using System;
using UnityEngine;

namespace NightclubArcadia.UI
{
    /// <summary>
    /// Owns the two independent UI state flags — dialogue active and menu open —
    /// and raises <see cref="StateChanged"/> so HUD, camera framing, and panels
    /// can derive their visibility from a single source of truth.
    /// </summary>
    public sealed class UIStateController : MonoBehaviour
    {
        public static UIStateController Instance { get; private set; }

        public bool IsDialogueActive { get; private set; }
        public bool IsMenuOpen { get; private set; }

        /// <summary>Raised after any state change. Subscribers derive their own visibility.</summary>
        public event Action StateChanged;

        void Awake()
        {
            if (Instance != null && Instance != this)
            {
                Debug.LogError($"[{nameof(UIStateController)}] Duplicate instance on '{name}'. Destroying this component.", this);
                Destroy(this);
                return;
            }

            Instance = this;
        }

        void OnDestroy()
        {
            if (Instance == this)
            {
                Instance = null;
            }
        }

        public void SetDialogueActive(bool value)
        {
            if (IsDialogueActive == value)
            {
                return;
            }

            IsDialogueActive = value;
            StateChanged?.Invoke();
        }

        public void SetMenuOpen(bool value)
        {
            if (IsMenuOpen == value)
            {
                return;
            }

            IsMenuOpen = value;
            StateChanged?.Invoke();
        }
    }
}