<?php

function parseFrontMatter($raw) {
    if (preg_match('/^---\r?\n(.+?)\r?\n---\r?\n(.*)$/s', $raw, $m)) {
        $meta = [];
        foreach (preg_split('/\r?\n/', $m[1]) as $line) {
            if (strpos($line, ':') === false) continue;
            [$key, $value] = explode(':', $line, 2);
            $meta[trim($key)] = trim($value, " \t\"'");
        }
        return [$meta, $m[2]];
    }
    return [[], $raw];
}

function makeExcerpt($body, $length = 220) {
    $text = preg_replace('/```.*?```/s', '', $body);   // code blocks
    $text = preg_replace('/[#>*_`~\[\]]/', '', $text);  // markdown symbols
    $text = preg_replace('/\(.*?\)/', '', $text);       // link targets
    $text = preg_replace('/\s+/', ' ', $text);          // collapse whitespace
    $text = trim($text);
    if (mb_strlen($text) > $length) {
        $text = mb_substr($text, 0, $length) . '…';
    }
    return $text;
}

function getPosts($dir) {
    $skip = ['.', '..', 'list.php', 'feed.php', 'posts.php'];
    $files = array_diff(scandir($dir), $skip);

    $posts = [];
    foreach ($files as $file) {
        $ext = strtolower(pathinfo($file, PATHINFO_EXTENSION));
        if (!in_array($ext, ['html', 'md'])) continue;

        $path = $dir . '/' . $file;
        $fallbackTitle = ucwords(str_replace(['-', '_'], ' ', pathinfo($file, PATHINFO_FILENAME)));
        $created = filectime($path);

        $meta = [];
        $body = '';
        if ($ext === 'md') {
            $raw = file_get_contents($path);
            [$meta, $body] = parseFrontMatter($raw);
        }

        $title = $meta['title'] ?? $fallbackTitle;
        $date  = isset($meta['date']) ? strtotime($meta['date']) : $created;
        $tags  = isset($meta['tags']) && trim($meta['tags']) !== ''
            ? array_map('trim', explode(',', $meta['tags']))
            : [];

        $posts[] = [
            'file'    => $file,
            'title'   => $title,
            'type'    => $ext,
            'created' => $date ?: $created,
            'date'    => date('F j, Y', $date ?: $created),
            'tags'    => $tags,
            'excerpt' => $body ? makeExcerpt($body) : '',
        ];
    }

    usort($posts, fn($a, $b) => $b['created'] - $a['created']); // newest first

    return $posts;
}