using Cielonos.MainGame.Characters;
using UnityEngine;

namespace Cielonos.MainGame
{
    public partial class TraceMoveSubmodule : MoveSubmoduleBase
    {
        public Transform projectile => owner.topParent;
        public CharacterBase target;
        public float angularSpeed;
        public float angularAcceleration;
        public float moveSpeed;
        public float moveAcceleration;

        public bool autoConnect;
        public bool autoDisconnect;
        public float detectRadius;

        private float deltaTime => owner.creator.selfTimeSm.DeltaTime;
        private Vector3 step;
        
        public TraceMoveSubmodule(AttackAreaBase attackArea, CharacterBase target, 
            float moveSpeed, float moveAcceleration, float angularSpeed, float angularAcceleration, Vector3 initialDirection, 
            bool autoConnect, bool autoDisconnect, float detectRadius, bool stopWhenHit) : base(attackArea, stopWhenHit)
        {
            this.target = target;
            this.angularSpeed = angularSpeed;
            this.angularAcceleration = angularAcceleration;
            this.moveSpeed = moveSpeed;
            this.moveAcceleration = moveAcceleration;
            this.autoConnect = autoConnect;
            this.autoDisconnect = autoDisconnect;
            this.detectRadius = detectRadius;
            projectile.forward = initialDirection;
        }

        public override void Update()
        {
            if (target == null || target.statusSm.isDead)
            {
                moveSpeed += moveAcceleration * deltaTime;
                moveSpeed = Mathf.Max(moveSpeed, 0f);
                unscaledVelocity = projectile.forward * moveSpeed;
                scaledVelocity = timeScaleCoefficient * unscaledVelocity;
                projectile.position += scaledVelocity * deltaTime;

                if (autoConnect)
                {
                    if (owner.creator == MainGameManager.Player)
                    {
                        CharacterBase detectEnemy = BattleManager.EnemySm.GetNearestEnemy(detectRadius, owner.transform);
                        if (detectEnemy != null)
                        {
                            target = detectEnemy;
                        }
                    }
                }

                return;
            }

            angularSpeed += angularAcceleration * deltaTime;
            moveSpeed += moveAcceleration * deltaTime;
            angularSpeed = Mathf.Max(angularSpeed, 0f);
            moveSpeed = Mathf.Max(moveSpeed, 0f);
                
            Vector3 direction = target.centerPoint.position - projectile.position;
            if (direction != Vector3.zero) 
            {
                Quaternion targetRotation = Quaternion.LookRotation(direction);
                // RotateTowards 保证恒定转速，不会因为角度小而变慢
                projectile.rotation = Quaternion.RotateTowards(projectile.rotation, targetRotation, angularSpeed * deltaTime);
            }
            
            unscaledVelocity = projectile.forward * moveSpeed;
            scaledVelocity = unscaledVelocity * timeScaleCoefficient;
            projectile.position += scaledVelocity * deltaTime;

            if (autoDisconnect)
            {
                float distanceToTarget = Vector3.Distance(projectile.position, target.centerPoint.position);
                if (distanceToTarget > detectRadius)
                {
                    target = null;
                }
            }
        }
    }
}