src/shared/breeder.ts

import { generateName } from './nameGenerator';
import { generatePhenotype } from './phenotype';
import { newId, randomChoice, type RandomSource } from './rng';
import { canAttempt, cloneAlleles, cloneStabilities, findSeed, nowIso, reexpressSeed } from './state';
import type { Alleles, ColorAlleles, ColorTraitKey, GameState, Hsv, NumericTraitKey, PlantType, SeedProfile, Stabilities } from './types';

const NUMERIC_TRAITS: NumericTraitKey[] = ['THC', 'CBD', 'Yield', 'GrowTime'];
const COLOR_TRAITS: ColorTraitKey[] = ['LeafColor', 'BudColor'];

const NUMERIC_LIMITS: Record<NumericTraitKey, [number, number]> = {
  THC: [0, 60],
  CBD: [0, 20],
  Yield: [25, 180],
  GrowTime: [35, 96],
};

function clamp(value: number, min: number, max: number): number {
  return Math.max(min, Math.min(max, value));
}

function clamp01(value: number): number {
  return clamp(value, 0, 1);
}

function wrapHue(hue: number): number {
  return ((hue % 360) + 360) % 360;
}

function jitter(rng: RandomSource): number {
  return (rng() + rng() + rng()) / 3 - 0.5;
}

function lowDominates(trait: NumericTraitKey): boolean {
  return trait === 'GrowTime';
}

function dominantNumeric(values: [number, number], trait: NumericTraitKey): number {
  return lowDominates(trait) ? Math.min(...values) : Math.max(...values);
}

function recessiveNumeric(values: [number, number], trait: NumericTraitKey): number {
  return lowDominates(trait) ? Math.max(...values) : Math.min(...values);
}

function selectNumericAllele(values: [number, number], stability: number, trait: NumericTraitKey, rng: RandomSource): number {
  const boundedStability = clamp01(stability);
  const dominant = dominantNumeric(values, trait);
  const recessive = recessiveNumeric(values, trait);
  const dominantChance = 0.5 + boundedStability * 0.43;
  const inherited = rng() < dominantChance ? dominant : recessive;
  const volatility = 1 - boundedStability;
  const [min, max] = NUMERIC_LIMITS[trait];
  const driftScale: Record<NumericTraitKey, number> = { THC: 1.7, CBD: 0.8, Yield: 8.5, GrowTime: 5.2 };
  const rareSurge = trait === 'THC' && inherited >= 28 && rng() < 0.05 + volatility * 0.13;
  const directionBias = rareSurge ? 0.45 : 0;
  const drift = (jitter(rng) + directionBias) * (0.08 + volatility * driftScale[trait]);
  return Math.round(clamp(inherited + drift, min, max) * 100) / 100;
}

function inheritTraitStability(left: number, right: number, rng: RandomSource): number {
  const leftPower = 0.1 + clamp01(left) ** 1.45;
  const rightPower = 0.1 + clamp01(right) ** 1.45;
  const anchor = rng() < leftPower / (leftPower + rightPower) ? clamp01(left) : clamp01(right);
  const partner = anchor === clamp01(left) ? clamp01(right) : clamp01(left);
  const volatility = 1 - anchor;
  const inherited = anchor * 0.78 + partner * 0.22 + jitter(rng) * (0.04 + volatility * 0.18);
  return Math.round(clamp01(inherited) * 1000) / 1000;
}

export function inheritStabilities(left: Stabilities, right: Stabilities, rng: RandomSource = Math.random): Stabilities {
  return {
    THC: inheritTraitStability(left.THC ?? 0.5, right.THC ?? 0.5, rng),
    CBD: inheritTraitStability(left.CBD ?? 0.5, right.CBD ?? 0.5, rng),
    Yield: inheritTraitStability(left.Yield ?? 0.5, right.Yield ?? 0.5, rng),
    GrowTime: inheritTraitStability(left.GrowTime ?? 0.5, right.GrowTime ?? 0.5, rng),
    LeafColor: inheritTraitStability(left.LeafColor ?? 0.5, right.LeafColor ?? 0.5, rng),
    BudColor: inheritTraitStability(left.BudColor ?? 0.5, right.BudColor ?? 0.5, rng),
  };
}

function colorStrength(hsv: Hsv): number {
  return hsv[1] * 0.68 + hsv[2] * 0.32;
}

function colorHsvAt(alleles: ColorAlleles, index: 0 | 1): Hsv {
  return [wrapHue(alleles.Hue[index]), clamp01(alleles.Saturation[index]), clamp01(alleles.Value[index])];
}

function hueDistance(left: number, right: number): number {
  return Math.abs((((left - right) % 360) + 540) % 360 - 180);
}

function colorAlleleContrast(alleles: ColorAlleles): number {
  return hueDistance(alleles.Hue[0], alleles.Hue[1]);
}

function colorAlleleBalance(alleles: ColorAlleles): number {
  const left = colorStrength(colorHsvAt(alleles, 0));
  const right = colorStrength(colorHsvAt(alleles, 1));
  return Math.min(left, right) / Math.max(0.001, Math.max(left, right));
}

function injectDistantHueVolatility(baseStability: number, alleles: ColorAlleles, rng: RandomSource): number {
  const base = clamp01(baseStability);
  const contrast = colorAlleleContrast(alleles);
  const balance = colorAlleleBalance(alleles);
  const contrastPressure = clamp((contrast - 55) / 125, 0, 1);
  const balancePressure = clamp((balance - 0.38) / 0.62, 0, 1);
  const crossPressure = contrastPressure * (0.62 + balancePressure * 0.38);
  if (crossPressure <= 0.02) return Math.round(base * 1000) / 1000;

  const distanceDrop = crossPressure * 0.3;
  const wildChance = 0.035 + crossPressure * 0.12 + (1 - base) * 0.05;
  const wildDrop = rng() < wildChance ? (0.07 + rng() * 0.16) * crossPressure : 0;
  const floor = crossPressure > 0.86 && balance > 0.55 ? 0.28 : 0.38;
  return Math.round(clamp(base - distanceDrop - wildDrop, floor, 0.98) * 1000) / 1000;
}

function selectColorAllele(alleles: ColorAlleles, stability: number, rng: RandomSource): Hsv {
  const boundedStability = clamp01(stability);
  const first = colorHsvAt(alleles, 0);
  const second = colorHsvAt(alleles, 1);
  const firstStrength = colorStrength(first);
  const secondStrength = colorStrength(second);
  const dominant = firstStrength >= secondStrength ? first : second;
  const recessive = dominant === first ? second : first;
  const dominantChance = 0.48 + boundedStability * 0.45;
  const inherited = rng() < dominantChance ? dominant : recessive;
  const volatility = 1 - boundedStability;
  return [
    wrapHue(inherited[0] + jitter(rng) * (2 + volatility * 54)),
    clamp01(inherited[1] + jitter(rng) * volatility * 0.24),
    clamp01(inherited[2] + jitter(rng) * volatility * 0.2),
  ];
}

function colorAllelesFromHsv(left: Hsv, right: Hsv): ColorAlleles {
  return {
    Hue: [Math.round(left[0] * 10) / 10, Math.round(right[0] * 10) / 10],
    Saturation: [Math.round(left[1] * 1000) / 1000, Math.round(right[1] * 1000) / 1000],
    Value: [Math.round(left[2] * 1000) / 1000, Math.round(right[2] * 1000) / 1000],
  };
}

export function recombineProfiles(parentOne: SeedProfile, parentTwo: SeedProfile, rng: RandomSource = Math.random): { alleles: Alleles; stabilities: Stabilities } {
  const stabilities = inheritStabilities(parentOne.stabilities, parentTwo.stabilities, rng);
  const alleles = {} as Alleles;
  for (const trait of NUMERIC_TRAITS) {
    alleles[trait] = [
      selectNumericAllele(parentOne.alleles[trait], parentOne.stabilities[trait], trait, rng),
      selectNumericAllele(parentTwo.alleles[trait], parentTwo.stabilities[trait], trait, rng),
    ];
  }
  for (const trait of COLOR_TRAITS) {
    alleles[trait] = colorAllelesFromHsv(
      selectColorAllele(parentOne.alleles[trait], parentOne.stabilities[trait], rng),
      selectColorAllele(parentTwo.alleles[trait], parentTwo.stabilities[trait], rng)
    );
    stabilities[trait] = injectDistantHueVolatility(stabilities[trait], alleles[trait], rng);
  }
  return { alleles, stabilities };
}

export function recombine(parentOne: Alleles, parentTwo: Alleles, rng: RandomSource = Math.random): Alleles {
  return {
    THC: [randomChoice(parentOne.THC, rng), randomChoice(parentTwo.THC, rng)],
    CBD: [randomChoice(parentOne.CBD, rng), randomChoice(parentTwo.CBD, rng)],
    Yield: [randomChoice(parentOne.Yield, rng), randomChoice(parentTwo.Yield, rng)],
    GrowTime: [randomChoice(parentOne.GrowTime, rng), randomChoice(parentTwo.GrowTime, rng)],
    LeafColor: colorAllelesFromHsv(selectColorAllele(parentOne.LeafColor, 0.5, rng), selectColorAllele(parentTwo.LeafColor, 0.5, rng)),
    BudColor: colorAllelesFromHsv(selectColorAllele(parentOne.BudColor, 0.5, rng), selectColorAllele(parentTwo.BudColor, 0.5, rng)),
  };
}

function buildSeed(input: {
  strainName: string;
  type: PlantType;
  alleles: Alleles;
  stabilities: Stabilities;
  baseImageName: string;
  lineage: [string | null, string | null];
  description: string;
  isStarter?: boolean;
}): SeedProfile {
  const phenotype = generatePhenotype(input.alleles, input.stabilities);
  return {
    seedId: newId('seed'),
    strainName: input.strainName,
    type: input.type,
    alleles: cloneAlleles(input.alleles),
    stabilities: cloneStabilities(input.stabilities),
    thc: Math.round(phenotype.thc * 10) / 10,
    cbd: Math.round(phenotype.cbd * 10) / 10,
    yield: Math.round(phenotype.yield * 10) / 10,
    growTime: Math.round(phenotype.growTime * 10) / 10,
    budColor: phenotype.budColorRgb,
    leafColor: phenotype.leafColorRgb,
    budPalette: phenotype.budPaletteRgb,
    leafPalette: phenotype.leafPaletteRgb,
    budPattern: phenotype.budPattern,
    leafPattern: phenotype.leafPattern,
    baseImageName: input.baseImageName,
    growthStage: 'SEED',
    lineage: input.lineage,
    description: input.description,
    quantity: 1,
    attemptsUsed: 0,
    maxAttempts: 2,
    isStarter: input.isStarter ?? false,
  };
}

export function breedProfiles(parentOne: SeedProfile, parentTwo: SeedProfile, rng: RandomSource = Math.random): SeedProfile {
  if (parentOne.growthStage !== 'MATURE' || parentTwo.growthStage !== 'MATURE') {
    throw new Error('Both parents must be fully mature before breeding');
  }
  if (!canAttempt(parentOne) || !canAttempt(parentTwo)) {
    throw new Error('One or both parents have reached max breeding/cloning attempts');
  }
  const { alleles, stabilities } = recombineProfiles(parentOne, parentTwo, rng);
  return buildSeed({
    strainName: generateName('Hybrid', rng),
    type: 'Hybrid',
    alleles,
    stabilities,
    baseImageName: randomChoice([parentOne.baseImageName, parentTwo.baseImageName], rng),
    lineage: [parentOne.seedId, parentTwo.seedId],
    description: `Child of ${parentOne.strainName} and ${parentTwo.strainName}`,
  });
}

export function cloneProfile(parent: SeedProfile): SeedProfile {
  if (parent.growthStage !== 'MATURE') {
    throw new Error(`${parent.strainName} must be fully mature before cloning`);
  }
  if (!canAttempt(parent)) {
    throw new Error(`${parent.strainName} has reached max breeding/cloning attempts`);
  }
  const seedId = newId('seed');
  return reexpressSeed({
    ...parent,
    seedId,
    strainName: `${parent.strainName} Clone ${seedId.slice(-4)}`,
    alleles: cloneAlleles(parent.alleles),
    stabilities: cloneStabilities(parent.stabilities),
    growthStage: 'SEED',
    maturesAt: null,
    lineage: [parent.seedId, null],
    description: `Clone of ${parent.strainName}`,
    quantity: 1,
    attemptsUsed: 0,
    maxAttempts: parent.maxAttempts,
    isStarter: false,
  });
}

export function breedInState(
  state: GameState,
  parentOneId: string,
  parentTwoId: string,
  rng: RandomSource = Math.random
): { state: GameState; offspring: SeedProfile } {
  const parentOne = findSeed(state, parentOneId);
  const parentTwo = findSeed(state, parentTwoId);
  if (!parentOne || !parentTwo) {
    throw new Error('Parents not found');
  }
  let offspring = breedProfiles(parentOne, parentTwo, rng);
  const takenNames = new Set(state.seeds.map((seed) => seed.strainName));
  if (takenNames.has(offspring.strainName)) {
    offspring = { ...offspring, strainName: `${offspring.strainName} ${offspring.seedId.slice(-4)}` };
  }
  const seeds = state.seeds.map((seed) => {
    if (seed.seedId === parentOne.seedId || seed.seedId === parentTwo.seedId) {
      return { ...seed, attemptsUsed: seed.attemptsUsed + 1 };
    }
    return seed;
  });
  return {
    offspring,
    state: { ...state, seeds: [...seeds, offspring], updatedAt: nowIso() },
  };
}

export function cloneInState(state: GameState, seedId: string): { state: GameState; clone: SeedProfile } {
  const parent = findSeed(state, seedId);
  if (!parent) {
    throw new Error('Seed not found');
  }
  const clone = cloneProfile(parent);
  const seeds = state.seeds.map((seed) =>
    seed.seedId === parent.seedId ? { ...seed, attemptsUsed: seed.attemptsUsed + 1 } : seed
  );
  return {
    clone,
    state: { ...state, seeds: [...seeds, clone], updatedAt: nowIso() },
  };
}