using UnityEngine;
using RR.Game2D.Core;
using RR.Common.Interfaces;

namespace RR.Game2D.Behaviour
{
    [RequireComponent(typeof(Rigidbody2D),
                      typeof(Collider2D),
                      typeof(Animator))]
    public class EnemyController : MonoBehaviour, IDamageable
    {

        [Header("Обзор")]
        [SerializeField] private float viewDistance = 5f;
        [SerializeField] private float viewAngle = 60f;

        [Header("Движение")]
        [SerializeField] private float moveSpeed = 4f;
        [SerializeField] private float acceleration = 10f;

        [Header("Препятствия")]
        [SerializeField] private LayerMask obstacleMask;

        [Header("Здоровье")]
        [SerializeField] private int maxHealth = 1;
        private Health health;
        public int CurrentHealth => health?.CurrentHealth ?? 0;
        public int MaxHealth => health?.MaxHealth ?? 0;

        private Animator animator;
        private Rigidbody2D rb;
        private Collider2D col;
        
        private GameObject playerObj;

        // Аниматор
        private static readonly int Speed = Animator.StringToHash("Speed");

        void Start()
        {
            rb = GetComponent<Rigidbody2D>();
            col = GetComponent<Collider2D>();
            animator = GetComponent<Animator>();

            playerObj = GameManager.Instance.PlayerObj;
            if (playerObj == null)
            {
                playerObj = GameObject.FindGameObjectWithTag("Player");
            }

            health = GetComponent<Health>();
            if (health == null)
            {
                health = gameObject.AddComponent<Health>();
            }
            health.ResetHealth();
            health.SetOwner(this);
            health.SetMaxHealth(maxHealth);
        }

        void FixedUpdate()
        {
            if (!playerObj) return;

            Vector2 playerCenter = playerObj.transform.position;

            if (PlayerInSight())
            {
                Vector2 toPlayer = playerCenter - (Vector2)transform.position;
                float dist = toPlayer.magnitude;

                if (dist > 0.01f)
                    rb.linearVelocity = toPlayer / dist * moveSpeed;
                else
                    rb.linearVelocity = Vector2.zero;
            }
            else
            {
                rb.linearVelocity = Vector2.MoveTowards(
                    rb.linearVelocity, Vector2.zero, acceleration * Time.fixedDeltaTime);
            }

            animator.SetFloat(Speed, Mathf.Abs(rb.linearVelocity.magnitude));
        }

        void OnCollisionEnter2D(Collision2D collision)
        {
            if (collision.collider.CompareTag("Player"))
            {
                Rigidbody2D playerRb = collision.collider.GetComponent<Rigidbody2D>();
                playerObj.TryGetComponent(out PlayerController playerController);
                if (playerRb == null) return;
                Vector2 contactNormal = collision.GetContact(0).normal;
                if (contactNormal.y < -0.5f)
                {
                    playerRb.linearVelocity = new Vector2(playerRb.linearVelocity.x, 35f);
                    TakeDamage(MaxHealth);
                }
                else
                {
                    playerController.TakeDamage(1);
                }
            }
            else if (collision.collider.CompareTag("Projectile"))
            {
                TakeDamage(1);
            }
        }

        private bool PlayerInSight()
        {
            if (!playerObj) return false;

            Transform player = playerObj.transform;

            Vector2 eyePos = new(rb.position.x, col.bounds.center.y);

            Vector2 toPlayer = (Vector2)player.position - eyePos;
            float dist = toPlayer.magnitude;
            if (dist > viewDistance) return false;

            Vector2 forward = transform.localEulerAngles.y >= 180f ? Vector2.right : Vector2.left;

            float cosHalf = Mathf.Cos(0.5f * viewAngle * Mathf.Deg2Rad);
            float dot = Vector2.Dot(forward.normalized, toPlayer / Mathf.Max(dist, 1e-6f));
            if (dot < cosHalf) return false;

            int mask = obstacleMask;
            mask &= ~(1 << gameObject.layer);
            mask &= ~(1 << playerObj.layer);

            Vector2 origin = eyePos + forward.normalized * 0.05f;

            RaycastHit2D hit = Physics2D.Raycast(origin, toPlayer.normalized, dist, mask);
            if (hit.collider != null) return false;

            return true;
        }

        public void TakeDamage(int amount)
        {
            health.TakeDamage(amount);
        }
        public void Heal(int amount)
        {
            health.Heal(amount);
        }
        public void Die()
        {
            Destroy(gameObject);
        }

#if UNITY_EDITOR
        private void OnDrawGizmos()
        {
            if (!playerObj) return;

            Vector2 origin = new(rb.position.x, rb.position.y + 1.45f);
            Vector2 forward = transform.localEulerAngles.y >= 180f ? Vector2.right : Vector2.left;
            float half = viewAngle * 0.5f;

            Vector2 edgeA = (Quaternion.Euler(0, 0, +half) * forward);
            Vector2 edgeB = (Quaternion.Euler(0, 0, -half) * forward);

            Gizmos.color = Color.yellow;
            Gizmos.DrawLine(origin, origin + edgeA * viewDistance);
            Gizmos.DrawLine(origin, origin + edgeB * viewDistance);
            Gizmos.DrawWireSphere(origin, viewDistance);

            Vector2 toPlayer = (Vector2)playerObj.transform.position - origin;
            if (toPlayer.magnitude <= viewDistance)
            {
                Gizmos.color = Color.red;
                Gizmos.DrawLine(origin, playerObj.transform.position);
            }
        }
#endif
    }
}