"""
haTerm - v0.1
(c) Kieler Mia, Chiara Wohlwend, Sophia Schmidhofer

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()