import { ethers } from 'ethers';
import { getContract } from '@/lib/ethers';

declare global {
  interface Window {
    ethereumProvider?: ethers.providers.ExternalProvider & {
      isMetaMask?: boolean;
      request?: (method: string, params?: unknown[]) => Promise<unknown>;
    };
  }
}

type ToastFunction = (options: {
  title: string;
  variant?: 'default' | 'destructive' | null | undefined;
}) => void;

export const buyHandler = async (
  eventId: number,
  numTickets: number,
  toast: ToastFunction
): Promise<void> => {
  if (eventId < 0) {
    toast({ title: 'Please enter a valid Event ID.', variant: 'destructive' });
    return;
  }

  if (numTickets <= 0) {
    toast({
      title: 'Please select at least one ticket.',
      variant: 'destructive',
    });
    return;
  }

  toast({
    title:
      'You might be asked to approve multiple transactions if you buy multiple tickets',
  });

  while (numTickets > 0) {
    try {
      if (typeof window.ethereum === 'undefined') {
        toast({
          title: 'Please install MetaMask or another Ethereum wallet',
          variant: 'destructive',
        });
        return;
      }

      const provider = new ethers.providers.Web3Provider(window.ethereum);
      const signer = provider.getSigner();
      const contract = getContract().connect(signer);

      const singleTicketCost = await contract.getEventPriceFlare(eventId);
      const totalTicketCost = singleTicketCost
        .mul(numTickets)
        .mul(105)
        .div(100);

      const balance = await provider.getBalance(await signer.getAddress());
      if (balance.lt(totalTicketCost)) {
        toast({
          title: 'Insufficient balance to cover ticket cost and gas fees.',
          variant: 'destructive',
        });
        return;
      }

      const tx = await contract.buyTicket(eventId, { value: totalTicketCost });
      const receipt = await tx.wait();

      toast({
        title: `Tickets purchased successfully! Transaction Hash: ${receipt.transactionHash}`,
      });

      numTickets -= 1;
    } catch (error) {
      console.error('Error buying tickets:', error);
      toast({
        title: 'Transaction failed. Please try again.',
        variant: 'destructive',
      });
    }
  }
};