using System;
using UnityEngine;

[Serializable]
public class EnemyIdle : State<Character>
{
    StatData actionDelayStat;
    float actionDelayTime => actionDelayStat != null ? actionDelayStat.Value : 0;
    float actionDelayElapsedTime;
    bool IsInActionDelay => actionDelayTime > actionDelayElapsedTime;

    StatData attackDistanceStat;

    EnemyChasePlayer chaseState;
    EnemyAttack attackState;
    EnemyCastSkill castSkillState;

    protected override void OnInitialize()
    {
        Owner.Excutor.Data.TryGetStat(StatID.ActionDelay, out actionDelayStat);
        Owner.Excutor.Data.TryGetStat(StatID.AttackDistance, out attackDistanceStat);
        
        Owner.TryGetState(out chaseState);
        Owner.TryGetState(out attackState);
        Owner.TryGetState(out castSkillState);

        Debug.Assert(chaseState != null, "chase state not exist");
        Debug.Assert(attackState != null, "attack state not exist");
        Debug.Assert(castSkillState != null, "cast skill state not exist");

        actionDelayElapsedTime = actionDelayTime;
        Debug.Assert(Owner.Excutor.SkeletonAnimation.TryGetAnimation("idle", out Spine.Animation _), "idle animation not exist");
    }

    public override void Enter()
    {
        Owner.Excutor.IsBattleReady = true;
        Owner.Excutor.SkeletonAnimation.AnimationState.SetAnimation(0, "idle", true);
    }

    public override void Excute()
    {
        actionDelayElapsedTime = MathF.Min(actionDelayElapsedTime + Time.fixedDeltaTime, actionDelayTime);

        if (IsInActionDelay) return;

        if (castSkillState.TryGetCurrentTopSkill(out var topSkill) && !topSkill.IsInCoolTime) // if there is a skill to cast
        {
            topSkill.transform.position = Owner.Excutor.CenterPivot;
            if (topSkill.IsTargetExistInCastRange())
            {
                Owner.ChangeState<EnemyCastSkill>();
                actionDelayElapsedTime = 0f;
            }
            else if (TargetFinder.TryFindNearest(Owner.Excutor.Position, Owner.Excutor.TargetTags, out var nearest))
            {
                chaseState.SetTarget(nearest as Entity, topSkill.CastDistance);
                Owner.ChangeState<EnemyChasePlayer>();
            }
        }
        else if(attackDistanceStat != null)
        {
            if (!TargetFinder.TryFindNearest(Owner.Excutor.Position, Owner.Excutor.TargetTags, out var nearest)) return;

            float attackDistance = attackDistanceStat.Value;

            Vector2 to = (nearest as Entity).Position - Owner.Excutor.Position;
            if(to.sqrMagnitude <= attackDistance * attackDistance)
            {
                attackState.Target = nearest;
                Owner.ChangeState<EnemyAttack>();
                actionDelayElapsedTime = 0f;
            }
            else
            {
                chaseState.SetTarget(nearest as Entity, attackDistance);
                Owner.ChangeState<EnemyChasePlayer>();
            }
        }
    }
}