import React from 'react';
import { View, Alert } from 'react-native';
import { tw, AppContainer } from 'common-ui';
import CouponForm from '@/src/components/CouponForm';
import { trpc } from '@/src/trpc-client';
import { useRouter } from 'expo-router';

export default function CreateCoupon() {
  const router = useRouter();
  const createCoupon = trpc.admin.coupon.create.useMutation();
  const createReservedCoupon = trpc.admin.coupon.createReservedCoupon.useMutation();
  const { refetch: refetchCoupons } = trpc.admin.coupon.getAll.useInfiniteQuery(
    { limit: 20, search: '' },
    {
      enabled: false,
      getNextPageParam: (lastPage) => lastPage.nextCursor,
    }
  )
  const { refetch: refetchReservedCoupons } = trpc.admin.coupon.getReservedCoupons.useInfiniteQuery(
    { limit: 20, search: '' },
    {
      enabled: false,
      getNextPageParam: (lastPage) => lastPage.nextCursor,
    }
  )

  const handleCreateCoupon = async (values: any) => {
    const { isReservedCoupon, couponCodes, ...rest } = values;
    // Transform targetUsers array to targetUser for backend compatibility
    const payload = {
      ...rest,
      targetUser: rest.targetUsers?.[0] || undefined,
    };
    delete payload.targetUsers;

    // For flat discounts, send the discount value as maxValue too
    if (payload.flatDiscount !== undefined) {
      payload.maxValue = payload.flatDiscount;
    }

    const codes = (couponCodes || []).map((c: string) => c.trim()).filter(Boolean);
    if (codes.length === 0) {
      Alert.alert('Error', 'At least one coupon code is required');
      return;
    }

    const mutation = isReservedCoupon ? createReservedCoupon : createCoupon;
    try {
      await mutation.mutateAsync({ ...payload, couponCodes: codes });
      await refetchCoupons()
      await refetchReservedCoupons()
      Alert.alert('Success', `${codes.length} coupon${codes.length > 1 ? 's' : ''} created successfully`, [
        { text: 'OK', onPress: () => router.back() }
      ]);
    } catch (error: any) {
      Alert.alert('Error', error.message || 'Failed to create coupons');
    }
  };

  return (
    <AppContainer>
      <CouponForm
        onSubmit={handleCreateCoupon}
        isLoading={createCoupon.isPending || createReservedCoupon.isPending}
      />
    </AppContainer>
  );
}