using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using GDIDrawer;
using System.Threading;
using System.Drawing;

namespace CNT1300TravisRalstonAssignment12
{
    class ProjectileMotion
    {

        static CDrawer screen = new CDrawer();
        static Random rand = new Random();
        static double gravity = 9.81;

        static void Main(string[] args)
        {
            bool stopped = false;
            double velocity = 75.0;
            int radius = 5;
            double degrees = 60;
            double radians = ToRadians(degrees);
            double touchGroundLoss = 0.05;
            double bouncePercRetain = 0.9;
            int tickTime = 10; // Milliseconds
            int timePerTick = 50; // Milliseconds

            int time = 1;
            double Vx = 0, Vy = 0, Vo = velocity;

            Color color = RandomColor();
            int iterations = 0;

            double tan = Math.Tan(radians);
            double g = gravity/(2*Vo*Vo*CosSquared(radians));
            int x = 0;
            int displayX = 0;
            int xShift = 0;
            int lastX = 0;
            bool reverse = false;
            while (!stopped)
            {
                // Anti-OHGODWHY
                iterations++;
                if (iterations > 1100)
                {
                    break;
                }

                // Math
                displayX = reverse ? --lastX:++lastX;
                x++;
                int xCalc = x - xShift;
                Vx = Vo * Math.Cos(radians);
                Vy = (Vo * Math.Sin(radians)) - (gravity * time);

                // New Math
                int y = (int)((tan * xCalc) - (g * xCalc * xCalc));

                Console.WriteLine("({0}, {1}) Vx={2}  Vy={3}  Vo={4}  Xcalc={5}", x, y, Vx, Vy, Vo, xCalc);

                // Corrections
                y = screen.m_ciHeight - y;

                // Physics
                bool bounced = false;
                if (y >= screen.m_ciHeight)
                {
                    bounced = true;
                    Vy = Vy * bouncePercRetain;
                    xShift = x;
                }
                if (y == screen.m_ciHeight)
                {
                    bounced = true;
                    Vx -= touchGroundLoss;
                }
                if (displayX > screen.m_ciWidth || displayX < 0)
                {
                    reverse = !reverse;
                    color = RandomColor();
                }

                // Recalc Vo
                if (bounced)
                {
                    Vo = Math.Sqrt((Vy * Vy) + (Vx * Vx));
                    g = gravity / (2 * Vo * Vo * CosSquared(radians));
                }

                // Draw
                screen.AddCenteredEllipse(displayX, y, radius * 2, radius * 2, color);

                // Misc
                stopped = IsStopped(Vx, Vy, y, time);
                time += timePerTick;
                Thread.Sleep(tickTime);
            }
            Console.ReadKey(); // TODO: Remove if needed
        }

        static double CosSquared(double radians)
        {
            double cosine = Math.Cos(radians);
            return cosine * cosine;
        }

        static double SinSquared(double radians)
        {
            double sine = Math.Sin(radians);
            return sine * sine;
        }

        static double ToRadians(double degrees)
        {
            return Math.PI * degrees / 180.0;
        }

        static bool IsStopped(double horizontalVelocity, double verticalVelocity, int yPosition, int time)
        {
            if (yPosition >= screen.m_ciHeight - 1 && time != 0)
            {
                double roundedHV = Math.Round(horizontalVelocity, 1);
                double roundedVV = Math.Round(verticalVelocity, 0);
                if (roundedHV == 0.0 && roundedVV == 0.0)
                {
                    return true;
                }
            }
            return false;
        }

        static Color RandomColor()
        {
            int r = rand.Next(0, 256);
            int g = rand.Next(0, 256);
            int b = rand.Next(0, 256);
            return Color.FromArgb(r, g, b);
        }
    }
}