<?php

function resolveTemplate(string $templateName): string {
    $customTemplate = dirname(__DIR__) . "/custom/templates/$templateName.php";
    $defaultTemplate = __DIR__ . "/default/templates/$templateName.php";
    return file_exists($customTemplate) ? $customTemplate : $defaultTemplate;
}

function getSubdirectories(string $dir): array {
    if (!is_dir($dir)) return [];
    return array_filter(
        scandir($dir) ?: [],
        fn($item) => !in_array($item, ['.', '..']) && is_dir("$dir/$item")
    );
}

function extractTitle(string $filePath): ?string {
    $files = findAllContentFiles($filePath);
    if (empty($files)) return null;

    // Check the first content file for a title
    $file = $files[0];
    $ext = pathinfo($file, PATHINFO_EXTENSION);
    $content = file_get_contents($file);

    if ($ext === 'md' && preg_match('/^#\s+(.+)$/m', $content, $matches)) {
        return trim($matches[1]);
    }
    if (in_array($ext, ['html', 'php']) && preg_match('/<h1[^>]*>(.*?)<\/h1>/i', $content, $matches)) {
        return strip_tags($matches[1]);
    }
    return null;
}

function extractDateFromFolder(string $folderName): ?string {
    if (preg_match('/^(\d{4})-(\d{2})-(\d{2})-/', $folderName, $matches)) {
        $dateString = $matches[1] . '-' . $matches[2] . '-' . $matches[3];
        // Let plugins format the date
        return Hooks::apply(Hook::PROCESS_CONTENT, $dateString, 'date_format');
    }
    return null;
}

function findCoverImage(string $dirPath): ?string {
    $found = array_find(
        COVER_IMAGE_EXTENSIONS,
        fn($ext) => file_exists("$dirPath/cover.$ext")
    );
    return $found ? "cover.$found" : null;
}

function findPdfFile(string $dirPath): ?string {
    $pdfs = glob("$dirPath/*.pdf") ?: [];
    return $pdfs ? basename($pdfs[0]) : null;
}

function findPageCss(string $dirPath, string $contentDir): ?array {
    $cssFile = "$dirPath/styles.css";
    if (!file_exists($cssFile) || !is_file($cssFile)) {
        return null;
    }

    $relativePath = str_replace($contentDir, '', $dirPath);
    $relativePath = trim($relativePath, '/');
    $cssUrl = '/' . ($relativePath ? $relativePath . '/' : '') . 'styles.css';

    return [
        'url' => $cssUrl,
        'hash' => hash_file('md5', $cssFile)
    ];
}

function extractMetaDescription(string $dirPath, ?array $metadata): ?string {
    // 1. Check for search_description in metadata
    if ($metadata && isset($metadata['search_description'])) {
        return $metadata['search_description'];
    }

    // 2. Fall back to summary in metadata
    if ($metadata && isset($metadata['summary'])) {
        return $metadata['summary'];
    }

    // 3. Fall back to first paragraph in content files
    $files = findAllContentFiles($dirPath);
    if (empty($files)) return null;

    foreach ($files as $file) {
        $ext = pathinfo($file, PATHINFO_EXTENSION);
        $content = file_get_contents($file);

        if ($ext === 'md') {
            $lines = explode("\n", $content);
            foreach ($lines as $line) {
                $line = trim($line);
                if (empty($line) || str_starts_with($line, '#')) continue;
                if (strlen($line) > 20) {
                    return strip_tags($line);
                }
            }
        } elseif (in_array($ext, ['html', 'php'])) {
            if (preg_match('/<p[^>]*>(.*?)<\/p>/is', $content, $matches)) {
                return strip_tags($matches[1]);
            }
        }
    }

    return null;
}