using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.AI;
using System.Linq;
using UnityEngine.InputSystem;
using Invector;
using Invector.vCharacterController;
using Random = UnityEngine.Random;

[Serializable]
public class DialogueResult { public string text; public float speedMod; public float suspicionMod; }

// Quy trình ưu tiên: Né đòn (Bị bắn) --> Panic (Thấp máu) --> Bắn hạ (Chiến đấu) --> Đuổi theo --> Điều tra --> Nói chuyện --> Đi tuần
[RequireComponent(typeof(NavMeshAgent))]
[RequireComponent(typeof(Rigidbody))]
[RequireComponent(typeof(vHealthController))]
public class EnemyAI : MonoBehaviour
{
    [Header("References")]
    public Transform player;
    private NavMeshAgent agent;
    private Rigidbody rb;
    private FieldOfView fov;
    private Collider mainCollider;
    private vHealthController health;

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

    [Header("Patrol Settings")]
    public float patrolWaitTime = 2f;
    private float currentWaitTime = 0f;
    public float patrolSpeed = 2.5f;
    public float patrolRadius = 12f;      
    private Vector3 startPosition; 

    [Header("Combat State")]
    public bool playerHasArtifact;
    public bool isAggroedBySound;
    public GameObject laserPrefab;
    public Transform firePoint;
    public float minShootDelay = 1.5f; 
    public float maxShootDelay = 3.5f;
    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("Advanced AI States (New)")]
    public bool isPanicking = false;
    public bool isEnraged = false;
    public float panicHealthThreshold = 40f; // Dưới 40% máu sẽ panic
    public float regenRate = 2f; // Hồi 2 máu mỗi giây
    public float regenDelay = 5f; // Cần 5s không nhận dame để bắt đầu hồi
    private float lastDamageTime;

    [Header("Artifact Combat Upgrades")]
    public float minStrafeDuration = 0.5f; 
    public float maxStrafeDuration = 2.2f;
    public float maxSpreadAngle = 6f; 
    public float burstInterval = 0.12f; 
    
    public float approachWeight = 0.35f; 
    public float minCombatDistance = 5.0f;

    private float nextStrafeChangeTime;
    private int strafeDirectionSign = 1; 
    private bool isShootingBurst = false; 

    public bool IsDodging => isDodging;
    public bool IsShootingBurst => isShootingBurst;

    [Header("Conversation Settings")]
    public string npcName = "Guard";
    [TextArea] public string persona = "You are a bored security guard. You love coffee and hate night shifts.";
    public float talkRange = 12f;
    public float talkCooldown = 60f;
    private float lastTalkTime;
    public bool isTalking; 
    private EnemyAI talkingPartner;
    private Hallucinate.UI.ChatBubble chatBubble;

    [Header("Suspicion Settings")]
    public float suspicionLevel = 0f;
    public float investigationThreshold = 30f;
    public float alertNeighborsThreshold = 70f;
    public float alertRange = 25f; // Tăng tầm gọi hội
    
    public Node rootNode;

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

        // Thiết lập Invector Health
        health.onReceiveDamage.AddListener(OnReceiveDamage);
        health.onDead.AddListener(OnDead);

        // Tự động gán Layer Enemy
        if (gameObject.layer == LayerMask.NameToLayer("Default"))
            gameObject.layer = LayerMask.NameToLayer("Enemy");

        rb.isKinematic = true;
        rb.freezeRotation = true;
        startPosition = transform.position;

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

        InitTree();
    }

    void InitTree()
    {
        // 1. Phản xạ tức thì (Dodge)
        var dodgeSequence = new Sequence(new List<Node> { new TaskNode(CheckDodgeConditions), new TaskNode(ActionDodge) });
        
        // 2. Hoảng loạn (Panic)
        var panicSequence = new Sequence(new List<Node> { new TaskNode(CheckPanicConditions), new TaskNode(ActionPanic) });

        // 3. Tấn công (Laser)
        var laserSequence = new Sequence(new List<Node> { new TaskNode(CheckCombatConditions), new TaskNode(ActionFocusAndShoot) });
        
        // 4. Các hành vi khác
        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,
            panicSequence,
            laserSequence,
            chaseSequence,
            investigateSequence,
            talkSequence,
            patrolAction
        });
    }

    void Update()
    {
        if (player == null || health.isDead) return;

        // Đảm bảo Collider luôn bật
        if (mainCollider != null && !mainCollider.enabled) mainCollider.enabled = true;

        HandleHealthRegen();

        suspicionLevel = Mathf.Max(0, suspicionLevel - Time.deltaTime * 0.5f);

        if (suspicionLevel <= 0f && !isEnraged) isAggroedBySound = false;

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

        rootNode?.Evaluate();
    }

    private void HandleHealthRegen()
    {
        if (Time.time > lastDamageTime + regenDelay && health.currentHealth < health.maxHealth)
        {
            health.AddHealth((int)(regenRate * Time.deltaTime));
        }
    }

    #region HEALTH EVENTS

    private void OnReceiveDamage(vDamage damage)
    {
        lastDamageTime = Time.time;
        isAggroedBySound = true;
        suspicionLevel = 100f;
        StopConversation();
        
        // Gọi hội ngay khi bị bắn
        AlertNeighbors(damage.hitPosition);

        // Né đòn ngay lập tức khi bị trúng dame (phản xạ Elden Ring)
        if (Time.time > nextDodgeTime && !isDodging)
        {
            StartCoroutine(DodgeRollRoutine());
        }

        // Kiểm tra Enrage (Phase 2)
        if (health.currentHealth < health.maxHealth * 0.5f && !isEnraged)
        {
            EnterEnrageMode();
        }
    }

    private void OnDead(GameObject killer)
    {
        Debug.Log($"<color=black>[AI {npcName}] DIED.</color>");
        // Khi chết, làm những con xung quanh Enraged gắt hơn
        Collider[] hitColliders = Physics.OverlapSphere(transform.position, alertRange);
        foreach (var hit in hitColliders)
        {
            EnemyAI ally = hit.GetComponentInParent<EnemyAI>();
            if (ally != null && ally != this) ally.EnterEnrageMode();
        }
        
        agent.enabled = false;
        this.enabled = false;
    }

    public void EnterEnrageMode()
    {
        if (isEnraged) return;
        isEnraged = true;
        isPanicking = false; // Hết sợ, chuyển sang liều mạng
        
        // Buff stats mạnh mẽ như Elden Ring boss phase 2
        moveSpeed *= 1.5f;
        minShootDelay *= 0.5f;
        maxShootDelay *= 0.5f;
        maxSpreadAngle *= 0.6f; // Bắn chính xác hơn
        approachWeight = 0.8f; // Áp sát cực gắt
        minCombatDistance = 2.0f; // Đứng sát mặt Player để bắn
        
        if (chatBubble != null) chatBubble.Show("FOR THE BROTHERHOOD! DIE!", 3f);
        Debug.Log($"<color=red>[AI {npcName}] ENRAGED!</color> Stats boosted.");
    }

    #endregion

    #region CONDITIONS

    private NodeState CheckDodgeConditions()
    {
        if (isDodging) return NodeState.Success;
        // Tự né khi thấy Player click chuột trái (đang bắn)
        if (fov != null && fov.canSeePlayer && Mouse.current.leftButton.isPressed && Time.time > nextDodgeTime)
            return NodeState.Success;
        return NodeState.Failure;
    }

    private NodeState CheckPanicConditions()
    {
        if (isEnraged) return NodeState.Failure; // Đang điên thì không sợ
        if (health.currentHealth < (health.maxHealth * (panicHealthThreshold / 100f)))
        {
            return NodeState.Success;
        }
        return NodeState.Failure;
    }

    private NodeState CheckCombatConditions()
    {
        bool shouldCombat = playerHasArtifact || isAggroedBySound || isEnraged;
        if (shouldCombat) StopConversation();
        return shouldCombat ? NodeState.Success : NodeState.Failure;
    }

    private NodeState CheckCanSeePlayer()
    {
        bool canSee = fov != null && fov.canSeePlayer;
        if (canSee) { StopConversation(); AlertNeighbors(transform.position); suspicionLevel = 100; }
        return canSee ? NodeState.Success : NodeState.Failure;
    }

    private NodeState CheckHasInvestigateTarget()
    {
        if (fov != null && fov.lastKnownPlayerPosition != Vector3.zero && suspicionLevel > investigationThreshold)
            return NodeState.Success;
        return NodeState.Failure;
    }

    private NodeState CheckCanTalkToNPC()
    {
        if (playerHasArtifact || isAggroedBySound || isEnraged || (fov != null && fov.canSeePlayer)) return NodeState.Failure;
        if (Time.time < lastTalkTime + talkCooldown || isTalking) return NodeState.Failure;
        if (Hallucinate.AI.ConversationManager.Instance == null || !Hallucinate.AI.ConversationManager.Instance.CanStartConversation()) return NodeState.Failure;

        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 && !other.isEnraged)
            {
                if (gameObject.GetInstanceID() < other.gameObject.GetInstanceID())
                {
                    Hallucinate.AI.ConversationManager.Instance.StartConversation(this, other);
                    return NodeState.Success;
                }
            }
        }
        return NodeState.Failure;
    }

    #endregion

    #region ACTIONS

    public void HearNoise(Vector3 location, float volume)
    {
        suspicionLevel += volume * 15f;
        if (fov != null) fov.lastKnownPlayerPosition = location;
        if (suspicionLevel >= investigationThreshold) isAggroedBySound = true;
        if (suspicionLevel >= alertNeighborsThreshold) AlertNeighbors(location);
        StopConversation();
    }

    public void AlertNeighbors(Vector3 threatPos)
    {
        Collider[] hitColliders = Physics.OverlapSphere(transform.position, alertRange);
        foreach (var hit in hitColliders)
        {
            EnemyAI neighbor = hit.GetComponentInParent<EnemyAI>();
            if (neighbor != null && neighbor != this)
            {
                neighbor.TriggerCombatAlert(threatPos);
            }
        }
    }

    public void TriggerCombatAlert(Vector3 sourceLocation)
    {
        if (isEnraged) return;
        suspicionLevel = 100f;
        isAggroedBySound = true;
        if (fov != null) fov.lastKnownPlayerPosition = sourceLocation;
        StopConversation();
    }

    private NodeState ActionPanic()
    {
        isPanicking = true;
        agent.speed = moveSpeed * 1.3f;
        
        // Chạy trốn khỏi Player đến một điểm ngẫu nhiên xa Player
        if (!agent.pathPending && agent.remainingDistance < 1f)
        {
            Vector3 runDir = (transform.position - player.position).normalized;
            Vector3 escapePoint = transform.position + runDir * 10f + Random.insideUnitSphere * 5f;
            
            NavMeshHit hit;
            if (NavMesh.SamplePosition(escapePoint, out hit, 10f, 1))
                agent.SetDestination(hit.position);
        }

        if (chatBubble != null && Random.value < 0.01f) chatBubble.Show("HELP! HE'S KILLING US!", 1f);
        
        return NodeState.Running;
    }

    private NodeState ActionTalk()
    {
        if (isTalking) { agent.isStopped = true; return NodeState.Running; }
        return NodeState.Failure;
    }

    private void StopConversation()
    {
        if (isTalking && Hallucinate.AI.ConversationManager.Instance != null)
        {
            Hallucinate.AI.ConversationManager.Instance.InterruptConversation(this);
        }
    }

    private NodeState ActionPatrol()
    {
        isPanicking = false;
        agent.isStopped = false;
        agent.speed = patrolSpeed;
        if (!agent.pathPending && agent.remainingDistance <= agent.stoppingDistance)
        {
            currentWaitTime += Time.deltaTime;
            if (currentWaitTime >= patrolWaitTime)
            {
                Vector3 randomDest = startPosition + Random.insideUnitSphere * patrolRadius;
                NavMeshHit hit;
                if (NavMesh.SamplePosition(randomDest, out hit, patrolRadius, 1)) agent.SetDestination(hit.position);
                currentWaitTime = 0f; 
            }
        }
        return NodeState.Running;
    }

    private NodeState ActionChasePlayer()
    {
        isPanicking = false;
        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)
        {
            currentWaitTime += Time.deltaTime;
            if (currentWaitTime > 3f) { fov.lastKnownPlayerPosition = Vector3.zero; return NodeState.Success; }
        }
        return NodeState.Running;
    }

    private NodeState ActionFocusAndShoot()
    {
        isPanicking = false;
        if (player == null) return NodeState.Failure;
        if (agent.hasPath) agent.ResetPath();
        agent.isStopped = false;

        Vector3 targetPos = player.position;
        if (!playerHasArtifact && fov != null && !fov.canSeePlayer && fov.lastKnownPlayerPosition != Vector3.zero)
            targetPos = fov.lastKnownPlayerPosition;

        // Xoay về phía mục tiêu
        Vector3 bodyDir = (targetPos - transform.position);
        bodyDir.y = 0f;
        if (bodyDir != Vector3.zero)
            transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.LookRotation(bodyDir), rotateSpeed * Time.deltaTime);

        // Strafe di chuyển linh hoạt
        if (Time.time >= nextStrafeChangeTime)
        {
            strafeDirectionSign = new int[] { -1, 1, 0 }[Random.Range(0, 3)];
            nextStrafeChangeTime = Time.time + Random.Range(minStrafeDuration, maxStrafeDuration);
        }

        Vector3 moveDir = Vector3.zero;
        if (strafeDirectionSign != 0 && bodyDir != Vector3.zero)
        {
            Vector3 normal = bodyDir.normalized;
            moveDir = new Vector3(-normal.z, 0, normal.x) * strafeDirectionSign;
            if (Vector3.Distance(transform.position, targetPos) > minCombatDistance) moveDir += normal * approachWeight;
        }

        if (moveDir != Vector3.zero)
        {
            agent.speed = moveSpeed * (isEnraged ? 1f : 0.75f);
            agent.Move(moveDir.normalized * agent.speed * Time.deltaTime);
        }

        if (firePoint != null)
            firePoint.rotation = Quaternion.LookRotation((targetPos + Vector3.up * 1f) - firePoint.position);

        if (Time.time >= nextShootTime && !isShootingBurst)
        {
            StartCoroutine(ShootBurstRoutine(Random.Range(1, isEnraged ? 6 : 4)));
            nextShootTime = Time.time + Random.Range(minShootDelay, maxShootDelay);
        }

        return NodeState.Running;
    }

    private IEnumerator ShootBurstRoutine(int bulletCount)
    {
        isShootingBurst = true;
        for (int i = 0; i < bulletCount; i++)
        {
            if (laserPrefab == null || firePoint == null) break;
            float spread = isEnraged ? maxSpreadAngle * 0.5f : maxSpreadAngle;
            Quaternion rot = firePoint.rotation * Quaternion.Euler(Random.Range(-spread, spread), Random.Range(-spread, spread), 0f);
            Instantiate(laserPrefab, firePoint.position, rot);
            yield return new WaitForSeconds(isEnraged ? burstInterval * 0.7f : burstInterval);
        }
        isShootingBurst = false;
    }

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

    private IEnumerator DodgeRollRoutine()
    {
        isDodging = true;
        agent.enabled = false;
        rb.isKinematic = false;
        if (mainCollider != null) mainCollider.enabled = true;

        Vector3 dir = (player.position - transform.position).normalized;
        Vector3 perp = new Vector3(-dir.z, 0, dir.x) * (Random.value > 0.5f ? 1 : -1);
        rb.AddForce(perp * (isEnraged ? dodgeForce * 1.5f : dodgeForce), ForceMode.Impulse);

        yield return new WaitForSeconds(dodgeDuration);
        rb.linearVelocity = Vector3.zero;
        rb.isKinematic = true;
        agent.enabled = true;
        nextDodgeTime = Time.time + (isEnraged ? dodgeCooldown * 0.5f : dodgeCooldown);
        isDodging = false;
    }

    public void ProcessDialogueResult(string json)
    {
        try
        {
            DialogueResult result = JsonUtility.FromJson<DialogueResult>(json);
            if (chatBubble != null) chatBubble.Show(result.text);

            moveSpeed += result.speedMod;
            suspicionLevel = Mathf.Clamp(suspicionLevel + result.suspicionMod, 0, 100);
            lastTalkTime = Time.time;
        }
        catch { if (chatBubble != null) chatBubble.Show(json); }
    }

    public void SetTalkingPartner(EnemyAI partner) { talkingPartner = partner; }
    public 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()
    {
        Gizmos.color = isEnraged ? Color.red : Color.green;
        Gizmos.DrawWireSphere(transform.position, alertRange);
    }
}