<?php

declare(strict_types=1);

$file = $argv[1] ?? 'pytania.txt';
$baseDir = dirname(__DIR__);
$path = $baseDir . '/' . $file;

if (!is_file($path)) {
    fwrite(STDERR, "File not found: {$file}\n");
    exit(1);
}

$lines = file($path, FILE_IGNORE_NEW_LINES);
$errors = [];
$question = null;
$questionLine = 0;
$answers = 0;
$questionCount = 0;

$finishQuestion = static function () use (&$errors, &$question, &$questionLine, &$answers, &$questionCount): void {
    if ($question === null) {
        return;
    }

    if ($answers === 0) {
        $errors[] = "Line {$questionLine}: question has no answers.";
    }

    $questionCount++;
    $question = null;
    $questionLine = 0;
    $answers = 0;
};

foreach ($lines as $i => $rawLine) {
    $lineNo = $i + 1;
    $line = trim($rawLine);

    if ($line === '' || str_starts_with($line, '//')) {
        continue;
    }

    if (!str_starts_with($line, '-')) {
        $finishQuestion();
        $question = $line;
        $questionLine = $lineNo;
        continue;
    }

    if ($question === null) {
        $errors[] = "Line {$lineNo}: answer appears before any question.";
        continue;
    }

    if (str_starts_with($line, '-|')) {
        $answer = trim(substr($line, 2));
    } else {
        $answer = trim(substr($line, 1));
    }

    if ($answer === '') {
        $errors[] = "Line {$lineNo}: answer is empty.";
    }

    $answers++;
}

$finishQuestion();

$content = file_get_contents($path) ?: '';
preg_match_all('/<img\s+[^>]*src=["\']([^"\']+)["\'][^>]*>/i', $content, $matches);
foreach ($matches[1] ?? [] as $src) {
    if (str_starts_with($src, 'img/') && !is_file($baseDir . '/' . $src)) {
        $errors[] = "Missing image referenced from pytania.txt: {$src}";
    }
}

if ($questionCount === 0) {
    $errors[] = 'No questions found.';
}

if ($errors !== []) {
    foreach ($errors as $error) {
        fwrite(STDERR, $error . PHP_EOL);
    }
    exit(1);
}

echo "OK: {$questionCount} questions validated.\n";