﻿// Copyright (c) Microsoft Corporation
// The Microsoft Corporation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Windows.Input;

namespace ImageResizer.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);
    }

    [System.Diagnostics.CodeAnalysis.SuppressMessage("StyleCop.CSharp.MaintainabilityRules", "SA1402:File may only contain a single type", Justification = "abstract T and abstract")]
    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)
        {
            this.execute = execute ?? throw new ArgumentNullException(nameof(execute));
            this.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);
    }
}
