using UnityEngine;

[RequireComponent(typeof(CharacterController))]
public class PlayerMovement : MonoBehaviour
{
    [Header("Movement Settings")]
    [SerializeField] private float moveSpeed = 4f;
    [SerializeField] private float crouchSpeed = 2f;
    [SerializeField] private float gravity = -9.81f;

    [Header("Crouch Settings")]
    [SerializeField] private KeyCode crouchKey = KeyCode.LeftControl;
    [SerializeField] private float standHeight = 2.0f;
    [SerializeField] private float crouchHeight = 1.0f;
    [SerializeField] private float crouchTransitionSpeed = 10f;
    [SerializeField] private Transform playerCamera; // Ссылка на камеру игрока

    [Header("Ground Check")]
    [SerializeField] private Transform groundCheck;
    [SerializeField] private float groundDistance = 0.4f;
    [SerializeField] private LayerMask groundMask;

    private CharacterController controller;
    private Vector3 velocity;
    private bool isGrounded;

    private float initialHeight;
    private Vector3 standCameraPos;
    private Vector3 crouchCameraPos;
    private Vector3 initialCenter;
    private bool isCrouching;

    private void Awake()
    {
        controller = GetComponent<CharacterController>();
    }

    private void Start()
    {
        // Запоминаем исходные значения из Инспектора
        initialHeight = controller.height;
        initialCenter = controller.center;

        if (playerCamera == null)
        {
            Camera cam = GetComponentInChildren<Camera>();
            if (cam != null) playerCamera = cam.transform;
        }

        if (playerCamera != null)
        {
            standCameraPos = playerCamera.localPosition;
            // Камера опускается ровно на разницу высоты
            crouchCameraPos = new Vector3(
                standCameraPos.x, 
                standCameraPos.y - (standHeight - crouchHeight), 
                standCameraPos.z
            );
        }
    }

    private void Update()
    {
        HandleCrouch();
    }

    private void HandleCrouch()
    {
        isCrouching = Input.GetKey(crouchKey);

        float targetHeight = isCrouching ? crouchHeight : standHeight;
        float currentDelta = initialHeight - targetHeight;

        // ГЛАВНАЯ ФОРМУЛА: дно капсулы остается на земле
        Vector3 targetCenter = new Vector3(
            initialCenter.x,
            initialCenter.y - (currentDelta * 0.5f),
            initialCenter.z
        );

        controller.height = Mathf.MoveTowards(controller.height, targetHeight, Time.deltaTime * crouchTransitionSpeed);
        controller.center = Vector3.MoveTowards(controller.center, targetCenter, Time.deltaTime * crouchTransitionSpeed);

        if (playerCamera != null)
        {
            Vector3 targetCamPos = isCrouching ? crouchCameraPos : standCameraPos;
            playerCamera.localPosition = Vector3.MoveTowards(playerCamera.localPosition, targetCamPos, Time.deltaTime * crouchTransitionSpeed);
        }
    }

    public void ProcessMove(Vector2 input)
    {
        // Проверка касания земли (сфера на уровне ног)
        isGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundMask);

        if (isGrounded && velocity.y < 0)
        {
            velocity.y = -2f; // Небольшое прижатие к земле для стабильного спуска по склонам
        }

        // Выбор текущей скорости в зависимости от состояния приседа
        float currentSpeed = isCrouching ? crouchSpeed : moveSpeed;

        // Движение относительно локальных координат игрока
        Vector3 move = transform.right * input.x + transform.forward * input.y;
        controller.Move(move * (currentSpeed * Time.deltaTime));

        // Применение гравитации
        velocity.y += gravity * Time.deltaTime;
        controller.Move(velocity * Time.deltaTime);
    }
}