using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Drawing;
using Engine;

namespace Collision
{
    class Level : State
    {
        public override void Create()
        {
            base.Create(); //call the base create function

            //create a new small ball and set its position
            GameObject sCircle = new SmallBall();
            sCircle.Position.X = -200;
            ObjectManager.AddGameObject(sCircle);

            //Create the large circle, set it to the right of the screen
            GameObject Rect2 = new GameObject("Rect2", 64, 128, "RectVertical.png");

            Rect2.Position.X = 200;

            ObjectManager.AddGameObject(Rect2);
        }

        bool CheckCircleCircleCollision(PointF c1Position, float c1Radius,
             PointF c2Position, float c2Radius)
        {
            //Calculate the squared sum of radius1 and radius2
            float radiiSquared = (c1Radius + c2Radius) * (c1Radius + c2Radius);
            //calculate the change in x by subtracting the x positions of the circles
            float deltaX = c1Position.X - c2Position.X;
            //calculate the change in y by subtracting the y positions of the circles
            float deltaY = c1Position.Y - c2Position.Y;
            //calculate the distance squared using pythagoreans theroem (x^2 + y^2 = c^2)
            float distanceSqaured = deltaX * deltaX + deltaY * deltaY;
            //If the distance squared is <= radii squared
            if (distanceSqaured <= radiiSquared)
            {
                //colliding, return true
                return true;
            }

            //otherwise, return false.
            return false;
        }

        bool CheckRectangleRectangleCollision(PointF r1Position, float r1HalfWidth, float r1HalfHeight,
             PointF r2Position, float r2HalfWidth, float r2HalfHeight)
        {
            //Left: Check if r1's right side is further left than r2's left side
            if (r1Position.X + r1HalfWidth < r2Position.X - r2HalfWidth)
            {
                //if it is, there can bo no collision, so return false.
                return false;
            }

            //Right: check if r1's left side is further right than r2's right side
            if (r1Position.X - r1HalfWidth > r2Position.X + r1HalfWidth)
            {
                //if it is, there can be no collision, so return false.
                return false;
            }

            //Bottom: Check if r1's top side is below r2's bottom side
            if (r1Position.Y + r1HalfHeight < r2Position.Y - r2HalfHeight)
            {
                //if it is, there can be no collision so return false.
                return false;
            }

            //Top: Check r1's bottom side is above r2's top side.
            if (r1Position.Y - r1HalfHeight > r2Position.Y + r2HalfHeight)
            {
                //if it is, there can be no collision so return false
                return false;
            }

            //if none of those conditions are true, return true, as anything left is a collision
            return true;
        }

        bool CheckPointCircleCollision(PointF pPos, PointF cPos, float cRadius)
        {
            //Calculate the squared radius.
            float radiusSquared = cRadius * cRadius;
            //subtract the X positions of the point and the circle
            float deltaX = cPos.X - pPos.X;
            //subtract the y positions of the point and circle
            float deltaY = cPos.Y - pPos.Y;
            //Calculate the squared distance
            float distanceSquared = deltaX * deltaX + deltaY * deltaY;
            //if the distance is less than the radius
            if (distanceSquared < radiusSquared)
            {
                //we are colliding
                return true;
            }

            //if we get here, then we are not collding.
            return false;
        }

        public override void Update()
        {
            base.Update();
            //float smallRadius = 32;
            //float largeRadius = 64;

            //half widths and heights of first rectangle
            float halfWidth1 = 64;
            float halfHeight1 = 32;
            //half widths and heights of second rectangle
            float halfWidth2 = 32;
            float halfHeight2 = 64;
            //bool to hold collision return
            bool collision = false;
            //find rect1 and rect2 and store them in my own variables
            GameObject Rect1 = ObjectManager.GetObjectByName("Rect1");
            GameObject Rect2 = ObjectManager.GetObjectByName("Rect2");

            //check for collision between circles
            //collision = CheckCircleCircleCollision(sCircle.Position, smallRadius, lCircle.Position, largeRadius);
            //check for collision between rectangles
            collision = CheckRectangleRectangleCollision(Rect1.Position, halfWidth1, halfHeight1, Rect2.Position, halfWidth2, halfHeight2);
            //check if collision is true or false
            if (collision)
            {
                //reset the position of the small circle
                Rect1.Position.X = -200;
                Rect1.Position.Y = 0;
            }
        }

    }
}