Genarrative/apps/mobile-shell/src/host-bridge/dispatch.ts

import * as Clipboard from 'expo-clipboard';
import * as Haptics from 'expo-haptics';
import * as Linking from 'expo-linking';
import * as Notifications from 'expo-notifications';
import {
  Appearance,
  Platform,
  PushNotificationIOS,
} from 'react-native';

import {
  type ClipboardReadTextResult,
  type ClipboardWriteTextPayload,
  type HapticsImpactPayload,
  HOST_BRIDGE_VERSION,
  type HostBridgeError,
  type HostBridgeRequest,
  type NavigateNativePagePayload,
  normalizeHostBridgeBadgeCount,
  normalizeHostBridgeClipboardText,
  normalizeHostBridgeColorScheme,
  normalizeHostBridgeExternalUrl,
  normalizeHostBridgeHapticsImpactStyle,
  normalizeHostBridgeLocalNotification,
  type OpenExternalUrlPayload,
  type SetBadgeCountPayload,
} from '../../../../packages/shared/src/contracts/hostBridge';
import { resolveMobileShellWebViewUrl } from '../shell/navigation';
import { getMobileNetworkStatus } from '../shell/network';
import { MOBILE_SHELL_HOST_VERSION } from '../shell/runtime';
import { resolveMobileHostCapabilities } from './capabilities';
import {
  captureImageFile,
  exportAudioFile,
  exportImageFile,
  exportTextFile,
  importAudioFile,
  importImageFile,
  importTextFile,
} from './files';
import {
  type MobileHostBridgeNavigation,
  failure,
  invalidRequest,
  ok,
  unsupported,
} from './protocol';
import { resetQrScannerForTest, scanQrCode } from './scanner';
import { openShare } from './share';
import { buildMobileShellUrl } from '../shell/url';

const LOCAL_NOTIFICATION_CHANNEL_ID = 'genarrative-local';

Notifications.setNotificationHandler({
  handleNotification: async () => ({
    shouldShowBanner: true,
    shouldShowList: true,
    shouldPlaySound: false,
    shouldSetBadge: false,
  }),
});

let currentShareTarget: unknown = null;
let navigation: MobileHostBridgeNavigation | null = null;

export function configureMobileHostBridgeNavigation(
  nextNavigation: MobileHostBridgeNavigation | null,
) {
  navigation = nextNavigation;
}

async function openExternalUrl(payload: unknown) {
  const url = normalizeHostBridgeExternalUrl(
    (payload as OpenExternalUrlPayload | undefined)?.url,
  );
  if (!url) {
    throw invalidRequest('url must use an allowed external protocol');
  }

  if (!(await Linking.canOpenURL(url))) {
    throw {
      code: 'host_error',
      message: 'external URL cannot be opened',
    } satisfies HostBridgeError;
  }

  await Linking.openURL(url);
  return true;
}

async function writeClipboard(payload: unknown) {
  const text = (payload as ClipboardWriteTextPayload | undefined)?.text;
  if (typeof text !== 'string') {
    throw invalidRequest('text is required');
  }

  await Clipboard.setStringAsync(text);
  return true;
}

async function readClipboard(): Promise<ClipboardReadTextResult> {
  const result = normalizeHostBridgeClipboardText(
    await Clipboard.getStringAsync(),
  );
  if (!result) {
    throw {
      code: 'host_error',
      message: 'clipboard text unavailable',
    } satisfies HostBridgeError;
  }

  return result;
}

async function runHaptics(payload: unknown) {
  const style = normalizeHostBridgeHapticsImpactStyle(
    (payload as HapticsImpactPayload | undefined)?.style,
  );
  if (!style) {
    throw invalidRequest('haptics impact style must be light, medium, or heavy');
  }

  const impactStyle =
    style === 'heavy'
      ? Haptics.ImpactFeedbackStyle.Heavy
      : style === 'medium'
        ? Haptics.ImpactFeedbackStyle.Medium
        : Haptics.ImpactFeedbackStyle.Light;

  await Haptics.impactAsync(impactStyle);
  return true;
}

function setBadgeCount(payload: unknown) {
  if (Platform.OS !== 'ios') {
    throw {
      code: 'unsupported_capability',
      message: 'app badge count is only supported on iOS mobile shell',
    } satisfies HostBridgeError;
  }

  const count = normalizeHostBridgeBadgeCount(
    (payload as SetBadgeCountPayload | undefined)?.count,
  );
  if (count === null) {
    throw invalidRequest('count must be an integer between 0 and 99999');
  }

  PushNotificationIOS.setApplicationIconBadgeNumber(count);
  return true;
}

function hasNotificationPermission(
  permission: Awaited<ReturnType<typeof Notifications.getPermissionsAsync>>,
) {
  return (
    permission.granted ||
    permission.ios?.status === Notifications.IosAuthorizationStatus.PROVISIONAL
  );
}

async function ensureNotificationPermission() {
  const currentPermission = await Notifications.getPermissionsAsync();
  if (hasNotificationPermission(currentPermission)) {
    return;
  }

  const requestedPermission = await Notifications.requestPermissionsAsync({
    ios: {
      allowAlert: true,
      allowBadge: false,
      allowSound: false,
    },
  });
  if (!hasNotificationPermission(requestedPermission)) {
    throw {
      code: 'host_error',
      message: 'notification permission denied',
    } satisfies HostBridgeError;
  }
}

async function showLocalNotification(payload: unknown) {
  const notification = normalizeHostBridgeLocalNotification(payload);
  if (!notification) {
    throw invalidRequest('title is required');
  }

  await ensureNotificationPermission();
  if (Platform.OS === 'android') {
    await Notifications.setNotificationChannelAsync(
      LOCAL_NOTIFICATION_CHANNEL_ID,
      {
        name: 'Genarrative',
        importance: Notifications.AndroidImportance.DEFAULT,
      },
    );
  }

  await Notifications.scheduleNotificationAsync({
    content: notification,
    trigger:
      Platform.OS === 'android'
        ? { channelId: LOCAL_NOTIFICATION_CHANNEL_ID }
        : null,
  });
  return true;
}

function getColorScheme() {
  return {
    colorScheme: normalizeHostBridgeColorScheme(Appearance.getColorScheme()),
  };
}

function openNativePage(payload: unknown) {
  if (!navigation) {
    throw unsupported('navigation.openNativePage');
  }

  const url = (payload as NavigateNativePagePayload | undefined)?.url;
  if (typeof url !== 'string') {
    throw invalidRequest('url is required');
  }

  const webViewUrl = resolveMobileShellWebViewUrl(
    url,
    navigation.allowedOrigin,
  );
  if (!webViewUrl) {
    throw invalidRequest('url must be an allowed same-origin web path');
  }

  navigation.openWebViewUrl(
    buildMobileShellUrl(webViewUrl, navigation.urlOptions),
  );
  return true;
}

function reloadWebView() {
  if (!navigation) {
    throw unsupported('app.reloadWebView');
  }

  navigation.reloadWebView();
  return true;
}

export async function dispatchMobileHostBridgeRequest(
  request: HostBridgeRequest,
) {
  switch (request.method) {
    case 'host.getRuntime':
      return ok(request, {
        shell: 'expo_mobile',
        platform: Platform.OS === 'ios' ? 'ios' : 'android',
        hostVersion: MOBILE_SHELL_HOST_VERSION,
        bridgeVersion: HOST_BRIDGE_VERSION,
        capabilities: resolveMobileHostCapabilities(),
      });
    case 'appearance.getColorScheme':
      return ok(request, getColorScheme());
    case 'app.openExternalUrl':
      return ok(request, await openExternalUrl(request.payload));
    case 'app.reloadWebView':
      return ok(request, reloadWebView());
    case 'network.status':
      return ok(request, await getMobileNetworkStatus());
    case 'clipboard.writeText':
      return ok(request, await writeClipboard(request.payload));
    case 'clipboard.readText':
      return ok(request, await readClipboard());
    case 'file.exportText':
      return ok(request, await exportTextFile(request.payload));
    case 'file.importText':
      return ok(request, await importTextFile());
    case 'file.exportImage':
      return ok(request, await exportImageFile(request.payload));
    case 'file.importImage':
      return ok(request, await importImageFile());
    case 'file.captureImage':
      return ok(request, await captureImageFile());
    case 'scanner.scanQrCode':
      return ok(request, await scanQrCode());
    case 'file.importAudio':
      return ok(request, await importAudioFile());
    case 'file.exportAudio':
      return ok(request, await exportAudioFile(request.payload));
    case 'haptics.impact':
      return ok(request, await runHaptics(request.payload));
    case 'notification.showLocal':
      return ok(request, await showLocalNotification(request.payload));
    case 'app.setBadgeCount':
      return ok(request, setBadgeCount(request.payload));
    case 'share.open':
      return ok(request, await openShare(request.payload, currentShareTarget));
    case 'share.setTarget':
      currentShareTarget =
        request.payload && typeof request.payload === 'object'
          ? (request.payload as { target?: unknown }).target
          : null;
      return ok(request, true);
    case 'navigation.openNativePage':
      return ok(request, openNativePage(request.payload));
    case 'auth.requestLogin':
    case 'payment.request':
      return failure(request, unsupported(request.method));
    default:
      return failure(request, unsupported(request.method));
  }
}

export function resetMobileHostBridgeDispatchForTest() {
  currentShareTarget = null;
  navigation = null;
  resetQrScannerForTest();
}