using UnityEngine;

[RequireComponent(typeof(Rigidbody))]
[RequireComponent(typeof(Collider))]
public class DraggableObject : MonoBehaviour
{
    [Header("Přetahování")]
    public float dragSmoothness = 15f;

    [Header("Vizuální zpětná vazba")]
    public Renderer Renderer;
    public Color normalColor = Color.white;
    public Color dragColor = new Color(1f, 1f, 0.5f);
    public float scaleOnDrag = 1.15f;

    private Rigidbody rb;
    private Camera mainCamera;
    private bool isDragging = false;
    private Vector3 targetPosition;
    private Vector3 originalScale;
    private bool hasBeenScored = false;
    private Plane _dragPlane;
    private Collider col;

    void Awake()
    {
        rb = GetComponent<Rigidbody>();
        col = GetComponent<Collider>();
        mainCamera = Camera.main;
        originalScale = transform.localScale;
        if (Renderer == null)
            Renderer = GetComponent<Renderer>();
    }

    void Start()
    {
        rb.useGravity = false;
        rb.constraints = RigidbodyConstraints.FreezeRotation;
        targetPosition = transform.position;
    }

    void Update()
    {
        HandleInput();
    }
    void FixedUpdate()
    {
        if (isDragging)
        {
            Vector3 newPos = Vector3.Lerp(rb.position, targetPosition, Time.fixedDeltaTime * dragSmoothness);
            rb.MovePosition(newPos);
        }
    }

    void HandleInput()
    {
        if (Input.touchCount > 0)
        {
            Touch touch = Input.GetTouch(0);
            //Vector3 worldPos = mainCamera.ScreenToWorldPoint(new Vector3(touch.position.x, touch.position.y, 10f));

            if (touch.phase == TouchPhase.Began)
                TryStartDrag(touch.position);
            else if (touch.phase == TouchPhase.Moved || touch.phase == TouchPhase.Stationary)
            {
                if (isDragging) UpdateDrag(touch.position);
            }
            else if (touch.phase == TouchPhase.Ended || touch.phase == TouchPhase.Canceled)
            {
                if (isDragging) EndDrag();
            }
        }
        else
        {
            //Vector3 worldPos = mainCamera.ScreenToWorldPoint(new Vector3(Input.mousePosition.x, Input.mousePosition.y, 10f));

            if (Input.GetMouseButtonDown(0))
                TryStartDrag(Input.mousePosition);
            else if (Input.GetMouseButton(0) && isDragging)
                UpdateDrag(Input.mousePosition);
            else if (Input.GetMouseButtonUp(0) && isDragging)
                EndDrag();
        }
    }

    void TryStartDrag(Vector3 screenPos)
    {
        Debug.Log("Trying to start drag at: " + screenPos);
        Ray ray = mainCamera.ScreenPointToRay(screenPos);
        RaycastHit hit;

        if (Physics.Raycast(ray, out hit))
        {
            if (hit.collider == col)
            {
                StartDrag(hit.point);
            }
        }
    }

    void StartDrag(Vector3 hitPoint)
    {
        Debug.Log("Started dragging at: " + hitPoint);
        isDragging = true;
        rb.isKinematic = false;
        rb.linearVelocity = Vector3.zero;
        _dragPlane = new Plane(-mainCamera.transform.forward, hitPoint);
        targetPosition = hitPoint;
        transform.localScale = originalScale * scaleOnDrag;
        if (Renderer != null)
        {
            Renderer.material.color = dragColor;
        }
    }
    void UpdateDrag(Vector3 screenPos)
    {
        Ray ray = mainCamera.ScreenPointToRay(screenPos);
        float distance;
        if (_dragPlane.Raycast(ray, out distance))
        {
            targetPosition = ray.GetPoint(distance);
        }
    }
    void EndDrag()
    {
        Debug.Log("Ended dragging");
        isDragging = false;
        rb.isKinematic = true;
        transform.localScale = originalScale;
        if (Renderer != null)
        {
            Renderer.material.color = normalColor;
        }
    }

    public void OnScored()
    {
        Debug.Log("Object scored");
        if (hasBeenScored) return;
        hasBeenScored = true;
        isDragging = false;
        StartCoroutine(SinkIntoHole());
    }

    System.Collections.IEnumerator SinkIntoHole()
    {
        float duration = 0.35f;
        float elapsed = 0f;
        Vector3 startScale = transform.localScale;

        while (elapsed < duration)
        {
            elapsed += Time.deltaTime;
            float t = elapsed / duration;
            transform.localScale = Vector3.Lerp(startScale, Vector3.zero, t);
            if (Renderer != null)
                Renderer.material.color = new Color(normalColor.r, normalColor.g, normalColor.b, 1f - t);
            yield return null;
        }

        gameObject.SetActive(false);
        LevelManager.Instance?.RegisterItem();
    }
}