// server/sim/content/kits/ops/op-chen2.js — 假日威龙陈 (char_1013_chen2) 自选 operator kit: 6★ 散射手 (狙击), an owned-6★ pick
// of the tier-5 and tier-6 自选 slots; every skill, both talents, the trait and both modules (RPR-X 沙滩战斗套装, RPR-Y 假期的
// 最后一天) at every form. Kit contract and the 自选 rules: ../README.md ("How to add an operator (自选)").
//
// Forms (data/backups.json units.char_1013_chen2): normal = E2 Lv1, skills at rank 4, no module; elite = E2 Lv60, rank 7,
// the picked module at stage 1 (tier 5) or 3 (tier 6) — the owner's decision of 2026-10-05. Potential 0 [ASSUMED: no
// account]. Sources: character_table / skill_table / battle_equip_table (zh_CN, as built into backups.json) and PRTS
// 假日威龙陈 (节约风气 修正 and 备注, 假日余韵 备注, S2 / S3 备注, the RPR-X stage-1 note); PRTS 作战机制 §地形TAG; PRTS 分支特性
// 信息 散射手 ("可对空", the trait's 1-3 front grid); gamedata_const ba.charged (蓄力).
// - Trait (散射手) "攻击范围内的所有敌人，对自己前方一横排的敌人攻击力提升至150%": the reaperrange profile — every enemy of
//   her range, air units too, ×atk_scale (trait bb) on the trait's front grid (her tile and the three ahead). RPR-X
//   overrides it with atk_scale 1.6 (the same trait, 160 %); RPR-Y adds "部署费用减少" (cost −8, in the stats: her
//   redeploy after a knock-out costs 8 DP less). Ranged physical arrows; blocks 1; ground enemies target her (no flag).
// - T1 节约风气 "在场时自身弹药类技能攻击时20%概率不消耗对应弹药，其他【狙击】干员的弹药类技能改为10%概率不消耗（同类效果取最
//   高）": while she is on the field, an attack made by a running 弹药类技能 (PRTS 备注: a skill whose text says "攻击装有X发
//   弹药 / 子弹" — never the 猎手 bullets) spends no ammo with that chance: hers spareshot_chen.prob, another 【狙击】
//   operator's 20 % — PRTS 修正 (原因 "描述与游戏实际表现不符合", and the RPR-X stage-1 note "实际应为…其他【狙击】干员…20%"):
//   the game gives the other snipers what she has, spareshot_chen.prob, not the text's / `prob`'s 10 % [the mechanism is
//   ASSUMED; the 20 % is PRTS's]. RPR-X stage 3 (talent change): herself e_spareshot_chen.prob 25 %, other 【狙击】
//   operators …[sniper].prob 20 %, other 远程 (RANGED) operators …[other].prob 12 %. 同类效果取最高: the highest chance of
//   every 假日威龙陈 on the field. One roll per attack ("一次性消耗多发弹药时仅进行一次判定"); a spared attack spends nothing
//   of what it would ("强制改为实耗0发"), and every `ammoUsed` of it still fires ("不影响以'消耗弹药'为效果触发条件的侦测":
//   the bullet is put back in that event, before the skill checks for its last bullet) — 拉特兰 / garrison counters see it.
// - T2 假日余韵 "攻击速度+8，当场地中存在水地形时改为攻击速度+12" ([common].attack_speed 8, [map].attack_speed +4). 水地形 is
//   a map TAG (PRTS 作战机制 §地形TAG): no level of this mode carries one (the act1 / act2 autochess level files' mapData.tags
//   are null), so +8. RPR-Y stage 3 "攻击力+15%，攻击速度+12，当场地中存在水地形时改为攻击力+28%，攻击速度+20，技能开启时，场地
//   视为水地形": +15 % / +12, and while her skill runs the field holds the water TAG (PRTS 备注 "在技能期间为当前关卡临时添加
//   '水地形TAG'；干员撤退时或技能结束时清除") — +28 % / +20 for her and for every 假日威龙陈 of that field. The module row's
//   [map] keys are the text's totals (20 / 0.28), the base row's [map] 4 the step over [common] 8 (8 + 4 = 12): read so.
// - S1 高压冲击 (AUTO, attack SP, data DEFAULT — an attack skill): ATK +atk, 4 bullets (attack@trigger_time), every enemy of
//   her range takes the trait's front-row multiplier ("对攻击范围内的所有敌人应用特性加成", as 送葬人 S1).
// - S2 “堇青之夜” (MANUAL, data DEFAULT): ATK +atk, 8 bullets (attack@trigger_time); 蓄力 (maxChargeTime 2; ba.charged "技力达
//   到上限可继续回复，回复至上限2倍时进入蓄力状态，此时开启技能会触发额外效果（任何时候开启均消耗全部技力）"): cast with both
//   charges stored ⇒ attack@another_trigger_time (20) bullets; every cast empties the SP. Every attack leaves slime (below).
// - S3 “假日风暴” (MANUAL, data ACTIVE_RANGE on its 2-6): range 2-6 while it runs, ATK +atk, every attack strikes twice and
//   takes the trait multiplier on every enemy, leaves slime; 32 bullets, 2 per attack — PRTS 备注 "即使剩余弹药数小于2发仍
//   可'消耗2发弹药'进行攻击；技能仅在弹药数归零后自动结束" (one `ammoUsed` per bullet).
// - Slime (S2 / S3 "每次攻击在范围内生成持续5秒的粘液，地面敌人经过时移动速度-N%、防御力-M（不叠加）"): each struck enemy's tile
//   holds slime for attack@projectile_life_time s [ASSUMED: one tile under each enemy an attack strikes — the data calls it
//   a projectile with a life time]; a ground enemy standing on slime moves ×(1 + attack@move_speed) and has DEF
//   attack@def (flat), refreshed every SLIME_IV s so it lapses just after it leaves [ASSUMED]; 不叠加 — one effect, the
//   strongest slime under it; PRTS 备注 "粘液的效果无视无法选择类效果（如隐匿与无敌）": stealthed / invulnerable enemies too.
//   The slime outlives her [ASSUMED]. Air units never (地面敌人).

import { num, talentBb, skillRec, up } from '../shared/tier1.js';
import { bodyKeys } from '../../../body.js';
import { COLS } from '../../../constants.js';

const S1 = 'skchr_chen2_1';
const S2 = 'skchr_chen2_2';
const S3 = 'skchr_chen2_3';
/** PRTS 节约风气 备注: a 弹药类技能 is one whose text says "攻击装有X发弹药" or "攻击装有X发子弹". */
const AMMO_SKILL = /攻击装有\d+发(?:弹药|子弹)/;
/** Slime refresh period and the length of one refresh (the effect lapses SLIME_DUR s after the enemy leaves it). */
const SLIME_IV = 0.1;
const SLIME_DUR = 0.15;
/** Buff key of the slime effect on an enemy (one for every 假日威龙陈: 不叠加). */
export const SLIME_KEY = 'chen2:slime';

const bbOf = (chess, id) => skillRec(chess, id)?.bb ?? {};
const count = (v, d) => Math.max(1, Math.floor(num(v, d)));

// ---- T1 节约风气: one battle-wide pair of handlers over every 假日威龙陈 of the battle ------------------------------------
/** battle → { srcs: Map(unit → { self, sniper, other }) }. */
const SPARE = new WeakMap();

/** The spare chance of `u`'s ammo-skill attack: the highest of the 假日威龙陈 on the field (同类效果取最高). */
export function spareChance(battle, u) {
  const st = SPARE.get(battle);
  if (!st || !u) return 0;
  const op = u.kind === 'op';
  let p = 0;
  for (const [s, v] of st.srcs) {
    if (!up(s)) continue;
    const q = u === s ? v.self : op && u.def?.profession === 'SNIPER' ? v.sniper : op && u.def?.position === 'RANGED' ? v.other : 0;
    if (q > p) p = q;
  }
  return Math.min(1, p);
}

function installSpare(battle, unit, probs) {
  let st = SPARE.get(battle);
  if (!st) {
    st = { srcs: new Map() };
    SPARE.set(battle, st);
    // the roll: when an attack is made by a running 弹药类技能, before its bullets are spent (skills.js onAttackPerformed
    // runs after the `attack` hook); one roll per attack (no draw when nobody's chance applies)
    battle.on('attack', (ctx) => {
      const u = ctx.attacker, sk = u?.skill;
      if (!u || u.side !== 'ally' || !sk || !sk.active || sk.kind !== 'ammo' || !AMMO_SKILL.test(String(sk.def?.description ?? ''))) return;
      const p = spareChance(battle, u);
      u.mem.chen2Spare = { t: battle.time, n: u.stats.attacks, proc: p > 0 && battle.rng.chance(p) };
      if (u.mem.chen2Spare.proc) battle.fx('reload', { x: u.x, y: u.y, id: u.id });
    }, { priority: -50 });
    // the spared attack's every bullet goes back in its own ammoUsed event (the event itself still fires)
    battle.on('ammoUsed', (ctx) => {
      const u = ctx.unit, m = u?.mem?.chen2Spare, sk = ctx.skill;
      if (!m || !m.proc || m.t !== battle.time || m.n !== u.stats.attacks || !sk || !sk.active || sk.kind !== 'ammo') return;
      sk.ammoLeft += 1;
    }, { priority: 100 });
  }
  st.srcs.set(unit, probs);
}

// ---- 水地形 TAG (RPR-Y stage 3): the units holding it on a battle -------------------------------------------------------
/** battle → Set(units whose running skill makes the field count as water). */
const WATER = new WeakMap();
/** Whether the field of `battle` counts as water terrain now (no level of the mode has the TAG of its own). */
export const waterOn = (battle) => (WATER.get(battle)?.size ?? 0) > 0;
function setWater(battle, unit, on) {
  let s = WATER.get(battle);
  if (!s) WATER.set(battle, (s = new Set()));
  if (on) s.add(unit); else s.delete(unit);
}

/**
 * 假日余韵's two lines: { common: { atkPct, aspd }, water: { atkPct, aspd } }. The base row's [map] value is the step over
 * [common] (8 + 4 = the text's 12); a module row's [map] values are the text's totals (RPR-Y: 改为 +28 % / +20).
 */
export function holidayLines(t) {
  const bb = t?.bb ?? {};
  const ca = num(bb['chen2_t_2[common].atk']), cs = num(bb['chen2_t_2[common].attack_speed']);
  const ma = num(bb['chen2_t_2[map].atk']), ms = num(bb['chen2_t_2[map].attack_speed']);
  const total = !!t?.fromModule;
  return { common: { atkPct: ca, aspd: cs }, water: total ? { atkPct: ma || ca, aspd: ms || cs } : { atkPct: ca + ma, aspd: cs + ms } };
}

// ---- slime (S2 / S3): one battle-wide pulse over every puddle ----------------------------------------------------------
/** battle → Map(tileKey → { until, ms, def, src }). */
const SLIME = new WeakMap();

/** The slime puddles of a battle (tile key → puddle), for tests and the pulse. */
export const slimeOf = (battle) => SLIME.get(battle) ?? null;

function slimeState(battle) {
  let m = SLIME.get(battle);
  if (m) return m;
  m = new Map();
  SLIME.set(battle, m);
  // no owner: puddles outlive the unit that left them [ASSUMED]
  battle.every(SLIME_IV, () => {
    if (!m.size) return;
    const now = battle.time;
    for (const [k, p] of m) if (p.until <= now + 1e-9) m.delete(k);
    if (!m.size) return;
    for (const e of battle.enemies) {
      // 地面敌人 only; 无视无法选择 — no targetability check (stealth, invulnerable)
      if (!e.alive || e.hidden || !e.deployed || e.isFlying) continue;
      let best = null;
      for (const k of bodyKeys(e)) {
        const p = m.get(k);
        if (p && (!best || Math.abs(p.def) > Math.abs(best.def) || (Math.abs(p.def) === Math.abs(best.def) && Math.abs(p.ms) > Math.abs(best.ms)))) best = p;
      }
      if (!best) continue;
      battle.addBuff(e, { key: SLIME_KEY, duration: SLIME_DUR, mods: { moveMul: Math.max(0, 1 + best.ms), defFlat: best.def }, source: best.src, tags: ['skill', 'slime'] });
    }
  });
  return m;
}

/**
 * S2 / S3 attack.onHit (once per struck enemy, at the arrow's impact): slime on that enemy's tile for life s; a puddle
 * already there is refreshed, keeping the stronger numbers [ASSUMED: one puddle per tile].
 */
function slimeOnHit(b) {
  const life = num(b['attack@projectile_life_time'], 5), ms = num(b['attack@move_speed']), def = num(b['attack@def']);
  return ({ battle, unit, x, y }) => {
    if (!(life > 0) || (!ms && !def)) return;
    const r = Math.round(y), c = Math.round(x);
    if (!battle.grid.inBounds(r, c)) return;
    const m = slimeState(battle);
    const k = r * COLS + c, until = battle.time + life, old = m.get(k);
    if (!old) {
      m.set(k, { until, ms, def, src: unit });
      battle.fx('zone', { x: c, y: r, radius: 0.5, dur: life, id: unit.id, skill: 'chen2:slime' });
      return;
    }
    if (Math.abs(def) > Math.abs(old.def) || (Math.abs(def) === Math.abs(old.def) && Math.abs(ms) > Math.abs(old.ms))) {
      old.ms = ms; old.def = def; old.src = unit;
    }
    old.until = Math.max(old.until, until);
  };
}

export default {
  char_1013_chen2: (bb, chess) => {
    const b1 = bbOf(chess, S1), b2 = bbOf(chess, S2), b3 = bbOf(chess, S3);
    const s3 = skillRec(chess, S3);
    const t0 = talentBb(chess, 0);
    const t1 = (chess?.talents ?? []).filter((t) => t && t.index !== -1)[1] ?? null;
    const lines = holidayLines(t1);
    const waterSkill = /技能开启时，场地视为水地形/.test(String(t1?.desc ?? ''));
    const frontAll = (battle, u) => num(u.profile?.frontScale, 1.5);
    const spare = {
      self: num(t0['e_spareshot_chen.prob'], num(t0['spareshot_chen.prob'])),
      sniper: num(t0['chen2_t_002[spareshot][sniper].prob'], num(t0['spareshot_chen.prob'])),
      other: num(t0['chen2_t_002[spareshot][other].prob']),
    };
    const s2Charged = count(b2['attack@another_trigger_time'], 0);
    return {
      skills: {
        [S1]: {
          kind: 'ammo',
          ammo: count(b1['attack@trigger_time'], 4),
          mods: { atkPct: num(b1.atk) },
          attack: { dmgMul: frontAll },
        },
        [S2]: {
          kind: 'ammo',
          ammo: count(b2['attack@trigger_time'], 8),
          mods: { atkPct: num(b2.atk) },
          attack: { onHit: slimeOnHit(b2) },
          onStart({ unit, skill }) {
            // 蓄力: cast with every charge stored (activate took one) ⇒ the charged bullets; any cast spends all the SP
            const charged = skill.maxCharges > 1 && skill.charges + 1 >= skill.maxCharges;
            unit.mem.chen2Charged = charged;
            if (charged && s2Charged > skill.ammoLeft) skill.addAmmo(s2Charged - skill.ammoLeft);
            skill.charges = 0;
            skill.sp = 0;
          },
          onEnd({ unit }) { unit.mem.chen2Charged = false; },
        },
        [S3]: {
          kind: 'ammo',
          ammo: count(b3['attack@trigger_time'], 32),
          mods: { atkPct: num(b3.atk) },
          targeting: s3?.rangeGrid ? { rangeGrid: s3.rangeGrid.map((p) => [p[0], p[1]]) } : undefined,
          attack: { hits: 2, dmgMul: frontAll, onHit: slimeOnHit(b3) },
          // 每次攻击消耗2发: the second bullet (the engine spends the other one); with one left she still attacks
          onAttack({ battle, unit, skill }) {
            if (skill.ammoLeft > 1) {
              skill.ammoLeft--;
              battle.emit('ammoUsed', { unit, left: skill.ammoLeft, skill });
            }
          },
        },
      },
      talents: [
        { install(battle, unit) { // 节约风气
          if (spare.self > 0 || spare.sniper > 0 || spare.other > 0) installSpare(battle, unit, spare);
        } },
        { install(battle, unit) { // 假日余韵: +ASPD (+ATK), the water line while the field counts as water
          const KEY = 'talent:chen2:holiday';
          const apply = () => {
            const w = waterOn(battle);
            if (unit.mem.chen2Water === w && unit.findBuff(KEY)) return;
            unit.mem.chen2Water = w;
            const l = w ? lines.water : lines.common;
            const mods = {};
            if (l.atkPct) mods.atkPct = l.atkPct;
            if (l.aspd) mods.aspd = l.aspd;
            if (Object.keys(mods).length) battle.addBuff(unit, { key: KEY, mods, persist: true, allowDead: true, tags: ['talent'] });
            else battle.removeBuff(unit, KEY);
          };
          apply();
          battle.on('tick', apply, { owner: unit });
          if (!waterSkill) return;
          // RPR-Y stage 3 "技能开启时，场地视为水地形": the TAG while her skill runs, gone when it ends or she leaves
          battle.on('skillStart', (ctx) => { if (ctx.unit === unit) { setWater(battle, unit, true); apply(); } }, { owner: unit });
          battle.on('skillEnd', (ctx) => { if (ctx.unit === unit) { setWater(battle, unit, false); apply(); } }, { owner: unit });
          battle.on('death', (ctx) => { if (ctx.unit === unit) setWater(battle, unit, false); }, { owner: unit });
        } },
      ],
    };
  },
};