/**
 * Monitor 3: User Analytics Service
 * Tracks feature usage and user interactions
 */

import { apiClient } from './api/client';
import { logger } from '@/utils/logger';

const MOCK_GLOBAL_STATS = {
  total_users: 12500,
  total_tracks: 3420,
  total_plays: 1205430,
  total_revenue: 14250.5,
  followers: 24500,
  profile_views: 45200,
  trends: { plays: 8.2, revenue: 12.5, followers: 2.1, views: -2.4 },
  sparklines: {
    plays: [40, 35, 50, 60, 55, 70, 80, 75, 90],
    revenue: [10, 12, 15, 14, 18, 20, 22, 25, 28],
    followers: [20, 21, 21, 22, 22, 23, 23, 24, 24],
    views: [50, 48, 45, 42, 40, 43, 41, 40, 38],
  },
};

const TOP_TRACKS = [
  { id: 't1', title: 'Neon Nights', plays: 15420, change: 12, revenue: 145.5 },
  { id: 't2', title: 'Cyber City', plays: 12100, change: -5, revenue: 98.2 },
  { id: 't3', title: 'System Failure', plays: 8500, change: 24, revenue: 65.0 },
  { id: 't4', title: 'Mainframe', plays: 6200, change: 8, revenue: 42.1 },
];

export const analyticsService = {
  /**
   * Monitor 3: Record a user analytics event
   * Tracks feature usage and user interactions
   * @param eventName - Name of the event (e.g., 'feature_used', 'button_clicked')
   * @param payload - Optional event data (e.g., { feature: 'search', query: '...' })
   */
  recordEvent: async (eventName: string, payload?: Record<string, unknown>) => {
    try {
      // Send event to backend analytics endpoint
      await apiClient.post('/analytics/events', {
        event_name: eventName,
        payload: payload || {},
      });

      // Log in development for debugging
      if (import.meta.env.DEV) {
        logger.debug('[Analytics] Event recorded', {
          event_name: eventName,
          payload,
        });
      }
    } catch (error) {
      // Don't throw errors for analytics - fail silently to avoid disrupting user experience
      if (import.meta.env.DEV) {
        logger.warn('[Analytics] Failed to record event', {
          event_name: eventName,
          error: error instanceof Error ? error.message : String(error),
        });
      }
    }
  },

  getGlobalStats: async (range: string = '30d') => {
    try {
      // Action 1.1: Connect to real backend analytics
      const response = await apiClient.get<any>('/analytics', {
        params: { days: range.replace('d', '') }
      });

      // Transform backend data to UI format if needed
      // If backend is empty, fallback to mock but log it
      if (!response.data || Object.keys(response.data).length === 0) {
        if (import.meta.env.DEV) logger.info('[Analytics] Backend returned empty stats, using baseline defaults');
        return MOCK_GLOBAL_STATS;
      }

      return {
        ...MOCK_GLOBAL_STATS, // Use as baseline for fields not yet in backend
        ...response.data,
      };
    } catch (error) {
      logger.error('[Analytics] Failed to fetch global stats', { error });
      return MOCK_GLOBAL_STATS;
    }
  },

  getTopTracks: async (range: string = '30d') => {
    try {
      const response = await apiClient.get<any[]>('/analytics/tracks/top', {
        params: { days: range.replace('d', '') }
      });

      if (!response.data || response.data.length === 0) {
        return TOP_TRACKS;
      }

      return response.data;
    } catch (error) {
      logger.error('[Analytics] Failed to fetch top tracks', { error });
      return TOP_TRACKS;
    }
  },

  getTrafficSources: async () => {
    // Traffic sources might not be in backend yet, keep mock but ready for API
    return [
      { label: 'Direct', val: 45, color: 'bg-primary' },
      { label: 'Social Media', val: 30, color: 'bg-destructive' },
      { label: 'Search', val: 15, color: 'bg-success' },
      { label: 'Referral', val: 10, color: 'bg-warning' },
    ];
  },

  getDeviceBreakdown: async () => {
    return { mobile: 65, desktop: 35 };
  },
};