// The MIT License(MIT)
//
// Copyright(c) 2021 Alberto Rodriguez Orozco & LiveCharts Contributors
//
// 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 LiveChartsCore.Drawing;
using LiveChartsCore.Kernel;
using LiveChartsCore.Motion;
using LiveChartsCore.SkiaSharpView.Drawing;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Web;
using SkiaSharp.Views.Blazor;

namespace LiveChartsCore.SkiaSharpView.Blazor;

/// <inheritdoc cref="MotionCanvas{TDrawingContext}"/>
public partial class MotionCanvas : IDisposable
{
    private SKGLView? _glView;
    private SKCanvasView? _canvas;
    private bool _disposing = false;
    private bool _isDrawingLoopRunning = false;
    private List<PaintSchedule<SkiaSharpDrawingContext>> _paintTasksSchedule = new();

    /// <summary>
    /// Called when the control is initialized.
    /// </summary>
    protected override void OnInitialized()
    {
        CanvasCore.Invalidated += CanvasCore_Invalidated;
    }

    /// <summary>
    /// Gets the <see cref="MotionCanvas{TDrawingContext}"/> (core).
    /// </summary>
    public MotionCanvas<SkiaSharpDrawingContext> CanvasCore { get; } = new();

    /// <summary>
    /// Gets or sets whether the web GL view should be used.
    /// </summary>
    [Parameter]
    public bool UseGLView { get; set; } = true;

    /// <summary>
    /// Gets or sets the FPS.
    /// </summary>
    [Parameter]
    public double MaxFps { get; set; } = 65;

    /// <summary>
    /// Gets or sets the paint tasks.
    /// </summary>
    [Parameter]
    public List<PaintSchedule<SkiaSharpDrawingContext>> PaintTasks
    {
        get => _paintTasksSchedule;
        set
        {
            _paintTasksSchedule = value;
            OnPaintTasksChanged();
        }
    }

    /// <summary>
    /// Gets or sets the pointer down callback.
    /// </summary>
    [Parameter]
    public EventCallback<PointerEventArgs> OnPointerDownCallback { get; set; }

    /// <summary>
    /// Gets or sets the pointer move callback.
    /// </summary>
    [Parameter]
    public EventCallback<PointerEventArgs> OnPointerMoveCallback { get; set; }

    /// <summary>
    /// Gets or sets the pointer up callback.
    /// </summary>
    [Parameter]
    public EventCallback<PointerEventArgs> OnPointerUpCallback { get; set; }

    /// <summary>
    /// Gets or sets the wheel changed callback.
    /// </summary>
    [Parameter]
    public EventCallback<WheelEventArgs> OnWheelCallback { get; set; }

    /// <summary>
    /// Gets or sets the pointer leave callback.
    /// </summary>
    [Parameter]
    public EventCallback<PointerEventArgs> OnPointerOutCallback { get; set; }

    /// <summary>
    /// Called when the pointer goes down.
    /// </summary>
    /// <param name="e"></param>
    protected virtual void OnPointerDown(PointerEventArgs e)
    {
        _ = OnPointerDownCallback.InvokeAsync(e);
    }

    /// <summary>
    /// Called when the pointer moves.
    /// </summary>
    /// <param name="e"></param>
    protected virtual void OnPointerMove(PointerEventArgs e)
    {
        _ = OnPointerMoveCallback.InvokeAsync(e);
    }

    /// <summary>
    /// Called when the pointer goes up.
    /// </summary>
    /// <param name="e"></param>
    protected virtual void OnPointerUp(PointerEventArgs e)
    {
        _ = OnPointerUpCallback.InvokeAsync(e);
    }

    /// <summary>
    /// Called when the wheel moves.
    /// </summary>
    /// <param name="e"></param>
    protected virtual void OnWheel(WheelEventArgs e)
    {
        _ = OnWheelCallback.InvokeAsync(e);
    }

    /// <summary>
    /// Called when the pointer leaves the control.
    /// </summary>
    /// <param name="e"></param>
    protected virtual void OnPointerOut(PointerEventArgs e)
    {
        _ = OnPointerOutCallback.InvokeAsync(e);
    }

    private void OnPaintGlSurface(SKPaintGLSurfaceEventArgs e)
    {
        CanvasCore.DrawFrame(new SkiaSharpDrawingContext(CanvasCore, e.Info, e.Surface, e.Surface.Canvas));
    }

    private void OnPaintSurface(SKPaintSurfaceEventArgs e)
    {
        CanvasCore.DrawFrame(new SkiaSharpDrawingContext(CanvasCore, e.Info, e.Surface, e.Surface.Canvas));
    }

    private void CanvasCore_Invalidated(MotionCanvas<SkiaSharpDrawingContext> sender)
    {
        RunDrawingLoop();
    }

    private async void RunDrawingLoop()
    {
        if (_isDrawingLoopRunning) return;
        _isDrawingLoopRunning = true;

        var ts = TimeSpan.FromSeconds(1 / MaxFps);

        if (UseGLView)
        {
            while (!CanvasCore.IsValid && !_disposing)
            {
                _glView?.Invalidate();
                await Task.Delay(ts);
            }
        }
        else
        {
            while (!CanvasCore.IsValid && !_disposing)
            {
                _canvas?.Invalidate();
                await Task.Delay(ts);
            }
        }

        _isDrawingLoopRunning = false;
    }

    private void OnPaintTasksChanged()
    {
        var tasks = new HashSet<IPaint<SkiaSharpDrawingContext>>();

        foreach (var item in _paintTasksSchedule)
        {
            item.PaintTask.SetGeometries(CanvasCore, item.Geometries);
            _ = tasks.Add(item.PaintTask);
        }

        CanvasCore.SetPaintTasks(tasks);
    }

    void IDisposable.Dispose()
    {
        _disposing = true;
    }
}
