brittany-ferries/main.py

#!/usr/bin/python3
"""Check prices of ferries to France."""

import collections
import inspect
import json
import os
import os.path
import re
import sys
import traceback
from datetime import date, datetime, timedelta
from typing import Any

import dateutil.parser
import flask
import pytz
import werkzeug
from werkzeug.debug.tbtools import DebugTraceback
from werkzeug.wrappers import Response

import ferry
from ferry.api import get_accommodations, get_prices
from ferry.read_config import ferry_config, vehicle_from_config

app = flask.Flask(__name__)
app.debug = True

routes = {
    "outbound": [
        ("PORTSMOUTH", "CAEN"),
        ("PORTSMOUTH", "CHERBOURG"),
        ("PORTSMOUTH", "ST MALO"),
        ("PORTSMOUTH", "LE HAVRE"),
        ("POOLE", "CHERBOURG"),
        ("PLYMOUTH", "ROSCOFF"),
    ],
    "return": [
        ("CAEN", "PORTSMOUTH"),
        ("CHERBOURG", "PORTSMOUTH"),
        ("ST MALO", "PORTSMOUTH"),
        ("LE HAVRE", "PORTSMOUTH"),
        ("CHERBOURG", "POOLE"),
        ("ROSCOFF", "PLYMOUTH"),
    ],
}


def cache_location() -> str:
    """Cache location for the current user."""
    return os.path.expanduser(ferry_config.get("cache", "location"))


def cache_filename(params: str) -> str:
    """Get a filename to use for caching."""
    now_str = datetime.utcnow().strftime("%Y-%m-%d_%H%M")
    params = params.replace(":", "_").replace(".", "_")

    return os.path.join(cache_location(), now_str + "_" + params + ".json")


def time_to_minutes(t: str) -> int:
    """Convert time (22:50) into minutes since midnight."""
    m = re.match(r"^(\d\d):(\d\d)$", t)
    assert m
    hours, minutes = [int(j) for j in m.groups()]

    return (60 * hours) + minutes


def get_duration(depart: str, arrive: str, time_delta: int) -> str:
    """Given two times calculate the duration and return as string."""
    depart_min = time_to_minutes(depart)
    arrive_min = time_to_minutes(arrive) + time_delta

    duration = arrive_min - depart_min

    if depart_min > arrive_min:
        duration += 60 * 24

    return f"{duration // 60}h{ duration % 60:02d}m"


@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 = 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,
    )


def parse_date(d: str) -> date:
    """Parse a date from a string in ISO format."""
    return datetime.strptime(d, "%Y-%m-%d").date()


@app.route("/")
def start() -> Response | str:
    """Start page."""
    return flask.render_template("index.html")


def cabins_url(
    dep: str,
    arr: str,
    crossing: dict[str, Any],
    ticket_tier: str,
    rear_mounted_bike_carrier: bool,
) -> str:
    """Generate a URL for the cabins on a given crossing."""
    dt = datetime.fromisoformat(crossing["departureDateTime"]["iso"])
    utc_dt = dt.astimezone(pytz.utc)
    adults_str = flask.request.args.get("adults")
    small_dogs_str = flask.request.args.get("small_dogs")

    return flask.url_for(
        "cabins",
        sailing_id=int(crossing["sailingId"]),
        departure_port=ferry.ports[dep],
        arrival_port=ferry.ports[arr],
        departure_date=utc_dt.strftime("%Y-%m-%dT%H:%M:%S.000Z"),
        ticket_tier=ticket_tier,
        adults=adults_str,
        small_dogs=small_dogs_str,
        rear_mounted_bike_carrier=("true" if rear_mounted_bike_carrier else None),
    )


def get_days_until_start() -> int:
    """How long until the travel date."""
    start = date.fromisoformat(ferry_config.get("dates", "start"))
    return (start - date.today()).days


PriceData = list[tuple[str, str, list[dict[str, Any]]]]


def check_cache_for_prices(params: str) -> PriceData | None:
    """Look for prices in cache."""
    existing_files = os.listdir(cache_location())
    existing = [f for f in existing_files if f.endswith(params + ".json")]
    if not existing:
        return None

    recent_filename = max(existing)
    recent = datetime.strptime(recent_filename, f"%Y-%m-%d_%H%M_{params}.json")

    now = datetime.utcnow()

    delta = now - recent
    if delta < timedelta(hours=1):
        full = os.path.join(cache_location(), recent_filename)
        data: PriceData = json.load(open(full))
        return data
    return None


def get_prices_with_cache(
    direction: str,
    start: str,
    end: str,
    selection: list[tuple[str, str]],
    adults: int,
    small_dogs: int,
    refresh: bool = False,
    rear_mounted_bike_carrier: bool = False,
) -> PriceData:
    """Get price data using cache."""
    params = (
        f"{direction}_{start}_{end}_{adults}_{small_dogs}_{rear_mounted_bike_carrier}"
    )
    if not refresh:
        data = check_cache_for_prices(params)
        if data:
            return data

    vehicle = vehicle_from_config(ferry_config)

    all_data = [
        (
            dep,
            arr,
            get_prices(
                ferry.ports[dep],
                ferry.ports[arr],
                start,
                end,
                vehicle,
                adults,
                small_dogs,
                rear_mounted_bike_carrier,
            )["crossings"],
        )
        for dep, arr in selection
    ]

    with open(cache_filename(params), "w") as out:
        json.dump(all_data, out, indent=2)

    return all_data


Pax = collections.namedtuple("Pax", ["adults", "small_dogs"])


def read_pax() -> Pax:
    """Get the number of adults and dogs that are travelling."""
    config_adults = int(ferry_config.get("pax", "adults"))
    config_dogs = int(ferry_config.get("pax", "dogs"))

    adults_str = flask.request.args.get("adults")
    adults = int(adults_str) if adults_str else config_adults

    small_dogs_str = flask.request.args.get("small_dogs")
    small_dogs = int(small_dogs_str) if small_dogs_str else config_dogs

    return Pax(adults=adults, small_dogs=small_dogs)


pax_options = [
    {"pax": Pax(adults=1, small_dogs=0), "label": "1 adult"},
    {"pax": Pax(adults=2, small_dogs=0), "label": "2 adults"},
    {"pax": Pax(adults=2, small_dogs=1), "label": "2 adults and a dog"},
]


def build_outbound(section: str) -> str:
    """Show all routes on one page."""
    start = ferry_config.get(section, "from")
    end = ferry_config.get(section, "to")
    refresh = bool(flask.request.args.get("refresh"))
    rear_mounted_bike_carrier = (
        flask.request.args.get("rear_mounted_bike_carrier") == "true"
    )

    pax = read_pax()

    direction = section[:-1] if section[-1].isdigit() else section

    all_data = get_prices_with_cache(
        direction,
        start,
        end,
        routes["outbound"],
        pax.adults,
        pax.small_dogs,
        refresh,
        rear_mounted_bike_carrier,
    )

    return flask.render_template(
        "all_routes.html",
        data=all_data,
        days_until_start=get_days_until_start(),
        ports=ferry.ports,
        parse_date=parse_date,
        from_date=start,
        to_date=end,
        cabins_url=cabins_url,
        get_duration=get_duration,
        time_delta=-60,
        format_pet_options=format_pet_options,
        pax=pax,
        pax_options=pax_options,
        rear_mounted_bike_carrier=rear_mounted_bike_carrier,
    )


def build_return(section: str) -> str:
    """Show all routes on one page."""
    start = ferry_config.get(section, "from")
    end = ferry_config.get(section, "to")
    refresh = bool(flask.request.args.get("refresh"))
    pax = read_pax()
    rear_mounted_bike_carrier = (
        flask.request.args.get("rear_mounted_bike_carrier") == "true"
    )

    direction = section[:-1] if section[-1].isdigit() else section

    all_data = get_prices_with_cache(
        direction,
        start,
        end,
        routes["return"],
        pax.adults,
        pax.small_dogs,
        refresh,
        rear_mounted_bike_carrier,
    )

    return flask.render_template(
        "all_routes.html",
        data=all_data,
        ports=ferry.ports,
        days_until_start=get_days_until_start(),
        parse_date=parse_date,
        from_date=start,
        to_date=end,
        cabins_url=cabins_url,
        get_duration=get_duration,
        time_delta=60,
        format_pet_options=format_pet_options,
        pax=pax,
        pax_options=pax_options,
        rear_mounted_bike_carrier=rear_mounted_bike_carrier,
    )


@app.route("/outbound1")
def outbound1_page() -> str:
    return build_outbound("outbound1")


@app.route("/outbound2")
def outbound2_page() -> str:
    return build_outbound("outbound2")


@app.route("/outbound3")
def outbound3_page() -> str:
    return build_outbound("outbound3")


@app.route("/return1")
def return1_page() -> str:
    return build_return("return1")


@app.route("/return2")
def return2_page() -> str:
    return build_return("return2")


def format_pet_options(o: dict[str, bool]) -> list[str]:
    """Read pet options from API and format for display."""
    ret = []
    if o.get("petCabinAvailable"):
        ret.append("pet cabins")
    if o.get("smallKennelAvailable"):
        ret.append("small kennel")
    if o.get("stayInCarAvailable"):
        ret.append("pets stay in car")

    return ret


def get_accommodations_with_cache(
    dep: str,
    arr: str,
    d: str,
    ticket_tier: str,
    refresh: bool = False,
    rear_mounted_bike_carrier: bool = False,
) -> dict[str, list[dict[str, Any]]]:
    pax = read_pax()

    params = f"{dep}_{arr}_{d}_{ticket_tier}_{pax.adults}_{pax.small_dogs}_{rear_mounted_bike_carrier}"
    existing_files = os.listdir(cache_location())
    existing = [f for f in existing_files if f.endswith(params + ".json")]
    if not refresh and existing:
        recent_filename = max(existing)
        recent = datetime.strptime(recent_filename, f"%Y-%m-%d_%H%M_{params}.json")

        now = datetime.utcnow()

        delta = now - recent
        if delta < timedelta(hours=1):
            full = os.path.join(cache_location(), recent_filename)
            data = json.load(open(full))
            return data

    vehicle = vehicle_from_config(ferry_config)
    filename = cache_filename(params)
    data = get_accommodations(
        dep,
        arr,
        d,
        ticket_tier,
        vehicle,
        pax.adults,
        pax.small_dogs,
        rear_mounted_bike_carrier,
    )

    with open(filename, "w") as out:
        print(filename)
        json.dump(data, out, indent=2)

    return data


def get_start_end(section: str) -> tuple[str, str]:
    start = ferry_config.get(section, "from")
    end = ferry_config.get(section, "to")
    return start, end


def get_return_section(departure_date: str) -> tuple[str, str, str]:
    section = "return1"
    start, end = get_start_end(section)
    dep = departure_date[:10]
    if start <= dep <= end:
        return section, start, end

    section = "return2"
    start, end = get_start_end(section)
    if start <= dep <= end:
        return section, start, end


def get_outbound_section(departure_date: str) -> tuple[str, str, str]:
    section = "outbound1"
    start, end = get_start_end(section)
    dep = departure_date[:10]
    if start <= dep <= end:
        return section, start, end

    section = "outbound2"
    start, end = get_start_end(section)
    if start <= dep <= end:
        return section, start, end

    section = "outbound3"
    start, end = get_start_end(section)
    if start <= dep <= end:
        return section, start, end


def lookup_sailing_id(prices: PriceData, sailing_id: int) -> dict[str, Any] | None:
    for dep, arr, price_list in prices:
        for i in price_list:
            for j in i["prices"]:
                crossing: dict[str, Any] = j["crossingPrices"]
                if int(crossing["sailingId"]) == sailing_id:
                    return crossing

    return None


@app.route(
    "/cabins/<int:sailing_id>/<departure_port>/<arrival_port>/<departure_date>/<ticket_tier>"
)
def cabins(
    sailing_id: int,
    departure_port: str,
    arrival_port: str,
    departure_date: str,
    ticket_tier: str,
) -> str:
    """Get details of cabins."""
    direction = {"GB": "outbound", "FR": "return"}[departure_port[:2]]
    if direction == "return":
        section, start, end = get_return_section(departure_date[:10])
        start, end = get_start_end(section)
        time_delta = 60
    else:
        section, start, end = get_outbound_section(departure_date[:10])
        time_delta = -60

    pax = read_pax()
    rear_mounted_bike_carrier = (
        flask.request.args.get("rear_mounted_bike_carrier") == "true"
    )

    prices = get_prices_with_cache(
        direction,
        start,
        end,
        routes[direction],
        pax.adults,
        pax.small_dogs,
        False,
        rear_mounted_bike_carrier,
    )
    crossing = lookup_sailing_id(prices, sailing_id)

    cabin_data = get_accommodations_with_cache(
        departure_port,
        arrival_port,
        departure_date,
        ticket_tier,
        False,
        rear_mounted_bike_carrier,
    )
    accommodations = [
        a
        for a in cabin_data["accommodations"]
        if a["quantityAvailable"] > 0 and a["code"] != "RS"
        # and "Inside" not in a["description"]
    ]

    pax_labels = {i["pax"]: i["label"] for i in pax_options}

    dep = dateutil.parser.isoparse(departure_date)

    return flask.render_template(
        "cabins.html",
        port_lookup=ferry.port_lookup,
        departure_port=departure_port,
        arrival_port=arrival_port,
        departure_date=dep,
        ticket_tier=ticket_tier,
        accommodations=accommodations,
        pet_accommodations=cabin_data["petAccommodations"],
        crossing=crossing,
        get_duration=get_duration,
        time_delta=time_delta,
        format_pet_options=format_pet_options,
        section=section,
        pax=pax,
        pax_label=pax_labels[pax],
        rear_mounted_bike_carrier=rear_mounted_bike_carrier,
    )


if __name__ == "__main__":
    app.run(host="0.0.0.0", port=5001)