} = {$dataLength}\n";

// Step 3: Data bytes
$dataBitsStr = '';
for ($i = 0; $i < $dataLength; $i++) {
    $byte = ord($testData[$i]);
    $byteBits = str_pad(decbin($byte), 8, '0', STR_PAD_LEFT);
    $dataBitsStr .= $byteBits;
    echo "3.{$i} Data byte '{$testData[$i]}': {$byteBits} = {$byte}\n";
}

echo "\n";

// Step 4: Build bit string
$bits = $modeBits . $countBits . $dataBitsStr;
echo "Total bits before terminator: " . strlen($bits) . "\n";

// Step 5: Terminator
$ecInfo = ReedSolomonEncoder::getECInfo(
    $config->version->getVersionNumber(),
    $config->errorCorrectionLevel->value
);
$requiredBits = $ecInfo['dataCodewords'] * 8;
echo "Required bits: {$requiredBits}\n";

$terminatorLength = min(4, max(0, $requiredBits - strlen($bits)));
$bits .= str_repeat('0', $terminatorLength);
echo "Terminator bits: {$terminatorLength}\n";
echo "Bits after terminator: " . strlen($bits) . "\n\n";

// Step 6: Pad to multiple of 8
$remainder = strlen($bits) % 8;
if ($remainder !== 0) {
    $bits .= str_repeat('0', 8 - $remainder);
}
echo "Bits after padding to 8: " . strlen($bits) . "\n";

// Step 7: Add pad codewords
$padBytes = ['11101100', '00010001'];
$padIndex = 0;
while (strlen($bits) < $requiredBits) {
    $bits .= $padBytes[$padIndex % 2];
    $padIndex++;
}
echo "Bits after pad codewords: " . strlen($bits) . "\n";
echo "Pad codewords added: {$padIndex}\n\n";

// Step 8: Convert to codewords
$codewords = [];
for ($i = 0; $i < strlen($bits); $i += 8) {
    $byte = substr($bits, $i, 8);
    $codewords[] = bindec($byte);
}

echo "Generated codewords (" . count($codewords) . "):\n";
echo implode(', ', $codewords) . "\n\n";

// Expected codewords
$expected = [64, 180, 132, 84, 196, 196, 242, 5, 116, 245, 174, 59, 64, 109, 236, 233];
echo "Expected codewords (16):\n";
echo implode(', ', $expected) . "\n\n";

// Compare
$matches = 0;
for ($i = 0; $i < min(count($codewords), count($expected)); $i++) {
    if ($codewords[$i] === $expected[$i]) {
        $matches++;
    } else {
        echo "❌ Codeword {$i}: got {$codewords[$i]}, expected {$expected[$i]}\n";
        echo "   Bits: " . substr($bits, $i * 8, 8) . " vs expected: " . str_pad(decbin($expected[$i]), 8, '0', STR_PAD_LEFT) . "\n";
    }
}

if ($matches === count($expected)) {
    echo "✅ All codewords match!\n";
} else {
    echo "❌ {$matches}/" . count($expected) . " codewords match\n";
}

// Show bit string breakdown
echo "\n=== Bit String Breakdown ===\n";
echo "Mode (4): " . substr($bits, 0, 4) . "\n";
echo "Count (8): " . substr($bits, 4, 8) . "\n";
echo "Data (88): " . substr($bits, 12, 88) . "\n";
echo "Terminator + Pad: " . substr($bits, 100) . "\n";