using System;
using System.Windows.Input;

namespace NotepadRs4.Helpers
{
    public class RelayCommand : ICommand
    {
        private readonly Action _execute;

        private readonly Func<bool> _canExecute;

        public event EventHandler CanExecuteChanged;

        public RelayCommand(Action execute)
            : this(execute, null)
        {
        }

        public RelayCommand(Action execute, Func<bool> canExecute)
        {
            _execute = execute ?? throw new ArgumentNullException(nameof(execute));
            _canExecute = canExecute;
        }

        public bool CanExecute(object parameter) => _canExecute == null || _canExecute();

        public void Execute(object parameter) => _execute();

        public void OnCanExecuteChanged() => CanExecuteChanged?.Invoke(this, EventArgs.Empty);
    }

    public class RelayCommand<T> : ICommand
    {
        private readonly Action<T> _execute;

        private readonly Func<T, bool> _canExecute;

        public event EventHandler CanExecuteChanged;

        public RelayCommand(Action<T> execute)
            : this(execute, null)
        {
        }

        public RelayCommand(Action<T> execute, Func<T, bool> canExecute)
        {
            _execute = execute ?? throw new ArgumentNullException(nameof(execute));
            _canExecute = canExecute;
        }

        public bool CanExecute(object parameter) => _canExecute == null || _canExecute((T)parameter);

        public void Execute(object parameter) => _execute((T)parameter);

        public void OnCanExecuteChanged() => CanExecuteChanged?.Invoke(this, EventArgs.Empty);
    }
}
