/**
 * Request utilities for validation and helper functions
 */

import type { Record as WispSettings } from '@wisp/lexicons/types/place/wisp/settings';
import { access } from 'fs/promises';

/**
 * Default index file names to check for directory requests
 * Will be checked in order until one is found
 */
export const DEFAULT_INDEX_FILES = ['index.html', 'index.htm'];

/**
 * Get index files list from settings or use defaults
 */
export function getIndexFiles(settings: WispSettings | null): string[] {
  if (settings?.indexFiles && settings.indexFiles.length > 0) {
    return settings.indexFiles;
  }
  return DEFAULT_INDEX_FILES;
}

/**
 * Match a file path against a glob pattern
 * Supports * wildcard and basic path matching
 */
export function matchGlob(path: string, pattern: string): boolean {
  // Normalize paths
  const normalizedPath = path.startsWith('/') ? path : '/' + path;
  const normalizedPattern = pattern.startsWith('/') ? pattern : '/' + pattern;

  // Convert glob pattern to regex
  const regexPattern = normalizedPattern
    .replace(/\./g, '\\.')
    .replace(/\*/g, '.*')
    .replace(/\?/g, '.');

  const regex = new RegExp('^' + regexPattern + '$');
  return regex.test(normalizedPath);
}

/**
 * Apply custom headers from settings to response headers
 */
export function applyCustomHeaders(headers: Record<string, string>, filePath: string, settings: WispSettings | null) {
  if (!settings?.headers || settings.headers.length === 0) return;

  for (const customHeader of settings.headers) {
    // If path glob is specified, check if it matches
    if (customHeader.path) {
      if (!matchGlob(filePath, customHeader.path)) {
        continue;
      }
    }
    // Apply the header
    headers[customHeader.name] = customHeader.value;
  }
}

/**
 * Validate site name (rkey) to prevent injection attacks
 * Must match AT Protocol rkey format
 */
export function isValidRkey(rkey: string): boolean {
  if (!rkey || typeof rkey !== 'string') return false;
  if (rkey.length < 1 || rkey.length > 512) return false;
  if (rkey === '.' || rkey === '..') return false;
  if (rkey.includes('/') || rkey.includes('\\') || rkey.includes('\0')) return false;
  const validRkeyPattern = /^[a-zA-Z0-9._~:-]+$/;
  return validRkeyPattern.test(rkey);
}

/**
 * Async file existence check
 */
export async function fileExists(path: string): Promise<boolean> {
  try {
    await access(path);
    return true;
  } catch {
    return false;
  }
}

/**
 * Extract and normalize headers from request
 */
export function extractHeaders(rawHeaders: Headers): Record<string, string> {
  const headers: Record<string, string> = {};
  rawHeaders.forEach((value, key) => {
    headers[key.toLowerCase()] = value;
  });
  return headers;
}