"""
haTerm - v0.1
(c) Chiara Wohlwend

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.
"""

import backend
from prompt_toolkit import Application
from prompt_toolkit.buffer import Buffer
from prompt_toolkit.layout.layout import Layout
from prompt_toolkit.layout.containers import Window, VSplit, HSplit
from prompt_toolkit.layout.controls import BufferControl
from prompt_toolkit.key_binding import KeyBindings
import threading


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()

    prefixBuffer = Buffer()
    prefixBuffer.text = "Haltestelle eingeben: "
    prefixBuffer.read_only = True
    
    userinputBuffer = Buffer()

    arrivalBuffer = Buffer()
    departureBuffer = Buffer()
    stop_event = threading.Event()
    app_state = "MONITOR"

    arrivalBuffer.text = "Ankünfte:\n"
    departureBuffer.text = "Abfahrten:\n"



    root_container = HSplit(children=[
        VSplit(children=[
            Window(content=BufferControl(buffer=prefixBuffer, focusable=False),width=22),
            Window(content=BufferControl(buffer=userinputBuffer, focusable=True)),
            Window(width=1, char='│', style="fg:#9D1D75"),

            HSplit(children=[
                Window(content=BufferControl(buffer=arrivalBuffer, focusable=True)),
                Window(height=1, char='-', style="fg:#9D1D75"),
                Window(content=BufferControl(buffer=departureBuffer, focusable=True)),
        ]),
        ]),
        Window(height=1, char='-', style="bg:#9D1D75 fg:#FFFFFF"),
    ])

    layout = Layout(root_container, focused_element=userinputBuffer)

    @keyB.add("enter")
    def handle_enter(event):
        global app_state

        user_input = userinputBuffer.text.strip()

        if not user_input:
            app_state = "MONITOR"
            return

        app_state = "RESULTS"
        results = hafas.getStationNames(user_input)

        if not results:
            arrivalBuffer.text = f"Keine Stationen gefunden für: {user_input}"
            departureBuffer.text = ""
            userinputBuffer.text = ""
            app_state = "MONITOR"
            return

        station_name = results[0][0]
        station_id = results[0][1]

        arrivals = hafas.getArrDep(station_id, arrdep="ARR", count=5)
        arrivalBuffer.text = (
            f"Ankünfte für {station_name}:\n"
            + "\n".join(f"  {arrival["departure_time_real"]} {arrival["line"]} <-- {arrival["name"]}" for arrival in arrivals)
        )

        departures = hafas.getArrDep(station_id, arrdep="DEP", count=5)
        departureBuffer.text = (
            f"Abfahrten für {station_name}:\n"
            + "\n".join(f"  {departure["departure_time_real"]} {departure["line"]} --> {departure["name"]}"  for departure in departures)
        )

        userinputBuffer.text = ""
                

    @keyB.add("c-q")
    def exit_(event):
        stop_event.set()
        event.app.exit()

    app = Application(layout=layout, full_screen=True, key_bindings=keyB)

    try:
        app.run()
    except KeyboardInterrupt:
        pass
    finally:
        stop_event.set()