import { useState } from 'react';
import toast from 'react-hot-toast';
import { paymentOptionsApi, PaymentOptionsConfig } from '@/lib/api';

/**
 * Manages the event-level payment override editor state: loading global +
 * override config, computing effective values, editing, saving and resetting.
 */
export function usePaymentOverrides(eventId: string, locale: string) {
  const [globalPaymentOptions, setGlobalPaymentOptions] = useState<PaymentOptionsConfig | null>(null);
  const [paymentOverrides, setPaymentOverrides] = useState<Partial<PaymentOptionsConfig>>({});
  const [hasPaymentOverrides, setHasPaymentOverrides] = useState(false);
  const [savingPayments, setSavingPayments] = useState(false);
  const [loadingPayments, setLoadingPayments] = useState(false);

  const loadPaymentOptions = async () => {
    if (globalPaymentOptions) return;
    setLoadingPayments(true);
    try {
      const [globalRes, overridesRes] = await Promise.all([
        paymentOptionsApi.getGlobal(),
        paymentOptionsApi.getEventOverrides(eventId),
      ]);
      setGlobalPaymentOptions(globalRes.paymentOptions);
      if (overridesRes.overrides) {
        setPaymentOverrides(overridesRes.overrides);
        setHasPaymentOverrides(true);
      }
    } catch (error) {
      toast.error('Failed to load payment options');
    } finally {
      setLoadingPayments(false);
    }
  };

  const getEffectivePaymentOption = <K extends keyof PaymentOptionsConfig>(key: K): PaymentOptionsConfig[K] => {
    if (paymentOverrides[key] !== undefined && paymentOverrides[key] !== null) {
      return paymentOverrides[key] as PaymentOptionsConfig[K];
    }
    return globalPaymentOptions?.[key] as PaymentOptionsConfig[K];
  };

  const updatePaymentOverride = <K extends keyof PaymentOptionsConfig>(
    key: K,
    value: PaymentOptionsConfig[K] | null
  ) => {
    setPaymentOverrides((prev) => ({ ...prev, [key]: value }));
    setHasPaymentOverrides(true);
  };

  const handleSavePaymentOptions = async () => {
    setSavingPayments(true);
    try {
      await paymentOptionsApi.updateEventOverrides(eventId, paymentOverrides);
      toast.success(locale === 'es' ? 'Opciones de pago guardadas' : 'Payment options saved');
    } catch (error: any) {
      toast.error(error.message || 'Failed to save payment options');
    } finally {
      setSavingPayments(false);
    }
  };

  const handleResetToGlobal = async () => {
    if (!confirm(locale === 'es'
      ? '¿Resetear a la configuración global? Se eliminarán todas las personalizaciones de este evento.'
      : 'Reset to global settings? This will remove all customizations for this event.')) {
      return;
    }
    setSavingPayments(true);
    try {
      await paymentOptionsApi.deleteEventOverrides(eventId);
      setPaymentOverrides({});
      setHasPaymentOverrides(false);
      toast.success(locale === 'es' ? 'Restablecido a configuración global' : 'Reset to global settings');
    } catch (error: any) {
      toast.error(error.message || 'Failed to reset payment options');
    } finally {
      setSavingPayments(false);
    }
  };

  return {
    globalPaymentOptions,
    paymentOverrides,
    hasPaymentOverrides,
    savingPayments,
    loadingPayments,
    loadPaymentOptions,
    getEffectivePaymentOption,
    updatePaymentOverride,
    handleSavePaymentOptions,
    handleResetToGlobal,
  };
}

export type PaymentOverridesController = ReturnType<typeof usePaymentOverrides>;