"""Read events from YAML."""

import os
import typing
from datetime import date, datetime

import dateutil.rrule
import isodate  # type: ignore
import yaml

from . import uk_tz
from .event import Event


def midnight(d: date) -> datetime:
    """Convert from date to midnight on that day."""
    return datetime.combine(d, datetime.min.time())


def dates_from_rrule(
    rrule: str, start: date, end: date
) -> typing.Sequence[datetime | date]:
    """Generate events from an RRULE between start_date and end_date."""
    all_day = not any(param in rrule for param in ["BYHOUR", "BYMINUTE", "BYSECOND"])

    return [
        i.date() if all_day else uk_tz.localize(i)
        for i in dateutil.rrule.rrulestr(rrule, dtstart=midnight(start)).between(
            midnight(start), midnight(end)
        )
    ]


def get_yaml_event_date_field(item: dict[str, str]) -> str:
    """Event date field name."""
    return (
        "end_date"
        if item["name"] == "travel_insurance"
        else ("start_date" if "start_date" in item else "date")
    )


def get_yaml_event_end_date_field(item: dict[str, str]) -> str:
    """Event date field name."""
    return (
        "end_date"
        if item["name"] == "travel_insurance"
        else ("start_date" if "start_date" in item else "date")
    )


def read(
    data_dir: str, start: date, end: date, skip_trips: bool = False
) -> list[Event]:
    """Read eventes from YAML file."""
    events: list[Event] = []
    for item in yaml.safe_load(open(os.path.join(data_dir, "events.yaml"))):
        if "trip" in item and skip_trips:
            continue
        duration = (
            isodate.parse_duration(item["duration"]) if "duration" in item else None
        )
        dates = (
            dates_from_rrule(item["rrule"], start, end)
            if "rrule" in item
            else [item[get_yaml_event_date_field(item)]]
        )
        for dt in dates:
            e = Event(
                name=item["name"],
                date=dt,
                end_date=(
                    dt + duration
                    if duration
                    else (
                        item.get("end_date")
                        if item["name"] != "travel_insurance"
                        else None
                    )
                ),
                title=item.get("title"),
                url=item.get("url"),
            )
            events.append(e)
    return events