import { useQuery } from '@tanstack/react-query';
import { api } from '../lib/api';
import type { ApiResponse, PaginatedResponse } from '../lib/api';

/** A derived per-patient payment status shown on the list (node 1). */
export type PaymentRowStatus = 'paid' | 'unpaid' | 'unsettled';

export interface PatientPaymentRow {
  patient_uuid: string;
  patient_name: string | null;
  national_code: string | null;
  invoice_count: number;
  paid_rials: number;
  remaining_rials: number;
  status: PaymentRowStatus;
}

export interface PatientPaymentFilters {
  page: number;
  national_code?: string;
  status?: string;   // paid | unsettled | unpaid
  from?: number;     // unix seconds
  to?: number;       // unix seconds
}

/** A single invoice status on the detail table (node 2) — two-state. */
export type InvoiceRowStatus = 'paid' | 'unsettled';

export interface PatientInvoiceRow {
  uuid: string;
  number: number;
  issued_at: number;
  total_rials: number;
  status: InvoiceRowStatus;
  service_title: string | null;
  items: Array<{ uuid: string; title: string; quantity: number; total_rials: number; patient_rials: number }>;
}

export interface PatientInvoicesPayload {
  patient: { uuid: string; name: string | null; national_code: string | null };
  data: PatientInvoiceRow[];
  meta: { totalRecords: number; totalPages: number; currentPage: number };
}

const LIMIT = 20;

/** Node 1 — paginated per-patient payment summary for the current tenant. */
export function usePatientPayments(filters: PatientPaymentFilters) {
  const qs = new URLSearchParams({ page: String(filters.page), limit: String(LIMIT) });
  if (filters.national_code) qs.set('national_code', filters.national_code);
  if (filters.status)        qs.set('status', filters.status);
  if (filters.from)          qs.set('from', String(filters.from));
  if (filters.to)            qs.set('to', String(filters.to));

  return useQuery<PaginatedResponse<PatientPaymentRow>>({
    queryKey: ['patient-payments', filters],
    queryFn: () => api.get(`/api/v1/my/billing/patient-payments?${qs.toString()}`),
  });
}

/** Node 2 — a single patient's recorded invoices (header + paginated list). */
export function usePatientInvoices(patientUuid: string | undefined, page: number) {
  return useQuery<ApiResponse<PatientInvoicesPayload>>({
    queryKey: ['patient-invoices', patientUuid, page],
    queryFn: () => api.get(`/api/v1/my/billing/patients/${patientUuid}/invoices?page=${page}&limit=${LIMIT}`),
    enabled: !!patientUuid,
  });
}

export const MY_PAYMENTS_LIMIT = LIMIT;