# tests/test_julian.py

from datetime import datetime, timezone, timedelta
from freezegun import freeze_time
from tools.julian import julian_date, epoch_days


# Freeze time to exactly Jan 1, 2000, 12:00:00 UTC (The J2000 epoch)
@freeze_time("2000-01-01 12:00:00", tz_offset=0)
def test_julian_date_j2000():
    # J2000 should be exactly Julian Date 2451545.0
    jd = julian_date()
    assert jd == 2451545.0


@freeze_time("2000-01-01 12:00:00", tz_offset=0)
def test_epoch_days():
    # Since we are exactly on the epoch, days should be 0
    days = epoch_days()
    assert days == 0.0


def test_julian_date_with_timezone():
    # Create a timezone-aware datetime
    tz = timezone(timedelta(hours=2))
    dt = datetime(2023, 10, 15, 12, 0, 0, tzinfo=tz)

    jd = julian_date(dt)
    # 2023-10-15 12:00 GMT+2 is exactly 2460232.91666...
    assert round(jd, 4) == 2460232.9167