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

public class Canvas3DImpl : Singleton<Canvas3DImpl>
{
    private Dictionary<int, Sprite3D> m_childSprites = new Dictionary<int, Sprite3D>();
    private Dictionary<int, TextMesh> m_childText = new Dictionary<int, TextMesh>();
    private int m_depth = 0;
    private bool m_needRefreshLayout = false;
    private Dictionary<string, AutoAtlasInfo> m_atlas = new Dictionary<string, AutoAtlasInfo>();
    private bool m_needRebuildAtlas = false;


    private class AutoAtlasInfo
    {
        private static int[] textureSize =
        {
            128,
            256,
            512,
            1024
        };

        private int counter = 1;
        private Dictionary<int, AtlasInfo.UVDetail> textures = new Dictionary<int, AtlasInfo.UVDetail>();  //Texture的GUID和uv的映射关系
        public bool needRebuildAtlas = false;
        private bool needCompress = false;
        private int padding = 0;
        private HashSet<Sprite3D> sprites = new HashSet<Sprite3D>();
        public Texture2D atlas = null;
        public Texture2D altasAlpha = null; //做纹理压缩用的
        private Material mat = null;
        private Dictionary<int, Texture2D> waitForCombineTextures = new Dictionary<int, Texture2D>();

        public void Register(Sprite3D sprite)
        {
            if (null == sprite || null == sprite.texture)
            {
                return;
            }
            int id = sprite.texture.GetNativeTextureID();
            sprite.m_textureGUID = id;
            AtlasInfo.UVDetail uv = null;
            padding = Mathf.Max(padding, sprite.padding);
            needCompress = needCompress | sprite.compress;
            if (textures.TryGetValue(id, out uv))
            {
                sprites.Add(sprite);
                if (null != mat)
                {
                    sprite.SetMaterial(mat);
                }
                sprite.SetAutoAtlas(atlas, uv);
                return;
            }
            else
            {
                uv = new AtlasInfo.UVDetail();
                uv.width = 0;
                uv.height = 0;
                uv.width = sprite.texture.width;
                uv.height = sprite.texture.height;
                uv.rotate = false;
                textures.Add(id, uv);
                waitForCombineTextures.Add(id, sprite.texture);
            }
            needRebuildAtlas = true;
            sprites.Add(sprite);
        }

        public void Unregister(Sprite3D sprite)
        {
            sprites.Remove(sprite);
            if (sprites.Count == 0)
            {
                textures.Clear();
                if (mat != null)
                {
                    Object.Destroy(mat);
                }
                mat = null;
                if (atlas != null)
                {
                    Object.Destroy(atlas);
                }
                atlas = null;
            }
        }

        public void Rebuild()
        {
            needRebuildAtlas = false;

            bool succ = false;
            for (int i = 0; i < textureSize.Length; ++i)
            {
                if (atlas != null && textureSize[i] < atlas.width)
                {
                    continue;
                }
                succ = Pack(textureSize[i]);
                if (succ)
                {
                    break;
                }
            }
            if (!succ)
            {
                var it = sprites.GetEnumerator();
                it.MoveNext();
                Debug.LogError("Dynamic Combine Atlas Failed, maybe too many pictures of atlas tag:\"" + it.Current.autoAtlasTag + "\"");
            }

        }

        private bool Pack(int size)
        {
            int columnPosition = 0;
            int x = 0;
            int y = 0;
            int spacing = padding;
            Vector2 atlasSize = Vector2.zero;
            Dictionary<int, AtlasInfo.UVDetail> tmp = new Dictionary<int, AtlasInfo.UVDetail>();
            var iter = textures.GetEnumerator();
            while (iter.MoveNext())
            {
                int width = iter.Current.Value.width;
                int height = iter.Current.Value.height;
                AtlasInfo.UVDetail uv = new AtlasInfo.UVDetail();
                uv.rotate = false;
                tmp.Add(iter.Current.Key, uv);
                if (y + height + spacing <= size && x + width + spacing <= size)
                {
                    uv.x = x;
                    uv.y = y;
                    uv.width = width;
                    uv.height = height;
                    y += height + spacing;
                    if (columnPosition < x + width + spacing)
                        columnPosition = x + width + spacing;
                }
                else if (columnPosition + width <= size && height <= size)
                {
                    x = columnPosition;
                    uv.x = x;
                    uv.y = 0;
                    uv.width = width;
                    uv.height = height;
                    y = height + spacing;
                    columnPosition = x + width + spacing;
                }
                else
                {
                    return false;
                }
            }

            TextureFormat format = TextureFormat.ARGB32;
            if (needCompress)
            {
#if UNITY_ANDROID && !UNITY_EDITOR
                format = TextureFormat.ARGB32;     //format = TextureFormat.ETC_RGB4;
#elif UNITY_IOS && !UNITY_EDITOR
                format = TextureFormat.ARGB32; //format = TextureFormat.PVRTC_RGBA4;
#else
                format = TextureFormat.ARGB32;
#endif
            }
            Texture2D newTex = new Texture2D(size, size, format, false);
            Color[] clearColor = new Color[newTex.width * newTex.height]; //默认全是0
            newTex.SetPixels(clearColor);
            newTex.name = "Auto_UI3D_Atlas_" + size + "_" + counter + "_format" + format.ToString();

            counter++;
            iter = textures.GetEnumerator();
            while (iter.MoveNext())
            {
                Texture2D tex = null;
                if (!waitForCombineTextures.TryGetValue(iter.Current.Key, out tex))
                {
                    tex = this.atlas;
                }
                var uv = iter.Current.Value;
                var uvNew = tmp[iter.Current.Key];
                Color[] orig = tex.GetPixels(uv.x, uv.y, uv.width, uv.height);
                newTex.SetPixels(uvNew.x, uvNew.y, uv.width, uv.height, orig);
                newTex.Apply(false, false);



                uvNew.uvTL = new Vector2((float)uvNew.x / newTex.width, (float)(uvNew.y + uvNew.height) / newTex.height);
                uvNew.uvTR = new Vector2((float)(uvNew.x + uvNew.width) / newTex.width, (float)(uvNew.y + uvNew.height) / newTex.height);
                uvNew.uvBL = new Vector2((float)uvNew.x / newTex.width, (float)(uvNew.y) / newTex.height);
                uvNew.uvBR = new Vector2((float)(uvNew.x + uvNew.width) / newTex.width, (float)(uvNew.y) / newTex.height);
            }
            textures = tmp;
            Object.Destroy(atlas);
            atlas = newTex;


            //Shader shader = CResourceManager.GetInstance().GetResource("Shaders/UI/UI3D.shader", typeof(Shader), enResourceType.BattleScene, true, true).m_content as Shader;
            //todo bhy
            Shader shader = Shader.Find("UI/UI3D");
            mat = new Material(shader);
            mat.SetTexture("_MainTex", atlas);

            var iterSprites = sprites.GetEnumerator();
            while (iterSprites.MoveNext())
            {
                iterSprites.Current.SetMaterial(mat);
                iterSprites.Current.SetAutoAtlas(atlas, textures[iterSprites.Current.m_textureGUID]);
            }
            var iterWaitForRelease = waitForCombineTextures.GetEnumerator();
            waitForCombineTextures.Clear();

            //todo bhy
            //CResourceManager.GetInstance().UnloadUnusedAssets();
            return true;
        }
    }

    public void Reset()
    {
        m_childSprites.Clear();
        m_childText.Clear();
#if UNITY_EDITOR
        var iter = m_atlas.GetEnumerator();
        while (iter.MoveNext())
        {
            if (iter.Current.Value.atlas != null)
            {
                Debug.LogError("还有3D UI自动生成的altas没有清理干净！");
            }
        }
#endif
        m_atlas.Clear();
       
        //todo bhy
        //CResourceManager.GetInstance().UnloadUnusedAssets();
    }

    public void Update(Transform root)
    {
        if (m_needRefreshLayout)
        {
            _DoRefreshLayout(root);
            m_needRefreshLayout = false;
        }
        if (m_needRebuildAtlas)
        {
            _DoRebuildAtlas();
            m_needRebuildAtlas = true;
        }
    }

    public void registerAutoAtlas(Sprite3D sprite)
    {
        if (sprite.texture == null)
        {
            return;
        }
#if UNITY_EDITOR
        //非运行时也不做任何合并工作
        if (string.IsNullOrEmpty(sprite.autoAtlasTag) || !UnityEditor.EditorApplication.isPlayingOrWillChangePlaymode)
#else
        if (string.IsNullOrEmpty(sprite.autoAtlasTag))
#endif
        {
            //不打图集的直接就生成uv了
            AtlasInfo.UVDetail uv = new AtlasInfo.UVDetail();
            uv.uvBL = new Vector2(0, 0);
            uv.uvTL = new Vector2(0, 1);
            uv.uvBR = new Vector2(1, 0);
            uv.uvTR = new Vector2(1, 1);
            uv.rotate = false;
            uv.x = 0;
            uv.y = 0;
            uv.width = sprite.texture.width;
            uv.height = sprite.texture.height;
            sprite.SetUV(uv);
            return;
        }
        AutoAtlasInfo info = null;
        if (!m_atlas.TryGetValue(sprite.autoAtlasTag, out info))
        {
            info = new AutoAtlasInfo();
            m_atlas.Add(sprite.autoAtlasTag, info);
        }
        info.Register(sprite);
        m_needRebuildAtlas = true;
    }

    public void registerSprite3D(Sprite3D sprite)
    {
        if (!m_childSprites.ContainsKey(sprite.transform.GetInstanceID()))
        {
            m_childSprites.Add(sprite.transform.GetInstanceID(), sprite);
        }
    }

    public void unregisterSprite3d(Sprite3D sprite)
    {
        m_childSprites.Remove(sprite.transform.GetInstanceID());
    }

    public void unregisterAutoAtlas(Sprite3D sprite)
    {
        if (sprite.texture == null || string.IsNullOrEmpty(sprite.autoAtlasTag))
        {
            return;
        }
        AutoAtlasInfo info = null;
        if (!m_atlas.TryGetValue(sprite.autoAtlasTag, out info))
        {
            return;
        }
        info.Unregister(sprite);
    }

    private void _DoRebuildAtlas()
    {
        var iter = m_atlas.GetEnumerator();
        while (iter.MoveNext())
        {
            AutoAtlasInfo info = iter.Current.Value;
            if (!info.needRebuildAtlas)
            {
                continue;
            }
            info.Rebuild();
        }
    }

    private void RefreshHierachy(Transform root)
    {
        if (root == null) return;

        if (!root.gameObject.activeSelf)
        {
            return;
        }

        for (int i = root.childCount - 1; i >= 0; --i)
        {
            RefreshHierachy(root.GetChild(i));
        }

        Sprite3D sprite = null;
        if (m_childSprites.TryGetValue(root.GetInstanceID(), out sprite))
        {
            if (null != sprite)
            {
                ++m_depth;
#if UNITY_EDITOR
                if (!UnityEditor.EditorApplication.isPlayingOrWillChangePlaymode)
                {
                    sprite.PrepareMesh();
                    registerAutoAtlas(sprite);
                    sprite.GenerateMesh();
                    sprite.RefreshAtlasMaterial();
                    sprite.RefreshAutoAtlasMaterial();
                }
#endif
                sprite.depth = m_depth;
            }
        }
        else
        {
#if UNITY_EDITOR
            if (UnityEditor.EditorApplication.isPlayingOrWillChangePlaymode)
            {
                //Debug.LogError("GameObject \"" + root.name + "\" with Sprite3D is not registered in Canvas3D!");
            }
#endif
            sprite = root.GetComponent<Sprite3D>();
            m_childSprites.Add(root.GetInstanceID(), sprite);
            if (null != sprite)
            {
                ++m_depth;
#if UNITY_EDITOR
                if (!UnityEditor.EditorApplication.isPlayingOrWillChangePlaymode)
                {

#if UNITY_EDITOR
                    if (!UnityEditor.EditorApplication.isPlayingOrWillChangePlaymode)
                    {
                        sprite.PrepareMesh();
                        registerAutoAtlas(sprite);
                        sprite.GenerateMesh();
                        sprite.RefreshAtlasMaterial();
                        sprite.RefreshAutoAtlasMaterial();
                    }
#endif
                }
#endif
                sprite.depth = m_depth;
            }
        }


        TextMesh text = null;
        //针对文本的排序
        if (sprite == null)
        {
            if (m_childText.TryGetValue(root.GetInstanceID(), out text))
            {
                if (null != text)
                {
                    ++m_depth;
                    text.offsetZ = (float)m_depth / 10;
                }
            }
            else
            {
                text = root.GetComponent<TextMesh>();
                m_childText.Add(root.GetInstanceID(), text);
                if (null != text)
                {
                    ++m_depth;
                    text.offsetZ = (float)m_depth / 10;
                }
            }
        }
    }

    public void RebuildAtlasImmediately()
    {
        _DoRebuildAtlas();
    }

    public void RefreshLayout(Transform root = null)
    {
        m_needRefreshLayout = true;
#if UNITY_EDITOR
        if (!UnityEditor.EditorApplication.isPlayingOrWillChangePlaymode)
        {
            _DoRefreshLayout(root);
        }
#endif
    }

    private void _DoRefreshLayout(Transform root)
    {
        m_depth = 0;
        RefreshHierachy(root);
    }
}