using UnityEngine;

namespace TKS.OutGame
{
    /// <summary>
    /// 내정 훈련 규칙(기획서 §7 · S9 · PD #1093 C) — 병종마다 HP·공·방 3항목 골드 레벨업(항목당 Lv max) · 비용 = gold_cost(Lv) × cost_mult(랭크) ·
    /// 3항목 Max → 랭크 승급(promote_gold · 레벨 리셋 · 랭크 보너스 유지) · train_bonus(병종, 항목) = rank_pct(랭크) + stat_pct(Lv) → §3-2 공식(그 병종 영웅·병사 전원).
    /// </summary>
    public static class TrainingRules
    {
        public static int StatIndex(string stat)
        {
            return System.Array.IndexOf(TrainingTable.Stats, stat);
        }

        static TrainState Find(SaveData d, UnitType t)
        {
            if (d == null || d.training == null) return null;
            var key = UnitTypeInfo.Key(t);
            foreach (var s in d.training)
                if (s.type == key) return s;
            return null;
        }

        public static int Rank(SaveData d, UnitType t)
        {
            var s = Find(d, t);
            return s != null ? Mathf.Max(1, s.rank) : 1;
        }

        public static int Lv(SaveData d, UnitType t, int stat)
        {
            var s = Find(d, t);
            return s != null && s.lv != null && stat >= 0 && stat < s.lv.Length ? s.lv[stat] : 0;
        }

        /// <summary>훈련 보너스 % = 랭크 보너스 + 항목 Lv 누적 %.</summary>
        public static float Bonus(OutGameData db, SaveData d, UnitType t, string stat)
        {
            if (db == null || db.Training == null || d == null) return 0f;
            var rank = db.Training.RankOf(Rank(d, t));
            int lv = Lv(d, t, StatIndex(stat));
            var row = lv > 0 ? db.Training.Get(t, stat, lv) : null;
            return (rank != null ? rank.rankPct : 0f) + (row != null ? row.statPct : 0f);
        }

        /// <summary>다음 Lv 비용(최고 Lv = 0).</summary>
        public static int Cost(OutGameData db, SaveData d, UnitType t, int stat)
        {
            int lv = Lv(d, t, stat);
            var row = db.Training.Get(t, TrainingTable.Stats[stat], lv + 1);
            var rank = db.Training.RankOf(Rank(d, t));
            if (row == null) return 0;
            return Mathf.RoundToInt(row.goldCost * (rank != null ? rank.costMult : 1f));
        }

        public static string CanLevel(OutGameData db, SaveData d, UnitType t, int stat)
        {
            if (Lv(d, t, stat) >= db.Training.MaxLevel) return "Max";
            int cost = Cost(db, d, t, stat);
            if (d.gold < cost) return "골드 부족 " + d.gold.ToString("N0") + " / " + cost.ToString("N0");
            return null;
        }

        public static string Level(OutGameData db, SaveData d, UnitType t, int stat)
        {
            var why = CanLevel(db, d, t, stat);
            if (why != null) return why;
            d.gold -= Cost(db, d, t, stat);
            d.Train(t).lv[stat]++;
            return null;
        }

        /// <summary>이 랭크에서 남은 레벨 수(3항목 × Max − 합).</summary>
        public static int Remaining(OutGameData db, SaveData d, UnitType t)
        {
            int left = 0;
            for (int i = 0; i < TrainingTable.Stats.Length; i++) left += db.Training.MaxLevel - Lv(d, t, i);
            return left;
        }

        public static int PromoteCost(OutGameData db, SaveData d, UnitType t)
        {
            var r = db.Training.RankOf(Rank(d, t));
            return r != null ? r.promoteGold : 0;
        }

        public static string CanPromote(OutGameData db, SaveData d, UnitType t)
        {
            if (Rank(d, t) >= db.Training.MaxRank) return "최종 랭크";
            int left = Remaining(db, d, t);
            if (left > 0) return "남은 레벨 " + left;
            int cost = PromoteCost(db, d, t);
            if (d.gold < cost) return "골드 부족 " + d.gold.ToString("N0") + " / " + cost.ToString("N0");
            return null;
        }

        /// <summary>랭크 +1 · 3항목 Lv 리셋(랭크 보너스는 새 랭크 값).</summary>
        public static string Promote(OutGameData db, SaveData d, UnitType t)
        {
            var why = CanPromote(db, d, t);
            if (why != null) return why;
            d.gold -= PromoteCost(db, d, t);
            var s = d.Train(t);
            s.rank++;
            s.lv = new int[TrainingTable.Stats.Length];
            return null;
        }

        public static string RankName(OutGameData db, int rank)
        {
            var r = db.Training.RankOf(rank);
            return r != null ? r.nameKo : "";
        }
    }
}