export const HOST_BRIDGE_PROTOCOL = 'GenarrativeHostBridge';
export const HOST_BRIDGE_VERSION = 1;

export type HostShellKind = 'browser' | 'wechat_mini_program' | 'native_app';

export type NativeHostShell = 'expo_mobile' | 'tauri_desktop';

export type NativeHostPlatform =
  | 'ios'
  | 'android'
  | 'macos'
  | 'windows'
  | 'linux'
  | 'unknown';

export type HostBridgeMethod =
  | 'host.getRuntime'
  | 'auth.requestLogin'
  | 'payment.request'
  | 'share.setTarget'
  | 'share.open'
  | 'navigation.openNativePage'
  | 'app.openExternalUrl'
  | 'app.setTitle'
  | 'clipboard.writeText'
  | 'haptics.impact';

export type HostBridgeCapability =
  | HostBridgeMethod
  | 'host.events'
  | 'navigation.canGoBack';

export type HostBridgeRuntimeResult = {
  shell: NativeHostShell;
  platform: NativeHostPlatform;
  hostVersion: string | null;
  bridgeVersion: number;
  capabilities: HostBridgeCapability[];
};

export type HostBridgeRequest<Payload = unknown> = {
  bridge: typeof HOST_BRIDGE_PROTOCOL;
  version: typeof HOST_BRIDGE_VERSION;
  id: string;
  method: HostBridgeMethod;
  payload?: Payload;
  timeoutMs?: number;
};

export type HostBridgeError = {
  code:
    | 'invalid_request'
    | 'unsupported_method'
    | 'unsupported_capability'
    | 'timeout'
    | 'cancelled'
    | 'host_error';
  message: string;
};

export type HostBridgeResponse<Result = unknown> = {
  bridge: typeof HOST_BRIDGE_PROTOCOL;
  version: typeof HOST_BRIDGE_VERSION;
  id: string;
} & (
  | {
      ok: true;
      result?: Result;
    }
  | {
      ok: false;
      error: HostBridgeError;
    }
);

export type HostBridgeEvent<Payload = unknown> = {
  bridge: typeof HOST_BRIDGE_PROTOCOL;
  version: typeof HOST_BRIDGE_VERSION;
  event: string;
  payload?: Payload;
};

export type NavigateNativePagePayload = {
  url: string;
};

export type OpenExternalUrlPayload = {
  url: string;
};

export type SetTitlePayload = {
  title: string;
};

export const HOST_BRIDGE_EXTERNAL_URL_PROTOCOLS = [
  'http:',
  'https:',
  'mailto:',
  'tel:',
] as const;

export type HostBridgeExternalUrlProtocol =
  (typeof HOST_BRIDGE_EXTERNAL_URL_PROTOCOLS)[number];

function hasHostBridgeControlCharacter(value: string) {
  return [...value].some((character) => {
    const codePoint = character.codePointAt(0) ?? 0;
    return codePoint <= 31 || codePoint === 127;
  });
}

export function normalizeHostBridgeExternalUrl(rawUrl: unknown) {
  if (typeof rawUrl !== 'string') {
    return null;
  }

  const urlText = rawUrl.trim();
  if (!urlText || hasHostBridgeControlCharacter(urlText)) {
    return null;
  }

  try {
    const url = new URL(urlText);
    if (
      !HOST_BRIDGE_EXTERNAL_URL_PROTOCOLS.includes(
        url.protocol as HostBridgeExternalUrlProtocol,
      )
    ) {
      return null;
    }

    return url.toString();
  } catch {
    return null;
  }
}

export type ClipboardWriteTextPayload = {
  text: string;
};

export type HapticsImpactPayload = {
  style?: 'light' | 'medium' | 'heavy';
};

export type ShareSetTargetPayload = {
  target: unknown;
};

export type ShareOpenPayload = {
  title?: string;
  message?: string;
  url?: string;
};