import apiClient from './authApi';

export interface RequestStats {
  totalRequests: number;
  openRequests: number;
  approvedRequests: number;
  rejectedRequests: number;
  closedRequests: number;
  pausedRequests?: number;
  draftRequests: number;
  changeFromPrevious: {
    total: string;
    open: string;
    approved: string;
    rejected: string;
  };
}

export interface TATEfficiency {
  avgTATCompliance: number;
  avgCycleTimeHours: number;
  avgCycleTimeDays: number;
  delayedWorkflows: number;
  totalCompleted: number;
  compliantWorkflows: number;
  changeFromPrevious: {
    compliance: string;
    cycleTime: string;
  };
}

export interface ApproverLoad {
  pendingActions: number;
  completedToday: number;
  completedThisWeek: number;
  changeFromPrevious: {
    pending: string;
    completed: string;
  };
}

export interface EngagementStats {
  workNotesAdded: number;
  attachmentsUploaded: number;
  changeFromPrevious: {
    workNotes: string;
    attachments: string;
  };
}

export interface AIInsights {
  avgConclusionRemarkLength: number;
  aiSummaryAdoptionPercent: number;
  totalWithConclusion: number;
  aiGeneratedCount: number;
  manualCount: number;
  changeFromPrevious: {
    adoption: string;
    length: string;
  };
}

export interface DashboardKPIs {
  requestVolume: RequestStats;
  tatEfficiency: TATEfficiency;
  approverLoad: ApproverLoad;
  engagement: EngagementStats;
  aiInsights: AIInsights;
  dateRange: {
    start: string;
    end: string;
    label: string;
  };
}

export interface RecentActivity {
  activityId: string;
  requestId: string;
  requestNumber: string;
  requestTitle: string;
  type: string;
  action: string;
  details?: any;
  userId: string;
  userName: string;
  timestamp: string;
  priority: string;
}

export interface CriticalRequest {
  requestId: string;
  requestNumber: string;
  title: string;
  priority: string;
  status: string;
  currentLevel: number;
  totalLevels: number;
  submissionDate: string;
  totalTATHours: number;
  originalTATHours: number;
  breachCount: number;
  isCritical: boolean;
  approverId?: string | null;
  approverEmail?: string | null;
}

export interface AIRemarkUtilization {
  totalUsage: number;
  totalEdits: number;
  editRate: number;
  monthlyTrends: Array<{
    month: string;
    aiUsage: number;
    manualEdits: number;
  }>;
}

export interface ApproverPerformance {
  approverId: string;
  approverName: string;
  totalApproved: number;
  approvedCount: number;
  rejectedCount: number;
  closedCount: number;
  tatCompliancePercent: number;
  avgResponseHours: number;
  pendingCount: number;
  withinTatCount: number;
  breachedCount: number;
}

export interface UpcomingDeadline {
  levelId: string;
  requestId: string;
  requestNumber: string;
  requestTitle: string;
  levelNumber: number;
  approverName: string;
  approverEmail: string;
  tatHours: number;
  elapsedHours: number;
  remainingHours: number;
  tatPercentageUsed: number;
  levelStartTime: string;
  priority: string;
}

export interface DepartmentStats {
  department: string;
  totalRequests: number;
  approved: number;
  rejected: number;
  inProgress: number;
  approvalRate: number;
}

export interface PriorityDistribution {
  priority: string;
  totalCount: number;
  avgCycleTimeHours: number;
  approvedCount: number;
  breachedCount: number;
  complianceRate: number;
}

export type DateRange = 'all' | 'today' | 'week' | 'month' | 'quarter' | 'year' | 'last30days' | 'custom';

class DashboardService {
  /**
   * Get all KPI metrics
   */
  async getKPIs(dateRange?: DateRange, startDate?: Date, endDate?: Date, viewAsUser?: boolean): Promise<DashboardKPIs> {
    try {
      const params: any = { dateRange };
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      if (viewAsUser) {
        params.viewAsUser = 'true';
      }
      const response = await apiClient.get('/dashboard/kpis', { params });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch KPIs:', error);
      throw error;
    }
  }

  /**
   * Get request statistics
   */
  async getRequestStats(
    dateRange?: DateRange,
    startDate?: string,
    endDate?: string,
    status?: string,
    priority?: string,
    templateType?: string,
    department?: string,
    initiator?: string,
    approver?: string,
    approverType?: 'current' | 'any',
    search?: string,
    slaCompliance?: string,
    viewAsUser?: boolean
  ): Promise<RequestStats> {
    try {
      const params: any = { dateRange };
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate;
        params.endDate = endDate;
      }
      // Add filters
      if (status && status !== 'all') {
        params.status = status;
      }
      if (priority && priority !== 'all') {
        params.priority = priority;
      }
      if (templateType && templateType !== 'all') {
        params.templateType = templateType;
      }
      if (department && department !== 'all') {
        params.department = department;
      }
      if (initiator && initiator !== 'all') {
        params.initiator = initiator;
      }
      if (approver && approver !== 'all') {
        params.approver = approver;
      }
      if (approverType) {
        params.approverType = approverType;
      }
      if (search) {
        params.search = search;
      }
      if (slaCompliance && slaCompliance !== 'all') {
        params.slaCompliance = slaCompliance;
      }
      // Pass viewAsUser flag to tell backend to treat admin as normal user
      if (viewAsUser) {
        params.viewAsUser = 'true';
      }
      const response = await apiClient.get('/dashboard/stats/requests', { params });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch request stats:', error);
      throw error;
    }
  }

  /**
   * Get TAT efficiency metrics
   */
  async getTATEfficiency(dateRange?: DateRange): Promise<TATEfficiency> {
    try {
      const response = await apiClient.get('/dashboard/stats/tat-efficiency', {
        params: { dateRange }
      });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch TAT efficiency:', error);
      throw error;
    }
  }

  /**
   * Get approver load
   */
  async getApproverLoad(dateRange?: DateRange): Promise<ApproverLoad> {
    try {
      const response = await apiClient.get('/dashboard/stats/approver-load', {
        params: { dateRange }
      });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch approver load:', error);
      throw error;
    }
  }

  /**
   * Get engagement statistics
   */
  async getEngagementStats(dateRange?: DateRange): Promise<EngagementStats> {
    try {
      const response = await apiClient.get('/dashboard/stats/engagement', {
        params: { dateRange }
      });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch engagement stats:', error);
      throw error;
    }
  }

  /**
   * Get AI insights
   */
  async getAIInsights(dateRange?: DateRange): Promise<AIInsights> {
    try {
      const response = await apiClient.get('/dashboard/stats/ai-insights', {
        params: { dateRange }
      });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch AI insights:', error);
      throw error;
    }
  }

  /**
   * Get recent activity feed with pagination
   */
  async getRecentActivity(page: number = 1, limit: number = 10, viewAsUser?: boolean): Promise<{ 
    activities: RecentActivity[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { page, limit };
      if (viewAsUser) {
        params.viewAsUser = 'true';
      }
      const response = await apiClient.get('/dashboard/activity/recent', { params });
      return {
        activities: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch recent activity:', error);
      throw error;
    }
  }

  /**
   * Get critical requests with pagination
   */
  async getCriticalRequests(page: number = 1, limit: number = 10, viewAsUser?: boolean): Promise<{ 
    criticalRequests: CriticalRequest[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { page, limit };
      if (viewAsUser) {
        params.viewAsUser = 'true';
      }
      const response = await apiClient.get('/dashboard/requests/critical', { params });
      return {
        criticalRequests: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch critical requests:', error);
      throw error;
    }
  }

  /**
   * Get upcoming deadlines with pagination
   */
  async getUpcomingDeadlines(page: number = 1, limit: number = 10, viewAsUser?: boolean): Promise<{ 
    deadlines: UpcomingDeadline[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { page, limit };
      if (viewAsUser) {
        params.viewAsUser = 'true';
      }
      const response = await apiClient.get('/dashboard/deadlines/upcoming', { params });
      return {
        deadlines: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch upcoming deadlines:', error);
      throw error;
    }
  }

  /**
   * Get department-wise statistics
   */
  async getDepartmentStats(dateRange?: DateRange, startDate?: Date, endDate?: Date): Promise<DepartmentStats[]> {
    try {
      const params: any = { dateRange };
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      const response = await apiClient.get('/dashboard/stats/by-department', { params });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch department stats:', error);
      throw error;
    }
  }

  /**
   * Get priority distribution
   */
  async getPriorityDistribution(dateRange?: DateRange, startDate?: Date, endDate?: Date): Promise<PriorityDistribution[]> {
    try {
      const params: any = { dateRange };
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      const response = await apiClient.get('/dashboard/stats/priority-distribution', { params });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch priority distribution:', error);
      throw error;
    }
  }

  /**
   * Get AI Remark Utilization with monthly trends
   */
  async getAIRemarkUtilization(dateRange?: DateRange, startDate?: Date, endDate?: Date): Promise<AIRemarkUtilization> {
    try {
      const params: any = { dateRange };
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      const response = await apiClient.get('/dashboard/stats/ai-remark-utilization', { params });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch AI remark utilization:', error);
      throw error;
    }
  }

  /**
   * Get Approver Performance metrics with pagination
   * Supports priority and SLA filters for consistent stats behavior
   */
  async getApproverPerformance(
    dateRange?: DateRange, 
    page: number = 1, 
    limit: number = 10, 
    startDate?: Date, 
    endDate?: Date,
    priority?: string,
    slaCompliance?: string
  ): Promise<{ 
    performance: ApproverPerformance[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { 
        dateRange, 
        page, 
        limit: limit || 10  // Explicitly set limit (default 10 if not provided)
      };
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      if (priority && priority !== 'all') {
        params.priority = priority;
      }
      if (slaCompliance && slaCompliance !== 'all') {
        params.slaCompliance = slaCompliance;
      }
      
      
      const response = await apiClient.get('/dashboard/stats/approver-performance', { params });
      return {
        performance: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch approver performance:', error);
      throw error;
    }
  }

  /**
   * Get Request Lifecycle Report
   */
  async getLifecycleReport(
    page: number = 1, 
    limit: number = 50,
    dateRange?: DateRange,
    startDate?: Date,
    endDate?: Date
  ): Promise<{ 
    lifecycleData: any[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { page, limit };
      if (dateRange) params.dateRange = dateRange;
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      const response = await apiClient.get('/dashboard/reports/lifecycle', { params });
      return {
        lifecycleData: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch lifecycle report:', error);
      throw error;
    }
  }

  /**
   * Get enhanced User Activity Log Report
   */
  async getActivityLogReport(
    page: number = 1, 
    limit: number = 50,
    dateRange?: DateRange,
    filterUserId?: string,
    filterType?: string,
    filterCategory?: string,
    filterSeverity?: string,
    startDate?: Date,
    endDate?: Date
  ): Promise<{ 
    activities: any[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { page, limit, filterUserId, filterType, filterCategory, filterSeverity };
      if (dateRange) params.dateRange = dateRange;
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      const response = await apiClient.get('/dashboard/reports/activity-log', { params });
      return {
        activities: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch activity log report:', error);
      throw error;
    }
  }

  /**
   * Get list of departments (metadata for filtering)
   */
  async getDepartments(): Promise<string[]> {
    try {
      const response = await apiClient.get('/dashboard/metadata/departments');
      return response.data.data.departments || [];
    } catch (error) {
      console.error('Failed to fetch departments:', error);
      throw error;
    }
  }

  /**
   * Get Workflow Aging Report
   */
  async getWorkflowAgingReport(
    threshold: number = 7,
    page: number = 1,
    limit: number = 50,
    dateRange?: DateRange,
    startDate?: Date,
    endDate?: Date
  ): Promise<{ 
    agingData: any[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { threshold, page, limit };
      if (dateRange) params.dateRange = dateRange;
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      const response = await apiClient.get('/dashboard/reports/workflow-aging', { params });
      return {
        agingData: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch workflow aging report:', error);
      throw error;
    }
  }

  /**
   * Get single approver stats only (dedicated endpoint for performance)
   * Only respects date, priority, and SLA filters
   */
  async getSingleApproverStats(
    approverId: string,
    dateRange?: DateRange,
    startDate?: Date,
    endDate?: Date,
    priority?: string,
    slaCompliance?: string
  ): Promise<ApproverPerformance> {
    try {
      const params: any = { approverId };
      if (dateRange) params.dateRange = dateRange;
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      if (priority && priority !== 'all') params.priority = priority;
      if (slaCompliance && slaCompliance !== 'all') params.slaCompliance = slaCompliance;
      
      const response = await apiClient.get('/dashboard/stats/single-approver', { params });
      return response.data.data;
    } catch (error) {
      console.error('Failed to fetch single approver stats:', error);
      throw error;
    }
  }

  /**
   * Get requests filtered by approver ID for detailed performance analysis
   */
  async getRequestsByApprover(
    approverId: string,
    page: number = 1,
    limit: number = 50,
    dateRange?: DateRange,
    startDate?: Date,
    endDate?: Date,
    status?: string,
    priority?: string,
    slaCompliance?: string,
    search?: string
  ): Promise<{ 
    requests: any[], 
    pagination: {
      currentPage: number,
      totalPages: number,
      totalRecords: number,
      limit: number
    }
  }> {
    try {
      const params: any = { approverId, page, limit };
      if (dateRange) params.dateRange = dateRange;
      if (dateRange === 'custom' && startDate && endDate) {
        params.startDate = startDate.toISOString();
        params.endDate = endDate.toISOString();
      }
      if (status) params.status = status;
      if (priority) params.priority = priority;
      if (slaCompliance) params.slaCompliance = slaCompliance;
      if (search) params.search = search;
      
      const response = await apiClient.get('/dashboard/requests/by-approver', { params });
      return {
        requests: response.data.data,
        pagination: response.data.pagination
      };
    } catch (error) {
      console.error('Failed to fetch requests by approver:', error);
      throw error;
    }
  }
}

export const dashboardService = new DashboardService();
export default dashboardService;