"""
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
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 = "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)),
        ]),
        Window(height=1, char='-', style="bg:#9D1D75 fg:#FFFFFF"),
    ])

    layout = Layout(root_container, focused_element=inputBuffer)

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

        user_input = inputBuffer.text.replace("Haltestelle eingeben: ", "").strip()

        if user_input:
            app_state = "RESULTS"
            # 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]}")

        else:
            app_state = "MONITOR"

    @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()