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

namespace GummingCommon
{
    
    public class DelegateCommand : ICommand
    {
        public static List<string> ButtonInfo = new List<string>();

        #region ICommand realization

        [DebuggerStepThrough]
        public bool CanExecute(object parameter)
        {
            return _canExecute == null ? true : _canExecute(parameter);
        }

        private event EventHandler _internalCanExecuteChanged;
        public event EventHandler CanExecuteChanged
        {
            add
            {
                _internalCanExecuteChanged += value;
                CommandManager.RequerySuggested += value;
            }
            remove
            {
                _internalCanExecuteChanged -= value;
                CommandManager.RequerySuggested -= value;
            }
        }

        public void Execute(object parameter)
        {
            ButtonInfo.Add(string.Format("{0}|{1}|{2}", _execute.Method.DeclaringType.Namespace, _execute.Method.DeclaringType.Name, _execute.Method.Name));

            _execute(parameter);
            RaiseCanExecuteState();
        }

        #endregion

        readonly Action<object> _execute;
        readonly Predicate<object> _canExecute;

        public DelegateCommand(Action<object> execute)
            : this(execute, null)
        { }

        public DelegateCommand(Action<object> execute, Predicate<object> canExecute)
        {
            if (execute == null)
                throw new ArgumentNullException("RelayCommand argument can not be null!");

            _execute = execute;
            _canExecute = canExecute;
        }

        public void RaiseCanExecuteState()
        {
            if (_canExecute != null)
                OnCanExecuteChanged();
        }

        protected virtual void OnCanExecuteChanged()
        {
            EventHandler eCanExecuteChanged = _internalCanExecuteChanged;
            if (eCanExecuteChanged != null)
                eCanExecuteChanged(this, EventArgs.Empty);
        }
    }
}