import curses
import os
import random

def  main(bildschirm):
    bildschirm.clear()
    maxY, maxX = bildschirm.getmaxyx()
    bildschirm.addstr(1, 0, f"({maxY}, {maxX})")

    curses.mousemask(curses.BUTTON1_CLICKED)
    for y in range(maxY):
        for x in range(maxX):
            try:
                bildschirm.addstr(y, x, " ")
            except curses.error as e:
                pass

    xPos = maxX // 2
    yPos = maxY // 2

    while True:
        bildschirm.addstr(0, 0, f"({yPos}, {xPos})")

        zeichen = chr(bildschirm.inch(yPos, xPos) & 0xFF) 
        if zeichen == " ":
            neu = "A"
        elif zeichen == "Z":
            neu = "A"
        else: 
            neu = chr(ord(zeichen) + 1)

        try:
            bildschirm.addstr(yPos, xPos, neu)
        except curses.error as e:
            pass
        bildschirm.move(yPos, xPos)

        taste = bildschirm.getch()
        bildschirm.addstr(1, 0, str(taste))

        if taste == curses.KEY_UP:
            if yPos > 0:
                yPos = yPos - 1
        elif taste == curses.KEY_DOWN:
            if yPos + 1 < maxY:
                yPos = yPos + 1
        elif taste == curses.KEY_LEFT:
            xPos = max(xPos - 1, 0)
        elif taste == curses.KEY_RIGHT:
            xPos = min(xPos + 1, maxX - 1)
        elif taste == curses.KEY_MOUSE: 
            mausID, mausX, mausY, mausZ, drueckZustand = curses.getmouse()
            if 0 <= mausX < maxX and 0 <= mausY < maxY:
                xPos = mausX
                yPos = mausY
        elif taste == 27: 
            break

# https://stackoverflow.com/questions/27372068/why-does-the-escape-key-have-a-delay-in-python-curses  
os.environ.setdefault('ESCDELAY', '25')

curses.wrapper(main)