ThreeKingdomsSlingshot/Assets/Scripts/OutGame/GachaRules.cs

using System.Collections.Generic;
using UnityEngine;

namespace TKS.OutGame
{
    /// <summary>뽑기 1장 결과.</summary>
    public class GachaPull
    {
        public string heroId;
        /// <summary>뽑힌 희귀도 등급(1~3 · 확률 표 기준).</summary>
        public int tier;
        public bool isNew;
        public bool pickup;
        public bool pity;
        public int shards;
        public int gold;
    }

    /// <summary>
    /// 영웅·유닛 뽑기(기획서 §4 · gacha.csv · gacha_pool.csv): 등급 확률 p_r3/p_r2/p_r1 · 천장 = pity 번째 ★★★ 확정(획득 시 0) ·
    /// ★★★ 중 pickup_share 는 픽업 영웅 · 10연 = ten_guarantee_rarity 이상 1 보장 · 병사 유닛 = ★ 풀 · 중복 = 조각(shard_dup_r*) / 병사 = 골드(soldier_dup_gold) · 첫 10연 무료.
    /// </summary>
    public static class GachaRules
    {
        public static bool FirstTenFree(OutGameData db, SaveData d)
        {
            return db.Gacha.FreeFirstTen && !d.gacha.firstTenUsed;
        }

        /// <summary>count 회 비용(1 = cost_single · ten_count = cost_ten · 첫 10연 무료).</summary>
        public static int Cost(OutGameData db, SaveData d, int count)
        {
            var g = db.Gacha;
            if (count == g.TenCount) return FirstTenFree(db, d) ? 0 : g.CostTen;
            return g.CostSingle * count;
        }

        public static string CanDraw(OutGameData db, SaveData d, int count)
        {
            int cost = Cost(db, d, count);
            if (d.gem < cost) return "보옥 부족 " + d.gem + " / " + cost;
            if (Candidates(db, 1).Count == 0) return "뽑기 풀 비었음";
            return null;
        }

        /// <summary>풀에서 등급 tier 에 나오는 유닛(영웅 = 희귀도 = tier · 병사 = ★ 풀).</summary>
        public static List<GachaConfig.PoolEntry> Candidates(OutGameData db, int tier)
        {
            var res = new List<GachaConfig.PoolEntry>();
            foreach (var p in db.Gacha.pool)
            {
                if (!p.inPool) continue;
                var h = db.Heroes.Get(p.heroId);
                if (h == null) continue;
                int t = h.isSoldier ? 1 : h.rarity;
                if (t == tier) res.Add(p);
            }
            return res;
        }

        public static List<GachaPull> Draw(OutGameData db, SaveData d, int count, System.Random rng)
        {
            var res = new List<GachaPull>();
            if (CanDraw(db, d, count) != null) return res;
            var g = db.Gacha;
            if (count == g.TenCount && FirstTenFree(db, d)) d.gacha.firstTenUsed = true;
            else d.gem -= Cost(db, d, count);

            int gearSlots = HeroRules.GearSlotCount(db);
            bool guaranteed = false;
            for (int i = 0; i < count; i++)
            {
                int n = d.gacha.pity + 1;
                int tier;
                bool pity = n >= g.Pity;
                if (pity) tier = 3;
                else
                {
                    double r = rng.NextDouble();
                    tier = r < g.P(3) ? 3 : r < g.P(3) + g.P(2) ? 2 : 1;
                }
                if (tier >= g.TenGuaranteeRarity) guaranteed = true;
                if (count == g.TenCount && i == count - 1 && !guaranteed) tier = g.TenGuaranteeRarity;
                d.gacha.pity = tier == 3 ? 0 : n;
                d.gacha.total++;
                var pull = Pick(db, tier, rng);
                if (pull == null) continue;
                pull.pity = pity;
                var h = db.Heroes.Get(pull.heroId);
                if (HeroRules.Grant(db, d, h, gearSlots)) pull.isNew = true;
                else if (h.isSoldier)
                {
                    pull.gold = db.Economy.SoldierDupGold;
                    d.gold += pull.gold;
                }
                else
                {
                    pull.shards = db.Economy.ShardDup(h.rarity);
                    d.Hero(h.id).shards += pull.shards;
                }
                res.Add(pull);
            }
            return res;
        }

        static GachaPull Pick(OutGameData db, int tier, System.Random rng)
        {
            var list = Candidates(db, tier);
            for (int t = tier; list.Count == 0 && t > 1; t--) list = Candidates(db, t - 1); // 그 등급 풀이 비면 아래 등급
            if (list.Count == 0) return null;
            if (tier == 3)
            {
                var pick = new List<GachaConfig.PoolEntry>();
                var rest = new List<GachaConfig.PoolEntry>();
                foreach (var p in list) (p.pickup ? pick : rest).Add(p);
                if (pick.Count > 0 && (rest.Count == 0 || rng.NextDouble() < db.Gacha.PickupShare)) list = pick;
                else if (rest.Count > 0) list = rest;
            }
            var e = list[rng.Next(list.Count)];
            return new GachaPull { heroId = e.heroId, tier = tier, pickup = e.pickup && tier == 3 };
        }
    }
}