using UnityEngine;
using System.Collections.Generic;

public class EnemyAI : MonoBehaviour
{
    public enum EnemyState { Patrol, Chase, Returning }
    public EnemyState currentState = EnemyState.Patrol;

    [Header("Movement Settings")]
    public float patrolSpeed = 3f;
    public float chaseSpeed = 6f;
    public float detectionRadius = 12f;
    public float maxChaseDistance = 30f;
    public float damagePerSecond = 20f;

    [Header("Hover Settings")]
    public float hoverHeight = 2.0f; // Distance above the ground
    public float hoverSmoothness = 5f; // Lower = smoother/floatier

    private Vector3 spawnPosition;
    public List<Vector3> patrolPoints = new List<Vector3>();
    private int currentPointIndex = 0;
    private Transform player;
    private LayerMask terrainLayer;

    void Start()
    {
        player = GameObject.FindGameObjectWithTag("Player").transform;
        terrainLayer = LayerMask.GetMask("Terrain");
        spawnPosition = transform.position;

        GeneratePatrolPoints();
    }

    void GeneratePatrolPoints()
    {
        patrolPoints.Clear();
        for (int i = 0; i < 3; i++)
        {
            // Raycast from high up to find the ground
            Vector3 randomPos = spawnPosition + new Vector3(Random.Range(-15f, 15f), 20f, Random.Range(-15f, 15f));
            if (Physics.Raycast(randomPos, Vector3.down, out RaycastHit hit, 50f, terrainLayer))
            {
                // We add the hoverHeight to the patrol point so they don't dive toward the grass
                patrolPoints.Add(hit.point + Vector3.up * hoverHeight);
            }
        }
    }

    void Update()
    {
        float distToPlayer = Vector3.Distance(transform.position, player.position);
        float distFromHome = Vector3.Distance(transform.position, spawnPosition);

        if (distToPlayer < detectionRadius && distFromHome < maxChaseDistance)
        {
            currentState = EnemyState.Chase;
        }
        else if (distFromHome > maxChaseDistance || (currentState == EnemyState.Chase && distToPlayer > detectionRadius))
        {
            currentState = EnemyState.Returning;
        }

        if (currentState == EnemyState.Returning && distFromHome < 2f)
        {
            currentState = EnemyState.Patrol;
        }

        ExecuteState();

        if (currentState == EnemyState.Chase && distToPlayer < 2.0f) // Slightly increased range for floating enemies
        {
            PlayerStats stats = player.GetComponent<PlayerStats>();
            if (stats != null) stats.TakeDamage(damagePerSecond * Time.deltaTime);
        }
    }

    void ExecuteState()
    {
        switch (currentState)
        {
            case EnemyState.Patrol:
                Patrol();
                break;
            case EnemyState.Chase:
                MoveTowards(player.position, chaseSpeed);
                break;
            case EnemyState.Returning:
                MoveTowards(spawnPosition, patrolSpeed);
                break;
        }
    }

    void Patrol()
    {
        if (patrolPoints.Count == 0)
        {
            GeneratePatrolPoints();
            return;
        }

        Vector3 target = patrolPoints[currentPointIndex];
        MoveTowards(target, patrolSpeed);

        // Check distance in 3D space now that we hover
        if (Vector3.Distance(transform.position, target) < 2.0f)
            currentPointIndex = (currentPointIndex + 1) % patrolPoints.Count;
    }

    void MoveTowards(Vector3 target, float speed)
    {
        // 1. Horizontal Direction
        Vector3 dir = (target - transform.position).normalized;
        dir.y = 0;

        // Obstacle avoidance (nudge direction if hitting a steep hill)
        RaycastHit wallHit;
        if (Physics.Raycast(transform.position + Vector3.up * 0.5f, dir, out wallHit, 1.5f, terrainLayer))
        {
            dir += wallHit.normal * 0.5f;
        }

        // 2. Apply Move
        transform.position += dir * speed * Time.deltaTime;

        // 3. Floating / Height Adjustment
        // Fire ray from above the enemy to find the ground directly beneath it
        if (Physics.Raycast(transform.position + Vector3.up * 10f, Vector3.down, out RaycastHit groundHit, 30f, terrainLayer))
        {
            float targetHeight = groundHit.point.y + hoverHeight;

            // Use Lerp for a floaty, smooth height change
            float newY = Mathf.Lerp(transform.position.y, targetHeight, Time.deltaTime * hoverSmoothness);
            transform.position = new Vector3(transform.position.x, newY, transform.position.z);
        }

        // 4. Rotation
        if (dir != Vector3.zero)
        {
            Quaternion targetRotation = Quaternion.LookRotation(dir);
            transform.rotation = Quaternion.Slerp(transform.rotation, targetRotation, Time.deltaTime * 5f);
        }
    }
}