using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Linq.Expressions;
using System.Reflection;
using System.Text;

using Revolucent.Dasso.Core;

namespace Revolucent.Dasso.Program.Binding
{
    class Binding<S, P>
        where S : INotifyPropertyChanged
    {
        private readonly PropertyChangedEventHandler handler = null;
        private readonly S source = default(S);

        public Binding(S source, Expression<Func<P>> sourceGetterExpression, params Action<P>[] targetSetters)
        {
            var sourceGetter = sourceGetterExpression.Compile();
            var memberExpression = (MemberExpression)sourceGetterExpression.Body;
            var propertyName = memberExpression.Member.Name;
            handler = (sender, e) =>
            {
                if (e.PropertyName != propertyName)
                    return;
                targetSetters.ForEach(setter => setter(sourceGetter()));
            };
            source.PropertyChanged += handler;
            handler(source, new PropertyChangedEventArgs(propertyName));
        }

        public void Revoke()
        {
            source.PropertyChanged -= handler;
        }
    }

    static class BindingHelper
    {
        public static Binding<S, P> SetBinding<S, P>(this S source, Expression<Func<P>> sourceGetterExpression, params Action<P>[] targetSetters)
            where S : INotifyPropertyChanged
        {
            return new Binding<S, P>(source, sourceGetterExpression, targetSetters);
        }
    }
}