Jyotisha/scripts/narayana_rath.py

#!/usr/bin/env python3
"""Narayana Dasha, Sanjay Rath profile (`sanjay_rath`) — research only (BUG-1215).

Astrologer round-4 ruling 2026-10-03, Q4: the second time axis should be Sanjay
Rath's Narayana Dasha (start from the stronger of Lagna and 7th, order by the
start sign, dual lords by the traditional profile). The current product axis
(`narayana_dasha.calc_narayana_mahadasha`) always starts from the Lagna and runs
zodiacally; it is labelled `legacy_reference_only` on user-visible surfaces.

This module builds the Rath sequence from the rule ledger ported from upstream
yinduzhanxing c7117f92 (`references/oracle/sanjay_rath_narayana_book_ledger_2026_08_28.json`,
`docs/research/sanjay_rath_narayana_book_ledger_2026_08_28.md`):

- start sign: stronger of Lagna / 7th (`rath_md_start_stronger_lagna_seventh`),
  decided by the existing `narayana_dasha.select_narayana_seed_sign`; a tie
  (`later_narayana_sign_strength_rules_required`) gives
  `status: parameter_sensitive` and both sequences;
- MD order: Table 10 by the start sign (`rath_md_general_order_table10`); Saturn
  in the start sign -> Table 11, zodiacal (`rath_saturn_start_exception`); Ketu
  in the start sign (no Saturn) -> Table 10 direction reversed (the reversal
  rule, `rath_ketu_reversal_exception`; the ledger tables only the AD form);
- years: `jaimini_odd_footed_dignity_v2` (Upadesa 1.1.25-27 odd/even-footed
  count with the fixed-sign exception, exalted +1 / debilitated -1, ledger
  `upadesa_1125_1126_odd_even_count`, `upadesa_1127_fixed_sign_exception`,
  `upadesa_bphs_exalt_debil_adjustment`); Scorpio / Aquarius lords by
  `jaimini_dual_lord_source_v1` (`upadesa_dual_lord_strength_chain`, partial);
- AD: twelve equal parts from the MD sign, Table 13 order; Saturn in the MD sign
  -> Table 11, Ketu -> Table 14 (`rath_ad_equal_twelfths`, `rath_ad_order_table13`).

Not wired into scoring, consultation or reports: the three book tables
(Table 15 / 17 / 18) are not all reproduced (see
`docs/tasks/PROGRESS-astrologer-rulings-batch2-20261003.md`, task red line 2).
"""

from __future__ import annotations

from typing import Any, Dict, List, Optional

try:  # scripts/ on sys.path
    import narayana_dasha as nd
except ImportError:  # pragma: no cover - package import
    from scripts import narayana_dasha as nd

PROFILE = "sanjay_rath"
DURATION_PROFILE = "jaimini_odd_footed_dignity_v2"
DUAL_LORD_PROFILE = "jaimini_dual_lord_source_v1"
SOURCE = ("Sanjay Rath, Narayana Dasa — rule ledger and Tables 10/11/13/14 "
          "(ported from upstream yinduzhanxing c7117f92)")
SIGNS = nd.SIGNS


def md_order(seed_sign_idx: int, planet_lons: Dict[str, float]) -> Dict[str, Any]:
    """MD sign order for one start sign, with the rule that decided it."""
    saturn = nd._get_planet_sign("Saturn", planet_lons) == seed_sign_idx
    ketu = nd._get_planet_sign("Ketu", planet_lons) == seed_sign_idx
    if saturn:
        order = nd.build_narayana_sign_sequence(seed_sign_idx, profile="rath_saturn_table11_v1")
        direction = "table11_saturn_zodiacal"
    elif ketu:
        table10 = nd.build_narayana_sign_sequence(seed_sign_idx, profile="rath_general_table10_v1")
        order = [(2 * seed_sign_idx - sign) % 12 for sign in table10]
        direction = "table10_reversed_ketu"
    else:
        order = nd.build_narayana_sign_sequence(seed_sign_idx, profile="rath_general_table10_v1")
        direction = "table10_general"
    return {"order": order, "direction": direction, "saturn_in_seed": saturn, "ketu_in_seed": ketu}


def _ad_order_profile(md_sign_idx: int, planet_lons: Dict[str, float]) -> str:
    if nd._get_planet_sign("Saturn", planet_lons) == md_sign_idx:
        return "rath_saturn_table11_v1"
    if nd._get_planet_sign("Ketu", planet_lons) == md_sign_idx:
        return "rath_ketu_table14_v1"
    return "rath_table13_v1"


def mahadasha_sequence(seed_sign_idx: int, planet_lons: Dict[str, float],
                       *, start_age: float = 0.0, cycle_count: int = 2) -> Dict[str, Any]:
    """Rath MD rows from one start sign (cycle 2 = twelve minus cycle 1)."""
    order = md_order(seed_sign_idx, planet_lons)
    rows: List[Dict[str, Any]] = []
    cursor = float(start_age)
    for position, sign_idx in enumerate(order["order"], start=1):
        lord = nd._resolve_narayana_lord(sign_idx, planet_lons, dual_lord_profile=DUAL_LORD_PROFILE)
        lord_sign_idx = nd._get_planet_sign(lord, planet_lons)
        if lord_sign_idx is None:
            lord_sign_idx = sign_idx
        years, adjustment = nd.calculate_narayana_period_years(sign_idx, lord, lord_sign_idx, profile=DURATION_PROFILE)
        rows.append({
            "sign": SIGNS[sign_idx], "sign_idx": sign_idx, "lord": lord,
            "lord_in_sign": SIGNS[lord_sign_idx], "lord_sign_idx": lord_sign_idx,
            "years": years, "dignity_adjustment": adjustment, "cycle_index": 1,
            "period_key": f"narayana_rath:1:{position:02d}:{SIGNS[sign_idx]}",
            "start_age": round(cursor, 4), "end_age": round(cursor + years, 4),
        })
        cursor += years
    if cycle_count == 2:
        for position, first in enumerate(list(rows), start=1):
            years = 12 - first["years"]
            rows.append({**first, "years": years, "dignity_adjustment": None, "cycle_index": 2,
                         "period_key": f"narayana_rath:2:{position:02d}:{first['sign']}",
                         "start_age": round(cursor, 4), "end_age": round(cursor + years, 4)})
            cursor += years
    return {**order, "seed_sign": SIGNS[seed_sign_idx], "seed_sign_idx": seed_sign_idx, "mahadasha": rows}


def antardasha(md_row: Dict[str, Any], planet_lons: Dict[str, float]) -> List[Dict[str, Any]]:
    """Twelve equal ADs from the MD sign (Table 13 / 11 / 14)."""
    profile = _ad_order_profile(md_row["sign_idx"], planet_lons)
    rows = nd.subdivide_narayana_equal_order(
        md_row, start_sign_idx=md_row["sign_idx"], order_profile=profile, level="AD",
        parent_key="parent_md", parent_name=md_row["sign"],
    )
    return rows


def calc_narayana_rath(lagna_sign_idx: int, planet_lons: Dict[str, float],
                       *, seed_sign_idx: Optional[int] = None, cycle_count: int = 2) -> Dict[str, Any]:
    """Rath Narayana Dasha for one chart.

    `seed_sign_idx` overrides the start sign (book-table replay only).
    """
    if seed_sign_idx is not None:
        selection = {"status": "explicit", "selected_sign_idx": seed_sign_idx}
    else:
        selection = nd.select_narayana_seed_sign(lagna_sign_idx, planet_lons)
    base = {
        "profile": PROFILE,
        "duration_profile": DURATION_PROFILE,
        "dual_lord_rule": DUAL_LORD_PROFILE,
        "source": SOURCE,
        "lagna_sign": SIGNS[lagna_sign_idx],
        "seed_selection": selection,
    }
    if selection["status"] in ("selected", "explicit"):
        seq = mahadasha_sequence(selection["selected_sign_idx"], planet_lons, cycle_count=cycle_count)
        return {**base, "status": "partial_verified" if selection["status"] == "selected" else "explicit_seed",
                "seed_sign": seq["seed_sign"],
                "seed_basis": ("explicit_seed" if selection["status"] == "explicit"
                               else "stronger_of_lagna_seventh:" + "+".join(selection.get("selection_levels", []))),
                "direction": seq["direction"], "mahadasha": seq["mahadasha"]}
    alternatives = {
        SIGNS[idx]: mahadasha_sequence(idx, planet_lons, cycle_count=cycle_count)
        for idx in (lagna_sign_idx, (lagna_sign_idx + 6) % 12)
    }
    lagna_seq = alternatives[SIGNS[lagna_sign_idx]]
    return {**base, "status": "parameter_sensitive", "reason": selection.get("reason"),
            "seed_sign": None, "seed_basis": "tie_lagna_seventh_both_listed",
            "direction": None, "mahadasha": None,
            "alternatives": {sign: {"seed_sign": seq["seed_sign"], "direction": seq["direction"],
                                    "mahadasha": seq["mahadasha"]} for sign, seq in alternatives.items()},
            "lagna_start_mahadasha": lagna_seq["mahadasha"]}