using System.Collections.Generic;
using UnityEngine;

[RequireComponent(typeof(Rigidbody2D))]
[RequireComponent(typeof(Collider2D))]
public class TrickController : MonoBehaviour
{
    [SerializeField] private string treatTag = "Interactable";
    [SerializeField] private float moveSpeed = 3.5f;
    [SerializeField] private float targetRefreshInterval = 0.4f;
    [SerializeField] private float consumeDistance = 0.35f;
    [SerializeField] private float wanderInterval = 1.2f;

    private Rigidbody2D body;
    private Transform target;
    private float nextTargetTime;
    private Vector2 wanderDirection;
    private float nextWanderTime;
    private bool isCarried;

    private void Awake()
    {
        body = GetComponent<Rigidbody2D>();
        body.bodyType = RigidbodyType2D.Dynamic;
        body.gravityScale = 1f;
        body.freezeRotation = true;
        body.collisionDetectionMode = CollisionDetectionMode2D.Continuous;
        body.interpolation = RigidbodyInterpolation2D.Interpolate;
    }

    private void Update()
    {
        if (isCarried)
        {
            return;
        }

        if (Time.time >= nextTargetTime)
        {
            target = FindNearestTreat();
            if (target == null)
            {
                // If we can't find treats while we're tagged Interactable, keep moving.
                wanderDirection = Random.insideUnitCircle.normalized;
                if (wanderDirection.sqrMagnitude < 0.01f)
                {
                    wanderDirection = Vector2.right;
                }
                nextWanderTime = Time.time + wanderInterval;
            }
            nextTargetTime = Time.time + targetRefreshInterval;
        }

        if (target == null && Time.time >= nextWanderTime)
        {
            wanderDirection = Random.insideUnitCircle.normalized;
            if (wanderDirection.sqrMagnitude < 0.01f)
            {
                wanderDirection = Vector2.right;
            }
            nextWanderTime = Time.time + wanderInterval;
        }

        TryConsumeTreat();
    }

    private void FixedUpdate()
    {
        if (isCarried)
        {
            return;
        }

        Vector2 desiredVelocity;
        var stopForTreat = false;
        if (target != null)
        {
            var direction = ((Vector2)target.position - (Vector2)transform.position).normalized;
            desiredVelocity = new Vector2(direction.x * moveSpeed, 0f);
            stopForTreat = Vector2.Distance(transform.position, target.position) <= consumeDistance;
        }
        else
        {
            desiredVelocity = new Vector2(wanderDirection.x * (moveSpeed * 0.6f), 0f);
        }

        var velocity = body.linearVelocity;
        velocity.x = stopForTreat ? 0f : desiredVelocity.x;
        body.linearVelocity = velocity;
    }

    private Transform FindNearestTreat()
    {
        var treats = GameObject.FindGameObjectsWithTag(treatTag);
        if (treats == null || treats.Length == 0)
        {
            return null;
        }

        Transform best = null;
        var bestDistance = float.MaxValue;
        var origin = transform.position;
        for (var i = 0; i < treats.Length; i++)
        {
            var candidate = treats[i];
            if (candidate == gameObject)
            {
                continue;
            }
            if (!candidate.activeInHierarchy)
            {
                continue;
            }

            if (!candidate.TryGetComponent<Collider2D>(out var collider) || !collider.enabled)
            {
                continue;
            }

            var distance = Vector2.Distance(origin, candidate.transform.position);
            if (distance < bestDistance)
            {
                bestDistance = distance;
                best = candidate.transform;
            }
        }

        return best;
    }

    private void TryConsumeTreat()
    {
        if (isCarried)
        {
            return;
        }

        var hits = Physics2D.OverlapCircleAll(transform.position, consumeDistance);
        for (var i = 0; i < hits.Length; i++)
        {
            var hit = hits[i];
            if (hit == null || hit.gameObject == gameObject || !hit.CompareTag(treatTag))
            {
                continue;
            }

            Destroy(hit.gameObject);
            if (target == hit.transform)
            {
                target = null;
            }
            break;
        }
    }

    public void SetCarried(bool carried)
    {
        isCarried = carried;
        if (carried)
        {
            target = null;
            var velocity = body.linearVelocity;
            velocity.x = 0f;
            body.linearVelocity = velocity;
        }
    }
}