using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Input;

namespace Hopetry.Services
{
    public class AsyncRelayCommand : ICommand
    {
        private readonly Func<Task> _executeAsync;
        private readonly Func<bool> _canExecute;

        public AsyncRelayCommand(Func<Task> executeAsync, Func<bool> canExecute = null)
        {
            _executeAsync = executeAsync ?? throw new ArgumentNullException(nameof(executeAsync));
            _canExecute = canExecute;
        }

        public event EventHandler CanExecuteChanged;

        // 这个方法决定了命令是否可执行
        public bool CanExecute(object parameter)
        {
            return _canExecute == null || _canExecute();
        }

        // 异步执行命令
        public async void Execute(object parameter)
        {
            if (_executeAsync != null)
            {
                await _executeAsync();  // 执行异步操作
            }
        }

        // 通知命令的可执行状态发生变化
        public void RaiseCanExecuteChanged()
        {
            CanExecuteChanged?.Invoke(this, EventArgs.Empty);
        }
    }
}