using UnityEngine;

namespace HotUpdate.Gameplay
{
    /// <summary>
    /// 营地伙伴闲逛控制器：在指定区域内随机漫步、呼吸待机，并在探险家靠近时好奇转身打招呼。
    /// </summary>
    public sealed class CampPetWanderer : MonoBehaviour
    {
        [Header("Wander Settings")]
        public Vector3 wanderCenter;
        public float wanderRadius = 2.8f;
        public float moveSpeed = 1.6f;
        public float turnSpeed = 480f;
        public float stopDistance = 0.35f;

        [Header("Timing")]
        public float minIdleTime = 2.5f;
        public float maxIdleTime = 6.0f;

        [Header("Social")]
        public float greetingDistance = 4.8f;

        [Header("Model Facing Convention")]
        [Tooltip("既有伙伴动物模型正面为局部 -Z（2026-10-24 之前旧资产规范），开启后使正面朝向移动方向")]
        public bool modelFacesMinusZ = true;

        Animator _animator;
        Transform _playerTransform;
        Vector3 _targetPosition;
        bool _isMoving;
        float _idleTimer;
        int _animParamMotion;

        public bool IsMoving => _isMoving;
        public Vector3 TargetPosition => _targetPosition;
        public Animator PetAnimator => _animator;

        void Awake()
        {
            EnsureInit();
        }

        public void EnsureInit()
        {
            if (_animator == null) _animator = GetComponentInChildren<Animator>();
            if (_animParamMotion == 0) _animParamMotion = Animator.StringToHash("Motion");
            if (wanderCenter == Vector3.zero) wanderCenter = transform.position;
            _targetPosition = transform.position;
            if (_idleTimer <= 0f) _idleTimer = Random.Range(minIdleTime * 0.5f, maxIdleTime);
        }

        void Start()
        {
            var explorer = GameObject.Find("Explorer");
            if (explorer != null) _playerTransform = explorer.transform;
        }

        /// <summary>
        /// 指挥伙伴移动到指定目标点。
        /// </summary>
        public void MoveTo(Vector3 target)
        {
            EnsureInit();
            _targetPosition = target;
            _isMoving = true;
            if (_animator != null) _animator.SetInteger(_animParamMotion, 1);
        }

        /// <summary>
        /// 停步并进入待机状态。
        /// </summary>
        public void Stop()
        {
            EnsureInit();
            _isMoving = false;
            _targetPosition = transform.position;
            _idleTimer = Random.Range(minIdleTime, maxIdleTime);
            if (_animator != null) _animator.SetInteger(_animParamMotion, 0);
        }

        void Update()
        {
            float dt = Time.deltaTime;

            // 探险家靠近时好奇注视
            if (_playerTransform != null)
            {
                Vector3 toPlayer = _playerTransform.position - transform.position;
                toPlayer.y = 0;
                if (toPlayer.sqrMagnitude < greetingDistance * greetingDistance)
                {
                    if (_isMoving) Stop();
                    if (toPlayer.sqrMagnitude > 0.001f)
                    {
                        Vector3 lookDir = modelFacesMinusZ ? -toPlayer.normalized : toPlayer.normalized;
                        Quaternion facePlayer = Quaternion.LookRotation(lookDir, Vector3.up);
                        transform.rotation = Quaternion.RotateTowards(transform.rotation, facePlayer, turnSpeed * dt);
                    }
                    return;
                }
            }

            if (_isMoving)
            {
                Vector3 toTarget = _targetPosition - transform.position;
                toTarget.y = 0;
                float dist = toTarget.magnitude;

                if (dist <= stopDistance)
                {
                    Stop();
                    return;
                }

                // 平滑转向并前进（结合模型正向规范）
                if (toTarget.sqrMagnitude > 0.0001f)
                {
                    Vector3 lookDir = modelFacesMinusZ ? -toTarget.normalized : toTarget.normalized;
                    Quaternion rot = Quaternion.LookRotation(lookDir, Vector3.up);
                    transform.rotation = Quaternion.RotateTowards(transform.rotation, rot, turnSpeed * dt);
                }

                float step = Mathf.Min(moveSpeed * dt, dist);
                transform.position += toTarget.normalized * step;
            }
            else
            {
                _idleTimer -= dt;
                if (_idleTimer <= 0f)
                {
                    PickNextDestination();
                }
            }
        }

        void PickNextDestination()
        {
            Vector2 rand2D = Random.insideUnitCircle * wanderRadius;
            Vector3 dest = wanderCenter + new Vector3(rand2D.x, 0, rand2D.y);

            // 避开喷泉中心
            Vector2 fountainCenter = new Vector2(0f, 0.8f);
            if (Vector2.Distance(new Vector2(dest.x, dest.z), fountainCenter) < 2.3f)
            {
                _idleTimer = 1.0f;
                return;
            }

            MoveTo(dest);
        }
    }
}