using System;
using UnityEngine;
using UnityEngine.UI;

namespace OctoCore.UI
{
    /// <summary>
    /// UI Manager component for managing canvas scaling.
    /// Automatically adjusts canvas scale factor based on screen size.
    /// </summary>
    [ExecuteAlways]
    public class OctoUIManager : MonoBehaviour
    {
        /// <summary>
        /// References to UI settings and canvas scaler.
        /// </summary>
        [System.Serializable]
        public class References
        {
            public CanvasScaler CanvasScaler;
        }

        [SerializeField] private bool dontDestroy = true;
        [SerializeField] private bool updateInEditor;
        [SerializeField] private References references;

        private Action<Vector2Int> onScreenResize;

    #if UNITY_EDITOR
        private Vector2Int currentScreenSize;
    #endif

        void Awake()
        {
    #if UNITY_EDITOR
            if (!Application.isPlaying && !updateInEditor) return;
    #endif

            if (dontDestroy)
                DontDestroyOnLoad(this);

            if (OctoCore.Instance)
                OctoCore.Instance.UI.SubscribeOnScreenResize(onScreenResize = OnScreenResize);
        }

        void OnEnable()
        {
    #if UNITY_EDITOR
            if (!Application.isPlaying && !updateInEditor) return;
    #endif

            RescaleCanvas();
        }
    
        void Update()
        {
    #if UNITY_EDITOR
            if (!Application.isPlaying && updateInEditor)
                RescaleCanvas(new Vector2Int(Screen.width, Screen.height));  
    #endif
        }

        void OnDestroy()
        {
    #if UNITY_EDITOR
            if (!Application.isPlaying && !updateInEditor) return;
    #endif

            if (onScreenResize != null && OctoCore.Instance)
            {
                OctoCore.Instance.UI.UnsubscribeOnScreenResize(onScreenResize);
                onScreenResize = null;
            }
        }

        private void OnScreenResize(Vector2Int screenSize)
        {
            RescaleCanvas(screenSize);
        }

        public void RescaleCanvas()
        {
            if (!OctoCore.Instance || !OctoCore.Instance.Settings) return;

            RescaleCanvas(OctoCore.Instance.UI.ScreenSize, OctoCore.Instance.Settings.Ui.ReferenceSize);
        }

        public void RescaleCanvas(Vector2Int screenSize)
        {
            if (!OctoCore.Instance || !OctoCore.Instance.Settings) return;

            RescaleCanvas(screenSize, OctoCore.Instance.Settings.Ui.ReferenceSize);
        }

        private void RescaleCanvas(Vector2Int screenSize, Vector2Int referenceSize)
        {
            if (!references.CanvasScaler) return;

    #if UNITY_EDITOR
            if (!Application.isPlaying && updateInEditor)
            {
                if (currentScreenSize == screenSize) return;
                currentScreenSize = screenSize;
            }
    #endif

            float scaleFactor = Mathf.Min((float)screenSize.x / referenceSize.x, (float)screenSize.y / referenceSize.y);
            if (scaleFactor == 0) return;

            references.CanvasScaler.scaleFactor = scaleFactor;

            if (OctoCore.Instance && OctoCore.Instance.Development.Log)
                Debug.Log($"Canvas scale factor updated: {scaleFactor}");
        }
    }
}