//-----------------------------------------------------------------------
// -----------------------------------------------------------------------
// file="ViewResponder"
// Project: StgSharp
// AuthorGroup: Nitload
// Copyright (c) Nitload. All rights reserved.
//     
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.
//     
// -----------------------------------------------------------------------
// -----------------------------------------------------------------------
using StgSharp.Controlling.UsrActivity;
using StgSharp.MVVM.ViewModel;

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

namespace StgSharp.MVVM
{
    public partial class ViewBase
    {

        protected interface IViewResponder<out TVIew> where TVIew: ViewBase
        {

            Action? this[IClickTrigger trigger] { get; set; }

            void CustomizedInitialize(Func<IClickTrigger, string, Action> keyRegister);

            void Initialize(MethodLookUpDelegate methodGetter);

            void ProcessUserInput();

            bool ValidateInitializing();

        }

        protected abstract class ViewResponder<TView> : IViewResponder<TView> where TView: ViewBase
        {

            private bool _isInitialized;
            private Dictionary<IClickTrigger, Action> keyCallbackIndex;
            private Dictionary<string, Action> nameToCallbackMap;
            private TView _binding;

            protected ViewResponder(TView binding)
            {
                keyCallbackIndex = new Dictionary<IClickTrigger, Action>();
                nameToCallbackMap = new Dictionary<string, Action>();
                _binding = binding;
            }

            #pragma warning disable CA1043
            public Action? this[IClickTrigger trigger]
            #pragma warning restore CA1043
            {
                get => keyCallbackIndex.TryGetValue(trigger, out Action callback) ? callback : null;
                set
                {
                    if (keyCallbackIndex.TryGetValue(trigger, out Action callback))
                    {
                        callback += value;
                    } else
                    {
                        keyCallbackIndex.Add(
                            trigger, value ?? throw new ArgumentNullException(nameof(value)));
                    }
                }
            }

            protected TView Binding => _binding;

            public abstract void CustomizedInitialize(Func<IClickTrigger, string, Action> keyRegister);

            public void Initialize(MethodLookUpDelegate methodGetter)
            {
                if (_isInitialized) {
                    return;
                }
                CustomizedInitialize((trigger, name) => {
                    if (!nameToCallbackMap.TryGetValue(name, out Action ret))
                    {
                        if (methodGetter(name, out Action lookup))
                        {
                            this[trigger] = lookup;
                        } else
                        {
                            throw new InvalidOperationException(
                                    $"Cannot find method named {name} in binded view model");
                        }
                    }
                    return ret;
                });
            }

            public void ProcessUserInput()
            {
                foreach (KeyValuePair<IClickTrigger, Action> pair in keyCallbackIndex)
                {
                    if (GraphicFramework.glfwGetKey(_binding.ViewHandle,
                                               pair.Key.TargetKeyOrButtonID) == pair.Key.TriggeredStatus) {
                        pair.Value();
                    }
                }
            }

            public abstract bool ValidateInitializing();

        }

    }
}