#!/usr/bin/python3
# coding: utf-8
import time
import shlex
import tkinter
from subprocess import Popen, PIPE

def Ausfuehren():
    if running.get() == True:
        print("Error: only one running command and once allowed!")
        status_label.configure(text="Error: another command is active!", fg="red")
        return
    command = option_choice.get()
    if eingabefeld.get() is not None:
        command = command + " " + eingabefeld.get()
    print("Befehl wird ausgefuehrt: %s" % command)
    running.set(True)
    status_label.configure(text="gestartet", fg="green")
    if run_command(command) != 0:
        status_label.configure(text="Fehler!", fg="red")
    else:
        status_label.configure(text="Beendet: "+str(option_choice.get()), fg="green")
    running.set(False)

def Beenden():
    print("Befehl wird beendet ...")
    status_label.configure(text="Beendet", fg="green")
    running.set(False)

def run_command(command):
    process = Popen(shlex.split(command), stdout=PIPE, stderr=PIPE, bufsize=1)
    for output in iter(process.stdout.readline, b''):
        Log.insert(tkinter.END, (output))
        print(output,)
    rc = process.poll()
    process.stdout.close()
    process.wait()
    print("\nDone")
    return rc


# TKinter Main Window
window = tkinter.Tk()
window.geometry("500x500+10+10")

status_label = tkinter.Label(master=window)
status_label.configure(text=" ", fg="red")
status_label.grid(row=0, column=0)

start_button = tkinter.Button(master=window, bg="#229", fg="white", text="Run", command=Ausfuehren)
stop_button = tkinter.Button(master=window, bg="#229", fg="white", text="Stop", command=Beenden)
exit_button   = tkinter.Button(master=window, bg="#229", fg="white", text="X", command=window.destroy)

running = tkinter.BooleanVar()
running.set(False)

choices = ['apt-get update', 'apt-get upgrade', 'apt-get install', 'ls -la']
option_choice = tkinter.StringVar(window)
options = tkinter.OptionMenu(window, option_choice, *choices)
options.grid(row=1, column=0)
eingabefeld = tkinter.Entry(master=window, width=20)
eingabefeld.grid(row=1, column=3)

start_button.grid(row=1, column=1)
stop_button.grid(row=1, column=2)
exit_button.grid(row=0, column=4)

ScrollLog = tkinter.Scrollbar(window)
Log = tkinter.Text(master=window, height=30, width=60)
Log.grid(row=2, column=0, columnspan=5)
ScrollLog.grid(row=2, column=5)
ScrollLog.configure(command=Log.yview)
Log.configure(yscrollcommand=ScrollLog.set)

try:
    window.mainloop()
except (KeyboardInterrupt, SystemExit):
    print("Schliesse Programm.")