#!/usr/bin/python3
# -*- coding: utf-8 -*-


import os, sys, termios, tty, time, random
from math import sin, cos, tan, sqrt
from time import sleep


# pi is not defined by default
pi = 3.1416
deg2rad = pi / 180


########################################################################################
def berechneflugbahn(xmax, ymax, steps, startwinkel, startgeschwindigkeit, xmin=0, ymin=0, starthoehe=0, gravitation=9.81, xstep=1):
    x = 0
    y = x**2

    # in scala the resulting coordinates will be returned
    scala = []

    startwinkel = startwinkel * deg2rad

    # Calculate time of flight, actually not used
    flugdauer = startgeschwindigkeit * sin(startwinkel) / gravitation
    # Calculate maximum height
    hoehe = 0.5 * gravitation * flugdauer**2 + starthoehe

    # calculate length of flight, actually not used
    wurfweite = (
        startgeschwindigkeit
        * cos(startwinkel)
        * (startgeschwindigkeit * sin(startwinkel) + sqrt(startgeschwindigkeit**2 * sin(startwinkel) ** 2 + 2 * gravitation * starthoehe))
    ) / gravitation

    first_run = True

    # cowlength is 2, if cow is an UTF8-Icon, otherwise 1
    for x in range(xmin, steps - 1, xstep):
        # the formula, which generates the y position for the corresponding x, shamelessly ripped from some schoolbook and modified.
        y = (-(gravitation / (2 * startgeschwindigkeit**2 * cos(startwinkel) ** 2)) * x**2) + (tan(startwinkel) * x + starthoehe)

        # Ensure, that nothing has to be drawn outside the viewport

        if x >= xmax:
            x = xmax

        if y >= ymax:
            y = ymax

        elif y <= ymin:
            y = ymin

        # Stash away the coordinates into scala, which will be returned
        scala += [x, int((y * 100 + 50) / 100)]

        if y == ymin and not first_run:
            break

        first_run = False

    return scala


#############################################################################################
# berechneflugbahn(cow, xmin, xmax, ymin, ymax, startwinkel, startgeschwindigkeit, starthoehe):

# some useful control
clear, home, curoff, curon = "'\x1b[2J\x1b[H", "\x1b[H", "\x1b[?25l", "\x1b[?25h"


g_erde = 9.81  # gravitation examples
mond = 1.6
jupiter = 24

# set position of cursor
def curpos(x, y):
    print("\033[%d;%dH" % (ymax - y, x), end="", flush=True)


if __name__ == "__main__":
    # Randomly choose a cow
    cows = "🐵🐒🦍🦧🐕🐯🦝🐩🐅🐴🐎🦄🦌🐗🐂🐃🐄🐪🐫🦙🦒🐹🦘🦡🐧🕊️ 🦅🦆🦉🐍🦎🐊🦜🦚🦩🐲🐉🦕"
    cowlistlength = len(cows)
    cow = cows[random.randint(0, cowlistlength - 1)]


    # Needed: find our screensize. We are in textmode here
    termsize_xy = os.get_terminal_size()

    ### I m p o r t a n t   p a r a m e t e r s ###

    # X-Resolution of the display
    xmax = termsize_xy[0] - 1
    xsteps = xmax * 2
    ymax = termsize_xy[1]
    ymin = 0
    xmin = 0
    startwinkel = 34
    startgeschwindigkeit = 60
    starthoehe = 0
    schlafzeit = 0.05
    ###

    # needed for erasing old position
    xold = xmin
    yold = ymin
    x = xmin
    y = xmin

    # Call the function, which calculates the coordinates)
    ergebnis = berechneflugbahn(xmax, ymax, xsteps, startwinkel, startgeschwindigkeit, starthoehe, gravitation=g_erde, xstep=2)
    print(curoff)
    # here we draw the cow
    for count in range(xmin, len(ergebnis), 2):
        xold, yold = x, y
        x, y = ergebnis[count], ergebnis[count + 1]
        curpos(x, y)
        print(cow, end="")
        sleep(schlafzeit)
        curpos(xold, yold)
        print("☁️ ", end="")

    sleep(2)


    sys.exit(home + curon)