<?php
// Root router — serve frontend or API
// Works at web root or in a subdirectory (e.g. /protocol-droid/)

// Detect the base path (for subdirectory deployments)
$scriptName = $_SERVER['SCRIPT_NAME'] ?? '/index.php';
$basePath = rtrim(str_replace('\\', '/', dirname($scriptName)), '/');
// If basePath is just / or . , clear it
if ($basePath === '/' || $basePath === '.') $basePath = '';

$uri = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);

// Strip base path from URI for routing
if ($basePath && strpos($uri, $basePath) === 0) {
    $uri = substr($uri, strlen($basePath));
}

if (preg_match('#^/api(/|$)#', $uri)) {
    require __DIR__ . '/api/index.php';
    exit;
}

// Everything else: serve frontend files
// Normalize the path to prevent traversal
$uri = preg_replace('#/+#', '/', $uri);
$file = __DIR__ . '/frontend' . $uri;

// Resolve real path and verify it's within the frontend directory
$real_file = realpath($file);
$frontend_dir = realpath(__DIR__ . '/frontend');

// Helper: get meta tags for a given path (for social media previews)
// Returns ['title' => ..., 'description' => ..., 'url' => ...] or null
function get_meta_for_path(string $uri): ?array {
    // Match protocol/collection/user routes (path-based, not hash-based)
    // e.g. /protocols/slug, /collections/slug, /users/username
    if (!preg_match('#^/(protocols|collections|users)/([^/]+)#', $uri, $m)) {
        return null;
    }

    $type = $m[1];
    $slug = $m[2];

    // Load minimal DB access without full API overhead
    require_once __DIR__ . '/api/db.php';
    require_once __DIR__ . '/api/config.php';

    if ($type === 'protocols') {
        $row = db_one(
            "SELECT p.title, p.description, p.source, u.username AS author_username
             FROM protocols p LEFT JOIN users u ON p.author_id = u.id
             WHERE p.slug = ? AND p.visibility = 'public'",
            [$slug]
        );
        if (!$row) return null;
        return [
            'title' => $row['title'],
            'description' => $row['description'] ?: ($row['source'] ? 'Source: ' . $row['source'] : ''),
            'type' => 'article',
        ];
    }

    if ($type === 'collections') {
        $row = db_one(
            "SELECT c.title, c.description, u.username AS author_username
             FROM collections c LEFT JOIN users u ON c.author_id = u.id
             WHERE c.slug = ? AND c.visibility = 'public'",
            [$slug]
        );
        if (!$row) return null;
        return [
            'title' => $row['title'],
            'description' => $row['description'] ?: '',
            'type' => 'website',
        ];
    }

    if ($type === 'users') {
        $row = db_one("SELECT username, display_name, bio FROM users WHERE username = ?", [$slug]);
        if (!$row) return null;
        $name = $row['display_name'] ?: '@' . $row['username'];
        return [
            'title' => $name,
            'description' => $row['bio'] ?: 'Protocols by ' . $name,
            'type' => 'profile',
        ];
    }

    return null;
}

// Helper: serve index.html with asset paths rewritten for subdirectory deployments
// Injects social media meta tags when viewing a specific protocol/collection/user
$serve_index = function() use ($basePath, $uri) {
    $index = __DIR__ . '/frontend/index.html';
    if (file_exists($index)) {
        header('Content-Type: text/html');
        $html = file_get_contents($index);

        // Inject meta tags for social media previews
        $meta = get_meta_for_path($uri);
        if ($meta) {
            require_once __DIR__ . '/api/config.php';
            $siteName = config_get('site_name', 'Protocol Droid');
            $fullTitle = $meta['title'] . ' · ' . $siteName;
            $desc = $meta['description'];
            $canonical = ($basePath ?: '') . $uri;

            // Build canonical URL (scheme + host + path)
            $scheme = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https' : 'http';
            $host = $_SERVER['HTTP_HOST'] ?? 'localhost';
            $canonicalUrl = $scheme . '://' . $host . $canonical;

            $metaTags = "<title>$fullTitle</title>\n";
            $metaTags .= "<meta name=\"description\" content=\"" . htmlspecialchars($desc, ENT_QUOTES) . "\">\n";
            $metaTags .= "<meta property=\"og:title\" content=\"" . htmlspecialchars($meta['title'], ENT_QUOTES) . "\">\n";
            $metaTags .= "<meta property=\"og:description\" content=\"" . htmlspecialchars($desc, ENT_QUOTES) . "\">\n";
            $metaTags .= "<meta property=\"og:type\" content=\"" . htmlspecialchars($meta['type'], ENT_QUOTES) . "\">\n";
            $metaTags .= "<meta property=\"og:site_name\" content=\"" . htmlspecialchars($siteName, ENT_QUOTES) . "\">\n";
            $metaTags .= "<meta property=\"og:url\" content=\"" . htmlspecialchars($canonicalUrl, ENT_QUOTES) . "\">\n";
            $metaTags .= "<meta name=\"twitter:card\" content=\"summary\">\n";
            $metaTags .= "<meta name=\"twitter:title\" content=\"" . htmlspecialchars($meta['title'], ENT_QUOTES) . "\">\n";
            $metaTags .= "<meta name=\"twitter:description\" content=\"" . htmlspecialchars($desc, ENT_QUOTES) . "\">\n";

            // Replace the default <title> tag with our enriched version
            $html = preg_replace('#<title>[^<]*</title>#', $metaTags, $html, 1);
        }

        // Rewrite absolute /frontend/ paths to include the base path
        if ($basePath) {
            $html = str_replace('/frontend/', $basePath . '/frontend/', $html);
        }
        echo $html;
        exit;
    }
    http_response_code(404);
    echo 'Frontend not found';
    exit;
};

if ($real_file === false || strpos($real_file, $frontend_dir) !== 0) {
    $serve_index();
}

if (!is_file($real_file)) {
    $serve_index();
}

$ext = pathinfo($real_file, PATHINFO_EXTENSION);
$types = [
    'css' => 'text/css',
    'js' => 'application/javascript',
    'html' => 'text/html',
    'svg' => 'image/svg+xml',
    'png' => 'image/png',
    'jpg' => 'image/jpeg',
    'json' => 'application/json',
];
if (isset($types[$ext])) header('Content-Type: ' . $types[$ext]);
readfile($real_file);