import tkinter as tk
import math
import random

root=tk.Tk()
#root.attributes("-fullscreen", True)
root.bind('<Escape>', lambda _ : root.quit())

canvas = tk.Canvas(root)
canvas.pack(fill=tk.BOTH, expand=tk.YES)

CELL = 24
width = 0
height = 0

field = []

all_chars = set()
all_streams = set()

font = ("Consolas", 24, "bold")

colors = []
for i in range(0, 30):
    if i < 10:
        r = math.floor(255 * (10 - i) / 10)
        b = r
        g = 255
        colors.append("#" + format(r, '02x') + format(g, '02x') + format(b, '02x') )
    elif i <= 20:
        g = math.floor(255 * (20 - i) / 10)
        colors.append("#00" + format(g, '02x') + "00")
    else:
        colors.append("black")

class Char:
    def __init__(self, stream, column, row):
        self.column = column
        self.row = row
        self.parent = stream
        self.prev = None
        self.next = None

        self.time = 0
        self.tick = False

        self.id = canvas.create_text((CELL * self.column, CELL * self.row),
            text=chr(random.randint(0, 26) + ord('a')),
            font = font,
            fill=colors[0])

        all_chars.add(self)

    def upd(self):
        self.tick = self.tick + 1
        if self.tick < 3:
            return
        self.tick = 0
        self.time = self.time + 1
        if self.time >= 20:
            self.kill()
        else:
            canvas.itemconfig(self.id, fill=colors[self.time])
            if random.randint(0,20) == 0:
                canvas.itemconfig(self.id, text=chr(random.randint(0, 26) + ord('a')))

    def kill(self):
        field[self.column * height + self.row] = None
        self.parent.chars.remove(self)
        canvas.delete(self.id)
        all_chars.remove(self)

class Stream:
    def __init__(self, column, row):
        self.column = column
        self.row = row
        self.chars = set()
        self.ticks = 0
        self.grows = random.randint(2, 4)
        all_streams.add(self)

    def upd(self):
        self.ticks = self.ticks + 1
        if self.ticks < self.grows:
            return
        self.ticks = 0
        self.grow()

    def kill(self):
        all_streams.remove(self)

    def grow(self):
        if self.row >= height:
            if len(self.chars) == 0:
                self.kill()
            return

        old_char = field[self.column * height + self.row]
        if old_char:
            old_char.kill()

        char = Char(self, self.column, self.row)
        field[self.column * height + self.row] = char
        self.row = self.row + 1
        self.chars.add(char)


def add_stream():
    if random.randint(0,3) == 0:
        column = random.randint(0, width - 1)
        row = 0
        s = Stream(column, row)

def reset(evt):
    global width, height, field, all_chars, all_streams

    width = math.ceil(evt.width / CELL)
    height = math.ceil(evt.height / CELL)

    field = [None] * (width * height)
    all_chars = set()
    all_streams = set()

    canvas.delete("all")
    canvas.create_rectangle(0, 0, evt.width, evt.height, fill="black")

def upd():
    for stream in list(all_streams):
        stream.upd()
    for char in list(all_chars):
        char.upd()

    add_stream()

    root.after(math.ceil(1000 / 60.0), upd)

def main():
    canvas.bind("<Configure>", reset)
    root.after(math.ceil(1000 / 60.0), upd)
    root.mainloop()
    root.destroy()

import cProfile
cProfile.run('main()')