"""BUG-1321: the API fallback dasha year matches dasha_analyzer's 365.25 days.

Upstream 4d543209. The two 365.25636 constants in the API server made the
fallback timeline and the years-into-mahadasha figure drift from the analyzer.
"""

from __future__ import annotations

import importlib.util
import os
import sys
from datetime import datetime, timedelta

SCRIPTS = os.path.join(os.path.dirname(__file__), "..", "scripts")
if SCRIPTS not in sys.path:
    sys.path.insert(0, SCRIPTS)

from dasha_analyzer import build_dasha_timeline, lon_to_nakshatra  # noqa: E402


def _api_handler():
    """Reuse the existing unbound handler helper. Do not add another forgery site."""
    path = os.path.join(os.path.dirname(__file__), "test_api_server_security.py")
    spec = importlib.util.spec_from_file_location("_api_security_helpers_dasha", path)
    module = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(module)
    return module._handler()


def test_fallback_timeline_matches_analyzer_to_the_day() -> None:
    birth = datetime(2000, 1, 1)
    nak_info, progress, _pada = lon_to_nakshatra(0.0)
    timeline, _elapsed, _remaining, _lord = build_dasha_timeline("2000-01-01", nak_info, progress)
    handler = _api_handler()
    years = timeline[0]["years"]
    periods = handler._fallback_dasha_periods(birth, "generic", {"years": years * 9})
    assert periods[0]["lord"] == timeline[0]["lord"]
    assert periods[0]["start"] == timeline[0]["start"].strftime("%Y-%m-%d")
    assert periods[0]["end"] == timeline[0]["end"].strftime("%Y-%m-%d")
    fallback_days = (
        datetime.strptime(periods[0]["end"], "%Y-%m-%d")
        - datetime.strptime(periods[0]["start"], "%Y-%m-%d")
    ).days
    analyzer_days = (timeline[0]["end"].date() - timeline[0]["start"].date()).days
    assert fallback_days - analyzer_days == 0

    long_periods = handler._fallback_dasha_periods(birth, "generic", {"years": 1422})
    expected = (birth + timedelta(days=158 * 365.25)).strftime("%Y-%m-%d")
    stale = (birth + timedelta(days=158 * 365.25636)).strftime("%Y-%m-%d")
    assert expected != stale
    assert long_periods[0]["end"] == expected


def test_years_into_mahadasha_uses_the_analyzer_year() -> None:
    birth = datetime(2000, 1, 1)
    today = datetime(2003, 1, 1)
    handler = _api_handler()
    layer = handler._compute_vimshottari_analysis_layer(birth, 0.0, current_date="2003-01-01")
    days = (today - birth).days
    years_into = layer["five_levels"]["mahadasha"]["years_into_period"]
    assert years_into == days / 365.25
    assert years_into != days / 365.25636