Genarrative/apps/mobile-shell/src/shell/navigation.ts

import { normalizeHostBridgeExternalUrl } from '../../../../packages/shared/src/contracts/hostBridge';

export type MobileShellExternalNavigator = {
  canOpenURL: (url: string) => Promise<boolean>;
  openURL: (url: string) => Promise<unknown>;
};

export function shouldOpenInMobileShellWebView(
  rawUrl: string,
  allowedOrigin: string,
) {
  if (rawUrl === 'about:blank') {
    return true;
  }

  if (
    !rawUrl.startsWith('/') &&
    !rawUrl.startsWith('#') &&
    !/^[a-z][a-z0-9+.-]*:/i.test(rawUrl)
  ) {
    return false;
  }

  try {
    const url = new URL(rawUrl, allowedOrigin);
    if (url.protocol !== 'http:' && url.protocol !== 'https:') {
      return false;
    }

    return url.origin === allowedOrigin;
  } catch {
    return false;
  }
}

export function resolveMobileShellExternalUrl(rawUrl: string) {
  return normalizeHostBridgeExternalUrl(rawUrl);
}

export async function openMobileShellExternalNavigation(
  navigator: MobileShellExternalNavigator,
  rawUrl: string,
) {
  const externalUrl = resolveMobileShellExternalUrl(rawUrl);
  if (!externalUrl) {
    return false;
  }

  if (!(await navigator.canOpenURL(externalUrl))) {
    return false;
  }

  await navigator.openURL(externalUrl);
  return true;
}

export function shouldAcceptMobileShellHostBridgeMessage(
  rawUrl: string,
  allowedOrigin: string,
) {
  return rawUrl !== 'about:blank' &&
    shouldOpenInMobileShellWebView(rawUrl, allowedOrigin);
}

export function resolveMobileShellWebViewUrl(
  rawUrl: string,
  allowedOrigin: string,
) {
  if (
    rawUrl === 'about:blank' ||
    !shouldOpenInMobileShellWebView(rawUrl, allowedOrigin)
  ) {
    return null;
  }

  try {
    return new URL(rawUrl, allowedOrigin).toString();
  } catch {
    return null;
  }
}