added basic connection between the files, fixed small issues. some parts were achieved using ai.

backend.py

@@ -13,7 +13,7 @@ from datetime import datetime
 from prompt_toolkit import Application
 from prompt_toolkit.completion import WordCompleter
 
-class hafasClient:
+class HafasClient:
     def __init__(self):
         self.session = requests.session()
         self.clientInfo = {"id": "VAO", "name": "webapp", "type": "WEB"}
@@ -90,5 +90,5 @@ class hafasClient:
 
 
 if __name__ == '__main__':
-    client = hafasClient()
+    client = HafasClient()
     client.runTests()

main.py

@@ -6,3 +6,90 @@ haTerm is a Terminal Based hafas client, using the ivb endpoint.
 Prompt_toolkit (https://github.com/prompt-toolkit/python-prompt-toolkit) will be used to render a terminal user interface (TUI).
 The application will provide routing information and station departures/arrivals.
 """
+
+from backend import HafasClient
+import route_planning
+import station_monitor
+
+from prompt_toolkit import Application
+from prompt_toolkit.layout import Layout, HSplit, VSplit, Window
+from prompt_toolkit.widgets import Button, Box
+from prompt_toolkit.key_binding import KeyBindings
+
+
+def pk_menu(client: HafasClient):
+	"""Display a centered menu with two buttons selectable by arrow keys.
+
+	The function runs a full-screen prompt_toolkit application. Left/right
+	arrows move focus between the buttons; Enter activates the focused
+	button. The function returns the chosen mode as a string or None when
+	the user quits.
+	"""
+	choice = {'value': None}
+
+	def on_rp():
+		choice['value'] = 'rp'
+		app.exit()
+
+	def on_sm():
+		choice['value'] = 'sm'
+		app.exit()
+
+	btn_rp = Button("Route Planning", handler=on_rp, width=20)
+	btn_sm = Button("Station Monitor", handler=on_sm, width=20)
+
+	buttons = [btn_rp, btn_sm]
+	index = {'i': 0}
+
+	kb = KeyBindings()
+
+	def focus_current():
+		app.layout.focus(buttons[index['i']])
+
+	@kb.add('left')
+	def _left(event):
+		index['i'] = max(0, index['i'] - 1)
+		focus_current()
+
+	@kb.add('right')
+	def _right(event):
+		index['i'] = min(len(buttons) - 1, index['i'] + 1)
+		focus_current()
+
+	@kb.add('q')
+	@kb.add('c-q')
+	@kb.add('c-c')
+	def _quit(event):
+		app.exit()
+
+	root = HSplit(children=[
+		Window(),
+		Box(VSplit(children=[
+			Window(),
+			Box(VSplit(children=buttons, padding=6), padding=2, style="bg:#2A71D5 fg:#FFFFFF"),
+			Window()
+        ])),
+        Window()
+	], align='CENTER')
+
+	app = Application(layout=Layout(root, focused_element=btn_rp), key_bindings=kb, full_screen=True)
+	app.run()
+	return choice['value']
+
+
+def main():
+	client = HafasClient()
+
+	while True:
+		result = pk_menu(client)
+		if result == 'rp':
+			route_planning.run_route_planning(client)
+		elif result == 'sm':
+			station_monitor.run_station_monitor(client)
+		else:
+			print("Exiting.")
+			break
+
+
+if __name__ == '__main__':
+	main()

route_planning.py

@@ -5,10 +5,16 @@ haTerm - v0.1
 haTerm is a Terminal Based hafas client, using the ivb endpoint.
 Prompt_toolkit (https://github.com/prompt-toolkit/python-prompt-toolkit) will be used to render a terminal user interface (TUI).
 The application will provide routing information and station departures/arrivals.
-"""
-#routenplanung mit promt tool kit
 
-import prompt_toolkit as pk
+Route planning UI.
+
+Wrapped in a function so it can be launched from `main.py` with a shared
+`HafasClient` instance from `backend.py`.
+
+Note: This module is a minimal TUI stub. Many features are not implemented
+yet (station lookup, route rendering). Add TODOs where appropriate.
+"""
+
 import time
 from prompt_toolkit import Application
 from prompt_toolkit.buffer import Buffer
@@ -17,25 +23,39 @@ from prompt_toolkit.layout.controls import BufferControl
 from prompt_toolkit.layout.layout import Layout
 from prompt_toolkit.key_binding import KeyBindings
 
+import backend
+
+
+def run_route_planning(hafas: backend.HafasClient | None = None):
+    """Run the route planning TUI.
+
+    Parameters:
+    - hafas: optional shared HafasClient instance. If omitted, a new one is
+      created. Prefer passing the shared client from `main.py`.
+    """
+    if hafas is None:
+        hafas = backend.HafasClient()
+
+    # TODO: integrate actual station search + routing using `hafas`.
     kb = KeyBindings()
     startBuffer = Buffer()
     endBuffer = Buffer()
 
-
     root_container = HSplit(children=[
         HSplit(children=[
             Window(content=BufferControl(buffer=startBuffer, focusable=True)),
             Window(width=1, char='-', style="fg:#2A71D5"),
-
             Window(content=BufferControl(buffer=endBuffer, focusable=True))
         ]),
         Window(height=1, char=' ', style="bg:#2A71D5 fg:black"),
-    #Window(content=BufferControl(buffer=userBuffer),height=4),
     ])
 
     layout = Layout(root_container)
-
     app = Application(layout=layout, key_bindings=kb, full_screen=True)
 
+    try:
         app.run()
+    except KeyboardInterrupt:
+        # graceful exit on Ctrl-C
+        return
 

station_monitor.py

@@ -7,6 +7,7 @@ Prompt_toolkit (https://github.com/prompt-toolkit/python-prompt-toolkit) will be
 The application will provide routing information and station departures/arrivals.
 """
 
+import backend
 from prompt_toolkit import Application
 from prompt_toolkit.buffer import Buffer
 from prompt_toolkit.layout.layout import Layout
@@ -17,22 +18,31 @@ import threading
 import time
 
 
+def run_station_monitor(hafas: backend.HafasClient | None = None):
+    """Run the station monitor TUI.
+
+    Parameters:
+    - hafas: optional shared HafasClient instance. If omitted, a new one is
+      created. Prefer passing the shared client from `main.py`.
+
+    Note: Some parts of this monitor are incomplete; see TODO markers.
+    """
+    if hafas is None:
+        hafas = backend.HafasClient()
+
     keyB = KeyBindings()
     inputBuffer = Buffer()
     resultBuffer = Buffer()
     stop_event = threading.Event()
     app_state = "MONITOR"
 
-inputBuffer.text = "Monitor\n\nHaltestelle eingeben: "
+    inputBuffer.text = "Haltestelle eingeben: "
     inputBuffer.cursor_position = len(inputBuffer.text)
-
     resultBuffer.text = "Ausgabe: "
 
-
     root_container = HSplit(children=[
         VSplit(children=[
             Window(content=BufferControl(buffer=inputBuffer, focusable=True)),
-        
             Window(width=1, char='│', style="fg:#9D1D75"),
             Window(content=BufferControl(buffer=resultBuffer, focusable=True)),
         ]),
@@ -49,16 +59,20 @@ def handle_enter(event):
 
         if user_input:
             app_state = "RESULTS"
-        resultBuffer.text = f"Ergebnisse für: {user_input}\n\n"
+            # TODO: handle case of no results gracefully
+            results = hafas.getStationNames(user_input)
+            inputBuffer.insert_line_below()
+            for station in results:
+                inputBuffer.insert_text(f"\n  {station[0]}")
+            resultBuffer.text = f"Ergebnisse für: {results[0][1]}\n\n"
+            station = results[0][1] if results else "Keine Ergebnisse gefunden."
+            result = hafas.getArrDep(station, arrdep="ARR", count=3)
+            inputBuffer.insert_line_below()
+            for entry in result:
+                resultBuffer.insert_text(f"\n  {result[0]}")
 
-        inputBuffer.text = "Haltestelle eingeben: "
-        inputBuffer.cursor_position = len(inputBuffer.text)
         else:
             app_state = "MONITOR"
-        resultBuffer.text = "MONITOR\n\n"
-
-        inputBuffer.text = "Haltestelle eingeben: "
-        inputBuffer.cursor_position = len(inputBuffer.text)
 
     @keyB.add("c-q")
     def exit_(event):