import { Platform } from 'react-native';
import { requireOptionalNativeModule } from 'expo-modules-core';

interface BbpNotifyNative {
  /**
   * Post/replace an ongoing notification with a native chronometer counting down
   * to endTimeMillis. Returns a short diagnostic string (e.g. "posted enabled=true").
   */
  showCountdown(title: string, body: string, endTimeMillis: number): Promise<string>;
  /** Same ticking countdown, plus "End" / "Pay" action buttons. */
  showCheckin(
    title: string,
    body: string,
    endTimeMillis: number,
    endLabel: string,
    payLabel: string,
  ): Promise<string>;
  /** Remove the countdown notification. */
  clear(): Promise<void>;
  /** Read + clear the action a notification button set: 'end' | 'pay' | ''. */
  consumePendingAction(): Promise<string>;
}

export type PendingAction = 'end' | 'pay' | null;

// Android-only, and only present in a build that includes the native module
// (returns null in Expo Go / other platforms — callers degrade gracefully).
const native =
  Platform.OS === 'android'
    ? (requireOptionalNativeModule('BbpNotify') as BbpNotifyNative | null)
    : null;

/** True when the native ticking-countdown module is available. */
export const hasNativeCountdown = native != null;

export async function showCountdown(
  title: string,
  body: string,
  endTimeMillis: number,
): Promise<string> {
  if (!native) return 'no-native-module';
  return native.showCountdown(title, body, endTimeMillis);
}

export async function showCheckin(
  title: string,
  body: string,
  endTimeMillis: number,
  endLabel: string,
  payLabel: string,
): Promise<string> {
  if (!native) return 'no-native-module';
  return native.showCheckin(title, body, endTimeMillis, endLabel, payLabel);
}

export async function clearCountdown(): Promise<void> {
  await native?.clear();
}

/** Read + clear a notification-button action taken while the app was away. */
export async function consumePendingAction(): Promise<PendingAction> {
  const a = await native?.consumePendingAction();
  return a === 'end' || a === 'pay' ? a : null;
}