using System;
using SLSUtilities.General;
using UnityEngine;

namespace Cielonos.MainGame.Characters
{
    public partial class AuxiliaryDrone : MonoBehaviour
    {
        public Player player => MainGameManager.Player;
        public GameObject droneModel;
        public Transform center;
        public Transform muzzle;
        public Vector3 velocity, offset;

        private void Start()
        {
            SetDroneEmissionColor(Color.cyan);
        }

        private void Update()
        {
            // selfTimeSm.TimeScale 不包含 Unity 的 Time.timeScale，
            // 因此暂停时 TimeScale 可能非零但 DeltaTime 为零，需检查 DeltaTime 避免除零。
            float deltaTime = player.selfTimeSm.DeltaTime;
            if (deltaTime < Mathf.Epsilon)
            {
                return;
            }
            
            Vector3 moveDirection = player.landMovementSc.horizontalMovement / deltaTime;
            moveDirection *= 0.1f;

            Transform playerTransform = player.transform;
            Vector3 cameraRight = player.viewSc.playerCamera.transform.right;
            float dot = Vector3.Dot(moveDirection.normalized, cameraRight);
            Vector3 realOffset = cameraRight * offset.x + playerTransform.up * offset.y;
            Vector3 targetPosition = playerTransform.position + moveDirection * Mathf.Max(0, dot) + realOffset;

            Vector3 dronePosition = transform.position;
            float posX = Mathf.SmoothDamp(dronePosition.x, targetPosition.x, ref velocity.x, 0.1f);
            float posY = Mathf.SmoothDamp(dronePosition.y, targetPosition.y, ref velocity.y, 0.3f);
            float posZ = Mathf.SmoothDamp(dronePosition.z, targetPosition.z, ref velocity.z, 0.1f);

            dronePosition = new Vector3(posX, posY, posZ);
            transform.position = dronePosition;
            
            /*EnemyController availableEnemy = GameManager.enemyManager.GetIdealEnemy(float.MaxValue, true);
            if (availableEnemy != null)
            {
                Vector3 enemyPosition = availableEnemy.flexibleCenterPoint.position;
                Vector3 lookAtDirection = (enemyPosition - dronePosition).normalized;
                transform.forward = Vector3.Lerp(transform.forward, lookAtDirection, 0.2f);
            }
            else*/
            {
                Vector3 lookAtDirection = player.viewSc.playerCamera.transform.forward;
                transform.forward = Vector3.Lerp(transform.forward, lookAtDirection, 0.2f);
            }
        }
    }

    public partial class AuxiliaryDrone
    {
        private static readonly int EmissionColor = Shader.PropertyToID("_EmissionColor");
        private Color _currentEmissionColor;
        
        public void SetDroneEmissionColor(Color color, float intensity = 3)
        {
            if (color == _currentEmissionColor) return;
            
            _currentEmissionColor = color * Mathf.Pow(2, intensity);
            Material droneMaterial = droneModel.GetComponent<MeshRenderer>().material;
            droneMaterial.SetColor(EmissionColor, _currentEmissionColor);
        }
    }
}