PalladiumWallet/src/App/ViewModels/MainWindowViewModel.Donate.cs

using System;
using System.Threading.Tasks;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using NBitcoin;
using PalladiumWallet.Core.Chain;
using PalladiumWallet.Core.Net;
using PalladiumWallet.Core.Wallet;

namespace PalladiumWallet.App.ViewModels;

public partial class MainWindowViewModel
{
    public const string DevAddress = "plm1qdq3gu2zvg9lyr8gxd6yln4wavc5tlp8prmvfay";

    [ObservableProperty]
    private string donateAmount = "";

    [ObservableProperty]
    private string donatePreview = "";

    [ObservableProperty]
    private bool hasPendingDonate;

    private BuiltTransaction? _pendingDonate;

    [RelayCommand]
    private async Task PrepareDonate()
    {
        _pendingDonate = null;
        HasPendingDonate = false;

        if (_account is null || _doc?.Cache is null || _lastTransactions is null)
        {
            DonatePreview = "Sincronizza prima di inviare.";
            return;
        }
        try
        {
            var destination = BitcoinAddress.Create(DevAddress, PalladiumNetworks.For(Net));
            if (!CoinAmount.TryParseIn(DonateAmount.Trim(), _config.Unit, out var amount) || amount <= 0)
            {
                DonatePreview = "Importo non valido.";
                return;
            }
            if (!decimal.TryParse(SendFeeRate, System.Globalization.NumberStyles.Any,
                    System.Globalization.CultureInfo.InvariantCulture, out var feeRate) || feeRate <= 0)
                feeRate = 1m;

            _pendingDonate = new TransactionFactory(_account).Build(
                _doc.Cache.Utxos, _lastTransactions, destination, amount, feeRate,
                _doc.Cache.NextChangeIndex, _doc.Cache.TipHeight, sendAll: false);

            DonatePreview = $"txid {_pendingDonate.Txid[..16]}… · " +
                $"fee {Fmt(_pendingDonate.Fee.Satoshi)} " +
                $"({_pendingDonate.Transaction.GetVirtualSize()} vB)" +
                (_pendingDonate.Signed ? "" : " · watch-only");
            HasPendingDonate = _pendingDonate.Signed;
        }
        catch (Exception ex)
        {
            _pendingDonate = null;
            HasPendingDonate = false;
            DonatePreview = $"Errore: {ex.Message}";
        }
        await Task.CompletedTask;
    }

    [RelayCommand]
    private async Task ConfirmDonate()
    {
        if (_pendingDonate is null || _client is null)
            return;
        try
        {
            var txid = await _client.BroadcastAsync(_pendingDonate.ToHex());
            DonatePreview = $"Grazie! txid: {txid}";
            DonateAmount = "";
            _pendingDonate = null;
            HasPendingDonate = false;
            await ConnectAndSync();
        }
        catch (Exception ex)
        {
            DonatePreview = $"Errore broadcast: {ex.Message}";
        }
    }

    private void ResetDonate()
    {
        DonateAmount = "";
        DonatePreview = "";
        HasPendingDonate = false;
        _pendingDonate = null;
    }
}