# tk_Elastic_Collision.py

# tk_Elastic_Collision.py ZZZ the deflection is often not mirroring properly

from tkinter import *
import math
import random

window = Tk()
window.title("Elastic Collision")
canvas = Canvas(window, width=500, height=500)
canvas.pack()

circles = []
colors = ['red', 'blue', 'green', 'yellow', 'purple']
diameters = [47, 99, 149, 180, 299]
for i in range(5):
    x = random.randint(0, 500)
    y = random.randint(0, 500)
    vx = random.randint(-5, 5)
    vy = random.randint(-5, 5)
    circles.append([x, y, vx, vy, diameters[i] / 2, colors[i]])

def update():
    for i in range(len(circles)):
        for j in range(i+1, len(circles)):
            # Calculate distance between centers of circles
            dx = circles[i][0] - circles[j][0]
            dy = circles[i][1] - circles[j][1]
            distance = (dx**2 + dy**2)**0.5

            # Calculate overlap between circles
            if distance < circles[i][4] + circles[j][4]:
                # Calculate the angle of the collision
                angle = math.atan2(dy, dx)

                # Calculate the mass ratio of the two circles
                m1 = circles[i][4]**2
                m2 = circles[j][4]**2
                mass_ratio = m2 / (m1 + m2)

                # Calculate the initial velocity of the two circles
                u1 = (circles[i][2] * math.cos(angle)) + (circles[i][3] * math.sin(angle))
                u2 = (circles[j][2] * math.cos(angle)) + (circles[j][3] * math.sin(angle))

                # Calculate the final velocities of the two circles after the collision
                v1 = (u1 * (m1 - m2) + 2 * m2 * u2) / (m1 + m2)
                v2 = (u2 * (m2 - m1) + 2 * m1 * u1) / (m1 + m2)

                # Update the velocities of the two circles
                circles[i][2] = (v1 * math.cos(angle)) - (circles[i][3] * math.sin(angle))
                circles[i][3] = (v1 * math.sin(angle)) + (circles[i][3] * math.cos(angle))
                circles[j][2] = (v2 * math.cos(angle)) - (circles[j][3] * math.sin(angle))
                circles[j][3] = (v2 * math.sin(angle)) + (circles[j][3] * math.cos(angle))

                # Update the positions of the two circles to prevent overlap
                overlap = (circles[i][4] + circles[j][4]) - distance
                circles[i][0] += overlap * math.cos(angle)
                circles[i][1] += overlap * math.sin(angle)
                circles[j][0] -= overlap * math.cos(angle)
                circles[j][1] -= overlap * math.sin(angle)

    # Update position of circles using their velocities
    for circle in circles:
        circle[0] += circle[2]
        circle[1] += circle[3]
        # Check if circle has reached the edge of the canvas and reverse its velocity if necessary
        if circle[0] <= circle[4]:
            circle[2] *= -1
            circle[0] = circle[4]
        elif circle[0] >= 500 - circle[4]:
            circle[2] *= -1
            circle[0] = 500 - circle[4]
        if circle[1] <= circle[4]:
            circle[3] *= -1
            circle[1] = circle[4]
        elif circle[1] >= 500 - circle[4]:
            circle[3] *= -1
            circle[1] = 500 - circle[4]

while True:
    # Clear the canvas
    canvas.delete("all")

    # Draw circles and update their positions
    for circle in circles:
        canvas.create_oval(circle[0] - circle[4], circle[1] - circle[4], circle[0] + circle[4], circle[1] + circle[4], fill=circle[5])

    # Check for and handle collisions
    update()

    # Refresh the window
    window.update()

    # Pause for a short amount of time
    window.after(20)

window.mainloop()