using Blazor.Extensions.Canvas.Canvas2D;
using Blazor.Extensions;
using Microsoft.AspNetCore.Components.Web;
using Microsoft.AspNetCore.Components;
using Microsoft.JSInterop;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json;
using System.Drawing;
using System.Threading;
using Microsoft.AspNetCore.Mvc.ApplicationModels;

namespace BlazorCanvas.Server.Components.Data;

// https://www.codeproject.com/Articles/5269947/Drawing-with-the-HTML-Canvas-Element-in-Blazor-Ser

public class CanvasService
{
    private Canvas2DContext? _currentCanvasContext;
    private IJSRuntime _jsRuntime;
    private CanvasCommand _lastCommand = new();

    public CanvasService(IJSRuntime jsRuntime)
    {
        _jsRuntime = jsRuntime;
    }

    public string currentColor { get; set; } = "Black";
    public int pointSize { get; set; } = 1;
    public bool snap { get; set; }
    public ElementReference divCanvas { get; set; }
    public BECanvasComponent myCanvas { get; set; } = new();

    // TODO: Dessiner à partir des commandes de Franz.

    public async void Draw(IEnumerable<CanvasCommand> lscommand)
    {
        if (_currentCanvasContext is null)
        {
            _currentCanvasContext = await myCanvas.CreateCanvas2DAsync();
            await _currentCanvasContext.ClearRectAsync(0, 0, 1920, 1080);
        }
        await _currentCanvasContext.BeginBatchAsync();
        foreach (CanvasCommand command in lscommand)
        {
            await _currentCanvasContext.SetFillStyleAsync(command.Color);
            await _currentCanvasContext.FillRectAsync(command.X, command.Y, command.PointSize, command.PointSize);
        }
        await _currentCanvasContext.EndBatchAsync();
    }

    public async void Draw(CanvasCommand command)
    {
        if (_currentCanvasContext is null)
        {
            _currentCanvasContext = await myCanvas.CreateCanvas2DAsync();
            await _currentCanvasContext.ClearRectAsync(0, 0, 1920, 1080);
        }
        await _currentCanvasContext.SetFillStyleAsync(command.Color);
        await _currentCanvasContext.FillRectAsync(command.X, command.Y, command.PointSize, command.PointSize);
    }

    public async void HandleMouse(MouseEventArgs eventArgs)
    {
        double mouseX = 0, mouseY = 0;

        if (eventArgs.Buttons == 0 || eventArgs.Buttons > 2)
            return; // Rien faire si aucun bouton est appuyé ou si les deux boutons/ d'autres boutons sont appuyés.

        if (divCanvas.Id?.Length > 0)
        {
            string data = await _jsRuntime.InvokeAsync<string>("getDivCanvasOffsets",
                new object[] { divCanvas });
            string color = "White";
            CanvasCommand command = new();
            JObject? offsets = (JObject?)JsonConvert.DeserializeObject(data);

            if (offsets is not null && offsets.HasValues)
            { // Translation entre le canvas et la souris.
                mouseX = eventArgs.PageX - offsets.Value<double>("offsetLeft");
                mouseY = eventArgs.PageY - offsets.Value<double>("offsetTop");
            }

            if (eventArgs.Buttons == 1) // Couleur si bouton gauche, blanc si bouton droit
                color = currentColor;

            if (snap)
            { // Magnétisme boboche.
                mouseX -= mouseX % pointSize;
                mouseY -= mouseY % pointSize;
            }

            command.X = mouseX;
            command.Y = mouseY;
            command.Color = color;
            command.PointSize = pointSize;

            if (command.Equals(_lastCommand))
                return; // Pour pas spammer des commandes si c'est pas pertinent.

            // TODO: Shipper les commandes à Franz.

            Draw(command);

            _lastCommand = command;
        }
    }
}