using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;

public enum NPCType
{
    Villager,
    QuestGiver,
    Vendor,
    Guard,
    Trainer
}

public enum NPCRelationship
{
    Hostile,
    Neutral,
    Friendly
}

public enum NPCState
{
    Idle,
    Wandering,
    Talking,
    Attacking,
    Dead
}

public enum DialogueBehavior
{
    SingleLine,
    Sequential,
    Random
}

[RequireComponent(typeof(Collider))]
public class NPC : MonoBehaviour, IInteractable
{
    [Header("Identity")]
    [SerializeField] private string npcName = "Villager";
    [SerializeField] private string npcTitle = "Townsperson";
    [SerializeField] private Sprite portrait;

    [Header("NPC Configuration")]
    [SerializeField] private NPCType npcType = NPCType.Villager;
    [SerializeField] private NPCRelationship relationship = NPCRelationship.Neutral;
    [SerializeField] private NPCState currentState = NPCState.Idle;
    [SerializeField] private float interactionRadius = 2.5f;

    public NPCRelationship Relationship
    {
        get => relationship;
        set => relationship = value;
    }

    public NPCState CurrentState
    {
        get => currentState;
        set => currentState = value;
    }

    [Header("Dialogue Settings")]
    [SerializeField] private DialogueBehavior dialogueType = DialogueBehavior.Sequential;
    [TextArea(2, 5)]
    [SerializeField] private string[] dialogueLines = new string[] { "Hello traveler!" };
    [SerializeField] private AudioClip talkSound;

    [Header("Wander Settings")]
    [SerializeField] private float wanderRadius = 5.0f;
    [SerializeField] private float wanderInterval = 4.0f;
    [SerializeField] private float moveSpeed = 2.0f;

    [Header("Vendor / Quest Data")]
    [SerializeField] private int questId = 0;
    [SerializeField] private List<string> vendorInventory = new List<string>();

    [Header("Events")]
    [SerializeField] private UnityEvent<GameObject> onInteractionStart;
    [SerializeField] private UnityEvent<string> onSpeakLine;

    private int currentDialogueIndex = 0;
    private Vector3 initialPosition;
    private Vector3 wanderTarget;
    private float wanderTimer;

    private void Start()
    {
        initialPosition = transform.position;
        wanderTimer = wanderInterval;

        // Ensure collider is present for raycasting
        Collider col = GetComponent<Collider>();
        if (col != null && !col.enabled) col.enabled = true;
    }

    private void Update()
    {
        if (currentState == NPCState.Wandering)
        {
            ProcessWander();
        }
    }

    // --- IInteractable Implementation ---
    public void Interact(GameObject interactor)
    {
        // Face player on interact
        Vector3 dir = (interactor.transform.position - transform.position);
        dir.y = 0;
        if (dir != Vector3.zero)
        {
            transform.rotation = Quaternion.LookRotation(dir);
        }

        currentState = NPCState.Talking;

        // Trigger dialogue / action based on NPC type
        SpeakNextLine();
        onInteractionStart?.Invoke(interactor);

        if (talkSound != null)
        {
            AudioSource.PlayClipAtPoint(talkSound, transform.position);
        }

        Debug.Log($"[{npcName} ({npcType})] Interacted with {interactor.name}");
    }

    public string GetInteractionPrompt()
    {
        return npcType switch
        {
            NPCType.QuestGiver => $"Talk to {npcName} [Quest]",
            NPCType.Vendor => $"Trade with {npcName}",
            NPCType.Guard => $"Ask {npcName}",
            _ => $"Talk to {npcName}"
        };
    }

    public float GetInteractionRadius() => interactionRadius;
    public Transform GetTransform() => transform;

    // --- Dialogue Handling ---
    private void SpeakNextLine()
    {
        if (dialogueLines == null || dialogueLines.Length == 0) return;

        string lineToSpeak = "";

        switch (dialogueType)
        {
            case DialogueBehavior.SingleLine:
                lineToSpeak = dialogueLines[0];
                break;

            case DialogueBehavior.Sequential:
                lineToSpeak = dialogueLines[currentDialogueIndex];
                currentDialogueIndex = (currentDialogueIndex + 1) % dialogueLines.Length;
                break;

            case DialogueBehavior.Random:
                int randIndex = UnityEngine.Random.Range(0, dialogueLines.Length);
                lineToSpeak = dialogueLines[randIndex];
                break;
        }

        onSpeakLine?.Invoke(lineToSpeak);
        Debug.Log($"<color=cyan>{npcName}:</color> \"{lineToSpeak}\"");
    }

    // --- Simple Wandering Logic ---
    private void ProcessWander()
    {
        wanderTimer += Time.deltaTime;
        if (wanderTimer >= wanderInterval)
        {
            wanderTimer = 0f;
            Vector2 randomCircle = UnityEngine.Random.insideUnitCircle * wanderRadius;
            wanderTarget = initialPosition + new Vector3(randomCircle.x, 0, randomCircle.y);
        }

        if (wanderTarget != Vector3.zero)
        {
            Vector3 moveDir = (wanderTarget - transform.position);
            moveDir.y = 0;
            if (moveDir.magnitude > 0.3f)
            {
                transform.rotation = Quaternion.Slerp(transform.rotation, Quaternion.LookRotation(moveDir), 8.0f * Time.deltaTime);
                transform.position += moveDir.normalized * moveSpeed * Time.deltaTime;
            }
        }
    }

    private void OnDrawGizmosSelected()
    {
        Gizmos.color = Color.yellow;
        Gizmos.DrawWireSphere(transform.position, interactionRadius);

        if (currentState == NPCState.Wandering)
        {
            Gizmos.color = Color.blue;
            Gizmos.DrawWireSphere(initialPosition, wanderRadius);
        }
    }
}