using UnityEngine;
using UnityGLTF.Cache;

namespace UnityGLTF
{
    /// <summary>
    /// Instantiated GLTF Object component that gets added to the root of every GLTF game object created by a scene importer.
    /// </summary>
    public class InstantiatedGLTFObject : MonoBehaviour
    {
        /// <summary>
        /// Ref-counted cache data for this object.
        /// The same instance of this cached data will be used for all copies of this GLTF object,
        /// and the data gets cleaned up when the ref counts goes to 0.
        /// </summary>
        private RefCountedCacheData cachedData;
        public RefCountedCacheData CachedData
        {
            get
            {
                return cachedData;
            }

            set
            {
                if (cachedData != value)
                {
                    if (cachedData != null)
                    {
                        cachedData.DecreaseRefCount();
                    }

                    cachedData = value;

                    if (cachedData != null)
                    {
                        cachedData.IncreaseRefCount();
                    }
                }
            }
        }

        /// <summary>
        /// Duplicates the instantiated GLTF object.
        /// Note that this should always be called if you intend to create a new instance of a GLTF object, 
        /// in order to properly preserve the ref count of the dynamically loaded mesh data, otherwise
        /// you will run into a memory leak due to non-destroyed meshes, textures and materials.
        /// </summary>
        /// <returns></returns>
        public InstantiatedGLTFObject Duplicate()
        {
            GameObject duplicatedObject = Instantiate(gameObject);

            InstantiatedGLTFObject newGltfObjectComponent = duplicatedObject.GetComponent<InstantiatedGLTFObject>();
            newGltfObjectComponent.CachedData = CachedData;

            return newGltfObjectComponent;
        }

        private void OnDestroy()
        {
            CachedData = null;
        }
    }
}