using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;

namespace Assets.ThoMagic.Renderer
{
    public class ObjectData
    {
        public readonly GameObject GameObject;
        public readonly HashSet<int> Owners = new HashSet<int>();
        public readonly uint prefabId;
        public float[] LodSizes;
        public float[] LodTransitions;
        public LOD[] LODs;
        public Vector4[] lods = new Vector4[8];
        public uint[] indirectArgsPerLodOffsets = new uint[8];
        public uint[] indirectArgsPerLodCounts = new uint[8];
        public uint[] indirectArgsPerLodWithShadowsCounts = new uint[8];
        public List<int> indirectArgsPerSubmeshOffsets = new List<int>();
        public uint lodCount = 1;
        public uint fadeLods = 0;
        public uint indirectArgsCount = 1;
        public uint count = 0;
        public IInstanceRenderSettings Settings;

        public List<GraphicsBuffer.IndirectDrawIndexedArgs> indirectDrawIndexedArgs = new List<GraphicsBuffer.IndirectDrawIndexedArgs>();

        public DrawGroup[] drawGroups;
        public DrawGroup[] drawShadowGroups;

        public int contentHashCache;
        private bool _isDisposed;

        public ObjectData(GameObject gameObject, IInstanceRenderSettings settings)
        {
            GameObject = gameObject;
            Settings = settings;

            var lodGroup = GameObject.GetComponent<LODGroup>();

            LOD[] lodArray;

            if (lodGroup == null)
                lodArray = new LOD[1]
                {
                        new LOD(0.0001f, GameObject.GetComponentsInChildren<MeshRenderer>())
                };
            else
                lodArray = lodGroup.GetLODs();

            LODs = lodArray;

            LodSizes = new float[lodArray.Length];
            LodTransitions = new float[lodArray.Length];
            lodCount = (uint)lodArray.Length;

            if (lodGroup != null && lodGroup.fadeMode == LODFadeMode.CrossFade)
                fadeLods = 1;

            for (int index = 0; index < lodArray.Length; ++index)
            {
                LodSizes[index] = CalculateBoundsForRenderers(lodArray[index].renderers);
                LodTransitions[index] = lodArray[index].screenRelativeTransitionHeight;
            }

            if (RendererPool.prefabDataFreeSlot.Count > 0)
            {
                prefabId = RendererPool.prefabDataFreeSlot.Dequeue();
                RendererPool.prefabData[(int)prefabId] = new PrefabData();
            }
            else
            {
                prefabId = (uint)RendererPool.prefabData.Count;
                RendererPool.prefabData.Add(new PrefabData());
            }

            RendererPool.rebuildPrefabs = true;

            indirectArgsCount = BuildRenderer(indirectDrawIndexedArgs);
        }

        public void Dispose()
        {
            if (this._isDisposed)
                return;

            foreach (var drawGroup in drawGroups)
            {
                drawGroup?.Dispose();
            }

            foreach (var drawGroup in drawShadowGroups)
            {
                drawGroup?.Dispose();
            }

            this._isDisposed = true;
        }

        private uint BuildRenderer(List<GraphicsBuffer.IndirectDrawIndexedArgs> indirectDrawIndexedArgs)
        {
            uint indirectArgsCount = 0;

            drawGroups = new DrawGroup[lodCount];
            drawShadowGroups = new DrawGroup[lodCount];

            for (int index = 0; index < lodCount; ++index)
            {
                uint indirectArgsPerLodCount = 0;

                foreach (var renderer in LODs[index].renderers)
                {
                    if (renderer != null)
                    {
                        if (renderer is MeshRenderer)
                        {
                            var meshFilter = renderer.GetComponent<MeshFilter>();
                            if (meshFilter != null)
                            {
                                var sharedMesh = meshFilter.sharedMesh;
                                var sharedMaterials = renderer.sharedMaterials;

                                if (sharedMesh != null && sharedMaterials != null && sharedMaterials.Length == sharedMesh.subMeshCount)
                                {
                                    if (drawGroups[index] == null)
                                        drawGroups[index] = new DrawGroup(index);

                                    RenderParams renderParams1 = new RenderParams();
                                    renderParams1.layer = renderer.gameObject.layer;
                                    renderParams1.receiveShadows = renderer.receiveShadows;
                                    renderParams1.rendererPriority = renderer.rendererPriority;
                                    renderParams1.renderingLayerMask = renderer.renderingLayerMask;
                                    renderParams1.shadowCastingMode = ShadowCastingMode.Off;
                                    renderParams1.reflectionProbeUsage = renderer.reflectionProbeUsage;
                                    renderParams1.motionVectorMode = renderer.motionVectorGenerationMode;

                                    var count = drawGroups[index].Add(sharedMesh, sharedMaterials, Matrix4x4.identity, //renderer.transform.localToWorldMatrix,
                                        indirectArgsCount, indirectDrawIndexedArgs, in renderParams1);
                                    indirectArgsPerLodCount += count;

                                }
                            }                                                       
                        }
                        else if (renderer is BillboardRenderer billboardRenderer)
                        {
                            if (billboardRenderer.billboard != null && billboardRenderer.billboard.material != null)
                            {
                                if (drawGroups[index] == null)
                                    drawGroups[index] = new DrawGroup(index);

                                RenderParams renderParams1 = new RenderParams();
                                renderParams1.layer = renderer.gameObject.layer;
                                renderParams1.receiveShadows = renderer.receiveShadows;
                                renderParams1.rendererPriority = renderer.rendererPriority;
                                renderParams1.renderingLayerMask = renderer.renderingLayerMask;
                                renderParams1.shadowCastingMode = ShadowCastingMode.Off;
                                renderParams1.reflectionProbeUsage = renderer.reflectionProbeUsage;
                                renderParams1.motionVectorMode = renderer.motionVectorGenerationMode;

                                var count = drawGroups[index].Add(billboardRenderer.billboard, billboardRenderer.material, renderer.transform.localToWorldMatrix,
                                    indirectArgsCount, indirectDrawIndexedArgs, in renderParams1);

                                indirectArgsPerLodCount += count;
                            }
                        }
                    }
                }

                indirectArgsPerLodCounts[index] = indirectArgsPerLodCount;
                uint indirectArgsPerLodCountShadowOffset = indirectArgsPerLodCount;

                foreach (var renderer in LODs[index].renderers)
                {
                    if (renderer != null)
                    {
                        if (renderer is MeshRenderer)
                        {
                            var meshFilter = renderer.GetComponent<MeshFilter>();
                            if (meshFilter != null)
                            {
                                var sharedMesh = meshFilter.sharedMesh;
                                var sharedMaterials = renderer.sharedMaterials;

                                if (sharedMesh != null && sharedMaterials != null && sharedMaterials.Length == sharedMesh.subMeshCount)
                                {
                                    if (renderer.shadowCastingMode > 0)
                                    {
                                        if (drawShadowGroups[index] == null)
                                            drawShadowGroups[index] = new DrawGroup(index);

                                        var renderParams1 = new RenderParams();
                                        renderParams1.layer = renderer.gameObject.layer;
                                        renderParams1.shadowCastingMode = ShadowCastingMode.ShadowsOnly;
                                        renderParams1.renderingLayerMask = renderer.renderingLayerMask;
                                        renderParams1.rendererPriority = renderer.rendererPriority;

                                        indirectArgsPerLodCount += drawShadowGroups[index].Add(sharedMesh, sharedMaterials, Matrix4x4.identity, //renderer.transform.localToWorldMatrix,
                                        indirectArgsPerLodCountShadowOffset + indirectArgsCount, indirectDrawIndexedArgs, in renderParams1);
                                    }
                                    else
                                    {
                                        //indirectArgsPerLodCount += (uint)sharedMesh.subMeshCount;
                                    }
                                }
                            }
                        }
                        else if (renderer is BillboardRenderer billboardRenderer)
                        {
                            if (renderer.shadowCastingMode > 0)
                            {
                                if (billboardRenderer.billboard != null && billboardRenderer.billboard.material != null)
                                {
                                    if (drawShadowGroups[index] == null)
                                        drawShadowGroups[index] = new DrawGroup(index);

                                    var renderParams1 = new RenderParams();
                                    renderParams1.layer = renderer.gameObject.layer;
                                    renderParams1.shadowCastingMode = ShadowCastingMode.ShadowsOnly;
                                    renderParams1.renderingLayerMask = renderer.renderingLayerMask;
                                    renderParams1.rendererPriority = renderer.rendererPriority;

                                    indirectArgsPerLodCount += drawShadowGroups[index].Add(billboardRenderer.billboard, billboardRenderer.material, renderer.transform.localToWorldMatrix,
                                         indirectArgsPerLodCountShadowOffset + indirectArgsCount, indirectDrawIndexedArgs, in renderParams1);
                                }
                                else
                                {
                                    //indirectArgsPerLodCount += 1;
                                }
                            }
                        }
                    }
                }

                indirectArgsPerLodWithShadowsCounts[index] = indirectArgsPerLodCount;
                indirectArgsCount += indirectArgsPerLodCount;
            }

            return indirectArgsCount;
        }

        private static float CalculateBoundsForRenderers(UnityEngine.Renderer[] renderers)
        {
            Bounds bounds = new Bounds();
            bool first = true;
            foreach (var renderer in renderers)
            {
                if (renderer != null)
                {
                    if (first)
                    {
                        bounds = renderer.bounds;
                        first = false;
                    }
                    else
                        bounds.Encapsulate(renderer.bounds);                    
                }
            }
            return Mathf.Max(Mathf.Max(bounds.size.x, bounds.size.y), bounds.size.z);
        }

        public override int GetHashCode()
        {
            return GameObject.GetHashCode();
        }
    }
}