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

export interface MixpanelAdapterOptions {
  /**
   * Pass the Mixpanel instance from `mixpanel-react-native`.
   *
   * Install peer dependency:
   *   npm install mixpanel-react-native
   *
   * Usage:
   *   import { Mixpanel } from 'mixpanel-react-native';
   *   const mixpanel = new Mixpanel('YOUR_TOKEN', true);
   *   await mixpanel.init();
   *   createAnalytics({ adapters: [createMixpanelAdapter({ instance: mixpanel })] });
   */
  instance: any;
  /** Track screen views as events with a custom event name (default: 'Screen Viewed') */
  screenEventName?: string;
}

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

  return {
    name: 'mixpanel',

    async initialize() {
      // Mixpanel 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) {
      instance.identify(payload.userId);
      if (payload.traits) {
        instance.getPeople().set(payload.traits);
      }
    },

    async group(payload: GroupPayload) {
      // Mixpanel groups require a group key — default to 'company'
      instance.setGroup('company', payload.groupId);
      if (payload.traits) {
        instance.getGroup('company', payload.groupId).set(payload.traits);
      }
    },

    async alias(payload) {
      instance.alias(payload.newId, payload.previousId);
    },

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

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