brittany-ferries/main.py

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

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

import dateutil.parser
import flask
import pytz
import werkzeug.exceptions
from werkzeug.debug.tbtools import get_current_traceback
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 = False


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):
    tb = get_current_traceback()
    last_frame = next(frame for frame in reversed(tb.frames) if not frame.is_library)
    last_frame_args = inspect.getargs(last_frame.code)
    return (
        flask.render_template(
            "show_error.html",
            tb=tb,
            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) -> str:
    """Generate a URL for the cabins on a given crossing."""
    dt = datetime.fromisoformat(crossing["departureDateTime"]["iso"])
    utc_dt = dt.astimezone(pytz.utc)

    return flask.url_for(
        "cabins",
        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,
    )


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, 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(
    name: str,
    start: str,
    end: str,
    selection: list[tuple[str, str]],
    refresh: bool = False,
) -> PriceData:
    """Get price data using cache."""
    params = f"{name}_{start}_{end}"
    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)[
                "crossings"
            ],
        )
        for dep, arr in selection
    ]

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

    return all_data


def build_outbound(section: str) -> str:
    """Show all routes on one page."""
    selection = [
        ("PORTSMOUTH", "CAEN"),
        ("PORTSMOUTH", "CHERBOURG"),
        ("PORTSMOUTH", "ST MALO"),
        # ("POOLE", "CHERBOURG"),
    ]

    start = ferry_config.get(section, "from")
    end = ferry_config.get(section, "to")
    refresh = bool(flask.request.args.get("refresh"))

    all_data = get_prices_with_cache(section, start, end, selection, refresh)

    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,
    )


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


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


def format_pet_options(o: dict[str, bool]) -> list[str]:
    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


@app.route("/return")
def return_page() -> str:
    """Show all routes on one page."""
    selection = [
        ("CAEN", "PORTSMOUTH"),
        ("CHERBOURG", "PORTSMOUTH"),
        ("ST MALO", "PORTSMOUTH"),
        # ("CHERBOURG", "POOLE"),
    ]

    start = ferry_config.get("return", "from")
    end = ferry_config.get("return", "to")
    refresh = bool(flask.request.args.get("refresh"))

    all_data = get_prices_with_cache("return", start, end, selection, refresh)

    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,
    )


def get_accommodations_with_cache(
    dep: str, arr: str, d: str, ticket_tier: str, refresh: bool = False
) -> dict[str, list[dict[str, Any]]]:
    params = f"{dep}_{arr}_{d}_{ticket_tier}"
    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)

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

    return data


@app.route("/cabins/<departure_port>/<arrival_port>/<departure_date>/<ticket_tier>")
def cabins(
    departure_port: str, arrival_port: str, departure_date: str, ticket_tier: str
) -> str:
    cabin_data = get_accommodations_with_cache(
        departure_port, arrival_port, departure_date, ticket_tier
    )
    accommodations = [
        a
        for a in cabin_data["accommodations"]
        if a["quantityAvailable"] > 0 and a["code"] != "RS"
        # and "Inside" not in a["description"]
    ]

    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"],
    )


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