using Sirenix.Utilities;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEditor;
using UnityEditor.Experimental.GraphView;
using UnityEngine;
using UnityEngine.UIElements;

namespace Ether
{
    /// <summary>
    /// 节点视图底图
    /// </summary>
    public class EtherNodeGraphViewer : GraphView
    {
        public Action<EtherNodeView> OnNodeSelected;

        public new class UxmlFactory : UxmlFactory<EtherNodeGraphViewer, GraphView.UxmlTraits> { }

        EtherNodeGraph graph;

        public EtherNodeGraph Graph { get { return graph; } }

        public EtherNodeGraphViewer()
        {
            Insert(0, new GridBackground());
            ContentZoomer contentZoomer = new ContentZoomer();
            contentZoomer.minScale = 0.15f;
            contentZoomer.maxScale = 2f;
            this.AddManipulator(contentZoomer); //缩放
            this.AddManipulator(new ContentDragger()); //拖拽
            this.AddManipulator(new SelectionDragger()); //点击拖拽
            this.AddManipulator(new RectangleSelector()); //框选
            var styleSheet = AssetDatabase.LoadAssetAtPath<StyleSheet>("Assets/Ether/Package/EtherNode/Editor/UI/NodeTreeViewer.uss");
            styleSheets.Add(styleSheet);
            Undo.undoRedoPerformed += OnUndoRedo;

            EventCenter.AddListener("EtherNodeEditorDeleteNode", () => { PopulateView(graph); });
        }

        /// <summary>
        /// 右键点击菜单
        /// </summary>
        public override void BuildContextualMenu(ContextualMenuPopulateEvent evt)
        {
            evt.menu.ClearItems();
            //var types = TypeCache.GetTypesDerivedFrom(tree.GetNodeType());
            Type nodeType = graph.GetNodeType();
            var types = CommonTools.GetChildTypes(nodeType);

            Vector2 createPosition = (evt.currentTarget as VisualElement).ChangeCoordinatesTo(contentViewContainer, evt.localMousePosition);

            List<(EtherNodeMenuNameAttribute, Type)> list = new List<(EtherNodeMenuNameAttribute, Type)>();
            foreach (var type in types)
            {
                if (!type.IsAbstract)
                {
                    EtherNodeMenuNameAttribute attr = type.GetAttribute<EtherNodeMenuNameAttribute>();
                    if (attr == null)
                    {
                        attr = new EtherNodeMenuNameAttribute(type.Name, 999);
                    }
                    list.Add((attr, type));

                }
            }

            list.Sort((a, b) =>
            {
                return b.Item1.order.CompareTo(a.Item1.order);
            });

            if (list.Count > 0)
            {
                foreach (var tuple in list)
                {
                    evt.menu.AppendAction($"创建{tuple.Item1.menuName}", (a) => CreateNode(tuple.Item2, createPosition));
                }
            }
        }

        private void OnUndoRedo()
        {
            PopulateView(graph);
            AssetDatabase.SaveAssets();
        }

        private void CreateNode(Type type, Vector2 createPos)
        {
            if (graph == null)
            {
                return;
            }

            EtherNode node = graph.CreateNode(type, createPos);
            CreateNodeView(node);
        }

        private void CreateNodeView(EtherNode node)
        {
            EtherNodeView nodeView = new EtherNodeView(node);
            nodeView.OnNodeSelected = OnNodeSelected;
            EtherNodeGraphViewer nodeGraphViewer = this;
            AddElement(nodeView);
            Undo.undoRedoPerformed += () =>
            {
                PopulateView(graph);
            };

        }

        internal void PopulateView(EtherNodeGraph tree)
        {
            this.graph = tree;
            graphViewChanged -= OnGraphViewChange;
            DeleteElements(graphElements);
            graphViewChanged += OnGraphViewChange;
            tree.allNodeDic.ForEach(n => { CreateNodeView(n.Value); });
            tree.allNodeDic.ForEach(n =>
            {
                var children = tree.GetChildren(n.Value);
                children.ForEach(c =>
                {
                    EtherNodeView parentView = FindNodeView(n.Value);
                    EtherNodeView childView = FindNodeView(c);
                    Edge edge = parentView.output.ConnectTo(childView.input);
                    AddElement(edge);
                });
            });

        }

        private GraphViewChange OnGraphViewChange(GraphViewChange graphViewChange)
        {
            if (graphViewChange.elementsToRemove != null)
            {
                graphViewChange.elementsToRemove.ForEach(elem =>
                {
                    EtherNodeView nodeView = elem as EtherNodeView;
                    if (nodeView != null)
                    {
                        graph.DeleteNode(nodeView.node);
                    }

                    Edge edge = elem as Edge;
                    if (edge != null)
                    {
                        EtherNodeView parentView = edge.output.node as EtherNodeView;
                        EtherNodeView childView = edge.input.node as EtherNodeView;
                        graph.RemoveChild(parentView.node, childView.node);
                    }
                });
            }

            if (graphViewChange.edgesToCreate != null)
            {
                graphViewChange.edgesToCreate.ForEach(edge =>
                {
                    EtherNodeView parentView = edge.output.node as EtherNodeView;
                    EtherNodeView childView = edge.input.node as EtherNodeView;
                    graph.AddChild(parentView.node, childView.node);
                });
            }

            return graphViewChange;
        }

        private EtherNodeView FindNodeView(EtherNode node)
        {
            return GetNodeByGuid(node.guid) as EtherNodeView;
        }

        public override List<Port> GetCompatiblePorts(Port startPort, NodeAdapter nodeAdapter)
        {
            return ports.ToList().Where(endport => endport.direction != startPort.direction && endport.node != startPort.node).ToList();
        }

        //public void UpdateNodeStates()
        //{
        //    nodes.ForEach(n =>
        //    {
        //        EtherNodeView view = n as EtherNodeView;
        //        view.SetNodeState();
        //    });
        //}

    }
}