using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;
using System.Linq;

// Quy trình ưu tiên: Né đòn --> Bắn hạ (Artifact) --> Đuổi theo (Vector) --> Điều tra --> Nói chuyện --> Đi tuần
[RequireComponent(typeof(NavMeshAgent))]
[RequireComponent(typeof(Rigidbody))]
public class EnemyAI : MonoBehaviour
{
    [Header("References")]
    public Transform player;
    private NavMeshAgent agent;
    private Rigidbody rb;
    private FieldOfView fov;

    [Header("Movement Settings")]
    public float moveSpeed = 3f;
    public float rotateSpeed = 10f;

    [Header("Patrol Settings")]
    public Transform[] patrolWaypoints;
    public int currentWaypointIndex = 0;
    public float patrolWaitTime = 2f;
    private float currentWaitTime = 0f;
    
    [Header("Combat State")]
    public bool playerHasArtifact;
    public GameObject laserPrefab;
    public Transform firePoint;
    public float minShootDelay = 1f;
    public float maxShootDelay = 3f;
    private float nextShootTime;

    [Header("Dodge Settings")]
    public float dodgeForce = 10f;
    public float dodgeDuration = 0.2f;
    public float dodgeCooldown = 1.2f;
    private bool isDodging = false;
    private float nextDodgeTime = 0f;

    [Header("Conversation Settings")]
    public string npcName = "Guard";
    [TextArea] public string persona = "You are a grumpy guard protecting gold.";
    public float talkRange = 10f;
    public float talkCooldown = 15f;
    private float lastTalkTime;
    public bool isTalking; // Public để debug
    private EnemyAI talkingPartner;
    private Hallucinate.UI.ChatBubble chatBubble;
    
    public Node rootNode;

    void Start()
    {
        agent = GetComponent<NavMeshAgent>();
        rb = GetComponent<Rigidbody>();
        fov = GetComponent<FieldOfView>();
        chatBubble = GetComponentInChildren<Hallucinate.UI.ChatBubble>(true);

        // Rigidbody setup cho Unity 6
        rb.isKinematic = true;
        rb.freezeRotation = true;

        if (player == null)
        {
            GameObject playerObj = GameObject.FindGameObjectWithTag("Player");
            if (playerObj != null) player = playerObj.transform;
        }

        /* 
        // Tạm thời comment đoạn này để tránh lỗi Tag chưa định nghĩa
        if (patrolWaypoints == null || patrolWaypoints.Length == 0)
        {
            patrolWaypoints = GameObject.FindGameObjectsWithTag("PatrolPoint")
                .Select(go => go.transform).ToArray();
        }
        */

        InitTree();
        
        Debug.Log($"<color=white>[AI {npcName}] Init complete. Waypoints: {patrolWaypoints.Length}</color>");
    }

    void InitTree()
    {
        var dodgeSequence = new Sequence(new List<Node> { new TaskNode(CheckDodgeConditions), new TaskNode(ActionDodge) });
        var laserSequence = new Sequence(new List<Node> { new TaskNode(CheckHasArtifact), new TaskNode(ActionFocusAndShoot) });
        var chaseSequence = new Sequence(new List<Node> { new TaskNode(CheckCanSeePlayer), new TaskNode(ActionChasePlayer) });
        var investigateSequence = new Sequence(new List<Node> { new TaskNode(CheckHasInvestigateTarget), new TaskNode(ActionInvestigate) });
        var talkSequence = new Sequence(new List<Node> { new TaskNode(CheckCanTalkToNPC), new TaskNode(ActionTalk) });
        var patrolAction = new TaskNode(ActionPatrol);

        rootNode = new Selector(new List<Node>
        {
            dodgeSequence,
            laserSequence,
            chaseSequence,
            investigateSequence,
            talkSequence,
            patrolAction
        });
    }

    void Update()
    {
        if (player == null) return;

        // An toàn cho NavMeshAgent
        if (!agent.isOnNavMesh)
        {
            Debug.LogWarning($"[AI {npcName}] NPC is NOT on NavMesh!");
            return;
        }

        if (!isTalking && !isDodging && agent.isStopped) 
            agent.isStopped = false;

        rootNode?.Evaluate();
    }

    #region CONDITIONS

    private NodeState CheckDodgeConditions()
    {
        if (isDodging) return NodeState.Success;
        if (fov != null && fov.canSeePlayer && Input.GetMouseButtonDown(0) && Time.time >= nextDodgeTime)
            return NodeState.Success;
        return NodeState.Failure;
    }

    private NodeState CheckHasArtifact()
    {
        if (playerHasArtifact) StopConversation();
        return playerHasArtifact ? NodeState.Success : NodeState.Failure;
    }

    private NodeState CheckCanSeePlayer()
    {
        bool canSee = fov != null && fov.canSeePlayer;
        if (canSee) StopConversation();
        return canSee ? NodeState.Success : NodeState.Failure;
    }

    private NodeState CheckHasInvestigateTarget()
    {
        return (fov != null && fov.lastKnownPlayerPosition != Vector3.zero) ? NodeState.Success : NodeState.Failure;
    }

    private NodeState CheckCanTalkToNPC()
    {
        if (playerHasArtifact || (fov != null && fov.canSeePlayer)) return NodeState.Failure;
        if (Time.time < lastTalkTime + talkCooldown) return NodeState.Failure;
        if (isTalking) return NodeState.Success;

        // Quét tìm NPC
        Collider[] hitColliders = Physics.OverlapSphere(transform.position, talkRange);
        foreach (var hit in hitColliders)
        {
            if (hit.gameObject == gameObject) continue;
            
            EnemyAI other = hit.GetComponentInParent<EnemyAI>();
            if (other != null && !other.isTalking && Time.time >= other.lastTalkTime + talkCooldown)
            {
                // Chỉ ID nhỏ hơn gọi để tránh trùng
                if (gameObject.GetInstanceID() < other.gameObject.GetInstanceID())
                {
                    talkingPartner = other;
                    return NodeState.Success;
                }
            }
        }
        return NodeState.Failure;
    }

    #endregion

    #region ACTIONS

    private NodeState ActionTalk()
    {
        if (talkingPartner == null) return NodeState.Failure;
        if (!isTalking)
        {
            isTalking = true;
            agent.isStopped = true;
            FaceTarget(talkingPartner.transform.position);
            
            Debug.Log($"<color=yellow>[AI {npcName}] Talking to {talkingPartner.npcName}</color>");
            
            string prompt = $"You are {npcName}. Speak 1 short sentence in English to your colleague {talkingPartner.npcName} about the shift.";
            Hallucinate.AI.GeminiService.Instance.GetResponse(persona, prompt, (response) => {
                if (chatBubble != null) chatBubble.Show(response);
                Invoke(nameof(EndConversation), 5f);
            });
            talkingPartner.OnPartnerTalked(this);
        }
        return NodeState.Running;
    }

    public void OnPartnerTalked(EnemyAI partner)
    {
        isTalking = true;
        talkingPartner = partner;
        agent.isStopped = true;
        FaceTarget(partner.transform.position);
        Invoke(nameof(EndConversation), 6f);
    }

    private void EndConversation()
    {
        isTalking = false;
        lastTalkTime = Time.time;
        if (agent != null && agent.isOnNavMesh) agent.isStopped = false;
        talkingPartner = null;
    }

    private void StopConversation()
    {
        if (!isTalking) return;
        CancelInvoke(nameof(EndConversation));
        EndConversation();
        if (chatBubble != null) chatBubble.Show("Wait, what's that?!", 2f);
    }

    private NodeState ActionPatrol()
    {
        if (patrolWaypoints == null || patrolWaypoints.Length == 0) return NodeState.Failure;

        agent.isStopped = false;
        agent.speed = moveSpeed * 0.5f;
        
        var target = patrolWaypoints[currentWaypointIndex];
        agent.SetDestination(target.position);

        if (Vector3.Distance(transform.position, target.position) < 1.5f)
        {
            currentWaitTime += Time.deltaTime;
            if (currentWaitTime >= patrolWaitTime)
            {
                currentWaypointIndex = (currentWaypointIndex + 1) % patrolWaypoints.Length;
                currentWaitTime = 0f;
            }
        }
        return NodeState.Running;
    }

    private NodeState ActionChasePlayer()
    {
        agent.isStopped = false;
        agent.speed = moveSpeed;
        agent.SetDestination(player.position);
        return NodeState.Running;
    }

    private NodeState ActionInvestigate()
    {
        agent.isStopped = false;
        agent.speed = moveSpeed * 0.7f;
        agent.SetDestination(fov.lastKnownPlayerPosition);
        if (Vector3.Distance(transform.position, fov.lastKnownPlayerPosition) < 1.5f)
        {
            fov.lastKnownPlayerPosition = Vector3.zero;
            return NodeState.Success;
        }
        return NodeState.Running;
    }

    private NodeState ActionFocusAndShoot()
    {
        agent.isStopped = true;
        FaceTarget(player.position);
        if (Time.time >= nextShootTime)
        {
            if (laserPrefab && firePoint) Instantiate(laserPrefab, firePoint.position, firePoint.rotation);
            nextShootTime = Time.time + Random.Range(minShootDelay, maxShootDelay);
        }
        return NodeState.Running;
    }

    private NodeState ActionDodge()
    {
        if (!isDodging) StartCoroutine(DodgeRollRoutine());
        return NodeState.Running;
    }

    private IEnumerator DodgeRollRoutine()
    {
        isDodging = true;
        agent.enabled = false;
        rb.isKinematic = false;
        Vector3 dir = (player.position - transform.position).normalized;
        Vector3 perp = new Vector3(-dir.z, 0, dir.x);
        rb.AddForce((Random.value > 0.5f ? perp : -perp) * dodgeForce, ForceMode.Impulse);
        yield return new WaitForSeconds(dodgeDuration);
        rb.linearVelocity = Vector3.zero;
        rb.isKinematic = true;
        agent.enabled = true;
        isDodging = false;
    }

    private void FaceTarget(Vector3 pos)
    {
        Vector3 dir = (pos - transform.position);
        dir.y = 0;
        if (dir != Vector3.zero) transform.rotation = Quaternion.LookRotation(dir);
    }

    #endregion

    private void OnDrawGizmos()
    {
        // Vẽ vùng nói chuyện (Xanh lá)
        Gizmos.color = Color.green;
        Gizmos.DrawWireSphere(transform.position, talkRange);

        // Vẽ đường nối tới bạn diễn nếu đang nói
        if (isTalking && talkingPartner != null)
        {
            Gizmos.color = Color.yellow;
            Gizmos.DrawLine(transform.position + Vector3.up, talkingPartner.transform.position + Vector3.up);
        }
    }
}