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

export const STATE_VERSION = 2;

const MAX_NUMBER = 1e300;
const MAX_OWNED = 4000; // keeps cost formulas (growth ** owned) finite
const MAX_MARKETING = 300;
const MAX_LEVEL = 1000;

const STAT_KEYS = ['gambleWins', 'gambleLosses', 'contractsDone', 'eventsClaimed', 'investProfit'];

// Fields that only exist while the game runs and are never saved.
const TRANSIENT = [
  'materialTimer',
  'materialTrend',
  'investTimer',
  'contractTimer',
  'eventTimer',
  'gambleCooldown',
];

// What a legacy reset keeps (the "meta" progression); everything else is the run.
export const META_KEYS = [
  'lifetimeProduced',
  'stats',
  'research',
  'labs',
  'rp',
  'legacy',
  'achievements',
];

function newInvest(ctx) {
  const ids = ctx.investments.societies.map((s) => s.id);
  return {
    prices: Object.fromEntries(ctx.investments.societies.map((s) => [s.id, s.basePrice])),
    holdings: Object.fromEntries(ids.map((id) => [id, 0])),
    basis: Object.fromEntries(ids.map((id) => [id, 0])),
    change: Object.fromEntries(ids.map((id) => [id, 0])),
  };
}

export function createState(ctx, now = Date.now()) {
  const { start, market, events, contracts } = ctx.rules;
  return {
    v: STATE_VERSION,

    // --- the run (reset by a legacy restart)
    units: start.units,
    funds: start.funds,
    material: start.material,
    totalProduced: 0,
    totalSold: 0,
    price: start.price ?? market.referencePrice,
    marketing: 0,
    materialFactor: 1,
    generators: Object.fromEntries(ctx.generators.map((g) => [g.id, 0])),
    upgrades: [],
    invest: newInvest(ctx),
    chips: 0,
    reliabilityLevel: 0,
    contracts: { offers: [], active: null },
    events: { current: null, buffs: [] },

    // --- meta progression (survives a legacy restart)
    lifetimeProduced: 0,
    stats: Object.fromEntries(STAT_KEYS.map((k) => [k, 0])),
    research: [],
    labs: 0,
    rp: 0,
    legacy: { points: 0, earned: 0, prestiges: 0, perks: {} },
    achievements: [],

    savedAt: now,

    // --- transient
    materialTimer: 0,
    materialTrend: 0, // -1 falling, 0 steady, 1 rising
    investTimer: 0,
    contractTimer: contracts.offerEverySeconds,
    eventTimer: events.minSeconds,
    gambleCooldown: 0,
  };
}

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));
}

function knownIds(list, known) {
  return [...new Set(Array.isArray(list) ? list : [])].filter((id) => known.has(id));
}

function sanitizeInvest(raw, ctx, base) {
  const inv = ctx.investments;
  const out = newInvest(ctx);
  for (const s of inv.societies) {
    out.prices[s.id] = num(raw?.prices?.[s.id], base.prices[s.id], s.basePrice * inv.minRatio, s.basePrice * inv.maxRatio);
    out.holdings[s.id] = num(raw?.holdings?.[s.id], 0);
    out.basis[s.id] = out.holdings[s.id] > 0 ? num(raw?.basis?.[s.id], 0) : 0;
    out.change[s.id] = num(raw?.change?.[s.id], 0, -1, 100);
  }
  return out;
}

function sanitizeContracts(raw, ctx) {
  const templates = new Set(ctx.rules.contracts.templates.map((t) => t.id));
  const rewardTypes = new Set(ctx.rules.contracts.rewards);
  const offer = (o) => {
    if (!o || !templates.has(o.template) || !rewardTypes.has(o.reward?.type)) return null;
    return {
      template: o.template,
      seconds: num(o.seconds, 60, 1, 3600),
      target: num(o.target, 1, 1),
      reward: { type: o.reward.type, amount: num(o.reward.amount, 0) },
    };
  };
  const offers = (Array.isArray(raw?.offers) ? raw.offers : []).map(offer).filter(Boolean);
  const active = offer(raw?.active?.offer);
  return {
    offers: offers.slice(0, ctx.rules.contracts.maxOffers),
    active: active
      ? {
          offer: active,
          progress: num(raw.active.progress, 0, 0, active.target),
          remaining: num(raw.active.remaining, active.seconds, 0, active.seconds),
        }
      : null,
  };
}

function sanitizeEvents(raw, ctx) {
  const types = new Map(ctx.rules.events.types.map((t) => [t.id, t]));
  const current = raw?.current;
  const buffTypes = new Set(['demand_mult', 'global_mult', 'material_price_mult']);
  return {
    current:
      current && types.has(current.type) && !types.get(current.type).auto
        ? { type: current.type, remaining: num(current.remaining, 0, 0, ctx.rules.events.claimSeconds) }
        : null,
    buffs: (Array.isArray(raw?.buffs) ? raw.buffs : [])
      .filter((b) => b && buffTypes.has(b.type) && Number.isFinite(b.value) && Number.isFinite(b.remaining))
      .slice(0, 20)
      .map((b) => ({
        type: b.type,
        value: clamp(b.value, 0.01, 100),
        remaining: clamp(b.remaining, 0, 3600),
      })),
  };
}

/**
 * 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.
 * Saves from older versions are upgraded: missing fields take their defaults.
 */
export function sanitizeState(raw, ctx, now = Date.now()) {
  if (!raw || typeof raw !== 'object' || Array.isArray(raw)) return null;
  const { market, materialMarket, gamble } = ctx.rules;
  const base = createState(ctx, now);

  const generators = Object.fromEntries(
    ctx.generators.map((g) => [g.id, int(raw.generators?.[g.id], MAX_OWNED)]),
  );
  const totalProduced = num(raw.totalProduced, 0);

  const perks = {};
  for (const perk of ctx.legacy) {
    const level = int(raw.legacy?.perks?.[perk.id], perk.maxLevel);
    if (level > 0) perks[perk.id] = level;
  }

  return {
    ...base,
    units: num(raw.units, base.units),
    funds: num(raw.funds, base.funds),
    material: num(raw.material, base.material),
    totalProduced,
    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,
    upgrades: knownIds(raw.upgrades, ctx.upgradesById),
    invest: sanitizeInvest(raw.invest, ctx, base.invest),
    chips: int(raw.chips, gamble.maxChips),
    reliabilityLevel: int(raw.reliabilityLevel, gamble.reliability.maxLevel),
    contracts: sanitizeContracts(raw.contracts, ctx),
    events: sanitizeEvents(raw.events, ctx),

    // Saves from before lifetime tracking: the current run is all we know.
    lifetimeProduced: Math.max(num(raw.lifetimeProduced, 0), totalProduced),
    stats: Object.fromEntries(STAT_KEYS.map((k) => [k, num(raw.stats?.[k], 0)])),
    research: knownIds(raw.research, ctx.researchById),
    labs: int(raw.labs, ctx.rules.research.labMax),
    rp: num(raw.rp, 0),
    legacy: {
      points: int(raw.legacy?.points, MAX_LEVEL * 100),
      earned: int(raw.legacy?.earned, MAX_LEVEL * 100),
      prestiges: int(raw.legacy?.prestiges, MAX_LEVEL),
      perks,
    },
    achievements: knownIds(raw.achievements, ctx.achievementsById),
    savedAt: num(raw.savedAt, now, 0, now),
  };
}

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