// Analytics service for API interactions
import { apiClient } from './api';
import type { AnalyticsSummary, TimeSeriesDataPoint, LitterTypeDistribution, QuantityAggregation } from '@/types';

class AnalyticsService {
  /**
   * Get summary statistics for the analytics dashboard
   */
  async getSummary(dateRange?: { start: string; end: string }): Promise<AnalyticsSummary> {
    const params = new URLSearchParams();
    
    if (dateRange) {
      params.append('startDate', dateRange.start);
      params.append('endDate', dateRange.end);
    }

    const queryString = params.toString();
    return apiClient.get<AnalyticsSummary>(`/analytics/summary${queryString ? `?${queryString}` : ''}`);
  }

  /**
   * Get time series data for report trends
   */
  async getTimeSeries(dateRange?: { start: string; end: string }): Promise<TimeSeriesDataPoint[]> {
    const params = new URLSearchParams();
    
    if (dateRange) {
      params.append('startDate', dateRange.start);
      params.append('endDate', dateRange.end);
    }

    const queryString = params.toString();
    return apiClient.get<TimeSeriesDataPoint[]>(`/analytics/trends${queryString ? `?${queryString}` : ''}`);
  }

  /**
   * Get litter type distribution data
   */
  async getLitterTypeDistribution(dateRange?: { start: string; end: string }): Promise<LitterTypeDistribution[]> {
    const params = new URLSearchParams();
    
    if (dateRange) {
      params.append('startDate', dateRange.start);
      params.append('endDate', dateRange.end);
    }

    const queryString = params.toString();
    return apiClient.get<LitterTypeDistribution[]>(`/analytics/litter-types${queryString ? `?${queryString}` : ''}`);
  }

  /**
   * Get quantity estimation aggregation data
   */
  async getQuantityAggregation(dateRange?: { start: string; end: string }): Promise<QuantityAggregation[]> {
    const params = new URLSearchParams();
    
    if (dateRange) {
      params.append('startDate', dateRange.start);
      params.append('endDate', dateRange.end);
    }

    const queryString = params.toString();
    return apiClient.get<QuantityAggregation[]>(`/analytics/quantities${queryString ? `?${queryString}` : ''}`);
  }

  /**
   * Export analytics data to CSV
   */
  async exportToCSV(dateRange?: { start: string; end: string }): Promise<Blob> {
    const params = new URLSearchParams();
    
    if (dateRange) {
      params.append('startDate', dateRange.start);
      params.append('endDate', dateRange.end);
    }

    const queryString = params.toString();
    const response = await fetch(
      `${import.meta.env.VITE_API_BASE_URL || 'http://localhost:3000/api'}/analytics/export${queryString ? `?${queryString}` : ''}`,
      {
        method: 'GET',
        headers: {
          'Accept': 'text/csv',
        },
      }
    );

    if (!response.ok) {
      throw new Error('Failed to export data');
    }

    return response.blob();
  }
}

export const analyticsService = new AnalyticsService();