from __future__ import annotations

from datetime import datetime, timezone

from canonical_layer.period_snapshot import (
    normalize_dt,
    parse_dt,
    parse_record_datetime,
    window_bounds_from_key,
    window_key,
)


def test_parse_dt_odata_and_iso() -> None:
    from_odata = parse_dt("/Date(1583020800000)/")
    assert from_odata is not None
    assert from_odata.year == 2020
    assert from_odata.month == 3
    assert from_odata.day == 1

    from_iso = parse_dt("2020-03-01T00:00:00Z")
    assert from_iso is not None
    assert from_iso.tzinfo is not None
    assert normalize_dt(from_iso).year == 2020


def test_window_key_and_bounds_month() -> None:
    dt = datetime(2020, 11, 15, 12, 0, 0, tzinfo=timezone.utc)
    key = window_key(dt, granularity="month")
    assert key == "2020-11"

    start, end = window_bounds_from_key(key, granularity="month")
    assert start.isoformat() == "2020-11-01T00:00:00+00:00"
    assert end.isoformat() == "2020-12-01T00:00:00+00:00"


def test_window_key_and_bounds_week() -> None:
    dt = datetime(2020, 12, 30, 7, 0, 0, tzinfo=timezone.utc)
    key = window_key(dt, granularity="week")
    assert key.startswith("2020-W")

    start, end = window_bounds_from_key(key, granularity="week")
    assert end > start


def test_parse_record_datetime_finds_common_fields() -> None:
    row = {"Date": "2020-05-20T10:00:00Z"}
    dt = parse_record_datetime(row)
    assert dt is not None
    assert dt.year == 2020
    assert dt.month == 5