//-----------------------------------------------------------------------
//-----------------------------------------------------------------------
//     file="ViewModel.cs"
//     Project: StgSharp
//     AuthorGroup: Nitload Space
//     Copyright (c) Nitload Space. 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.Graphics;
using StgSharp.Graphics.OpenGL;
using StgSharp.Math;
using StgSharp.MVVM.View;
using StgSharp.MVVM.ViewModel;
using StgSharp.Threading;
using StgSharp.Timing;

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Numerics;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;

using static StgSharp.Internal.InternalIO;

namespace StgSharp.MVVM.ViewModel
{
    public abstract partial class ViewModelBase
    {

        private FrameBufferSizeHandler _resizeCallback;
        private int _frameCount;
        private int _frameSpeed;
        private ViewPort viewPortDisplay;

        //internal IntPtr monitor;

        internal TimeSpanProvider fpsCountProvider;
        internal TimeSpanProvider frameTimeProvider;
        internal Vector4 backgroundColor;

        protected ViewModelBase( int frameSpeed )
        {
            viewPortDisplay = new ViewPort();
            allView = new();
            fpsCountProvider = new TimeSpanProvider(
                1.0, TimeSpanProvider.DefaultProvider );
            _frameSpeed = 0;
            _frameCount = 0;
            long frameLength = ( FrameSpeed > 0 ) ?
            ( ( 1000L * 1000L ) / FrameSpeed ) : 0;
            frameTimeProvider = new TimeSpanProvider(
                frameLength, TimeSpanProvider.DefaultProvider );
            FrameSizeCallback = DefaultFrameRewsizeCallback;
        }

        protected ViewModelBase( float frameLength )
        {
            viewPortDisplay = new ViewPort();
            allView = new();
            fpsCountProvider = new TimeSpanProvider(
                1.0, TimeSpanProvider.DefaultProvider );
            _frameSpeed = 0;
            _frameCount = 0;
            long _frameLength = ( FrameSpeed > 0 ) ?
            ( ( long )( 1000 * frameLength ) ) : 0;
            frameTimeProvider = new TimeSpanProvider(
                _frameLength, TimeSpanProvider.DefaultProvider );
            FrameSizeCallback = DefaultFrameRewsizeCallback;
        }

        public ViewModelBase( ViewPort vBinding, int frameSpeed )
        {
            viewPortDisplay = vBinding;
            allView = new();
            fpsCountProvider = new TimeSpanProvider(
                1.0, TimeSpanProvider.DefaultProvider );
            _frameSpeed = 0;
            _frameCount = 0;
            long frameLength = ( frameSpeed > 0 ) ?
            ( ( 1000L * 1000L ) / frameSpeed ) : 0;
            frameTimeProvider = new TimeSpanProvider(
                frameLength, TimeSpanProvider.DefaultProvider );
            FrameSizeCallback = DefaultFrameRewsizeCallback;
        }

        public ViewModelBase( ViewPort vBinding, float frameLength )
        {
            viewPortDisplay = vBinding;
            allView = new();
            fpsCountProvider = new TimeSpanProvider(
                1.0, TimeSpanProvider.DefaultProvider );
            _frameSpeed = 0;
            _frameCount = 0;
            long _frameLength = ( frameLength > 0 ) ?
            ( ( long )( 1000 * frameLength ) ) : 0;
            frameTimeProvider = new TimeSpanProvider(
                _frameLength, TimeSpanProvider.DefaultProvider );
            FrameSizeCallback = DefaultFrameRewsizeCallback;
        }

        public DataBindingEntry this[ string name ]
        {
            get
            {
                if( this.TryGetObjectReference(
                    name, out DataBindingEntry entry ) ) {
                    return entry;
                }
                throw new KeyNotFoundException();
            }
        }

        public bool ShouldClose
        {
            get => InternalIO.glfwWindowShouldClose(
                viewPortDisplay.ViewPortID ) != 0;
            set => InternalIO.glfwSetWindowShouldClose(
                viewPortDisplay.ViewPortID, value ? 1 : 0 );
        }

        public int CurrentFrameCount => frameTimeProvider.CurrentSpan;

        public int FrameSpeed => _frameSpeed;

        /// <summary>
        /// Height of this form, represent in <see cref="int" />
        /// </summary>
        public int Height
        {
            get => viewPortDisplay.Height;
        }

        /// <summary>
        /// Width of this form, represent in <see cref="int" />
        /// </summary>
        public int Width
        {
            get => viewPortDisplay.Width;
        }

        public unsafe IntPtr WindowID
        {
            get => viewPortDisplay.ViewPortID;
        }

        public string Name
        {
            get => viewPortDisplay.Name;
        }

        /// <summary>
        /// Width of this form, represent in <see cref="int" />
        /// </summary>
        public Vec2 Size
        {
            get => new Vec2( Width, Height );
        }

        public ViewPort ViewPortBinding
        {
            get => viewPortDisplay;
        }

        #pragma warning disable CA1044
        protected FrameBufferSizeHandler FrameSizeCallback
        {
            set
            {
                _resizeCallback = value;
                IntPtr handlerPtr = Marshal.GetFunctionPointerForDelegate(
                    value );
                InternalIO.glfwSetFramebufferSizeCallback(
                    viewPortDisplay.ViewPortID, handlerPtr );
            }
        }
        #pragma warning restore CA1044

        public abstract void CustomizeInitialize();

        /// <summary>
        /// Set the size limit of current form
        /// </summary>
        /// <param _name="minSize">
        /// Minimum size of current form. In form of a <see cref="Vec2" /> of (width,height)
        /// </param>
        /// <param _name="maxSize">
        /// Maximum size of current form. In form of a <see cref="Vec2" /> of (width,height)
        /// </param>
        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public void SetSizeLimit( Vec2 minSize, Vec2 maxSize )
        {
            ThreadHelper.MainThreadAssert();
            InternalIO.glfwSetWindowSizeLimits(
                this.viewPortDisplay.ViewPortID, ( int )minSize.X,
                ( int )minSize.Y, ( int )maxSize.X, ( int )maxSize.Y );
        }

        /// <summary>
        /// Set the size limit of current form
        /// </summary>
        /// <param _name="minWidth"> Minimum width of current form </param>
        /// <param _name="minHeight"> Minimum height of current form </param>
        /// <param _name="maxWidth"> Maximum width of current form </param>
        /// <param _name="maxHeight"> Maximum height of current form </param>
        [MethodImpl( MethodImplOptions.AggressiveInlining )]
        public void SetSizeLimit(
            int minWidth,
            int minHeight,
            int maxWidth,
            int maxHeight )
        {
            ThreadHelper.MainThreadAssert();
            InternalIO.glfwSetWindowSizeLimits(
                this.viewPortDisplay.ViewPortID, minWidth, minHeight, maxWidth,
                maxHeight );
        }

        public abstract bool TryGetObjectReference(
            string name,
            out DataBindingEntry entry );

        private void DefaultFrameRewsizeCallback(
            IntPtr windowHandle,
            int width,
            int height )
        {
            ViewPort.GetExistedViewPort( windowHandle, out ViewPort vp );
            vp.RequestFlushSizeInNextFrame( width, height );

            //Console.WriteLine($"{width}   {height}");
        }

    }
}