using System.Collections.Generic;
using System.Linq;

public class Buff {
    private BuffType mType;
    private int mAmount;
    private BattleTime mEnd;

    public Buff(BuffType type, int amount, BattleTime end) {
        mType = type;
        mAmount = amount;
        mEnd = end;
    }

    public BuffType Type {get => mType;}
    public int Amount {get => mAmount;}
    public BattleTime End {get => mEnd;}
}

public class BuffManager {

    private Dictionary<BattleParticipant, List<Buff>> mBuffs = new Dictionary<BattleParticipant, List<Buff>>();

    public BuffManager(BattleClock clock) {
        clock.OnTimeChanged += NotifyBattleTime;
    }
    
    public void AddBuff(BuffParticipantEffect effect, BattleTime timeNow) {
        List<Buff> current = GetAllBuffsFor(effect.Participant);
        current.Add(new Buff(effect.Type, effect.Amount, CalculateEnd(timeNow, effect.Duration)));
        mBuffs[effect.Participant] = current;
        effect.Participant.TriggerOnBuffsChanged();
    }

    public int GetTotalBuffAmountOfType(BattleParticipant participant, BuffType type) {
        int total = 0;
        foreach (Buff buff in GetAllBuffsFor(participant)) {
            if (buff.Type == type) {
                total += buff.Amount;
            }
        }
        return total;
    }

    public List<Buff> GetAllBuffsFor(BattleParticipant participant) {
        if (mBuffs.ContainsKey(participant)) {
            return mBuffs[participant];
        } else {
            return new List<Buff>();
        }
    }

    private void NotifyBattleTime(BattleTime timeNow) {
        foreach (KeyValuePair<BattleParticipant, List<Buff>> p in mBuffs) {
            BattleParticipant participant = p.Key;
            List<Buff> buffs = p.Value;
            int buffsRemoved = buffs.RemoveAll(buff => timeNow.Int >= buff.End.Int);
            if (buffsRemoved > 0) {
                participant.TriggerOnBuffsChanged();
            }
        }
    }

    private static BattleTime CalculateEnd(BattleTime timeNow, BuffDuration duration) {
        if (duration == BuffDuration.UntilEndOfNextHeroTurn) {
            return new BattleTime(timeNow.RoundNumber + 1, RoundStep.EndOfHeroTurn);
        }
        throw new System.Exception();
    }
}