/**
 * Customer Management Hooks
 */

import { useQuery, useInfiniteQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import apiClient from '../api/client';
import { Customer } from '../types';

interface CustomerFilters {
  status?: 'Active' | 'Inactive' | 'Blocked';
  search?: string;
}

interface PaginatedResponse {
  count: number;
  next: string | null;
  previous: string | null;
  results: any[];
}

/**
 * Transform backend customer data to frontend format
 */
const transformCustomer = (c: any): Customer => ({
  id: String(c.id),
  name: c.name || c.user?.name || '',
  email: c.email || c.user?.email || '',
  phone: c.phone || '',
  city: c.city,
  state: c.state,
  zip: c.zip,
  totalSpend: parseFloat(c.total_spend || 0),
  lastVisit: c.last_visit ? new Date(c.last_visit) : null,
  status: c.status,
  avatarUrl: c.avatar_url,
  tags: c.tags || [],
  userId: String(c.user_id || c.user),
  paymentMethods: [],
  user_data: c.user_data,
  notes: c.notes || '',
  email_verified: c.email_verified ?? false,
});

/**
 * Hook to fetch customers with infinite scroll pagination
 */
export const useCustomersInfinite = (filters?: CustomerFilters) => {
  return useInfiniteQuery<PaginatedResponse>({
    queryKey: ['customers', 'infinite', filters || {}],
    queryFn: async ({ pageParam = 1 }) => {
      const params = new URLSearchParams();
      params.append('page', String(pageParam));
      params.append('page_size', '25');
      if (filters?.status) params.append('status', filters.status);
      if (filters?.search) params.append('search', filters.search);

      const { data } = await apiClient.get(`/customers/?${params}`);

      // Handle both paginated and non-paginated responses
      if (Array.isArray(data)) {
        return {
          count: data.length,
          next: null,
          previous: null,
          results: data,
        };
      }
      return data;
    },
    initialPageParam: 1,
    getNextPageParam: (lastPage) => {
      if (lastPage.next) {
        // Extract page number from next URL
        const url = new URL(lastPage.next);
        const page = url.searchParams.get('page');
        return page ? parseInt(page, 10) : undefined;
      }
      return undefined;
    },
    retry: false,
  });
};

/**
 * Hook to fetch all customers (non-paginated, for backward compatibility)
 */
export const useCustomers = (filters?: CustomerFilters) => {
  return useQuery<Customer[]>({
    queryKey: ['customers', filters],
    queryFn: async () => {
      const params = new URLSearchParams();
      if (filters?.status) params.append('status', filters.status);
      if (filters?.search) params.append('search', filters.search);

      const { data } = await apiClient.get(`/customers/?${params}`);

      // Handle paginated response
      const results = data.results || data;
      return results.map(transformCustomer);
    },
    retry: false,
  });
};

interface CreateCustomerData {
  name?: string;
  firstName?: string;
  lastName?: string;
  email: string;
  phone?: string;
  city?: string;
  state?: string;
  zip?: string;
}

/**
 * Hook to create a customer
 */
export const useCreateCustomer = () => {
  const queryClient = useQueryClient();

  return useMutation({
    mutationFn: async (customerData: CreateCustomerData) => {
      // Parse name into first_name and last_name if provided as single field
      let firstName = customerData.firstName;
      let lastName = customerData.lastName;

      if (customerData.name && !firstName && !lastName) {
        const nameParts = customerData.name.trim().split(/\s+/);
        firstName = nameParts[0] || '';
        lastName = nameParts.slice(1).join(' ') || '';
      }

      const backendData = {
        first_name: firstName,
        last_name: lastName,
        email: customerData.email,
        phone: customerData.phone || '',
        // Note: city, state, zip are TODO in backend - not stored yet
      };

      const { data } = await apiClient.post('/customers/', backendData);
      return data;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['customers'] });
    },
  });
};

interface UpdateCustomerData {
  name?: string;
  firstName?: string;
  lastName?: string;
  email?: string;
  phone?: string;
  isActive?: boolean;
  notes?: string;
}

/**
 * Hook to update a customer
 */
export const useUpdateCustomer = () => {
  const queryClient = useQueryClient();

  return useMutation({
    mutationFn: async ({ id, updates }: { id: string; updates: UpdateCustomerData }) => {
      // Parse name into first_name and last_name if provided as single field
      let firstName = updates.firstName;
      let lastName = updates.lastName;

      if (updates.name && !firstName && !lastName) {
        const nameParts = updates.name.trim().split(/\s+/);
        firstName = nameParts[0] || '';
        lastName = nameParts.slice(1).join(' ') || '';
      }

      const backendData: Record<string, unknown> = {};

      if (firstName !== undefined) backendData.first_name = firstName;
      if (lastName !== undefined) backendData.last_name = lastName;
      if (updates.email !== undefined) backendData.email = updates.email;
      if (updates.phone !== undefined) backendData.phone = updates.phone;
      if (updates.isActive !== undefined) backendData.is_active = updates.isActive;
      if (updates.notes !== undefined) backendData.notes = updates.notes;

      const { data } = await apiClient.patch(`/customers/${id}/`, backendData);
      return data;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['customers'] });
    },
  });
};

/**
 * Hook to delete a customer
 */
export const useDeleteCustomer = () => {
  const queryClient = useQueryClient();

  return useMutation({
    mutationFn: async (id: string) => {
      await apiClient.delete(`/customers/${id}/`);
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['customers'] });
    },
  });
};

/**
 * Hook to verify a customer's email address
 */
export const useVerifyCustomerEmail = () => {
  const queryClient = useQueryClient();

  return useMutation({
    mutationFn: async (id: string) => {
      const { data } = await apiClient.post(`/customers/${id}/verify_email/`);
      return data;
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: ['customers'] });
    },
  });
};