using System.Collections;
using System.Linq;
using System.Collections.Generic;
using System;
using System.Reflection;
using UnityEngine;
using UnityEditor;
using UnityEditor.IMGUI.Controls;
using UnityEditor.SceneManagement;
using GameplayIngredients.Events;
using GameplayIngredients.Logic;
using GameplayIngredients.Actions;
using GameplayIngredients.StateMachines;
using UnityEngine.SceneManagement;

namespace GameplayIngredients.Editor
{
    public class CallTreeWindow : EditorWindow
    {
        CallTreeView m_TreeView;
        [MenuItem("Window/Gameplay Ingredients/Callable Tree Explorer", priority = MenuItems.kWindowMenuPriority)]
        static void OpenWindow()
        {
            s_Instance = GetWindow<CallTreeWindow>();
        }

        public static bool visible = false;
        static CallTreeWindow s_Instance;

        private void OnDisable()
        {
            visible = false;
            s_Instance = null;
        }

        private void OnEnable()
        {
            nodeRoots = new Dictionary<string, List<CallTreeNode>>();
            m_TreeView = new CallTreeView(nodeRoots);
            titleContent = new GUIContent("Callable Tree Explorer", CallTreeView.Styles.Callable);
            ReloadCallHierarchy();
            EditorSceneManager.sceneOpened += Reload;
            EditorSceneSetup.onSetupLoaded += ReloadSetup;
            visible = true;
        }

        void Reload(Scene scene, OpenSceneMode mode)
        {
            ReloadCallHierarchy();
        }

        void ReloadSetup(EditorSceneSetup setup)
        {
            ReloadCallHierarchy();
        }

        public static void Refresh()
        {
            s_Instance.ReloadCallHierarchy();
            s_Instance.Repaint();
        }

        private void OnGUI()
        {
            int tbHeight = 24;
            using (new GUILayout.HorizontalScope(EditorStyles.toolbar, GUILayout.Height(tbHeight)))
            {
                if (GUILayout.Button("Reload", EditorStyles.toolbarButton))
                {
                    ReloadCallHierarchy();
                }
                GUILayout.FlexibleSpace();
                EditorGUI.BeginChangeCheck();
                string filter = EditorGUILayout.DelayedTextField(m_TreeView.stringFilter, EditorStyles.toolbarSearchField);
                if (EditorGUI.EndChangeCheck())
                {
                    m_TreeView.SetStringFilter(filter);
                }


                Rect buttonRect = GUILayoutUtility.GetRect(52, 16);
                if (GUI.Button(buttonRect, "Filter", EditorStyles.toolbarDropDown))
                {
                    GenericMenu menu = new GenericMenu();
                    menu.AddItem(new GUIContent("Filter Selected"), false, () => {
                        m_TreeView.SetAutoFilter(false);
                        m_TreeView.SetObjectFilter(Selection.activeGameObject);
                    });
                    menu.AddItem(new GUIContent("Clear Filter"), false, () => {
                        m_TreeView.SetAutoFilter(false);
                        m_TreeView.SetObjectFilter(null);
                        m_TreeView.SetStringFilter(string.Empty);
                    });
                    menu.AddSeparator("");
                    menu.AddItem(new GUIContent("Automatic Filter"), m_TreeView.AutoFilter, () => {
                        m_TreeView.ToggleAutoFilter();
                    });
                    menu.DropDown(buttonRect);
                }

            }
            Rect r = GUILayoutUtility.GetRect(position.width, position.height - tbHeight);
            m_TreeView.OnGUI(r);
        }

        Dictionary<string, List<CallTreeNode>> nodeRoots;

        List<MonoBehaviour> erroneous;

        void ReloadCallHierarchy()
        {
            if (nodeRoots == null)
                nodeRoots = new Dictionary<string, List<CallTreeNode>>();
            else
                nodeRoots.Clear();

            erroneous = new List<MonoBehaviour>();

            AddToCategory<EventBase>("Events");
            AddToCategory<StateMachine>("State Machines");
            AddToCategory<Factory>("Factories");
            AddToCategory<SendMessageAction>("Messages");
            CollectErroneousCallables();
            m_TreeView.Reload();
        }

        void CollectErroneousCallables()
        {
            if (erroneous == null || erroneous.Count == 0)
                return;
            var root = new List<CallTreeNode>();
            nodeRoots.Add("Erroneous Callables", root);

            foreach(var callable in erroneous)
            {
                root.Add(new CallTreeNode(callable, CallTreeNodeType.Callable, callable.name));
            }
        }

        void AddErroneous(MonoBehaviour bhv)
        {
            if (!erroneous.Contains(bhv))
                erroneous.Add(bhv);
        }

        void AddToCategory<T>(string name) where T:MonoBehaviour
        {
            var list = Resources.FindObjectsOfTypeAll<T>().ToList();

            if (list.Count > 0)
                nodeRoots.Add(name, new List<CallTreeNode>());
            else
                return;

            var listRoot = nodeRoots[name];
            foreach (var item in list)
            {
                if (item.gameObject.scene == null || !item.gameObject.scene.isLoaded)
                    continue;

                var stack = new Stack<object>();
                
                if(typeof(T) == typeof(StateMachine))
                {
                    listRoot.Add(GetStateMachineNode(item as StateMachine, stack));
                }
                else if(typeof(T) == typeof(SendMessageAction))
                {
                    listRoot.Add(GetMessageNode(item as SendMessageAction, stack));
                }
                else
                {
                    listRoot.Add(GetNode(item, stack));
                }
            }

        }

        CallTreeNode GetNode(MonoBehaviour bhv, Stack<object> stack)
        {
            if(!stack.Contains(bhv))
            {
                stack.Push(bhv);
                var rootNode = new CallTreeNode(bhv, GetType(bhv), $"{bhv.gameObject.name} ({bhv.GetType().Name})");
                var type = bhv.GetType();
                foreach (var field in type.GetFields())
                {
                    // Find Fields that are Callable[]
                    if (field.FieldType.IsAssignableFrom(typeof(Callable[])))
                    {
                        var node = new CallTreeNode(bhv, CallTreeNodeType.Callable, field.Name);
                        var value = (Callable[])field.GetValue(bhv);

                        if (value != null && value.Length > 0)
                        {
                            rootNode.Children.Add(node);
                            // Add Callables from this Callable[] array
                            foreach (var call in value)
                            {
                                if (call != null)
                                    node.Children.Add(GetCallableNode(call, stack));
                                else
                                    AddErroneous(node.Target);
                            }
                        }
                    }
                }
                return rootNode;
            }
            else
            {
                return new CallTreeNode(bhv, GetType(bhv), $"RECURSED : {bhv.gameObject.name} ({bhv.GetType().Name})");
            }
        }

        CallTreeNode GetCallableNode(Callable c, Stack<object> stack)
        {
            if (!stack.Contains(c))
            {
                stack.Push(c);
                var rootNode = new CallTreeNode(c, GetType(c), $"{c.Name} ({c.gameObject.name} : {c.GetType().Name})");
                var type = c.GetType();
                foreach (var field in type.GetFields())
                {
                    // Find Fields that are Callable[]
                    if (field.FieldType.IsAssignableFrom(typeof(Callable[])))
                    {
                        var node = new CallTreeNode(c, CallTreeNodeType.Callable, field.Name);
                        var value = (Callable[])field.GetValue(c);

                        if (value != null && value.Length > 0)
                        {
                            rootNode.Children.Add(node);
                            // Add Callables from this Callable[] array
                            foreach (var call in value)
                            {
                                if (call != null)
                                    node.Children.Add(GetCallableNode(call, stack));
                                else
                                    AddErroneous(node.Target);
                            }
                        }
                    }
                }
                return rootNode;
            }
            else
            {
                return new CallTreeNode(c, GetType(c), $"RECURSED : {c.Name} ({c.gameObject.name} : {c.GetType().Name})");
            }
        }

        CallTreeNode GetMessageNode(SendMessageAction msg, Stack<object> stack)
        {
            if (!stack.Contains(msg))
            {
                stack.Push(msg);
                var rootNode = new CallTreeNode(msg, CallTreeNodeType.Message, $"{msg.MessageToSend} : ({msg.gameObject.name}.{msg.Name})");
                var all = Resources.FindObjectsOfTypeAll<OnMessageEvent>().Where(o=> o.MessageName == msg.MessageToSend).ToList();

                foreach(var evt in all)
                {
                    rootNode.Children.Add(GetNode(evt, stack));
                }
                return rootNode;
            }
            else
            {
                return new CallTreeNode(msg, GetType(msg), $"RECURSED :{msg.MessageToSend} : ({msg.gameObject.name}.{msg.Name})");
            }
        }


        CallTreeNode GetStateMachineNode(StateMachine sm, Stack<object> stack)
        {
            if (!stack.Contains(sm))
            {
                stack.Push(sm);
                var rootNode = new CallTreeNode(sm, CallTreeNodeType.StateMachine, sm.gameObject.name);
                var type = sm.GetType();
                foreach (var field in type.GetFields())
                {
                    // Find Fields that are State[]
                    if (field.FieldType.IsAssignableFrom(typeof(State[])))
                    {
                        // Add Callables from this Callable[] array
                        var value = (State[])field.GetValue(sm);
                        foreach (var state in value)
                        {
                            if (state != null)
                                rootNode.Children.Add(GetStateNode(state, stack));
                            else
                                AddErroneous(rootNode.Target);
                        }
                    }
                }
                return rootNode;
            }
            else
            {
                return new CallTreeNode(sm, GetType(sm), $"RECURSED :{sm.gameObject.name}");
            }

        }

        CallTreeNode GetStateNode(State st, Stack<object> stack)
        {
            if (!stack.Contains(st))
            {
                stack.Push(st);
                var rootNode = new CallTreeNode(st, CallTreeNodeType.State, st.gameObject.name);
                var type = st.GetType();
                foreach (var field in type.GetFields())
                {
                    // Find Fields that are Callable[]
                    if (field.FieldType.IsAssignableFrom(typeof(Callable[])))
                    {
                        var node = new CallTreeNode(st, CallTreeNodeType.Callable, field.Name);
                        rootNode.Children.Add(node);
                        // Add Callables from this Callable[] array
                        var value = (Callable[])field.GetValue(st);
                        foreach (var call in value)
                        {
                            if (call != null)
                                node.Children.Add(GetNode(call, stack));
                            else
                                AddErroneous(rootNode.Target);
                        }
                    }
                }
                return rootNode;
            }
            else
            {
                return new CallTreeNode(st, GetType(st), $"RECURSED :{st.gameObject.name}");
            }
        }

        CallTreeNodeType GetType(MonoBehaviour bhv)
        {
            if (bhv == null)
                return CallTreeNodeType.Callable;
            else if (bhv is EventBase)
                return CallTreeNodeType.Event;
            else if (bhv is LogicBase)
                return CallTreeNodeType.Logic;
            else if (bhv is ActionBase)
                return CallTreeNodeType.Action;
            else if (bhv is StateMachine)
                return CallTreeNodeType.StateMachine;
            else if (bhv is State)
                return CallTreeNodeType.State;
            else if (bhv is Factory)
                return CallTreeNodeType.Factory;
            else if (bhv is OnMessageEvent || bhv is SendMessageAction)
                return CallTreeNodeType.Message;
            else
                return CallTreeNodeType.Callable;
        }

        class CallTreeNode
        {
            public string Name;
            public MonoBehaviour Target;
            public List<CallTreeNode> Children;
            public CallTreeNodeType Type;
            public CallTreeNode(MonoBehaviour target, CallTreeNodeType type, string name = "")
            {
                Name = string.IsNullOrEmpty(name) ? target.GetType().Name : name;
                Target = target;
                Type = type;
                Children = new List<CallTreeNode>();
            }

            public bool Filter(GameObject go, string filter)
            {
                bool keep = (go == null || this.Target.gameObject == go) 
                    && (string.IsNullOrEmpty(filter) ? true : this.Name.Contains(filter));

                if(!keep)
                {
                    foreach (var node in Children)
                        keep = keep || node.Filter(go, filter);
                }

                return keep;
            }
        }

        public enum CallTreeNodeType
        {
            Callable,
            Event,
            Logic,
            Action,
            Message,
            StateMachine,
            State,
            Factory
        }

        class CallTreeView : TreeView
        {
            Dictionary<string, List<CallTreeNode>> m_Roots;
            Dictionary<int, CallTreeNode> m_Bindings;

            public CallTreeView(Dictionary<string, List<CallTreeNode>> roots) : base(new TreeViewState())
            {
                m_Roots = roots;
                m_Bindings = new Dictionary<int, CallTreeNode>();
            }

            public string stringFilter { get { return m_StringFilter; } }

            [SerializeField]
            GameObject m_filter = null;
            [SerializeField]
            string m_StringFilter = "";

            public bool AutoFilter { get; private set; }
            public void ToggleAutoFilter()
            {
                SetAutoFilter(!AutoFilter);
            }

            public void SetAutoFilter(bool value)
            {
                AutoFilter = value;
                if (AutoFilter)
                {
                    Selection.selectionChanged += UpdateAutoFilter;
                    if(this.HasSelection())
                    {
                        SetObjectFilter(m_Bindings[this.GetSelection()[0]].Target.gameObject);
                    }
                }
                else
                    Selection.selectionChanged -= UpdateAutoFilter;
            }

            void UpdateAutoFilter()
            {
                if (Selection.activeGameObject != null)
                    SetObjectFilter(Selection.activeGameObject);
            }

            public void SetObjectFilter(GameObject filter = null)
            {
                m_filter = filter;
                Reload();
            }

            public void SetStringFilter(string stringFilter)
            {
                m_StringFilter = stringFilter;
                Reload();
            }

            protected override TreeViewItem BuildRoot()
            {
                int id = -1;
                m_Bindings.Clear();
                var treeRoot = new TreeViewItem(++id, -1, "~Root");

                foreach(var kvp in m_Roots)
                {
                    if (kvp.Value == null || kvp.Value.Count == 0)
                        continue;

                    var currentRoot = new TreeViewItem(++id, 0, kvp.Key);
                    treeRoot.AddChild(currentRoot);
                    foreach (var node in kvp.Value)
                    {
                        if (node.Filter(m_filter, m_StringFilter))
                        {
                            currentRoot.AddChild(GetNode(node, ref id, 1));
                        }
                    }
                }
                if (treeRoot.children == null)
                {
                    treeRoot.AddChild(new TreeViewItem(1, 0, "(No Results)"));
                }

                return treeRoot;
            }

            TreeViewItem GetNode(CallTreeNode node, ref int id, int depth)
            {
                id++;
                var item = new TreeViewItem(id, depth, $"{node.Name}");
                item.icon = GetIcon(node.Target, node.Type);
                m_Bindings.Add(id, node);

                foreach(var child in node.Children)
                {
                    item.AddChild(GetNode(child, ref id, depth + 1));
                }
                return item;
            }

            Texture2D GetIcon(MonoBehaviour bhv, CallTreeNodeType type)
            {
                if(bhv != null && type != CallTreeNodeType.Callable)
                {
                    var texture = EditorGUIUtility.ObjectContent(bhv, bhv.GetType()).image;
                    if (texture != null)
                        return texture as Texture2D;
                }

                switch(type)
                {
                    default:
                    case CallTreeNodeType.Callable:
                        return Styles.Callable;
                    case CallTreeNodeType.Action:
                        return Styles.Action;
                    case CallTreeNodeType.Logic:
                        return Styles.Logic;
                    case CallTreeNodeType.Event:
                        return Styles.Event;
                    case CallTreeNodeType.Message:
                        return Styles.Message;
                    case CallTreeNodeType.State:
                        return Styles.State;
                    case CallTreeNodeType.Factory:
                        return Styles.Factory;
                    case CallTreeNodeType.StateMachine:
                        return Styles.StateMachine;
                }
            }

            protected override void SelectionChanged(IList<int> selectedIds)
            {
                if (AutoFilter)
                    return;

                base.SelectionChanged(selectedIds);
                if (selectedIds.Count > 0 && m_Bindings.ContainsKey(selectedIds[0]))
                    Selection.activeObject = m_Bindings[selectedIds[0]].Target;
            }

            public static class Styles
            {
                public static Texture2D Callable = Icon("Misc/ic-callable.png");
                public static Texture2D Action = Icon("Actions/ic-action-generic.png");
                public static Texture2D Logic = Icon("Logic/ic-generic-logic.png");
                public static Texture2D Event = Icon("Events/ic-event-generic.png");
                public static Texture2D Message = Icon("Events/ic-event-message .png");
                public static Texture2D StateMachine = Icon("Misc/ic-StateMachine.png");
                public static Texture2D State = Icon("Misc/ic-State.png");
                public static Texture2D Factory = Icon("Misc/ic-Factory.png");

                static Texture2D Icon(string path)
                {
                    return AssetDatabase.LoadAssetAtPath<Texture2D>($"Packages/net.peeweek.gameplay-ingredients/Icons/{path}");
                }
            }
        }
    }
}