using UnityEngine;
using UnityEngine.InputSystem;

[RequireComponent(typeof(Collider2D))]
[RequireComponent(typeof(Rigidbody2D))]
public class PaddleScript : MonoBehaviour
{
    [Header("Movement")]
    [SerializeField] private float moveSpeed = 10f;

    [Header("Bounds")]
    [Tooltip("Extra gap between the paddle edge and the camera edge.")]
    [SerializeField] private float edgePadding = 0.1f;

    private float _minX;
    private float _maxX;
    private float _halfWidth;
    private bool _useMouse = true;

    void Awake()
    {
        // Paddle is player-driven via transform — kinematic prevents physics forces from interfering.
        GetComponent<Rigidbody2D>().bodyType = RigidbodyType2D.Kinematic;
    }

    void Start()
    {
        _halfWidth = GetComponent<Collider2D>().bounds.extents.x;

        // Derive horizontal limits from the camera viewport so the paddle never leaves the screen.
        Camera cam = Camera.main;
        float distToCamera = Mathf.Abs(cam.transform.position.z);
        _minX = cam.ViewportToWorldPoint(new Vector3(0f, 0f, distToCamera)).x + _halfWidth + edgePadding;
        _maxX = cam.ViewportToWorldPoint(new Vector3(1f, 0f, distToCamera)).x - _halfWidth - edgePadding;
    }

    void Update()
    {
        var keyboard = Keyboard.current;
        var mouse = Mouse.current;

        float keyInput = 0f;
        if (keyboard != null)
        {
            if (keyboard.aKey.isPressed || keyboard.leftArrowKey.isPressed) keyInput -= 1f;
            if (keyboard.dKey.isPressed || keyboard.rightArrowKey.isPressed) keyInput += 1f;
        }

        // Any keyboard movement disables mouse; any mouse click re-enables mouse.
        if (Mathf.Abs(keyInput) > 0.01f)
            _useMouse = false;
        else if (mouse != null && mouse.leftButton.wasPressedThisFrame)
            _useMouse = true;

        Vector3 pos = transform.position;

        if (!_useMouse && Mathf.Abs(keyInput) > 0.01f)
        {
            // Keyboard: direct movement at moveSpeed.
            pos.x += keyInput * moveSpeed * Time.deltaTime;
        }
        else if (_useMouse && mouse != null)
        {
            // Mouse: smoothly move toward the cursor's world X at moveSpeed.
            Camera cam = Camera.main;
            Vector2 mouseScreen = mouse.position.ReadValue();
            Vector3 mouseWorld = cam.ScreenToWorldPoint(
                new Vector3(mouseScreen.x, mouseScreen.y, Mathf.Abs(cam.transform.position.z)));
            pos.x = Mathf.MoveTowards(pos.x, mouseWorld.x, moveSpeed * Time.deltaTime);
        }

        pos.x = Mathf.Clamp(pos.x, _minX, _maxX);
        transform.position = pos;
    }

    private void OnCollisionEnter2D(Collision2D collision)
    {
        if (!collision.gameObject.CompareTag("Ball"))
            return;

        Rigidbody2D ballRb = collision.rigidbody;
        if (ballRb == null)
            return;

        // Map hit position to [-1, 1]: -1 = left edge, 0 = centre, +1 = right edge.
        float hitOffset = (collision.transform.position.x - transform.position.x) / _halfWidth;
        hitOffset = Mathf.Clamp(hitOffset, -1f, 1f);

        // Preserve the ball's current speed so movement effects still apply.
        BallScript ballScript = collision.gameObject.GetComponent<BallScript>();
        float speed = ballScript != null ? ballScript.GetCurrentSpeed() : 10f;

        // A centre hit goes straight up; edge hits angle up to 75 degrees to either side.
        float angle = hitOffset * 75f * Mathf.Deg2Rad;
        ballRb.linearVelocity = new Vector2(Mathf.Sin(angle), Mathf.Cos(angle)) * speed;
    }
}