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;
    [SerializeField] private float consumeCooldown = 1.5f;
    [SerializeField] private TrickController trickPrefab;
    [SerializeField] private float avoidPlayerRadius = 1.2f;
    [SerializeField] private float avoidTrickRadius = 0.8f;
    [SerializeField] private float treatSeekWeight = 1f;
    [SerializeField] private float avoidPlayerWeight = 0.25f;
    [SerializeField] private float avoidTrickWeight = 0.2f;
    [SerializeField] private float wanderWeight = 0.4f;
    [SerializeField] private float jumpImpulse = 6f;
    [SerializeField] private float jumpCooldown = 1f;
    [SerializeField] private float jumpChancePerSecond = 0.5f;
    [SerializeField] private LayerMask groundMask = ~0;
    [SerializeField] private float groundCheckDistance = 0.05f;

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

    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 (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;
        var avoidPlayerDirection = GetAvoidPlayerDirection();
        var avoidTrickDirection = GetAvoidTrickDirection();
        var hasTarget = target != null;
        var canConsume = Time.time >= nextConsumeTime;

        var desiredX = 0f;
        if (hasTarget)
        {
            var direction = ((Vector2)target.position - (Vector2)transform.position).normalized;
            desiredX += direction.x * treatSeekWeight;
            stopForTreat = Vector2.Distance(transform.position, target.position) <= consumeDistance;
        }
        else
        {
            desiredX += wanderDirection.x * wanderWeight;
        }

        if (!hasTarget || !canConsume)
        {
            desiredX += avoidPlayerDirection * avoidPlayerWeight;
        }
        desiredX += avoidTrickDirection * avoidTrickWeight;

        if (Mathf.Abs(desiredX) < 0.01f)
        {
            desiredX = wanderDirection.x * 0.2f;
        }

        desiredVelocity = new Vector2(Mathf.Clamp(desiredX, -1f, 1f) * moveSpeed, 0f);

        var velocity = body.linearVelocity;
        desiredXVelocity = stopForTreat ? 0f : desiredVelocity.x;
        velocity.x = Mathf.Lerp(velocity.x, desiredXVelocity, 0.25f);
        body.linearVelocity = velocity;

        var isMoving = Mathf.Abs(desiredXVelocity) > 0.1f;
        TryJump(isMoving);
    }

    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;
        }

        if (Time.time < nextConsumeTime)
        {
            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;
            }

            var spawnPosition = hit.transform.position;
            Destroy(hit.gameObject);
            if (target == hit.transform)
            {
                target = null;
            }
            SpawnTrick(spawnPosition);
            nextConsumeTime = Time.time + consumeCooldown;
            break;
        }
    }

    private void SpawnTrick(Vector3 position)
    {
        if (trickPrefab != null)
        {
            Instantiate(trickPrefab, position, Quaternion.identity);
            return;
        }

        Instantiate(gameObject, position, Quaternion.identity);
    }

    private float GetAvoidPlayerDirection()
    {
        var players = FindObjectsByType<PlayerPlatformerController>(FindObjectsSortMode.None);
        if (players == null || players.Length == 0)
        {
            return 0f;
        }

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

            var dist = Vector2.Distance(origin, candidate.transform.position);
            if (dist < closestDist)
            {
                closestDist = dist;
                closest = candidate.transform;
            }
        }

        if (closest == null || closestDist > avoidPlayerRadius)
        {
            return 0f;
        }

        return Mathf.Sign(origin.x - closest.position.x);
    }

    private float GetAvoidTrickDirection()
    {
        var tricks = FindObjectsByType<TrickController>(FindObjectsSortMode.None);
        if (tricks == null || tricks.Length <= 1)
        {
            return 0f;
        }

        Transform closest = null;
        var closestDist = float.MaxValue;
        var origin = transform.position;
        for (var i = 0; i < tricks.Length; i++)
        {
            var candidate = tricks[i];
            if (candidate == null || candidate == this || !candidate.gameObject.activeInHierarchy)
            {
                continue;
            }

            var dist = Vector2.Distance(origin, candidate.transform.position);
            if (dist < closestDist)
            {
                closestDist = dist;
                closest = candidate.transform;
            }
        }

        if (closest == null || closestDist > avoidTrickRadius)
        {
            return 0f;
        }

        return Mathf.Sign(origin.x - closest.position.x);
    }

    private void TryJump(bool isMoving)
    {
        if (!isMoving || Time.time < nextJumpTime)
        {
            return;
        }

        if (!IsGrounded())
        {
            return;
        }

        var chance = jumpChancePerSecond * Time.fixedDeltaTime;
        if (Random.value > chance)
        {
            return;
        }

        var velocity = body.linearVelocity;
        velocity.y = 0f;
        body.linearVelocity = velocity;
        body.AddForce(Vector2.up * jumpImpulse, ForceMode2D.Impulse);
        nextJumpTime = Time.time + jumpCooldown;
    }

    private bool IsGrounded()
    {
        var collider = GetComponent<Collider2D>();
        if (collider == null)
        {
            return false;
        }

        var bounds = collider.bounds;
        var checkSize = new Vector2(bounds.size.x * 0.9f, groundCheckDistance * 2f);
        var checkCenter = new Vector2(bounds.center.x, bounds.min.y - groundCheckDistance);
        var hits = Physics2D.OverlapBoxAll(checkCenter, checkSize, 0f, groundMask);
        for (var i = 0; i < hits.Length; i++)
        {
            var hit = hits[i];
            if (hit != null && hit != collider)
            {
                return true;
            }
        }

        return false;
    }


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