import { google } from 'googleapis';
import { analyticsEnv, EventType } from '../config/analytics.config';

// GA4 service
export class GA4Service {
  private auth: any;

  constructor() {
    this.auth = google.auth.fromAPIKey(analyticsEnv.GA4_API_SECRET || 'placeholder');
  }

  /**
   * Initialize GA4 client
   */
  async initialize(): Promise<void> {
    // TODO: Initialize GA4 client with measurement ID
    console.log('GA4 client initialized');
  }

  /**
   * Send event to GA4
   */
  async sendEvent(
    eventName: string,
    params: {
      client_id: string;
      [key: string]: any;
    }
  ): Promise<void> {
    // TODO: Implement GA4 event tracking
    // const measurementId = analyticsEnv.GA4_MEASUREMENT_ID;
    // await fetch(`https://www.google-analytics.com/mp/collect?measurement_id=${measurementId}&api_secret=${analyticsEnv.GA4_API_SECRET}`, {
    //   method: 'POST',
    //   body: JSON.stringify({
    //     events: [{ name: eventName, params }],
    //   }),
    // });
    
    console.log('GA4 event:', eventName, params);
  }

  /**
   * Track page view
   */
  async trackPageView(clientId: string, path: string, title?: string): Promise<void> {
    await this.sendEvent('page_view', {
      client_id: clientId,
      page_path: path,
      page_title: title,
    });
  }

  /**
   * Track e-commerce purchase
   */
  async trackPurchase(
    clientId: string,
    transactionId: string,
    value: number,
    currency: string,
    items: Array<{ name: string; price: number; quantity: number }>
  ): Promise<void> {
    await this.sendEvent('purchase', {
      client_id: clientId,
      transaction_id: transactionId,
      value,
      currency,
      items,
    });
  }

  /**
   * Track conversion
   */
  async trackConversion(
    clientId: string,
    conversionName: string,
    metadata?: Record<string, any>
  ): Promise<void> {
    await this.sendEvent('conversion', {
      client_id: clientId,
      conversion_name: conversionName,
      ...metadata,
    });
  }

  /**
   * Get analytics data (for dashboards)
   */
  async getMetrics(
    dateRange: { startDate: string; endDate: string },
    metrics: string[],
    dimensions?: string[]
  ): Promise<any> {
    // TODO: Implement GA4 Analytics Data API
    return {
      rows: [],
      totals: [],
    };
  }
}

// Export instance
export const ga4Service = new GA4Service();
