using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.Diagnostics;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Timers;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows.Shapes;

namespace Signal_Generator
{
    public class DrawTask : Task, INotifyPropertyChanged
    {
        Canvas canvas;
        MultiSignal multiSignal;
        ProcedureModel procedureModel;

        private State _state;
        public State state
        {
            get { return _state; }
            set
            {
                _state = value;
                PropertyChanged?.Invoke(this, new PropertyChangedEventArgs("state"));
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;

        public enum State
        {
            Created, Running, Paused, Finished, Canceled
        }

        public DrawTask(Action a) : base(a) { }

        public void buildTask(ProcedureModel pm, Canvas c)
        {
            canvas = c;
            procedureModel = pm;
            multiSignal = MultiSignal.getInstance();
            state = State.Running;

            drawSignalAtCanvas();
        }

        private void drawSignalAtCanvas()
        {
            double lastX = 0, lastY = 0;
            double W = canvas.ActualWidth;
            double dX = (procedureModel.Duration / 1000) / W;
            for (int X = 0; X != (int)W; X++)
            {
                double Y = multiSignal.currentAmplitude(X * dX);
                updateTextBoxProps(Y, X * dX * 1000);
                drawLine(lastX, lastY, X, Y);
                lastX = X;
                lastY = Y;
                if (taskSemaphore() == false) return;
            }
            state = State.Finished;
        }

        private bool taskSemaphore()
        {
            Thread.Sleep(10);
            switch (state)
            {
                case State.Paused:
                    while (state == State.Paused)
                        Thread.Sleep(50);
                    break;
                case State.Canceled: return false;
            }
            return true;
        }

        private void updateTextBoxProps(double amp, double time)
        {
            amp = Math.Round(amp, 2);
            time = Math.Round(time, 2);
            procedureModel.CurrentAmplitude = amp.ToString();
            procedureModel.CurrentTime = time.ToString();
        }

        private void drawLine(double x1, double y1, double x2, double y2)
        {
            Action a = () => {
                Line l = new Line();
                l.StrokeThickness = 1;
                l.Stroke = Brushes.Red;
                l.X1 = x1;
                l.Y1 = remapOY(y1, 100, canvas.ActualHeight);
                l.X2 = x2;
                l.Y2 = remapOY(y2, 100, canvas.ActualHeight);
                canvas.Children.Add(l);
            };
            canvas.Dispatcher.Invoke(a);
        }

        private double remapOY(double x, double amp = 100.0, double height = 100.0)
        {
            return height + (x + amp) * (-height) / (2 * amp);
        }
    }
}