using System;
using System.Collections.Generic;
using System.Linq;
using AibisDream;
using UnityEditor;
using UnityEditor.Experimental.GraphView;
using UnityEngine;
using UnityEngine.UIElements;

namespace AibisDream.SystemEditor
{
    public class ChapterNode : Node
    {
        public TalkSceneSO SceneSo { get; }
        public Port InputPort { get; private set; }

        private const float PortLabelMaxWidth = 120f;

        public ChapterNode(TalkSceneSO so)
        {
            SceneSo = so ?? throw new ArgumentNullException(nameof(so));

            // 节点整体放大
            style.minWidth = 240;
            style.paddingTop = 8;
            style.paddingBottom = 8;
            style.paddingLeft = 10;
            style.paddingRight = 10;

            UpdateTitle();
            UpdateColor();
            BuildInputPort();
            BuildOutputPorts();
            BuildSubtitle();
            BuildAddExitButton();
            SetPosition(new Rect(so.graphPosition, Vector2.zero));

            // 放大标题
            var titleLabel = this.Q<Label>("title-label");
            if (titleLabel != null)
            {
                titleLabel.style.fontSize = 16;
                titleLabel.style.unityFontStyleAndWeight = FontStyle.Bold;
            }
        }

        public void UpdateTitle()
        {
            title = string.IsNullOrEmpty(SceneSo.title) ? SceneSo.name : SceneSo.title;
        }

        public override void BuildContextualMenu(ContextualMenuPopulateEvent evt)
        {
            base.BuildContextualMenu(evt);

            if (SceneSo.exits != null && SceneSo.exits.Count > 0)
            {
                for (int i = 0; i < SceneSo.exits.Count; i++)
                {
                    var exit = SceneSo.exits[i];
                    var name = string.IsNullOrEmpty(exit.exitName) ? $"出口{i}" : exit.exitName;
                    var idx = i;
                    evt.menu.AppendAction($"删除出口/{name}", _ => RemoveExitAt(idx));
                }
            }
        }

        public void UpdateColor()
        {
            style.backgroundColor = new StyleColor(SceneSo.nodeColor);
        }

        private void BuildInputPort()
        {
            InputPort = Port.Create<Edge>(
                Orientation.Horizontal,
                Direction.Input,
                Port.Capacity.Single,
                typeof(TalkSceneSO));
            InputPort.portName = "▶";
            InputPort.style.fontSize = 14;
            InputPort.AddManipulator(new EdgeConnector<Edge>(new EmptyEdgeListener()));
            inputContainer.Add(InputPort);
        }

        private void BuildOutputPorts()
        {
            outputContainer.Clear();
            if (SceneSo.exits == null) return;

            for (int i = 0; i < SceneSo.exits.Count; i++)
            {
                var exit = SceneSo.exits[i];
                var port = CreateOutputPort(exit, i);
                outputContainer.Add(port);
            }
        }

        private Port CreateOutputPort(SceneExit exit, int index)
        {
            var port = Port.Create<Edge>(
                Orientation.Horizontal,
                Direction.Output,
                Port.Capacity.Single,
                typeof(TalkSceneSO));

            port.portName = string.IsNullOrEmpty(exit.exitName) ? $"出口{index}" : exit.exitName;
            port.userData = index;

            // 限制端口标签宽度并放大字体
            var label = port.Q<Label>("type");
            if (label != null)
            {
                label.style.maxWidth = PortLabelMaxWidth;
                label.style.fontSize = 12;
            }

            port.AddManipulator(new EdgeConnector<Edge>(new EmptyEdgeListener()));

            port.RegisterCallback<ContextualMenuPopulateEvent>((evt) =>
            {
                var currentIndex = port.userData is int idx ? idx : -1;
                evt.menu.AppendAction("删除出口", (_) => RemoveExitAt(currentIndex));
            }, TrickleDown.TrickleDown);

            return port;
        }

        private void BuildSubtitle()
        {
            var subtitleLabel = new Label($"{SceneSo.name}")
            {
                style =
                {
                    fontSize = 12,
                    unityTextAlign = TextAnchor.MiddleCenter,
                    color = new Color(0.8f, 0.8f, 0.8f),
                    paddingTop = 4,
                    paddingBottom = 2
                }
            };
            extensionContainer.Add(subtitleLabel);
            RefreshExpandedState();
        }

        private void BuildAddExitButton()
        {
            var removeButton = new Button(() => RemoveLastExit())
            {
                text = "-",
                style =
                {
                    width = 26,
                    height = 22,
                    fontSize = 16,
                    unityFontStyleAndWeight = FontStyle.Bold,
                    marginRight = 4
                }
            };
            titleButtonContainer.Add(removeButton);

            var addButton = new Button(() => AddExit())
            {
                text = "+",
                style = { width = 26, height = 22, fontSize = 16, unityFontStyleAndWeight = FontStyle.Bold }
            };
            titleButtonContainer.Add(addButton);
        }

        private void RemoveLastExit()
        {
            if (SceneSo.exits == null || SceneSo.exits.Count == 0) return;
            RemoveExitAt(SceneSo.exits.Count - 1);
        }

        public void AddExit()
        {
            Undo.RecordObject(SceneSo, "Add Exit");
            if (SceneSo.exits == null)
                SceneSo.exits = new System.Collections.Generic.List<SceneExit>();

            var newExit = new SceneExit
            {
                exitName = $"exit_{SceneSo.exits.Count}"
            };
            SceneSo.exits.Add(newExit);
            EditorUtility.SetDirty(SceneSo);

            var newPort = CreateOutputPort(newExit, SceneSo.exits.Count - 1);
            outputContainer.Add(newPort);
            RefreshPorts();
        }

        public void RemoveExitAt(int index)
        {
            if (SceneSo.exits == null || index < 0 || index >= SceneSo.exits.Count) return;

            // 断开并移除该端口的所有边
            var portToRemove = GetOutputPort(index);
            if (portToRemove != null)
            {
                var edges = portToRemove.connections.ToList();
                foreach (var edge in edges)
                {
                    edge.input?.Disconnect(edge);
                    edge.output?.Disconnect(edge);
                    edge.RemoveFromHierarchy();
                }
                portToRemove.RemoveFromHierarchy();
            }

            Undo.RecordObject(SceneSo, "Remove Exit");
            SceneSo.exits.RemoveAt(index);
            EditorUtility.SetDirty(SceneSo);

            // 更新后续端口的 userData 和 portName
            for (int i = index; i < SceneSo.exits.Count; i++)
            {
                var port = GetOutputPort(i);
                if (port != null)
                {
                    port.userData = i;
                    var exit = SceneSo.exits[i];
                    port.portName = string.IsNullOrEmpty(exit.exitName) ? $"出口{i}" : exit.exitName;
                }
            }

            RefreshPorts();
        }

        public void RefreshOutputPorts()
        {
            // 先断开所有输出端口的边
            var edgesToRemove = outputContainer.Children()
                .OfType<Port>()
                .SelectMany(p => p.connections.ToList())
                .ToList();

            foreach (var edge in edgesToRemove)
            {
                edge.input?.Disconnect(edge);
                edge.output?.Disconnect(edge);
                edge.RemoveFromHierarchy();
            }

            BuildOutputPorts();
            RefreshPorts();
        }

        public Port GetOutputPort(int index)
        {
            return outputContainer.Children().OfType<Port>().ElementAtOrDefault(index);
        }

        public override void SetPosition(Rect newPos)
        {
            base.SetPosition(newPos);
            if (SceneSo != null)
            {
                SceneSo.graphPosition = newPos.position;
                EditorUtility.SetDirty(SceneSo);
            }
        }

        public void SyncPositionToSo()
        {
            if (SceneSo == null) return;
            var pos = GetPosition();
            if (SceneSo.graphPosition != pos.position)
            {
                SceneSo.graphPosition = pos.position;
                EditorUtility.SetDirty(SceneSo);
            }
        }

        private class EmptyEdgeListener : IEdgeConnectorListener
        {
            public void OnDropOutsidePort(Edge edge, Vector2 position) { }
            public void OnDrop(GraphView graphView, Edge edge) { }
        }
    }
}