import type {
  AnalyticsAdapter,
  AnalyticsEvent,
  IdentifyPayload,
  ScreenEvent,
} from '../types';

export interface AmplitudeAdapterOptions {
  /**
   * Pass the Amplitude instance from `@amplitude/analytics-react-native`.
   *
   * Install peer dependency:
   *   npm install @amplitude/analytics-react-native
   *
   * Usage:
   *   import * as amplitude from '@amplitude/analytics-react-native';
   *   await amplitude.init('YOUR_API_KEY').promise;
   *   createAnalytics({ adapters: [createAmplitudeAdapter({ instance: amplitude })] });
   */
  instance: any;
  /** Track screen views as events (default: 'Screen Viewed') */
  screenEventName?: string;
}

export function createAmplitudeAdapter(options: AmplitudeAdapterOptions): AnalyticsAdapter {
  const { instance, screenEventName = 'Screen Viewed' } = options;

  return {
    name: 'amplitude',

    async initialize() {
      // Amplitude is initialized before being passed in
    },

    async track(event: AnalyticsEvent) {
      instance.track(event.name, event.properties ?? {});
    },

    async screen(event: ScreenEvent) {
      instance.track(screenEventName, {
        screen_name: event.name,
        previous_screen: event.previousScreen,
        ...event.properties,
      });
    },

    async identify(payload: IdentifyPayload) {
      const { Identify } = instance;
      const identifyObj = new Identify();

      if (payload.traits) {
        Object.entries(payload.traits).forEach(([key, value]) => {
          identifyObj.set(key, value);
        });
      }

      instance.identify(identifyObj);
      instance.setUserId(payload.userId);
    },

    async reset() {
      instance.reset();
    },

    async flush() {
      await instance.flush().promise;
    },
  };
}