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

namespace OnlyScove.Scripts
{
    [RequireComponent(typeof(CharacterController), typeof(InputReader), typeof(Animator))]
    public class PlayerStateMachine : NetworkBehaviour
    {
        [field: Header("References")]
        [field: SerializeField] public CharacterController Controller { get; private set; }
        [field: SerializeField] public virtual InputReader Input { get; private set; }
        [field: SerializeField] public Animator Anim { get; private set; }
        [field: SerializeField] public EnvironmentScanner Scanner { get; private set; }
        public CameraController Cam { get; private set; }

        [field: Header("Animator Settings")]
        [SerializeField] private string speedParamName = "Speed";
        [SerializeField] private string velocityXParamName = "Velocity X";
        [SerializeField] private string velocityZParamName = "Velocity Z";

        private int speedHash;
        private int velocityXHash;
        private int velocityZHash;

        [field: Header("Movement Settings")]
        [field: SerializeField] public float WalkSpeed { get; private set; } = 3f;
        [field: SerializeField] public float RunSpeed { get; private set; } = 6f;
        [field: SerializeField] public float SprintSpeed { get; private set; } = 9f;
        [field: SerializeField] public float SneakSpeed { get; private set; } = 1.5f;
        [field: SerializeField] public float DashForce { get; private set; } = 10f;
        [field: SerializeField] public float RotationSpeed { get; private set; } = 500f;
        [field: SerializeField] public float AnimationDamping { get; private set; } = 0.2f;

        [field: Header("Airborne Settings")]
        [field: SerializeField] public float JumpHeight { get; private set; } = 2f;
        [field: SerializeField] public float Gravity { get; private set; } = -15f;
        [field: SerializeField] public float ThrustDownwardForce { get; private set; } = -20f;

        [field: Header("Ground Check")]
        [field: SerializeField] public float GroundCheckRadius { get; private set; } = 0.2f;
        [field: SerializeField] public Vector3 GroundCheckOffset { get; private set; }
        [field: SerializeField] public LayerMask GroundMask { get; private set; }

        [field: Header("Interaction")]
        [field: SerializeField] public float InteractionRange { get; private set; } = 2f;
        [field: SerializeField] public LayerMask InteractionMask { get; private set; }

        [Networked] public Quaternion NetworkedCameraRotation { get; set; }
        
        // Thuộc tính hỗ trợ lấy rotation của Camera an toàn cho cả Online và Offline
        public Quaternion CameraRotation 
        {
            get 
            {
                if (Runner != null && Runner.IsRunning && Object != null)
                    return NetworkedCameraRotation;
                
                if (Cam != null)
                    return Cam.PlanarRotation;
                
                return transform.rotation;
            }
        }

        [Networked] public Vector2 NetworkedMoveInput { get; set; }
        [Networked] public float NetworkedSpeed { get; set; }
        [Networked] public Vector3 NetworkedPosition { get; set; }

        public Vector2 MoveInput { get; private set; }
        public bool IsSprintHeld { get; private set; }
        public float VelocityY { get; set; }
        public bool IsGrounded { get; private set; }
        public bool WasGrounded { get; private set; }

        private List<IInteractable> interactablesNearby = new List<IInteractable>();
        private int currentInteractableIndex = 0;

        public string CurrentStateName => currentState != null ? currentState.GetType().Name : "None";

        public static PlayerStateMachine Local { get; private set; }

        private PlayerBaseState currentState;
        private bool hasControl = true;

        private bool hasSpeedParam;
        private bool hasVelocityXParam;
        private bool hasVelocityZParam;

        protected virtual void Awake()
        {
            Controller = GetComponent<CharacterController>();
            Input = GetComponent<InputReader>();
            Anim = GetComponentInChildren<Animator>();
            Scanner = GetComponent<EnvironmentScanner>();

            // Kiểm tra tham số có tồn tại trong Animator không để tránh lỗi log gây Disconnect
            if (Anim != null)
            {
                foreach (AnimatorControllerParameter param in Anim.parameters)
                {
                    if (param.name == speedParamName) hasSpeedParam = true;
                    if (param.name == velocityXParamName) hasVelocityXParam = true;
                    if (param.name == velocityZParamName) hasVelocityZParam = true;
                }
            }

            speedHash = Animator.StringToHash(speedParamName);
            velocityXHash = Animator.StringToHash(velocityXParamName);
            velocityZHash = Animator.StringToHash(velocityZParamName);
        }

        private void Start()
        {
            // Nếu chạy Offline (kéo prefab vào scene), Spawned() sẽ không được gọi.
            // Chúng ta khởi tạo tại đây để đảm bảo nhân vật hoạt động.
            if (Runner == null || !Runner.IsRunning)
            {
                InitializePlayer();
            }
        }

        public override void Spawned()
        {
            // Fusion gọi Spawned khi object được nạp vào mạng.
            InitializePlayer();

            // Nếu không có quyền điều khiển và đang ở Client, tắt Controller để tránh xung đột
            if (Object != null && !Object.HasInputAuthority && Runner.IsClient)
            {
                if (Controller != null) Controller.enabled = false;
            }
        }

        private void InitializePlayer()
        {
            if (currentState == null)
            {
                SwitchState(new PlayerIdleState(this));
            }

            bool isOffline = Runner == null || !Runner.IsRunning;
            bool hasAuthority = Object != null && Object.HasInputAuthority;

            if (isOffline || hasAuthority)
            {
                Local = this;
                
                CameraController cameraController = GameObject.FindAnyObjectByType<CameraController>();
                if (cameraController != null)
                {
                    Cam = cameraController;
                    Cam.followTarget = transform; 
                    Cam.inputReader = Input;
                }
                
                Input.OnNextInteractEvent += OnNextInteract;
                Input.OnPreviousInteractEvent += OnPreviousInteract;

                // Đảm bảo Controller được bật
                if (Controller != null) Controller.enabled = true;
            }
        }

        private float localAnimatorSpeed;

        public void Rotate(Vector3 moveDirection, float deltaTime)
        {
            if (moveDirection == Vector3.zero) return;

            Quaternion targetRot = Quaternion.LookRotation(moveDirection);
            transform.rotation = Quaternion.RotateTowards(
                transform.rotation, 
                targetRot, 
                RotationSpeed * deltaTime
            );
        }

        public void Move(Vector3 velocity, float animatorSpeed, float deltaTime)
        {
            // Cho phép di chuyển nếu:
            // 1. Không có mạng (Offline test)
            // 2. Có quyền điều khiển (Input Authority)
            // 3. Là Server (State Authority)
            bool canMove = (Runner == null || !Runner.IsRunning) || Object.HasInputAuthority || Runner.IsServer;
            if (!canMove) return;

            if (Controller != null && Controller.enabled)
            {
                Controller.Move(velocity * deltaTime);
                // Cập nhật vị trí mạng ngay sau khi di chuyển
                if (Object != null && Runner != null && Runner.IsRunning)
                {
                    NetworkedPosition = transform.position;
                }
            }

            localAnimatorSpeed = animatorSpeed;
            
            if (Object != null && Object.HasStateAuthority)
            {
                NetworkedSpeed = animatorSpeed;
                NetworkedMoveInput = MoveInput;
            }

            UpdateAnimator(deltaTime);
        }

        private void UpdateAnimator(float deltaTime)
        {
            if (Anim == null) return;

            float speedValue;
            Vector2 inputVector;

            if (Runner == null || !Runner.IsRunning || Object.HasInputAuthority)
            {
                speedValue = localAnimatorSpeed;
                inputVector = MoveInput;
            }
            else
            {
                speedValue = NetworkedSpeed;
                inputVector = NetworkedMoveInput;
            }

            // Chỉ Set nếu tham số thực sự tồn tại (Tránh lỗi Hash does not exist)
            if (hasSpeedParam) Anim.SetFloat(speedHash, speedValue, AnimationDamping, deltaTime);
            if (hasVelocityXParam) Anim.SetFloat(velocityXHash, inputVector.x * speedValue, AnimationDamping, deltaTime);
            if (hasVelocityZParam) Anim.SetFloat(velocityZHash, inputVector.y * speedValue, AnimationDamping, deltaTime);
        }

        public override void FixedUpdateNetwork()
        {
            bool isRunning = Runner != null && Runner.IsRunning;
            if (Object == null && isRunning) return;

            // ĐỒNG BỘ VỊ TRÍ: Ép nhân vật về vị trí mạng trước khi tính toán tick mới
            if (isRunning && NetworkedPosition != Vector3.zero)
            {
                if (Controller != null && !Object.HasInputAuthority)
                {
                    Controller.enabled = false;
                    transform.position = NetworkedPosition;
                    Controller.enabled = true;
                }
            }

            if (GetInput(out PlayerInputData data))
            {
                MoveInput = data.Direction;
                IsSprintHeld = data.sprint;
                // Chỉ gán biến Networked nếu đang chạy mạng
                if (isRunning) NetworkedCameraRotation = data.rot;
            }
            else if (!isRunning)
            {
                // FALLBACK INPUT: Nếu không có Fusion, lấy input trực tiếp từ Unity để Test
                MoveInput = new Vector2(UnityEngine.Input.GetAxisRaw("Horizontal"), UnityEngine.Input.GetAxisRaw("Vertical"));
                IsSprintHeld = UnityEngine.Input.GetKey(KeyCode.LeftShift);
                // Ở chế độ offline, chúng ta không gán vào NetworkedCameraRotation nữa
            }
            else
            {
                MoveInput = Vector2.zero;
                IsSprintHeld = false;
            }

            bool isSimulating = !isRunning || Object.HasInputAuthority || Runner.IsServer;

            if (!isSimulating)
            {
                UpdateAnimator(Runner.DeltaTime);
                return;
            }
            
            if (!hasControl) return;

            WasGrounded = IsGrounded;
            CheckGround();
            UpdateInteractablesList();
            
            float dt = isRunning ? Runner.DeltaTime : Time.fixedDeltaTime;
            currentState?.Tick(dt);
        }

        private void Update()
        {
            // Nếu không có NetworkRunner, Fusion sẽ không gọi FixedUpdateNetwork.
            // Chúng ta gọi thủ công để logic StateMachine vẫn chạy được khi Test Offline.
            if (Runner == null || !Runner.IsRunning)
            {
                FixedUpdateNetwork();
            }
        }

        private void CheckGround()
        {
            IsGrounded = Physics.CheckSphere(transform.TransformPoint(GroundCheckOffset), GroundCheckRadius, GroundMask);
        }

        private void UpdateInteractablesList()
        {
            interactablesNearby.Clear();
            IInteractable target = Scanner.ScanForInteractable(InteractionRange, InteractionMask);
            if (target != null) interactablesNearby.Add(target);
            currentInteractableIndex = 0;
        }

        private void OnNextInteract()
        {
            if (interactablesNearby.Count <= 1) return;
            currentInteractableIndex = (currentInteractableIndex + 1) % interactablesNearby.Count;
        }

        private void OnPreviousInteract()
        {
            if (interactablesNearby.Count <= 1) return;
            currentInteractableIndex--;
            if (currentInteractableIndex < 0) currentInteractableIndex = interactablesNearby.Count - 1;
        }

        public IInteractable GetInteractable()
        {
            if (interactablesNearby.Count == 0) return null;
            return interactablesNearby[currentInteractableIndex];
        }

        public void SetGroundCheck(float radius, Vector3 offset)
        {
            GroundCheckRadius = radius;
            GroundCheckOffset = offset;
        }

        public void SwitchState(PlayerBaseState newState)
        {
            currentState?.Exit();
            currentState = newState;
            currentState?.Enter();
        }

        public void SetControl(bool control)
        {
            hasControl = control;
            if (Controller != null) Controller.enabled = control;
            if (!control && Anim != null) Anim.SetFloat(speedHash, 0f);
        }

        private void OnDrawGizmosSelected()
        {
            Gizmos.color = new Color(0, 1, 0, 0.5f);
            Gizmos.DrawSphere(transform.TransformPoint(GroundCheckOffset), GroundCheckRadius);
        }
    }
}