using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class AIUtils {
    public static BattleHero GetNearestHero(MonsterViewpoint viewpoint,
            BattleParticipant owner) {
        int ownerPosition = GetMonsterPosition(viewpoint, owner);
        return GetNearestEnemy(ownerPosition, viewpoint.Heroes);
    }

    public static BattleMonster GetNearestMonster(MonsterViewpoint viewpoint,
            BattleParticipant owner) {
        int ownerPosition = GetHeroPosition(viewpoint, owner);
        return GetNearestEnemy(ownerPosition, viewpoint.Monsters);
    }

    private static ParticipantT GetNearestEnemy<ParticipantT>(
            int ownerPosition, ParticipantT[] otherTeam)
            where ParticipantT : BattleParticipant{
        int nearestIndex = -1;
        int nearestDistance = int.MaxValue;
        for (int i = 0; i < otherTeam.Length; i++) {
            if (!otherTeam[i].IsAlive()) continue;
            int distance = System.Math.Abs(i - ownerPosition);
            if (distance < nearestDistance) {
                nearestIndex = i;
                nearestDistance = distance;
            }
        }
        return ParticipantAtIndex(nearestIndex, otherTeam);
    }

    public static BattleHero GetFarthestHero(MonsterViewpoint viewpoint,
            BattleParticipant owner) {
        int ownerPosition = GetMonsterPosition(viewpoint, owner);

        int farthestHeroIndex = -1;
        int farthestDistance = -1;
        for (int i = 0; i < viewpoint.Heroes.Length; i++) {
            if (!viewpoint.Heroes[i].IsAlive()) continue;
            int distance = System.Math.Abs(i - ownerPosition);
            if (distance > farthestDistance) {
                farthestHeroIndex = i;
                farthestDistance = distance;
            }
        }
        return ParticipantAtIndex(farthestHeroIndex, viewpoint.Heroes);
    }

    private static int GetMonsterPosition(MonsterViewpoint viewpoint, BattleParticipant monster) {
        for (int i = 0; i < viewpoint.Monsters.Length; i++) {
            if (viewpoint.Monsters[i] == monster) return i;
        }
        return -1;
    }

    private static int GetHeroPosition(MonsterViewpoint viewpoint, BattleParticipant hero) {
        for (int i = 0; i < viewpoint.Heroes.Length; i++) {
            if (viewpoint.Heroes[i] == hero) return i;
        }
        return -1;
    }

    public static BattleHero GetHeroWithHighestHP(MonsterViewpoint viewpoint) {
        int highestHPHeroIndex = -1;
        int highestHP = -1;
        for (int i = 0; i < viewpoint.Heroes.Length; i++) {
            if (!viewpoint.Heroes[i].IsAlive()) continue;
            int heroHP = viewpoint.Heroes[i].GetHP();
            if (heroHP > highestHP) {
                highestHPHeroIndex = i;
                highestHP = heroHP;
            }
        }
        return ParticipantAtIndex(highestHPHeroIndex, viewpoint.Heroes);
    }

    private static ParticipantT ParticipantAtIndex<ParticipantT>(int index, ParticipantT[] team)
            where ParticipantT : BattleParticipant {
        if (index == -1) return null;
        return team[index];
    }
}