using System.Collections.Generic;
using UnityEngine;

public class ShieldController : MonoBehaviour
{
    public float followSpeed = 20f;
    public float pushForce = 10f;
    public LayerMask pushableLayers;

    private Rigidbody2D rb;
    private Camera mainCam;

    private HashSet<GameObject> hitEnemies = new HashSet<GameObject>();

    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
        mainCam = Camera.main;
    }

    void Update()
    {
        if (BalloonGameManager.IsGameOver) return;

        HandleMovement();
        DestroyOffscreenEnemies();
    }

    void HandleMovement()
    {
        if (Input.GetMouseButton(0))
        {
            Vector2 touchPosition = mainCam.ScreenToWorldPoint(Input.mousePosition);
            Vector2 direction = (touchPosition - rb.position);
            rb.velocity = direction * followSpeed;
        }
        else
        {
            rb.velocity = Vector2.zero;
        }

        // Clamp shield inside the camera
        Vector3 viewPos = mainCam.WorldToViewportPoint(transform.position);
        viewPos.x = Mathf.Clamp01(viewPos.x);
        viewPos.y = Mathf.Clamp01(viewPos.y);
        transform.position = mainCam.ViewportToWorldPoint(viewPos);
    }

    private void OnCollisionEnter2D(Collision2D collision)
    {
        if (((1 << collision.gameObject.layer) & pushableLayers) != 0)
        {
            Rigidbody2D otherRb = collision.rigidbody;
            if (otherRb != null && otherRb != rb)
            {
                Vector2 forceDir = collision.transform.position - transform.position;
                forceDir.Normalize();
                otherRb.AddForce(forceDir * pushForce, ForceMode2D.Impulse);

                // Add to list of hit enemies
                if (!hitEnemies.Contains(collision.gameObject))
                {
                    hitEnemies.Add(collision.gameObject);
                }
            }
        }
    }

    void DestroyOffscreenEnemies()
    {
        float buffer = 1f; // World units to extend camera bounds (adjust as needed)
        List<GameObject> toRemove = new List<GameObject>();

        foreach (GameObject enemy in hitEnemies)
        {
            if (enemy == null) continue;

            Vector3 enemyPos = enemy.transform.position;
            Vector3 camPos = mainCam.transform.position;

            float camHeight = 2f * mainCam.orthographicSize;
            float camWidth = camHeight * mainCam.aspect;

            float left = camPos.x - camWidth / 2f - buffer;
            float right = camPos.x + camWidth / 2f + buffer;
            float bottom = camPos.y - camHeight / 2f - buffer;
            float top = camPos.y + camHeight / 2f + buffer;

            if (enemyPos.x < left || enemyPos.x > right ||
                enemyPos.y < bottom || enemyPos.y > top)
            {
                Destroy(enemy);
                toRemove.Add(enemy);
            }
        }

        foreach (GameObject e in toRemove)
        {
            hitEnemies.Remove(e);
        }
    }
}