<?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;
}

// Build sorted list items for a directory
function buildListItems(string $dir, Context $ctx, ?array $parentMetadata): array {
    $subdirs = getSubdirectories($dir);

    $items = array_filter(array_map(function($item) use ($dir, $ctx) {
        $itemPath = "$dir/$item";
        $metadata = loadMetadata($itemPath);
        $coverImage = findCoverImage($itemPath);
        $pdfFile = findPdfFile($itemPath);

        $title = $metadata['title'] ?? extractTitle($itemPath) ?? $item;

        $rawDate = null;
        $date = null;
        if (isset($metadata['date'])) {
            $rawDate = $metadata['date'];
            $date = Hooks::apply(Hook::PROCESS_CONTENT, $rawDate, 'date_format');
        } else {
            $rawDate = extractRawDateFromFolder($item);
            if ($rawDate) {
                $date = Hooks::apply(Hook::PROCESS_CONTENT, $rawDate, 'date_format');
            } else {
                $rawDate = date("Y-m-d", filemtime($itemPath));
                $date = Hooks::apply(Hook::PROCESS_CONTENT, $rawDate, 'date_format');
            }
        }

        $urlSlug = ($metadata && isset($metadata['slug'])) ? $metadata['slug'] : $item;

        $langPrefix = $ctx->get('langPrefix', '');
        $baseUrl = $langPrefix . '/' . trim($ctx->requestPath, '/') . '/' . urlencode($urlSlug);
        $assetUrl = $langPrefix . '/' . trim($ctx->requestPath, '/') . '/' . urlencode($item);

        return [
            'title' => $title,
            'url' => $baseUrl . '/',
            'date' => $date,
            'rawDate' => $rawDate,
            'summary' => $metadata['summary'] ?? null,
            'cover' => $coverImage ? "$assetUrl/$coverImage" : null,
            'pdf' => $pdfFile ? "$assetUrl/$pdfFile" : null,
            'redirect' => $metadata['redirect'] ?? null,
            'dirPath' => $itemPath
        ];
    }, $subdirs));

    $sortOrder = strtolower($parentMetadata['order'] ?? 'descending');
    if ($sortOrder === 'ascending') {
        usort($items, fn($a, $b) => strcmp($a['date'] ?? '', $b['date'] ?? ''));
    } else {
        usort($items, fn($a, $b) => strcmp($b['date'] ?? '', $a['date'] ?? ''));
    }

    return $items;
}

function extractRawDateFromFolder(string $folderName): ?string {
    if (preg_match('/^(\d{4})-(\d{2})-(\d{2})-/', $folderName, $matches)) {
        return $matches[1] . '-' . $matches[2] . '-' . $matches[3];
    }
    return null;
}

function extractDateFromFolder(string $folderName): ?string {
    $raw = extractRawDateFromFolder($folderName);
    if ($raw) {
        return Hooks::apply(Hook::PROCESS_CONTENT, $raw, '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;
}