import { clamp } from './formulas.js';

export const STATE_VERSION = 1;

const MAX_NUMBER = 1e300;
const MAX_OWNED = 4000; // keeps cost formulas (growth ** owned) finite
const MAX_MARKETING = 300;

export function createState(ctx, now = Date.now()) {
  const { start, market } = ctx.rules;
  return {
    v: STATE_VERSION,
    units: start.units,
    funds: start.funds,
    material: start.material,
    totalProduced: 0,
    totalSold: 0,
    price: start.price ?? market.basePrice,
    marketing: 0,
    materialFactor: 1,
    generators: Object.fromEntries(ctx.generators.map((g) => [g.id, 0])),
    upgrades: [],
    savedAt: now,
    materialTimer: 0, // transient, never saved
  };
}

function num(value, fallback, min = 0, max = MAX_NUMBER) {
  return Number.isFinite(value) ? clamp(value, min, max) : fallback;
}

function int(value, max) {
  return Math.floor(num(value, 0, 0, max));
}

/**
 * Turn untrusted data (cookie, imported file) into a valid state.
 * Unknown ids are dropped and numbers are clamped; returns null if `raw` is not an object.
 */
export function sanitizeState(raw, ctx, now = Date.now()) {
  if (!raw || typeof raw !== 'object' || Array.isArray(raw)) return null;
  const { market, materialMarket } = ctx.rules;
  const base = createState(ctx, now);

  const owned = Array.isArray(raw.upgrades) ? raw.upgrades : [];
  return {
    ...base,
    units: num(raw.units, base.units),
    funds: num(raw.funds, base.funds),
    material: num(raw.material, base.material),
    totalProduced: num(raw.totalProduced, 0),
    totalSold: num(raw.totalSold, 0),
    price: Math.round(num(raw.price, base.price, market.minPrice, market.maxPrice) * 100) / 100,
    marketing: int(raw.marketing, MAX_MARKETING),
    materialFactor: num(raw.materialFactor, 1, materialMarket.minFactor, materialMarket.maxFactor),
    generators: Object.fromEntries(
      ctx.generators.map((g) => [g.id, int(raw.generators?.[g.id], MAX_OWNED)]),
    ),
    upgrades: [...new Set(owned)].filter((id) => ctx.upgradesById.has(id)),
    savedAt: num(raw.savedAt, now, 0, now),
  };
}

/** Compact JSON (numbers trimmed to 10 significant digits) for cookies and export. */
export function serializeState(state) {
  const { materialTimer, ...persisted } = state;
  return JSON.stringify(persisted, (_key, value) =>
    typeof value === 'number' && Number.isFinite(value) ? Number(value.toPrecision(10)) : value,
  );
}