/**
 * Essential dignities and rulerships.
 *
 * Pure table work — Swiss Ephemeris gives the position, this layer says what
 * the tradition takes that position to mean.
 *
 * Five essential dignities: domicile, exaltation, triplicity, terms (bounds)
 * and faces (decans). Detriment and fall are the opposites of domicile and
 * exaltation, so they are derived rather than tabulated.
 *
 * Triplicity rulers and terms depend on **sect**; the determination in
 * `sect.ts` feeds in here.
 */

import { Body, SIGNS, type Sign } from '../constants.js';
import type { Sect } from './sect.js';

/** The kinds of dignity, in traditional order of weight. */
export type DignityKind =
  | 'domicile' | 'exaltation' | 'triplicity' | 'term' | 'face'
  | 'detriment' | 'fall' | 'peregrine';

/** The classical seven — the dignity tables cover only these. */
export const TRADITIONAL_RULERS = [
  Body.Sun, Body.Moon, Body.Mercury, Body.Venus,
  Body.Mars, Body.Jupiter, Body.Saturn,
] as const;

/**
 * Domicile, the traditional assignment, indexed by sign (0 = Aries).
 *
 * Modern astrology gives Scorpio to Pluto, Aquarius to Uranus and Pisces to
 * Neptune; {@link MODERN_RULERS} carries that separately. The traditional
 * techniques — dignity scoring, profection, firdaria — need the classical
 * assignment.
 */
export const DOMICILE: readonly number[] = [
  Body.Mars,     // Koç
  Body.Venus,    // Boğa
  Body.Mercury,  // İkizler
  Body.Moon,     // Yengeç
  Body.Sun,      // Aslan
  Body.Mercury,  // Başak
  Body.Venus,    // Terazi
  Body.Mars,     // Akrep
  Body.Jupiter,  // Yay
  Body.Saturn,   // Oğlak
  Body.Saturn,   // Kova
  Body.Jupiter,  // Balık
];

/** The modern outer-planet assignments. Differs from traditional in three signs. */
export const MODERN_RULERS: readonly number[] = DOMICILE.map((ruler, sign) =>
  sign === 7 ? Body.Pluto : sign === 10 ? Body.Uranus : sign === 11 ? Body.Neptune : ruler,
);

/** Exaltation degrees: body to absolute longitude (0 = 0° Aries). */
export const EXALTATION: Readonly<Record<number, number>> = {
  [Body.Sun]: 19,          // 19° Koç
  [Body.Moon]: 33,         // 3° Boğa
  [Body.Mercury]: 165,     // 15° Başak
  [Body.Venus]: 357,       // 27° Balık
  [Body.Mars]: 298,        // 28° Oğlak
  [Body.Jupiter]: 105,     // 15° Yengeç
  [Body.Saturn]: 201,      // 21° Terazi
};

/** Dorothean triplicity rulers: element to [day, night, participating]. */
const TRIPLICITY: readonly (readonly number[])[] = [
  [Body.Sun, Body.Jupiter, Body.Saturn],    // ateş: Koç, Aslan, Yay
  [Body.Venus, Body.Moon, Body.Mars],       // toprak: Boğa, Başak, Oğlak
  [Body.Saturn, Body.Mercury, Body.Jupiter],// hava: İkizler, Terazi, Kova
  [Body.Venus, Body.Mars, Body.Moon],       // su: Yengeç, Akrep, Balık
];

/**
 * The Egyptian terms (bounds). Five divisions per sign, each `[ruler, end°]`.
 * End degrees are within the sign (0–30) and the last always ends at 30.
 */
const EGYPTIAN_TERMS: readonly (readonly (readonly [number, number])[])[] = [
  [[Body.Jupiter, 6], [Body.Venus, 12], [Body.Mercury, 20], [Body.Mars, 25], [Body.Saturn, 30]],
  [[Body.Venus, 8], [Body.Mercury, 14], [Body.Jupiter, 22], [Body.Saturn, 27], [Body.Mars, 30]],
  [[Body.Mercury, 6], [Body.Jupiter, 12], [Body.Venus, 17], [Body.Mars, 24], [Body.Saturn, 30]],
  [[Body.Mars, 7], [Body.Venus, 13], [Body.Mercury, 19], [Body.Jupiter, 26], [Body.Saturn, 30]],
  [[Body.Jupiter, 6], [Body.Venus, 11], [Body.Saturn, 18], [Body.Mercury, 24], [Body.Mars, 30]],
  [[Body.Mercury, 7], [Body.Venus, 17], [Body.Jupiter, 21], [Body.Mars, 28], [Body.Saturn, 30]],
  [[Body.Saturn, 6], [Body.Mercury, 14], [Body.Jupiter, 21], [Body.Venus, 28], [Body.Mars, 30]],
  [[Body.Mars, 7], [Body.Venus, 11], [Body.Mercury, 19], [Body.Jupiter, 24], [Body.Saturn, 30]],
  [[Body.Jupiter, 12], [Body.Venus, 17], [Body.Mercury, 21], [Body.Saturn, 26], [Body.Mars, 30]],
  [[Body.Mercury, 7], [Body.Jupiter, 14], [Body.Venus, 22], [Body.Saturn, 26], [Body.Mars, 30]],
  [[Body.Mercury, 7], [Body.Venus, 13], [Body.Jupiter, 20], [Body.Mars, 25], [Body.Saturn, 30]],
  [[Body.Venus, 12], [Body.Jupiter, 16], [Body.Mercury, 19], [Body.Mars, 28], [Body.Saturn, 30]],
];

/**
 * The faces (decans) — 10° divisions cycling through the Chaldean order.
 *
 * The sequence runs Saturn, Jupiter, Mars, Sun, Venus, Mercury, Moon, and the
 * first face of Aries starts with Mars. The table is generated from the
 * sequence rather than written out: thirty-six hand-typed entries invite a
 * silent ordering error.
 */
const CHALDEAN_ORDER = [
  Body.Saturn, Body.Jupiter, Body.Mars, Body.Sun,
  Body.Venus, Body.Mercury, Body.Moon,
] as const;

/** The first face of Aries is Mars — index 2 in the Chaldean sequence. */
const FIRST_FACE_INDEX = 2;

export const FACES: readonly number[] = Array.from(
  { length: 36 },
  (_, i) => CHALDEAN_ORDER[(FIRST_FACE_INDEX + i) % 7],
);

const norm = (d: number) => ((d % 360) + 360) % 360;

/** A sign's element: 0 fire, 1 earth, 2 air, 3 water. */
export const elementOf = (signIndex: number) => signIndex % 4;

export interface DignityReport {
  body: number;
  longitude: number;
  signIndex: number;
  sign: Sign;
  degreeInSign: number;

  /** The traditional lord of this sign. */
  domicileRuler: number;
  /** The triplicity ruler, chosen by sect. */
  triplicityRuler: number;
  /** The ruler of the term the body falls in. */
  termRuler: number;
  /** The ruler of the face the body falls in. */
  faceRuler: number;

  /** The dignities the body holds at this position, in order of weight. */
  dignities: DignityKind[];
  /**
   * Classical scoring: domicile 5, exaltation 4, triplicity 3, term 2,
   * face 1; detriment −5, fall −4. Zero means peregrine — no dignity at all.
   */
  score: number;
}

const SCORES: Record<DignityKind, number> = {
  domicile: 5, exaltation: 4, triplicity: 3, term: 2, face: 1,
  detriment: -5, fall: -4, peregrine: 0,
};

/**
 * Evaluates a body's essential dignities at a given longitude.
 *
 * Only meaningful for the classical seven; the outer planets have no place in
 * the traditional tables and come back with an empty `dignities` list.
 */
export function evaluateDignities(
  body: number,
  longitude: number,
  sect: Sect,
): DignityReport {
  const lon = norm(longitude);
  const signIndex = Math.floor(lon / 30);
  const degreeInSign = lon - signIndex * 30;

  const domicileRuler = DOMICILE[signIndex];
  const element = elementOf(signIndex);
  const triplicityRuler = TRIPLICITY[element][sect === 'day' ? 0 : 1];

  const termRuler = EGYPTIAN_TERMS[signIndex]
    .find(([, end]) => degreeInSign < end)?.[0]
    ?? EGYPTIAN_TERMS[signIndex][4][0];

  const faceRuler = FACES[signIndex * 3 + Math.min(2, Math.floor(degreeInSign / 10))];

  const dignities: DignityKind[] = [];

  if (domicileRuler === body) dignities.push('domicile');
  else if (DOMICILE[(signIndex + 6) % 12] === body) dignities.push('detriment');

  const exaltationDegree = EXALTATION[body];
  if (exaltationDegree !== undefined) {
    if (Math.floor(exaltationDegree / 30) === signIndex) dignities.push('exaltation');
    else if (Math.floor(norm(exaltationDegree + 180) / 30) === signIndex) dignities.push('fall');
  }

  if (triplicityRuler === body) dignities.push('triplicity');
  if (termRuler === body) dignities.push('term');
  if (faceRuler === body) dignities.push('face');

  const positive = dignities.filter((d) => SCORES[d] > 0);
  if (positive.length === 0 && !dignities.includes('detriment') && !dignities.includes('fall')) {
    dignities.push('peregrine');
  }

  return {
    body, longitude: lon, signIndex, sign: SIGNS[signIndex], degreeInSign,
    domicileRuler, triplicityRuler, termRuler, faceRuler,
    dignities,
    score: dignities.reduce((sum, d) => sum + SCORES[d], 0),
  };
}

/** A sign's ruler, traditional or modern. */
export function rulerOfSign(signIndex: number, modern = false): number {
  return (modern ? MODERN_RULERS : DOMICILE)[norm(signIndex * 30) / 30];
}

/** The term divisions of a sign — for display and inspection. */
export function termsOfSign(signIndex: number): { ruler: number; from: number; to: number }[] {
  let from = 0;
  return EGYPTIAN_TERMS[signIndex].map(([ruler, to]) => {
    const bound = { ruler, from, to };
    from = to;
    return bound;
  });
}