import dayjs from 'dayjs';
import useSWR from 'swr';
import { openmrsFetch, restBaseUrl } from '@openmrs/esm-framework';
import { type AppointmentsFetchResponse, BackendAppointmentStates } from '../types';
import { useSelectedDateContext } from './selected-date-context';

export function usePatientAppointmentHistory(patientUuid: string) {
  const abortController = new AbortController();
  const appointmentsSearchUrl = `${restBaseUrl}/appointments/search`;
  const { selectedDate } = useSelectedDateContext();

  const fetcher = () =>
    openmrsFetch(appointmentsSearchUrl, {
      method: 'POST',
      signal: abortController.signal,
      headers: {
        'Content-Type': 'application/json',
      },
      body: {
        patientUuid: patientUuid,
        startDate: selectedDate,
      },
    });

  const { data, error, isLoading, isValidating } = useSWR<AppointmentsFetchResponse, Error>(
    patientUuid ? appointmentsSearchUrl : null,
    fetcher,
  );

  // Helper function to extract appointment state value
  const getAppointmentStateValue = (appointment: any) => {
    if (appointment.appointmentState && typeof appointment.appointmentState === 'object') {
      return (
        (appointment.appointmentState as any).description ||
        (appointment.appointmentState as any).name ||
        (appointment.appointmentState as any).value
      );
    }
    return appointment.appointmentState || appointment.status;
  };

  // Helper function to categorize appointments by their state
  const categorizeAppointment = (appointment: any) => {
    const stateValue = getAppointmentStateValue(appointment);

    if (stateValue === BackendAppointmentStates.ATTENDED || stateValue === 'Completed') {
      return 'completed';
    }
    if (stateValue === BackendAppointmentStates.EXPIRED || stateValue === 'Missed') {
      return 'missed';
    }
    if (stateValue === BackendAppointmentStates.RETIRED || stateValue === 'Cancelled') {
      return 'cancelled';
    }
    if (
      stateValue === BackendAppointmentStates.UPCOMING ||
      (stateValue === BackendAppointmentStates.CONFIRMED &&
        dayjs(appointment.startDateTime || appointment.appointmentDate).isAfter(dayjs()))
    ) {
      return 'upcoming';
    }

    if (dayjs(appointment.startDateTime || appointment.appointmentDate).isAfter(dayjs())) {
      return 'upcoming';
    }

    return 'other';
  };

  const appointmentsByCategory =
    data?.data?.reduce((acc: any, appointment: any) => {
      const category = categorizeAppointment(appointment);
      acc[category] = (acc[category] || 0) + 1;
      return acc;
    }, {}) || {};

  const missedAppointments = appointmentsByCategory.missed || 0;
  const completedAppointments = appointmentsByCategory.completed || 0;
  const cancelledAppointments = appointmentsByCategory.cancelled || 0;
  const upcomingAppointments = appointmentsByCategory.upcoming || 0;

  return {
    appointmentsCount: {
      missedAppointments,
      completedAppointments,
      cancelledAppointments,
      upcomingAppointments,
    },
    error,
    isLoading,
    isValidating,
  };
}