// server/match/bondsMeta.js — bond member counting, activation tiers and persistent layers (DESIGN §6.3,
// research 02 §2.1–§2.2).
//
// Counting modes (data/bonds.json `countMode`):
//   BOARD            distinct base chess (normal/elite of one operator count once) on the board carrying the bond
//   BOARD_AND_DECK   BOARD + the hand (整备区; the 5 temporary slots do not count) — 远见 / 奇迹 / 投资人
//   BOARD_ALL_CHESS  every elite (精锐) chess on the board, duplicates included — 绝技 (thresholdTemplate *_golden)
// Membership = the chess's own `bonds` + bonds granted by 变形同构体 (an item with `canGiveBond`) worn together with
// an item that has a `giveBondId` (research 02 §2.1).
// Special rules:
//   调和 (maniShip): while active, every CORE bond that already has ≥ 1 real member on the board gets count +1
//                    (one +1 total, research 02 §2.1 [ASSUMED]).
//   助力 (deputShip): tier 1 needs `thresholds[0]` distinct operators; the upper tiers count operators that differ
//                    in name OR elite state (PRTS 修正).
//   独行 (soloShip, count_threshold_downward): active iff 1 ≤ count ≤ maxCount (distinct 独行 operators).
//   Bonds in the mode's static inactive list (FUNNY) never activate and are omitted.
// `tier` = number of thresholds reached (downward: 1 when active); `active = tier ≥ 1`.
// Layers (`ps.layers[bondId]`) persist the whole match; they are reported for every bond but only matter while active.

import { layerGainRoom } from '../../shared/constants.js';

export const HARMONY_BOND = 'maniShip';
export const DEPUTY_BOND = 'deputShip';

/**
 * Bonds of a chess piece: own bonds ∪ bonds granted by 变形同构体 pairings.
 * @param {import('./gamedata.js').GameData} gd
 * @param {{ id: string, items?: Array<{ id: string }> }} piece
 * @returns {string[]}
 */
export function pieceBonds(gd, piece) {
  const c = gd.chess(piece.id);
  const out = c && Array.isArray(c.bonds) ? c.bonds.slice() : [];
  const items = Array.isArray(piece.items) ? piece.items : [];
  if (items.length >= 2) {
    const recs = items.map((it) => gd.item(it.id)).filter(Boolean);
    if (recs.some((r) => r.canGiveBond)) {
      for (const r of recs) {
        if (r.canGiveBond) continue;
        if (typeof r.giveBondId === 'string' && gd.bond(r.giveBondId) && !out.includes(r.giveBondId)) out.push(r.giveBondId);
      }
    }
  }
  return out;
}

/**
 * Compute every bond's state for a player.
 * @param {import('./gamedata.js').GameData} gd
 * @param {{ board: Map<string, any>, hand: Array<any>, layers: Record<string, number>, bondCountBonus?: Record<string, number> }} ps
 * @returns {Record<string, { count: number, active: boolean, tier: number, layers: number }>}
 */
export function computeBonds(gd, ps) {
  const boardChess = [];
  for (const p of ps.board.values()) if (p && p.kind === 'chess') boardChess.push(p);
  const handChess = ps.hand.filter((p) => p && p.kind === 'chess');

  /** bondId → Set(baseId) on board / hand; bondId → Set(baseId|golden) on board */
  const onBoard = new Map();
  const onBoardVariant = new Map();
  const inHand = new Map();
  const add = (m, bond, key) => { let s = m.get(bond); if (!s) m.set(bond, (s = new Set())); s.add(key); };
  for (const p of boardChess) {
    const base = gd.baseIdOf(p.id);
    const golden = gd.isGolden(p.id);
    for (const b of pieceBonds(gd, p)) { add(onBoard, b, base); add(onBoardVariant, b, `${base}|${golden ? 1 : 0}`); }
  }
  for (const p of handChess) {
    const base = gd.baseIdOf(p.id);
    for (const b of pieceBonds(gd, p)) add(inHand, b, base);
  }
  const goldenOnBoard = boardChess.filter((p) => gd.isGolden(p.id)).length;

  /** @type {Record<string, { count: number, active: boolean, tier: number, layers: number }>} */
  const out = {};
  const layersOf = (id) => {
    const v = ps.layers && ps.layers[id];
    return Number.isFinite(v) && v > 0 ? v : 0;
  };
  const bonus = ps.bondCountBonus || {};
  const bonusOf = (id) => (Number.isInteger(bonus[id]) ? bonus[id] : 0);

  // first pass: raw counts
  const raw = {};
  for (const id of gd.bondIds) {
    if (gd.modeInactiveBonds.has(id)) continue;
    const bond = gd.bond(id);
    let count;
    if (bond.countMode === 'BOARD_ALL_CHESS' || bond.thresholdTemplate === 'count_threshold_upward_golden') {
      count = goldenOnBoard;
    } else if (bond.countMode === 'BOARD_AND_DECK') {
      const s = new Set([...(onBoard.get(id) || []), ...(inHand.get(id) || [])]);
      count = s.size;
    } else {
      count = (onBoard.get(id) || new Set()).size;
    }
    raw[id] = Math.max(0, count + bonusOf(id));
  }
  // 调和: +1 to core bonds with ≥ 1 real board member while it is active
  const harmony = gd.bond(HARMONY_BOND);
  const harmonyActive = harmony && raw[HARMONY_BOND] != null && tierFor(harmony, raw[HARMONY_BOND]) >= 1;
  for (const id of Object.keys(raw)) {
    const bond = gd.bond(id);
    let count = raw[id];
    if (harmonyActive && bond.isCore && (onBoard.get(id)?.size ?? 0) >= 1) count += 1;
    let tier = tierFor(bond, count);
    if (id === DEPUTY_BOND && tier >= 1) {
      // upper tiers: operators differing in name OR elite state
      const variants = (onBoardVariant.get(id)?.size ?? 0) + bonusOf(id);
      const th = thresholdsOf(bond);
      let t = 1;
      for (let i = 1; i < th.length; i++) if (variants >= th[i]) t = i + 1;
      tier = t;
    }
    out[id] = { count, active: tier >= 1, tier, layers: layersOf(id) };
  }
  return out;
}

/** Ascending member-count thresholds of a bond (fallback: activeCount). */
export function thresholdsOf(bond) {
  if (Array.isArray(bond.thresholds) && bond.thresholds.length) return bond.thresholds.filter((n) => Number.isFinite(n)).sort((a, b) => a - b);
  if (Number.isFinite(bond.activeCount)) return [bond.activeCount];
  return [2];
}

/** Tier for a member count (downward bonds: 1 while 1 ≤ count ≤ maxCount). */
export function tierFor(bond, count) {
  const th = thresholdsOf(bond);
  if (bond.thresholdTemplate === 'count_threshold_downward') {
    const max = Number.isFinite(bond.maxCount) ? bond.maxCount : th[0];
    return count >= th[0] && count <= max ? 1 : 0;
  }
  let t = 0;
  for (const n of th) if (count >= n) t++;
  return t;
}

/** Σ layers over active bonds (hidden-core check, 不朽盟约 title). */
export function activatedLayers(bonds) {
  let n = 0;
  for (const b of Object.values(bonds || {})) if (b.active) n += b.layers || 0;
  return n;
}

/**
 * View list for m.private / m.public: bonds with members or layers, active first, then layers desc, then data order.
 * @param {import('./gamedata.js').GameData} gd
 * @param {ReturnType<typeof computeBonds>} bonds
 * @param {{ full?: boolean }} [opts] full → include thresholds/countsHand (m.private)
 */
export function bondList(gd, bonds, { full = false } = {}) {
  const order = new Map(gd.bondIds.map((id, i) => [id, i]));
  const list = [];
  for (const [bondId, b] of Object.entries(bonds || {})) {
    if (!(b.count > 0 || b.layers > 0 || b.active)) continue;
    const e = { bondId, count: b.count, active: b.active, tier: b.tier, layers: b.layers };
    if (full) {
      const bond = gd.bond(bondId);
      e.thresholds = bond ? thresholdsOf(bond) : [];
      e.countsHand = !!(bond && bond.countMode === 'BOARD_AND_DECK');
    }
    list.push(e);
  }
  list.sort((a, b) => (b.active - a.active) || (b.layers - a.layers) || ((order.get(a.bondId) ?? 99) - (order.get(b.bondId) ?? 99)));
  return list;
}

/**
 * The bond states the views show (m.private / m.public players[].bonds, DESIGN §20.15): `bonds` with this round's
 * IN_BATTLE gains of a finished normal battle (`gains` = the result's layerGains, PlayerState.pendingLayerGains, set
 * when the COMBAT phase ends) added the way settle() will add them — at most up to BOND_LAYER_CAP — so the strip of a
 * player (and of a teammate watching him) keeps the layers his battle reached through the 联防 until the settlement
 * makes them persistent. `bonds` itself when there is nothing to add; the persistent state is never touched.
 * @param {ReturnType<typeof computeBonds>} bonds
 * @param {Record<string, number>|null|undefined} gains
 */
export function bondsWithGains(bonds, gains) {
  if (!gains || typeof gains !== 'object') return bonds;
  let out = null;
  for (const [id, n] of Object.entries(gains)) {
    const b = bonds && bonds[id];
    if (!b) continue;
    const add = layerGainRoom(b.layers, Math.floor(Number(n) || 0));
    if (!(add > 0)) continue;
    if (!out) out = { ...bonds };
    out[id] = { ...b, layers: (b.layers || 0) + add };
  }
  return out || bonds;
}

/** Snapshot for PlayerBattleInput.bonds: { [bondId]: { count, active, tier, layers } } (plain copy). */
export function bondSnapshot(bonds) {
  const o = {};
  for (const [id, b] of Object.entries(bonds || {})) o[id] = { count: b.count, active: b.active, tier: b.tier, layers: b.layers };
  return o;
}