import { useSyncExternalStore } from 'react';
import { Transaction } from '../primitives/index.js';
import {
  WalletP2PKH,
  Blockchain,
  AddressListUnspent,
} from '../wallet/index.js';

export function useWalletP2PKH(
  privateKeyBytes: Uint8Array,
  electrum: Blockchain,
) {
  const wallet = React.useMemo(
    () => new WalletP2PKHReact(privateKeyBytes, electrum),
    [privateKeyBytes, electrum],
  );

  const unspents = useSyncExternalStore(
    wallet.subscribeToUnspents,
    wallet.getUnspents,
  );

  const transactions = useSyncExternalStore(
    wallet.subscribeToTransactions,
    wallet.getTransactions,
  );

  const balance = React.useMemo(() => {
    return unspents.reduce((total, unspent) => total + unspent.value, 0);
  }, [unspents]);

  return { wallet, unspents, transactions, balance };
}

class WalletP2PKHReact extends WalletP2PKH {
  private rUnspents: AddressListUnspent['response'] = [];
  private rTransactions: Array<Transaction> = [];
  private unspentsListeners: Set<() => void> = new Set();
  private transactionsListeners: Set<() => void> = new Set();

  constructor(privateKeyBytes: Uint8Array, blockchain: Blockchain) {
    super(privateKeyBytes, blockchain);
    this.events.on('unspentsUpdated', (unspents) => {
      this.rUnspents = unspents;
      this.unspentsListeners.forEach((listener) => listener());
    });
    this.events.on('transactionsUpdated', (transactions) => {
      this.rTransactions = transactions;
      this.transactionsListeners.forEach((listener) => listener());
    });
  }

  subscribeToUnspents = (listener: () => void) => {
    this.unspentsListeners.add(listener);
    return () => {
      this.unspentsListeners.delete(listener);
    };
  };

  subscribeToTransactions = (listener: () => void) => {
    this.transactionsListeners.add(listener);
    return () => {
      this.transactionsListeners.delete(listener);
    };
  };

  getUnspents = () => {
    return this.rUnspents;
  };

  getTransactions = () => {
    return this.rTransactions;
  };
}