// frontend/src/api/services/forecasting.service.ts
/**
 * Forecasting Service
 * Handles forecast operations and predictions
 */

import { apiClient } from '../client';
import { RequestTimeouts } from '../client/config';
import type {
  SingleForecastRequest,
  BatchForecastRequest,
  ForecastResponse,
  BatchForecastResponse,
  ForecastAlert,
  QuickForecast,
  PaginatedResponse,
  BaseQueryParams,
} from '../types';

export class ForecastingService {
  /**
   * Create Single Product Forecast
   */
  async createSingleForecast(
      tenantId: string,
      request: SingleForecastRequest
    ): Promise<ForecastResponse[]> {
      console.log('🔮 Creating single forecast:', { tenantId, request });
      
      try {
        // Backend returns single ForecastResponse object
        const response = await apiClient.post(
          `/tenants/${tenantId}/forecasts/single`,
          request,
          {
            timeout: RequestTimeouts.MEDIUM,
          }
        );
        
        console.log('🔮 Forecast API Response:', response);
        console.log('- Type:', typeof response);
        console.log('- Is Array:', Array.isArray(response));
        
        // ✅ FIX: Convert single response to array
        if (response && typeof response === 'object' && !Array.isArray(response)) {
          // Single forecast response - wrap in array
          const forecastArray = [response as ForecastResponse];
          console.log('✅ Converted single forecast to array:', forecastArray);
          return forecastArray;
        } else if (Array.isArray(response)) {
          // Already an array (unexpected but handle gracefully)
          console.log('✅ Response is already an array:', response);
          return response;
        } else {
          console.error('❌ Unexpected response format:', response);
          throw new Error('Invalid forecast response format');
        }
        
      } catch (error) {
        console.error('❌ Forecast API Error:', error);
        throw error;
      }
  }

  /**
   * Create Batch Forecast
   */
  async createBatchForecast(
    tenantId: string,
    request: BatchForecastRequest
  ): Promise<BatchForecastResponse> {
    return apiClient.post(
      `/tenants/${tenantId}/forecasts/batch`,
      request,
      {
        timeout: RequestTimeouts.LONG,
      }
    );
  }

  /**
   * Get Forecast by ID
   */
  async getForecast(tenantId: string, forecastId: string): Promise<ForecastResponse> {
    return apiClient.get(`/tenants/${tenantId}/forecasts/${forecastId}`);
  }

  /**
   * Get Forecasts
   */
  async getForecasts(
    tenantId: string,
    params?: BaseQueryParams & {
      product_name?: string;
      start_date?: string;
      end_date?: string;
      model_id?: string;
    }
  ): Promise<PaginatedResponse<ForecastResponse>> {
    return apiClient.get(`/tenants/${tenantId}/forecasts`, { params });
  }

  /**
   * Get Batch Forecast Status
   */
  async getBatchForecastStatus(
    tenantId: string,
    batchId: string
  ): Promise<BatchForecastResponse> {
    return apiClient.get(`/tenants/${tenantId}/forecasts/batch/${batchId}/status`);
  }

  /**
   * Get Batch Forecasts
   */
  async getBatchForecasts(
    tenantId: string,
    params?: BaseQueryParams & {
      status?: string;
      start_date?: string;
      end_date?: string;
    }
  ): Promise<PaginatedResponse<BatchForecastResponse>> {
    return apiClient.get(`/tenants/${tenantId}/forecasts/batch`, { params });
  }

  /**
   * Cancel Batch Forecast
   */
  async cancelBatchForecast(tenantId: string, batchId: string): Promise<{ message: string }> {
    return apiClient.post(`/tenants/${tenantId}/forecasts/batch/${batchId}/cancel`);
  }

  /**
   * Get Quick Forecasts for Dashboard
   */
  async getQuickForecasts(tenantId: string, limit?: number): Promise<QuickForecast[]> {
    try {
      // TODO: Replace with actual /forecasts/quick endpoint when available
      // For now, use regular forecasts endpoint and transform the data
      const forecasts = await apiClient.get(`/tenants/${tenantId}/forecasts`, {
        params: { limit: limit || 10 },
      });
      
      // Transform regular forecasts to QuickForecast format
      // Handle response structure: { tenant_id, forecasts: [...], total_returned }
      let forecastsArray: any[] = [];
      
      if (Array.isArray(forecasts)) {
        // Direct array response (unexpected)
        forecastsArray = forecasts;
      } else if (forecasts && typeof forecasts === 'object' && Array.isArray(forecasts.forecasts)) {
        // Expected object response with forecasts array
        forecastsArray = forecasts.forecasts;
      } else {
        console.warn('Unexpected forecasts response format:', forecasts);
        return [];
      }
      
      return forecastsArray.map((forecast: any) => ({
        product_name: forecast.product_name,
        next_day_prediction: forecast.predicted_demand || 0,
        next_week_avg: forecast.predicted_demand || 0,
        trend_direction: 'stable' as const,
        confidence_score: forecast.confidence_level || 0.8,
        last_updated: forecast.created_at || new Date().toISOString()
      }));
    } catch (error) {
      console.error('QuickForecasts API call failed, using fallback data:', error);
      
      // Return mock data for common bakery products
      return [
        {
          product_name: 'Pan de Molde',
          next_day_prediction: 25,
          next_week_avg: 175,
          trend_direction: 'stable',
          confidence_score: 0.85,
          last_updated: new Date().toISOString()
        },
        {
          product_name: 'Baguettes',
          next_day_prediction: 20,
          next_week_avg: 140,
          trend_direction: 'up',
          confidence_score: 0.92,
          last_updated: new Date().toISOString()
        },
        {
          product_name: 'Croissants',
          next_day_prediction: 15,
          next_week_avg: 105,
          trend_direction: 'stable',
          confidence_score: 0.78,
          last_updated: new Date().toISOString()
        },
        {
          product_name: 'Magdalenas',
          next_day_prediction: 12,
          next_week_avg: 84,
          trend_direction: 'down',
          confidence_score: 0.76,
          last_updated: new Date().toISOString()
        }
      ];
    }
  }

  /**
   * Get Forecast Alerts
   */
  async getForecastAlerts(
    tenantId: string,
    params?: BaseQueryParams & {
      is_active?: boolean;
      severity?: string;
      alert_type?: string;
    }
  ): Promise<PaginatedResponse<ForecastAlert>> {
    return apiClient.get(`/tenants/${tenantId}/forecasts/alerts`, { params });
  }

  /**
   * Acknowledge Forecast Alert
   */
  async acknowledgeForecastAlert(
    tenantId: string,
    alertId: string
  ): Promise<ForecastAlert> {
    return apiClient.post(`/tenants/${tenantId}/forecasts/alerts/${alertId}/acknowledge`);
  }

  /**
   * Delete Forecast
   */
  async deleteForecast(tenantId: string, forecastId: string): Promise<{ message: string }> {
    return apiClient.delete(`/tenants/${tenantId}/forecasts/${forecastId}`);
  }

  /**
   * Export Forecasts
   */
  async exportForecasts(
    tenantId: string,
    format: 'csv' | 'excel' | 'json',
    params?: {
      product_name?: string;
      start_date?: string;
      end_date?: string;
    }
  ): Promise<Blob> {
    const response = await apiClient.request(`/tenants/${tenantId}/forecasts/export`, {
      method: 'GET',
      params: { ...params, format },
      headers: {
        'Accept': format === 'csv' ? 'text/csv' : 
                format === 'excel' ? 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' :
                'application/json',
      },
    });

    return new Blob([response], {
      type: format === 'csv' ? 'text/csv' : 
           format === 'excel' ? 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet' :
           'application/json',
    });
  }

  /**
   * Get Forecast Accuracy Metrics
   */
  async getForecastAccuracy(
    tenantId: string,
    params?: {
      product_name?: string;
      model_id?: string;
      start_date?: string;
      end_date?: string;
    }
  ): Promise<{
    overall_accuracy: number;
    product_accuracy: Array<{
      product_name: string;
      accuracy: number;
      sample_size: number;
    }>;
  }> {
    return apiClient.get(`/tenants/${tenantId}/forecasts/accuracy`, { params });
  }
}

export const forecastingService = new ForecastingService();