/**
 * @fileoverview Dashboard Service - API Communication Layer
 * @version 1.0.0
 * @since 2025-08-04
 * @lastUpdated 2025-08-04
 * @module DashboardService
 * @description Service for dashboard-related API operations and data management
 * @contributors Claude Code Agent
 * @dependencies ApiClient, AuthService
 * @requirements REQ-API-003 (Dashboard API integration)
 * @testCoverage API calls, error handling, data transformation
 */

import { ApiClient } from './ApiClient';
import { AuthService } from './AuthService';

/**
 * Dashboard Service
 *
 * @description Handles all dashboard-related API communications and data operations.
 *              Provides centralized interface for dashboard data management.
 *
 * @example
 * ```typescript
 * const dashboardService = new DashboardService();
 * const data = await dashboardService.getDashboardData();
 * ```
 *
 * @since 2025-08-04
 * @author Claude Code Agent
 * @requirements REQ-API-003 (Dashboard API), REQ-AUTH-002 (Authenticated requests)
 */
export class DashboardService {
  private apiClient: ApiClient;
  private authService: AuthService;

  constructor() {
    this.apiClient = ApiClient.getInstance();
    this.authService = AuthService.getInstance();
  }

  /**
   * Get comprehensive dashboard data
   *
   * @description Fetches all dashboard data in a single request
   *
   * @returns {Promise<DashboardData>} Complete dashboard data
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async getDashboardData(): Promise<DashboardData> {
    try {
      // Parallel requests for better performance
      const [userInfo, stats, recentQuizzes, recentActivity] = await Promise.all([
        this.getUserInfo(),
        this.getDashboardStats(),
        this.getRecentQuizzes(),
        this.getRecentActivity(),
      ]);

      return {
        user: userInfo,
        stats,
        recentQuizzes,
        recentActivity,
        lastUpdated: new Date().toISOString(),
      };
    } catch (error) {
      console.error('Failed to load dashboard data:', error);
      throw new Error('Unable to load dashboard. Please try again.');
    }
  }

  /**
   * Get current user information
   *
   * @description Fetches current user profile and permissions
   *
   * @returns {Promise<UserInfo>} User information
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async getUserInfo(): Promise<UserInfo> {
    try {
      const response = await this.apiClient.get('/dashboard/api/user');
      return response.data;
    } catch (error) {
      console.error('Failed to load user info:', error);
      throw new Error('Unable to load user information');
    }
  }

  /**
   * Get dashboard statistics
   *
   * @description Fetches user statistics and metrics
   *
   * @returns {Promise<DashboardStats>} Dashboard statistics
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async getDashboardStats(): Promise<DashboardStats> {
    try {
      const response = await this.apiClient.get('/dashboard/api/stats');
      return response.data;
    } catch (error) {
      console.error('Failed to load dashboard stats:', error);
      // Return default stats on error
      return {
        totalQuizzes: 0,
        totalResponses: 0,
        recentActivity: 0,
        completionRate: 0,
      };
    }
  }

  /**
   * Get recent quizzes
   *
   * @description Fetches user's recent quizzes with limit
   *
   * @param {number} limit - Maximum number of quizzes to fetch
   * @returns {Promise<Quiz[]>} Array of recent quizzes
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async getRecentQuizzes(limit: number = 5): Promise<Quiz[]> {
    try {
      const response = await this.apiClient.get(
        `/dashboard/api/quizzes?limit=${limit}&sort=recent`
      );
      return response.data.quizzes || [];
    } catch (error) {
      console.error('Failed to load recent quizzes:', error);
      return [];
    }
  }

  /**
   * Get recent activity
   *
   * @description Fetches user's recent activity feed
   *
   * @param {number} limit - Maximum number of activities to fetch
   * @returns {Promise<Activity[]>} Array of recent activities
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async getRecentActivity(limit: number = 10): Promise<Activity[]> {
    try {
      const response = await this.apiClient.get(`/dashboard/api/activity?limit=${limit}`);
      return response.data.activities || [];
    } catch (error) {
      console.error('Failed to load recent activity:', error);
      return [];
    }
  }

  /**
   * Get user's quiz analytics
   *
   * @description Fetches detailed analytics for user's quizzes
   *
   * @param {string} timeRange - Time range for analytics ('7d', '30d', '90d', 'all')
   * @returns {Promise<QuizAnalytics>} Quiz analytics data
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async getQuizAnalytics(timeRange: string = '30d'): Promise<QuizAnalytics> {
    try {
      const response = await this.apiClient.get(`/dashboard/api/analytics?timeRange=${timeRange}`);
      return response.data;
    } catch (error) {
      console.error('Failed to load quiz analytics:', error);
      throw new Error('Unable to load analytics data');
    }
  }

  /**
   * Update user profile
   *
   * @description Updates user profile information
   *
   * @param {Partial<UserProfile>} profileData - Profile data to update
   * @returns {Promise<UserInfo>} Updated user information
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async updateProfile(profileData: Partial<UserProfile>): Promise<UserInfo> {
    try {
      const response = await this.apiClient.put('/dashboard/api/user/profile', profileData);
      return response.data;
    } catch (error) {
      console.error('Failed to update profile:', error);
      throw new Error('Unable to update profile. Please try again.');
    }
  }

  /**
   * Create new quiz
   *
   * @description Creates a new quiz with basic information
   *
   * @param {CreateQuizData} quizData - Quiz creation data
   * @returns {Promise<Quiz>} Created quiz
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async createQuiz(quizData: CreateQuizData): Promise<Quiz> {
    try {
      const response = await this.apiClient.post('/quiz', quizData);
      return response.data;
    } catch (error) {
      console.error('Failed to create quiz:', error);
      throw new Error('Unable to create quiz. Please try again.');
    }
  }

  /**
   * Delete quiz
   *
   * @description Deletes a quiz by ID
   *
   * @param {string} quizId - Quiz ID to delete
   * @returns {Promise<void>}
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async deleteQuiz(quizId: string): Promise<void> {
    try {
      await this.apiClient.delete(`/quiz/${quizId}`);
    } catch (error) {
      console.error('Failed to delete quiz:', error);
      throw new Error('Unable to delete quiz. Please try again.');
    }
  }

  /**
   * Get quiz by ID
   *
   * @description Fetches detailed quiz information
   *
   * @param {string} quizId - Quiz ID to fetch
   * @returns {Promise<QuizDetail>} Detailed quiz information
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async getQuiz(quizId: string): Promise<QuizDetail> {
    try {
      const response = await this.apiClient.get(`/quiz/${quizId}`);
      return response.data;
    } catch (error) {
      console.error('Failed to load quiz:', error);
      throw new Error('Unable to load quiz details');
    }
  }

  /**
   * Search quizzes
   *
   * @description Searches user's quizzes with filters
   *
   * @param {QuizSearchParams} params - Search parameters
   * @returns {Promise<QuizSearchResult>} Search results
   *
   * @since 2025-08-04
   * @author Claude Code Agent
   */
  async searchQuizzes(params: QuizSearchParams): Promise<QuizSearchResult> {
    try {
      const queryString = new URLSearchParams(params as any).toString();
      const response = await this.apiClient.get(`/dashboard/api/quizzes/search?${queryString}`);
      return response.data;
    } catch (error) {
      console.error('Failed to search quizzes:', error);
      throw new Error('Search failed. Please try again.');
    }
  }
}

/**
 * Type Definitions
 */

export interface DashboardData {
  user: UserInfo;
  stats: DashboardStats;
  recentQuizzes: Quiz[];
  recentActivity: Activity[];
  lastUpdated: string;
}

export interface UserInfo {
  id: string;
  username: string;
  email?: string;
  firstName?: string;
  lastName?: string;
  roles: string[];
  permissions: string[];
  isActive: boolean;
  createdAt: string;
  lastLoginAt?: string;
}

export interface DashboardStats {
  totalQuizzes: number;
  totalResponses: number;
  recentActivity: number;
  completionRate: number;
}

export interface Quiz {
  id: string;
  title: string;
  description?: string;
  status: 'draft' | 'published' | 'archived';
  questions?: QuizQuestion[];
  createdAt: string;
  updatedAt: string;
  createdBy: string;
}

export interface QuizDetail extends Quiz {
  questions: QuizQuestion[];
  analytics?: QuizAnalytics;
  responses?: QuizResponse[];
}

export interface QuizQuestion {
  id: string;
  question: string;
  options: string[];
  answer: string;
  explanation?: string;
}

export interface Activity {
  id: string;
  type: 'quiz_created' | 'quiz_updated' | 'quiz_published' | 'response_received';
  title: string;
  description: string;
  timestamp: string;
  relatedId?: string;
}

export interface QuizAnalytics {
  totalResponses: number;
  averageScore: number;
  completionRate: number;
  responsesByDay: { date: string; count: number }[];
  questionAnalytics: QuestionAnalytics[];
}

export interface QuestionAnalytics {
  questionId: string;
  correctAnswers: number;
  totalAnswers: number;
  accuracy: number;
}

export interface UserProfile {
  firstName?: string;
  lastName?: string;
  email?: string;
  bio?: string;
  preferences?: {
    theme: 'light' | 'dark' | 'system';
    notifications: boolean;
    language: string;
  };
}

export interface CreateQuizData {
  title: string;
  description?: string;
  questions: Omit<QuizQuestion, 'id'>[];
  metadata?: {
    category?: string;
    difficulty?: 'easy' | 'medium' | 'hard';
    tags?: string[];
  };
}

export interface QuizSearchParams {
  query?: string;
  status?: 'draft' | 'published' | 'archived';
  category?: string;
  sortBy?: 'title' | 'createdAt' | 'updatedAt';
  sortOrder?: 'asc' | 'desc';
  limit?: number;
  offset?: number;
}

export interface QuizSearchResult {
  quizzes: Quiz[];
  total: number;
  hasMore: boolean;
}

export interface QuizResponse {
  id: string;
  userId?: string;
  answers: { questionId: string; answer: string }[];
  score: number;
  completedAt: string;
}