using System.Collections.Generic;
using Alchemy.Hierarchy;
using UnityEditor;
using UnityEngine;

namespace Alchemy.Editor
{
    public class HierarchyTreeMapDrawer : HierarchyDrawer
    {
        private static readonly Dictionary<string, Texture2D> TextureCached = new();

        public static Texture2D TreeMapCurrent
        {
            get
            {
                TextureCached.TryGetValue(nameof(TreeMapCurrent), out var tex);

                if (tex != null) return tex;
                tex = AssetHelper.FindAssetWithPath<Texture2D>("tree_map_current.png", "Editor/Hierarchy/Textures");
                TextureCached[nameof(TreeMapCurrent)] = tex;
                return tex;
            }
        }

        public static Texture2D TreeMapLast
        {
            get
            {
                TextureCached.TryGetValue(nameof(TreeMapLast), out var tex);

                if (tex != null) return tex;
                tex = AssetHelper.FindAssetWithPath<Texture2D>("tree_map_last.png", "Editor/Hierarchy/Textures");
                TextureCached[nameof(TreeMapLast)] = tex;
                return tex;
            }
        }

        public static Texture2D TreeMapLevel
        {
            get
            {
                TextureCached.TryGetValue(nameof(TreeMapLevel), out var tex);

                if (tex != null) return tex;
                tex = AssetHelper.FindAssetWithPath<Texture2D>("tree_map_level.png", "Editor/Hierarchy/Textures");
                TextureCached[nameof(TreeMapLevel)] = tex;
                return tex;
            }
        }

        public static Texture2D TreeMapLine
        {
            get
            {
                TextureCached.TryGetValue(nameof(TreeMapLine), out var tex);

                if (tex != null) return tex;
                tex = AssetHelper.FindAssetWithPath<Texture2D>("tree_map_line.png", "Editor/Hierarchy/Textures");
                TextureCached[nameof(TreeMapLine)] = tex;
                return tex;
            }
        }

#if UNITY_6000_4_OR_NEWER
        public override void OnGUI(EntityId instanceID, Rect selectionRect)
#else
        public override void OnGUI(int instanceID, Rect selectionRect)
#endif
        {
#if UNITY_6000_4_OR_NEWER
            var gameObject = EditorUtility.EntityIdToObject(instanceID) as GameObject;
#else
            var gameObject = EditorUtility.InstanceIDToObject(instanceID) as GameObject;
#endif
            if (gameObject == null) return;

            var settings = AlchemySettings.GetOrCreateSettings();

            var tempColor = GUI.color;

            if (settings.ShowTreeMap)
            {
                selectionRect.width = 14;
                selectionRect.height = 16;

                int childCount = gameObject.transform.childCount;
                int level = Mathf.RoundToInt(selectionRect.x / 14f);
                var t = gameObject.transform;
                Transform parent = null;

                for (int i = 0, j = level - 1; j >= 0; i++, j--)
                {
                    selectionRect.x = 14 * j;
                    if (i == 0)
                    {
                        if (childCount == 0)
                        {
                            GUI.color = settings.TreeMapColor;
                            GUI.DrawTexture(selectionRect, TreeMapLine);
                        }

                        t = gameObject.transform;
                    }
                    else if (i == 1)
                    {
                        GUI.color = settings.TreeMapColor;
                        if (parent == null)
                        {
                            if (t.GetSiblingIndex() == gameObject.scene.rootCount - 1)
                            {
                                GUI.DrawTexture(selectionRect, TreeMapLast);
                            }
                            else
                            {
                                GUI.DrawTexture(selectionRect, TreeMapCurrent);
                            }
                        }
                        else if (t.GetSiblingIndex() == parent.childCount - 1)
                        {
                            GUI.DrawTexture(selectionRect, TreeMapLast);
                        }
                        else
                        {
                            GUI.DrawTexture(selectionRect, TreeMapCurrent);
                        }

                        t = parent;
                    }
                    else
                    {
                        if (parent == null)
                        {
                            if (t.GetSiblingIndex() != gameObject.scene.rootCount - 1) GUI.DrawTexture(selectionRect, TreeMapLevel);
                        }
                        else if (t.GetSiblingIndex() != parent.childCount - 1) GUI.DrawTexture(selectionRect, TreeMapLevel);

                        t = parent;
                    }

                    if (t != null) parent = t.parent;
                    else break;
                }

                GUI.color = tempColor;
            }
        }
    }
}