#!/usr/bin/python3

"""Web page to show upcoming events."""

import decimal
import inspect
import operator
import os.path
import sys
import traceback
from datetime import date, datetime, timedelta

import flask
import UniAuth.auth
import werkzeug
import werkzeug.debug.tbtools
import yaml

import agenda.data
import agenda.error_mail
import agenda.fx
import agenda.holidays
import agenda.thespacedevs
import agenda.trip
from agenda import format_list_with_ampersand, travel, uk_tz
from agenda.types import Trip

app = flask.Flask(__name__)
app.debug = False
app.config.from_object("config.default")

agenda.error_mail.setup_error_mail(app)


@app.before_request
def handle_auth() -> None:
    """Handle autentication and set global user."""
    flask.g.user = UniAuth.auth.get_current_user()


@app.errorhandler(werkzeug.exceptions.InternalServerError)
def exception_handler(e: werkzeug.exceptions.InternalServerError) -> tuple[str, int]:
    """Handle exception."""
    exec_type, exc_value, current_traceback = sys.exc_info()
    assert exc_value
    tb = werkzeug.debug.tbtools.DebugTraceback(exc_value)

    summary = tb.render_traceback_html(include_title=False)
    exc_lines = "".join(tb._te.format_exception_only())

    last_frame = list(traceback.walk_tb(current_traceback))[-1][0]
    last_frame_args = inspect.getargs(last_frame.f_code)

    return (
        flask.render_template(
            "show_error.html",
            plaintext=tb.render_traceback_text(),
            exception=exc_lines,
            exception_type=tb._te.exc_type.__name__,
            summary=summary,
            last_frame=last_frame,
            last_frame_args=last_frame_args,
        ),
        500,
    )


@app.route("/")
async def index() -> str:
    """Index page."""
    now = datetime.now()
    data = await agenda.data.get_data(now, app.config)

    return flask.render_template("index.html", today=now.date(), **data)


@app.route("/launches")
def launch_list() -> str:
    """Web page showing List of space launches."""
    now = datetime.now()
    data_dir = app.config["DATA_DIR"]
    rocket_dir = os.path.join(data_dir, "thespacedevs")
    rockets = agenda.thespacedevs.get_launches(rocket_dir, limit=100)

    return flask.render_template(
        "launches.html", rockets=rockets, now=now, get_country=agenda.get_country
    )


@app.route("/gaps")
async def gaps_page() -> str:
    """List of available gaps."""
    now = datetime.now()
    trip_list = agenda.trip.build_trip_list()
    busy_events = agenda.data.get_busy_events(now.date(), app.config, trip_list)
    gaps = agenda.data.find_gaps(busy_events)
    return flask.render_template("gaps.html", today=now.date(), gaps=gaps)


@app.route("/weekends")
async def weekends() -> str:
    """List of available gaps."""
    now = datetime.now()
    trip_list = agenda.trip.build_trip_list()
    busy_events = agenda.data.get_busy_events(now.date(), app.config, trip_list)
    weekends = agenda.data.weekends(busy_events)
    return flask.render_template("weekends.html", today=now.date(), items=weekends)


@app.route("/travel")
def travel_list() -> str:
    """Page showing a list of upcoming travel."""
    data_dir = app.config["PERSONAL_DATA"]
    flights = agenda.trip.load_flights(data_dir)
    trains = [
        item
        for item in travel.parse_yaml("trains", data_dir)
        if isinstance(item["depart"], datetime)
    ]

    route_distances = agenda.travel.load_route_distances(app.config["DATA_DIR"])

    for train in trains:
        for leg in train["legs"]:
            agenda.travel.add_leg_route_distance(leg, route_distances)

        if all("distance" in leg for leg in train["legs"]):
            train["distance"] = sum(leg["distance"] for leg in train["legs"])

    return flask.render_template(
        "travel.html",
        flights=flights,
        trains=trains,
        fx_rate=agenda.fx.get_rates(app.config),
    )


def as_date(d: date | datetime) -> date:
    """Date of event."""
    return d.date() if isinstance(d, datetime) else d


@app.route("/conference")
def conference_list() -> str:
    """Page showing a list of conferences."""
    data_dir = app.config["PERSONAL_DATA"]
    filepath = os.path.join(data_dir, "conferences.yaml")
    items = yaml.safe_load(open(filepath))
    today = date.today()

    conference_trip_lookup = {}
    for trip in agenda.trip.build_trip_list():
        for trip_conf in trip.conferences:
            key = (trip_conf["start"], trip_conf["name"])
            conference_trip_lookup[key] = trip

    for conf in items:
        conf["start_date"] = as_date(conf["start"])
        conf["end_date"] = as_date(conf["end"])

        price = conf.get("price")
        if price:
            conf["price"] = decimal.Decimal(price)

        key = (conf["start"], conf["name"])
        if this_trip := conference_trip_lookup.get(key):
            conf["linked_trip"] = this_trip

    items.sort(key=operator.itemgetter("start_date"))

    past = [conf for conf in items if conf["end_date"] < today]
    current = [
        conf
        for conf in items
        if conf["start_date"] <= today and conf["end_date"] >= today
    ]
    future = [conf for conf in items if conf["start_date"] > today]

    return flask.render_template(
        "conference_list.html",
        current=current,
        past=past,
        future=future,
        today=today,
        get_country=agenda.get_country,
        fx_rate=agenda.fx.get_rates(app.config),
    )


@app.route("/accommodation")
def accommodation_list() -> str:
    """Page showing a list of past, present and future accommodation."""
    data_dir = app.config["PERSONAL_DATA"]
    items = travel.parse_yaml("accommodation", data_dir)

    stays_in_2024 = [item for item in items if item["from"].year == 2024]
    total_nights_2024 = sum(
        (stay["to"].date() - stay["from"].date()).days for stay in stays_in_2024
    )

    nights_abroad_2024 = sum(
        (stay["to"].date() - stay["from"].date()).days
        for stay in stays_in_2024
        if stay["country"] != "gb"
    )

    trip_lookup = {}

    for trip in agenda.trip.build_trip_list():
        for trip_stay in trip.accommodation:
            key = (trip_stay["from"], trip_stay["name"])
            trip_lookup[key] = trip

    for item in items:
        key = (item["from"], item["name"])
        if this_trip := trip_lookup.get(key):
            item["linked_trip"] = this_trip

    now = uk_tz.localize(datetime.now())

    past = [conf for conf in items if conf["to"] < now]
    current = [conf for conf in items if conf["from"] <= now and conf["to"] >= now]
    future = [conf for conf in items if conf["from"] > now]

    return flask.render_template(
        "accommodation.html",
        past=past,
        current=current,
        future=future,
        total_nights_2024=total_nights_2024,
        nights_abroad_2024=nights_abroad_2024,
        get_country=agenda.get_country,
        fx_rate=agenda.fx.get_rates(app.config),
    )


def get_trip_list(
    route_distances: agenda.travel.RouteDistances | None = None,
) -> list[Trip]:
    """Get list of trips respecting current authentication status."""
    return [
        trip
        for trip in agenda.trip.build_trip_list(route_distances=route_distances)
        if flask.g.user.is_authenticated or not trip.private
    ]


@app.route("/trip")
def trip_list() -> str:
    """Page showing a list of trips."""
    route_distances = agenda.travel.load_route_distances(app.config["DATA_DIR"])
    trip_list = get_trip_list(route_distances)
    today = date.today()

    current = [
        item
        for item in trip_list
        if item.start <= today and (item.end or item.start) >= today
    ]

    past = [item for item in trip_list if (item.end or item.start) < today]
    future = [item for item in trip_list if item.start > today]

    future_coordinates, future_routes = agenda.trip.get_coordinates_and_routes(future)
    past_coordinates, past_routes = agenda.trip.get_coordinates_and_routes(past)

    return flask.render_template(
        "trip_list.html",
        current=current,
        past=past,
        future=future,
        future_coordinates=future_coordinates,
        future_routes=future_routes,
        past_coordinates=past_coordinates,
        past_routes=past_routes,
        today=today,
        get_country=agenda.get_country,
        format_list_with_ampersand=format_list_with_ampersand,
        fx_rate=agenda.fx.get_rates(app.config),
    )


@app.route("/trip/text")
def trip_list_text() -> str:
    """Page showing a list of trips."""
    trip_list = get_trip_list()
    today = date.today()
    future = [item for item in trip_list if item.start > today]

    return flask.render_template(
        "trip_list_text.html",
        future=future,
        today=today,
        get_country=agenda.get_country,
        format_list_with_ampersand=format_list_with_ampersand,
    )


def human_readable_delta(future_date: date) -> str | None:
    """
    Calculate the human-readable time delta for a given future date.

    Args:
    future_date (date): The future date as a datetime.date object.

    Returns:
    str: Human-readable time delta.
    """
    # Ensure the input is a future date
    if future_date <= date.today():
        return None

    # Calculate the delta
    delta = future_date - date.today()

    # Convert delta to a more human-readable format
    months, days = divmod(delta.days, 30)
    weeks, days = divmod(days, 7)

    # Formatting the output
    parts = []
    if months > 0:
        parts.append(f"{months} months")
    if weeks > 0:
        parts.append(f"{weeks} weeks")
    if days > 0:
        parts.append(f"{days} days")

    return " ".join(parts) if parts else None


def get_prev_current_and_next_trip(
    start: str, trip_list: list[Trip]
) -> tuple[Trip | None, Trip | None, Trip | None]:
    """Get previous trip, this trip and next trip."""
    trip_iter = iter(trip_list)
    prev_trip = None
    for trip in trip_iter:
        if trip.start.isoformat() == start:
            break
        prev_trip = trip
    next_trip = next(trip_iter, None)

    return (prev_trip, trip, next_trip)


@app.route("/trip/<start>")
def trip_page(start: str) -> str:
    """Individual trip page."""
    route_distances = agenda.travel.load_route_distances(app.config["DATA_DIR"])
    trip_list = get_trip_list(route_distances)

    prev_trip, trip, next_trip = get_prev_current_and_next_trip(start, trip_list)
    if not trip:
        flask.abort(404)

    today = date.today()

    coordinates = agenda.trip.collect_trip_coordinates(trip)
    routes = agenda.trip.get_trip_routes(trip)

    agenda.trip.add_coordinates_for_unbooked_flights(routes, coordinates)

    for route in routes:
        if "geojson_filename" in route:
            route["geojson"] = agenda.trip.read_geojson(
                app.config["PERSONAL_DATA"], route.pop("geojson_filename")
            )

    if trip.end:
        countries = {c.alpha_2 for c in trip.countries}
        holidays = [
            hol
            for hol in agenda.holidays.get_all(
                trip.start, trip.end, app.config["DATA_DIR"]
            )
            if hol.country.upper() in countries
        ]
        holidays.sort(key=lambda item: (item.date, item.country))
    else:
        holidays = []

    return flask.render_template(
        "trip_page.html",
        trip=trip,
        prev_trip=prev_trip,
        next_trip=next_trip,
        today=today,
        coordinates=coordinates,
        routes=routes,
        get_country=agenda.get_country,
        format_list_with_ampersand=format_list_with_ampersand,
        holidays=holidays,
        human_readable_delta=human_readable_delta,
    )


@app.route("/holidays")
def holiday_list() -> str:
    """List of holidays."""
    today = date.today()
    data_dir = app.config["DATA_DIR"]
    next_year = today + timedelta(days=1 * 365)
    items = agenda.holidays.get_all(today - timedelta(days=2), next_year, data_dir)

    items.sort(key=lambda item: (item.date, item.country))

    return flask.render_template(
        "holiday_list.html", items=items, get_country=agenda.get_country, today=today
    )


@app.route("/callback")
def auth_callback() -> tuple[str, int] | werkzeug.Response:
    """Process the authentication callback."""
    return UniAuth.auth.auth_callback()


@app.route("/login")
def login() -> werkzeug.Response:
    """Login."""
    next_url = flask.request.args["next"]
    return UniAuth.auth.redirect_to_login(next_url)


@app.route("/logout")
def logout() -> werkzeug.Response:
    """Logout."""
    return UniAuth.auth.redirect_to_logout(flask.request.args["next"])


if __name__ == "__main__":
    app.run(host="0.0.0.0")