//********************************** Banshee Engine (www.banshee3d.com) **************************************************//
//**************** Copyright (c) 2016 Marko Pintera (marko.pintera@gmail.com). All rights reserved. **********************//
using System;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.IO;
using bs;

namespace bs.Editor
{
    /** @addtogroup General 
     *  @{
     */

    /// <summary>
    /// Available tools in the scene view.
    /// </summary>
    public enum SceneViewTool
    {
        View,
        Move,
        Rotate,
        Scale
    }

    /// <summary>
    /// Pivot mode used by the scene view tools.
    /// </summary>
    public enum HandlePivotMode
    {
        Center,
        Pivot
    }

    /// <summary>
    /// Coordinate mode used by the scene view tools.
    /// </summary>
    public enum HandleCoordinateMode
    {
        Local,
        World
    }

    /// <summary>
    /// Manages various generic and global settings relating to the editor.
    /// </summary>
    public class EditorApplication
    {
        internal const string CutBinding = "Cut";
        internal const string CopyBinding = "Copy";
        internal const string RenameBinding = "Rename";
        internal const string DuplicateBinding = "Duplicate";
        internal const string DeleteBinding = "Delete";
        internal const string PasteBinding = "Paste";

        internal const string EditorSceneDataPrefix = "__EditorSceneData";

        /// <summary>
        /// Determines the active tool shown in the scene view.
        /// </summary>
        public static SceneViewTool ActiveSceneTool
        {
            get { return EditorSettings.ActiveSceneTool; }
            set { EditorSettings.ActiveSceneTool = value; }
        }

        /// <summary>
        /// Determines the coordinate mode used by the tools in the scene view.
        /// </summary>
        public static HandleCoordinateMode ActiveCoordinateMode
        {
            get { return EditorSettings.ActiveCoordinateMode; }
            set { EditorSettings.ActiveCoordinateMode = value; }
        }

        /// <summary>
        /// Determines the pivot mode used by the tools in the scene view.
        /// </summary>
        public static HandlePivotMode ActivePivotMode
        {
            get { return EditorSettings.ActivePivotMode; }
            set { EditorSettings.ActivePivotMode = value; }
        }

        /// <summary>
        /// Camera used for rendering the scene view.
        /// </summary>
        public static Camera SceneViewCamera
        {
            get
            {
                SceneWindow sceneWindow = EditorWindow.GetWindow<SceneWindow>();
                return sceneWindow?.Camera.Camera;
            }
        }

        /// <summary>
        /// Absolute path to the folder containing the currently open project.
        /// </summary>
        public static string ProjectPath { get { return Internal_GetProjectPath(); } }

        /// <summary>
        /// Name of the currently open project.
        /// </summary>
        public static string ProjectName { get { return Internal_GetProjectName(); } }

        /// <summary>
        /// Checks is any project currently loaded.
        /// </summary>
        public static bool IsProjectLoaded { get { return Internal_GetProjectLoaded(); } }

        /// <summary>
        /// Determines is the game currently running in the editor, or is it stopped or paused. Setting this value to false
        /// will stop the game, but if you just want to pause it use <see cref="IsPaused"/> property.
        /// </summary>
        public static bool IsPlaying
        {
            get { return Internal_GetIsPlaying(); }
            set
            {
                ToggleToolbarItem("Play", value);
                ToggleToolbarItem("Pause", false);

                if (!value)
                    Selection.SceneObject = null;
                else
                {
                    if (EditorSettings.GetBool(LogWindow.CLEAR_ON_PLAY_KEY, true))
                    {
                        Debug.Clear();

                        LogWindow log = EditorWindow.GetWindow<LogWindow>();
                        if (log != null)
                            log.Refresh();
                    }
                }

                Internal_SetIsPlaying(value);
            }
        }

        /// <summary>
        /// Determines if the game is currently running in the editor, but paused. If the game is stopped and not running
        /// this will return false. If the game is not running and this is enabled, the game will start running but be 
        /// immediately paused.
        /// </summary>
        public static bool IsPaused
        {
            get { return Internal_GetIsPaused(); }
            set
            {
                ToggleToolbarItem("Play", !value);
                ToggleToolbarItem("Pause", value);
                Internal_SetIsPaused(value);
            }
        }

        /// <summary>
        /// Returns true if the game is currently neither running nor paused. Use <see cref="IsPlaying"/> or 
        /// <see cref="IsPaused"/> to actually change these states.
        /// </summary>
        public static bool IsStopped
        {
            get { return !IsPlaying && !IsPaused; }
        }

        /// <summary>
        /// Checks whether the editor currently has focus.
        /// </summary>
        public static bool HasFocus
        {
            get { return Internal_HasFocus(); }
        }

        /// <summary>
        /// Returns true if the editor is waiting on a scene to be asynchronously loaded.
        /// </summary>
        public static bool IsSceneLoading
        {
            get
            {
                if (lastLoadedScene != null)
                    return !lastLoadedScene.IsLoaded;

                return false;
            }
        }

        /// <summary>
        /// Returns the load progress of the scene that's being asynchronously loaded
        /// </summary>
        public static float SceneLoadProgress
        {
            get
            {
                if (lastLoadedScene != null)
                    return Resources.GetLoadProgress(lastLoadedScene);

                return 0.0f;
            }
        }

        /// <summary>
        /// Triggered right before the project is being saved.
        /// </summary>
        public static event Action OnProjectSave;

        /// <summary>
        /// Render target that the main camera in the scene (if any) will render its view to. This generally means the main 
        /// game window when running standalone, or the Game viewport when running in editor.
        /// </summary>
        internal static RenderTarget MainRenderTarget
        {
            set
            {
                IntPtr rtPtr = IntPtr.Zero;
                if (value != null)
                    rtPtr = value.GetCachedPtr();

                Internal_SetMainRenderTarget(rtPtr);
            }
        }

        /// <summary>
        /// Returns an object that can be used for storing data that persists throughout the entire editor session.
        /// </summary>
        internal static EditorPersistentData PersistentData => persistentData;

        /// <summary>
        /// Editor specific data for the currently loaded scene. Can be null if no scene is loaded.
        /// </summary>
        internal static EditorSceneData EditorSceneData
        {
            get => PersistentData.editorSceneData;
            private set => PersistentData.editorSceneData = value;
        }

        /// <summary>
        /// Returns the path where the script compiler is located at.
        /// </summary>
        internal static string CompilerPath { get { return Internal_GetCompilerPath(); } }

        /// <summary>
        /// Returns the absolute path to the executable capable of executing managed assemblies.
        /// </summary>
        internal static string MonoExecPath { get { return Internal_GetMonoExecPath(); } }

        /// <summary>
        /// Returns the path to the folder where the custom script assemblies are located at.
        /// </summary>
        internal static string ScriptAssemblyPath { get { return Internal_GetScriptAssemblyPath(); } }

        /// <summary>
        /// Returns the path to the folder where the .NET framework assemblies are located at.
        /// </summary>
        internal static string FrameworkAssemblyPath { get { return Internal_GetFrameworkAssemblyPath(); } }

        /// <summary>
        /// Name of the builtin assembly containing engine specific types.
        /// </summary>
        internal static string EngineAssemblyName { get { return Internal_GetEngineAssemblyName(); } }

        /// <summary>
        /// Name of the builtin assembly containing editor specific types.
        /// </summary>
        internal static string EditorAssemblyName { get { return Internal_GetEditorAssemblyName(); } }

        /// <summary>
        /// Name of the custom assembly compiled from non-editor scripts within the project.
        /// </summary>
        internal static string ScriptGameAssemblyName { get { return Internal_GetScriptGameAssemblyName(); } }

        /// <summary>
        /// Name of the custom assembly compiled from editor scripts within the project.
        /// </summary>
        internal static string ScriptEditorAssemblyName { get { return Internal_GetScriptEditorAssemblyName(); } }

        /// <summary>
        /// Returns the path to the folder where the builtin release script assemblies are located at.
        /// </summary>
        internal static string BuiltinReleaseAssemblyPath { get { return Internal_GetBuiltinReleaseAssemblyPath(); } }

        /// <summary>
        /// Returns the path to the folder where the builtin debug script assemblies are located at.
        /// </summary>
        internal static string BuiltinDebugAssemblyPath { get { return Internal_GetBuiltinDebugAssemblyPath(); } }

        internal static VirtualButton CutKey = new VirtualButton(CutBinding);
        internal static VirtualButton CopyKey = new VirtualButton(CopyBinding);
        internal static VirtualButton PasteKey = new VirtualButton(PasteBinding);
        internal static VirtualButton RenameKey = new VirtualButton(RenameBinding);
        internal static VirtualButton DuplicateKey = new VirtualButton(DuplicateBinding);
        internal static VirtualButton DeleteKey = new VirtualButton(DeleteBinding);

        private static FolderMonitor monitor;
        private static ScriptCodeManager codeManager;
        private static RRef<Prefab> lastLoadedScene;
        private static bool sceneDirty;
        private static bool unitTestsExecuted;
        private static EditorPersistentData persistentData;

        private static bool delayUnloadProject;
        private static Action delayUnloadCallback;

        #pragma warning disable 0414
        private static EditorApplication instance;
        #pragma warning restore 0414

        /// <summary>
        /// Constructs a new editor application. Called at editor start-up by the runtime, and any time assembly refresh
        /// occurs.
        /// </summary>
        internal EditorApplication()
        {
            instance = this;

            const string soName = "EditorPersistentData";
            SceneObject so = Scene.Root.FindChild(soName);
            if (so == null)
                so = new SceneObject(soName, true);

            persistentData = so.GetComponent<EditorPersistentData>();
            if (persistentData == null)
                persistentData = so.AddComponent<EditorPersistentData>();

            codeManager = new ScriptCodeManager();

            Scene.OnSceneLoad += OnSceneLoad;
            Scene.OnSceneUnload += OnSceneUnload;

            // Register controls
            InputConfiguration inputConfig = VirtualInput.KeyConfig;

            inputConfig.RegisterButton(SceneCamera.MoveForwardBinding, ButtonCode.W);
            inputConfig.RegisterButton(SceneCamera.MoveBackBinding, ButtonCode.S);
            inputConfig.RegisterButton(SceneCamera.MoveLeftBinding, ButtonCode.A);
            inputConfig.RegisterButton(SceneCamera.MoveRightBinding, ButtonCode.D);
            inputConfig.RegisterButton(SceneCamera.MoveUpBinding, ButtonCode.E);
            inputConfig.RegisterButton(SceneCamera.MoveDownBinding, ButtonCode.Q);
            inputConfig.RegisterButton(SceneCamera.MoveForwardBinding, ButtonCode.Up);
            inputConfig.RegisterButton(SceneCamera.MoveBackBinding, ButtonCode.Down);
            inputConfig.RegisterButton(SceneCamera.MoveLeftBinding, ButtonCode.Left);
            inputConfig.RegisterButton(SceneCamera.MoveRightBinding, ButtonCode.Right);
            inputConfig.RegisterButton(SceneCamera.FastMoveBinding, ButtonCode.LeftShift);
            inputConfig.RegisterButton(SceneCamera.RotateBinding, ButtonCode.MouseRight);
            inputConfig.RegisterButton(SceneCamera.PanBinding, ButtonCode.MouseMiddle);
            inputConfig.RegisterAxis(SceneCamera.HorizontalAxisBinding, InputAxis.MouseX);
            inputConfig.RegisterAxis(SceneCamera.VerticalAxisBinding, InputAxis.MouseY);
            inputConfig.RegisterAxis(SceneCamera.ScrollAxisBinding, InputAxis.MouseZ);

            inputConfig.RegisterButton(SceneWindow.ToggleProfilerOverlayBinding, ButtonCode.P, ButtonModifier.CtrlAlt);
            inputConfig.RegisterButton(SceneWindow.ViewToolBinding, ButtonCode.Q);
            inputConfig.RegisterButton(SceneWindow.FrameBinding, ButtonCode.F);
            inputConfig.RegisterButton(SceneWindow.MoveToolBinding, ButtonCode.W);
            inputConfig.RegisterButton(SceneWindow.RotateToolBinding, ButtonCode.E);
            inputConfig.RegisterButton(SceneWindow.ScaleToolBinding, ButtonCode.R);

            inputConfig.RegisterButton(CutBinding, ButtonCode.X, ButtonModifier.Ctrl);
            inputConfig.RegisterButton(CopyBinding, ButtonCode.C, ButtonModifier.Ctrl);
            inputConfig.RegisterButton(PasteBinding, ButtonCode.V, ButtonModifier.Ctrl);
            inputConfig.RegisterButton(DuplicateBinding, ButtonCode.D, ButtonModifier.Ctrl);
            inputConfig.RegisterButton(DeleteBinding, ButtonCode.Delete);
            inputConfig.RegisterButton(RenameBinding, ButtonCode.F2);

            if (IsProjectLoaded)
            {
                monitor = new FolderMonitor(ProjectLibrary.ResourceFolder);
                monitor.OnAdded += OnAssetModified;
                monitor.OnRemoved += OnAssetModified;
                monitor.OnModified += OnAssetModified;
            }
        }

        /// <summary>
        /// Updates <see cref="EditorSceneData"/> with the current state of the active scene.
        /// </summary>
        internal static void UpdateEditorSceneData()
        {
            if (EditorSceneData == null)
                EditorSceneData = EditorSceneData.FromScene(Scene.Root);
            else
                EditorSceneData.UpdateFromScene(Scene.Root);

            HierarchyWindow hierarcyWindow = EditorWindow.GetWindow<HierarchyWindow>();
            hierarcyWindow?.SaveHierarchyState(EditorSceneData);
        }


        /// <summary>
        /// Triggered when the scene has been loaded.
        /// </summary>
        /// <param name="uuid">UUID of the loaded scene.</param>
        private static void OnSceneUnload(UUID uuid)
        {
            UpdateEditorSceneData();

            string key = EditorSceneDataPrefix + uuid;
            ProjectSettings.SetObject(key, EditorSceneData);
        }

        /// <summary>
        /// Triggered when a scene is about to be unloaded.
        /// </summary>
        /// <param name="uuid">UUID of the scene to be unloaded.</param>
        private static void OnSceneLoad(UUID uuid)
        {
            string key = EditorSceneDataPrefix + uuid;
            EditorSceneData = ProjectSettings.GetObject<EditorSceneData>(key);

            if (EditorSceneData == null)
                EditorSceneData = EditorSceneData.FromScene(Scene.Root);
        }

        /// <summary>
        /// Triggered when the folder monitor detects an asset in the monitored folder was modified.
        /// </summary>
        /// <param name="path">Path to the modified file or folder.</param>
        private static void OnAssetModified(string path)
        {
            ProjectLibrary.Refresh(path);
        }

        /// <summary>
        /// Called every frame by the runtime.
        /// </summary>
        internal void OnEditorUpdate()
        {
            // Update managers
            ProjectLibrary.Update();
            codeManager.Update();

            if (delayUnloadProject)
            {
                delayUnloadProject = false;
                UnloadProject();

                delayUnloadCallback?.Invoke();
                delayUnloadCallback = null;
            }
        }

        /// <summary>
        /// Manually triggers a global shortcut.
        /// </summary>
        /// <param name="btn">Button for the shortcut. If this doesn't correspond to any shortcut, it is ignored.</param>
        internal static void TriggerGlobalShortcut(VirtualButton btn)
        {
            IGlobalShortcuts window = null;

            if (btn != PasteKey)
            {
                // The system ensures elsewhere that only either a resource or a scene object is selected, but not both
                if (Selection.ResourcePaths.Length > 0)
                {
                    window = EditorWindow.GetWindow<LibraryWindow>();
                }
                else if (Selection.SceneObjects.Length > 0)
                {
                    window = EditorWindow.GetWindow<HierarchyWindow>();
                    if (window == null)
                        window = EditorWindow.GetWindow<SceneWindow>();
                }

                if (window != null)
                {
                    if (btn == CopyKey)
                        window.OnCopyPressed();
                    else if (btn == CutKey)
                        window.OnCutPressed();
                    else if (btn == PasteKey)
                        window.OnPastePressed();
                    else if (btn == DuplicateKey)
                        window.OnDuplicatePressed();
                    else if (btn == RenameKey)
                        window.OnRenamePressed();
                    else if (btn == DeleteKey)
                        window.OnDeletePressed();
                }
            }
            else
            {

                HierarchyWindow hierarchy = EditorWindow.GetWindow<HierarchyWindow>();
                if (hierarchy != null && hierarchy.HasFocus)
                    window = hierarchy;
                else
                {
                    LibraryWindow library = EditorWindow.GetWindow<LibraryWindow>();
                    if (library != null && library.HasFocus)
                        window = library;
                }

                if (window != null)
                    window.OnPastePressed();
            }
        }

        /// <summary>
        /// Creates a new empty scene.
        /// </summary>
        [MenuItem("File/New Scene", 10051, true)]
        private static void NewScene()
        {
            LoadScene(null);
        }

        /// <summary>
        /// Opens a dialog that allows the user to select a new prefab to load as the current scene. If current scene
        /// is modified the user is offered a chance to save it.
        /// </summary>
        [MenuItem("File/Open Scene", ButtonModifier.Ctrl, ButtonCode.L, 10050)]
        private static void LoadScene()
        {
            string[] scenePaths;
            if (BrowseDialog.OpenFile(ProjectLibrary.ResourceFolder, "", false, out scenePaths))
            {
                if (scenePaths.Length > 0)
                    LoadScene(scenePaths[0]);
            }
        }

        /// <summary>
        /// Opens a dialog to allows the user to select a location where to save the current scene. If scene was previously
        /// saved it is instead automatically saved at the last location.
        /// </summary>
        public static void SaveScene(Action onSuccess = null, Action onFailure = null)
        {
            if (!Scene.ActiveSceneUUID.IsEmpty())
            {
                string scenePath = ProjectLibrary.GetPath(Scene.ActiveSceneUUID);
                if (!string.IsNullOrEmpty(scenePath))
                {
                    if (Scene.IsGenericPrefab)
                    {
                        SaveGenericPrefab(onSuccess, onFailure);
                    }
                    else
                    {
                        SaveScene(scenePath);

                        if (onSuccess != null)
                            onSuccess();
                    }
                }
                else
                    SaveSceneAs(onSuccess, onFailure);
            }
            else
                SaveSceneAs(onSuccess, onFailure);
        }

        /// <summary>
        /// Opens a dialog to allows the user to select a location where to save the current scene.
        /// </summary>
        public static void SaveSceneAs(Action onSuccess = null, Action onFailure = null)
        {
            string scenePath = "";
            if (BrowseDialog.SaveFile(ProjectLibrary.ResourceFolder, "*.prefab", out scenePath))
            {
                if (!PathEx.IsPartOf(scenePath, ProjectLibrary.ResourceFolder))
                {
                    DialogBox.Open("Error", "The location must be inside the Resources folder of the project.",
                        DialogBox.Type.OK,
                        x =>
                        {
                            if (onFailure != null)
                                onFailure();
                        });
                }
                else
                {
                    // TODO - If path points to an existing non-scene asset or folder I should delete it otherwise
                    //        Internal_SaveScene will silently fail.

                    scenePath = Path.ChangeExtension(scenePath, ".prefab");
                    SaveScene(scenePath);
                }
            }
            else
            {
                // User canceled, so technically a success
                if (onSuccess != null)
                    onSuccess();
            }
        }

        /// <summary>
        /// Loads a prefab as the current scene at the specified path. If current scene is modified the user is offered a 
        /// chance to save it.
        /// </summary>
        /// <param name="path">Path to a valid prefab relative to the resource folder. If path is empty a brand new
        ///                    scene will be loaded.</param>
        public static void LoadScene(string path)
        {
            Action<string> continueLoad =
                (scenePath) =>
                {
                    if (string.IsNullOrEmpty(path))
                    {
                        Scene.Clear();
                        lastLoadedScene = null;
                    }
                    else
                        lastLoadedScene = Scene.LoadAsync(path);

                    SetSceneDirty(false);

                    ProjectSettings.LastOpenScene = scenePath;
                    ProjectSettings.Save();
                };

            Action<DialogBox.ResultType> dialogCallback =
            (result) =>
            {
                if (result == DialogBox.ResultType.Yes)
                {
                    SaveScene();
                    continueLoad(path);
                }
                else if (result == DialogBox.ResultType.No)
                    continueLoad(path);
            };

            if (IsSceneModified())
            {
                DialogBox.Open("Warning", "You current scene has modifications. Do you wish to save them first?",
                    DialogBox.Type.YesNoCancel, dialogCallback);
            }
            else
                continueLoad(path);
        }

        /// <summary>
        /// Saves the currently loaded scene to the specified path.
        /// </summary>
        /// <param name="path">Path relative to the resource folder. This can be the path to the existing scene
        ///                    prefab if it just needs updating. </param>
        internal static void SaveScene(string path)
        {
            Prefab scene = Internal_SaveScene(path);
            Scene.SetActive(scene);

            ProjectLibrary.Refresh(true);
            SetSceneDirty(false);
        }

        /// <summary>
        /// Attempts to save the current scene by applying the changes to a prefab, instead of saving it as a brand new
        /// scene. This is necessary for generic prefabs that have don't have a scene root included in the prefab. If the
        /// object added any other objects to the root, or has moved or deleted the original generic prefab the user
        /// will be asked to save the scene normally, creating a brand new prefab.
        /// </summary>
        private static void SaveGenericPrefab(Action onSuccess = null, Action onFailure = null)
        {
            // Find prefab root
            SceneObject root = null;

            int numChildren = Scene.Root.GetNumChildren();
            int numNormalChildren = 0;

            for (int i = 0; i < numChildren; i++)
            {
                SceneObject child = Scene.Root.GetChild(i);

                if (EditorUtility.IsInternal(child))
                    continue;

                UUID prefabUUID = PrefabUtility.GetPrefabUUID(child);
                if (prefabUUID == Scene.ActiveSceneUUID)
                    root = child;

                // If user added any other prefabs other than the initial one, the scene no longer represents a generic
                // prefab (as we can now longer save it by applying changes only to that prefab)
                numNormalChildren++;
                if (numNormalChildren > 1)
                {
                    root = null;
                    break;
                }
            }
            
            if (root != null)
            {
                PrefabUtility.ApplyPrefab(root, false);

                ProjectLibrary.Refresh(true);
                SetSceneDirty(false);

                if (onSuccess != null)
                    onSuccess();
            }
            else
            {
                SaveSceneAs(onSuccess, onFailure);
            }
        }

        /// <summary>
        /// Checks does the folder at the provieded path contain a valid project.
        /// </summary>
        /// <param name="path">Absolute path to the root project folder.</param>
        /// <returns>True if the folder contains a valid project.</returns>
        public static bool IsValidProject(string path)
        {
            return Internal_IsValidProject(path);
        }

        /// <summary>
        /// Contains a new project in the provided folder.
        /// </summary>
        /// <param name="path">Absolute path to the folder to create the project in. Name of this folder will be used as the
        ///                    project's name.</param>
        public static void CreateProject(string path)
        {
            Internal_CreateProject(path);
        }

        /// <summary>
        /// Wrapper for menu items for <see cref="SaveScene(Action, Action)"/> method
        /// </summary>
        [MenuItem("File/Save Scene", ButtonModifier.Ctrl, ButtonCode.S, 10049)]
        [ToolbarItem("Save Scene", ToolbarIcon.SaveScene, "Save scene (Ctrl + S)", 1998)]
        private static void SaveSceneMenu()
        {
            SaveScene();
        }

        /// <summary>
        /// Wrapper for menu items for <see cref="SaveSceneAs(Action, Action)"/> method
        /// </summary>
        [MenuItem("File/Save Scene As", 10048)]
        private static void SaveSceneAsMenu()
        {
            SaveSceneAs();
        }

        /// <summary>
        /// Opens a Project Window allowing you to browse for or create a project.
        /// </summary>
        [MenuItem("File/Open Project", 10100)]
        [ToolbarItem("Open Project", ToolbarIcon.OpenProject, "Project manager", 2000)]
        public static void BrowseForProject()
        {
            ProjectWindow.Open();
        }

        /// <summary>
        /// Saves all data in the currently open project.
        /// </summary>
        [MenuItem("File/Save Project", 10099)]
        [ToolbarItem("Save Project", ToolbarIcon.SaveProject, "Save project", 1999)]
        public static void SaveProject()
        {
            OnProjectSave?.Invoke();

            // Apply changes to any animation clips edited using the animation editor
            foreach (var KVP in persistentData.dirtyAnimClips)
                KVP.Value.SaveToClip();

            // Save all dirty resources to disk
            foreach (var KVP in persistentData.dirtyResources)
            {
                UUID resourceUUID = KVP.Key;
                string path = ProjectLibrary.GetPath(resourceUUID);
                if (!IsNative(path))
                    continue; // Imported resources can't be changed

                Resource resource = ProjectLibrary.Load<Resource>(path);

                if(resource != null)
                    ProjectLibrary.Save(resource);
            }

            persistentData.dirtyAnimClips.Clear();
            persistentData.dirtyResources.Clear();
            SetStatusProject(false);

            Internal_SaveProject();
        }

        /// <summary>
        /// Loads the project at the specified path. This method executes asynchronously.
        /// </summary>
        /// <param name="path">Absolute path to the project's root folder.</param>
        public static void LoadProject(string path)
        {
            if (IsProjectLoaded && path == ProjectPath)
                return;

            if (!Internal_IsValidProject(path))
            {
                Debug.LogWarning("Provided path: \"" + path + "\" is not a valid project.");
                return;
            }

            if (IsProjectLoaded)
                TryUnloadProject(() => Internal_LoadProject(path));
            else
                Internal_LoadProject(path); // Triggers Internal_OnProjectLoaded when done
        }

        /// <summary>
        /// Closes the editor.
        /// </summary>
        public static void Quit()
        {
            Internal_Quit();
        }

        /// <summary>
        /// Toggles an existing toolbar button into an on or off state which changes the visuals of the button.
        /// </summary>
        /// <param name="name">Name of the existing button to toggle</param>
        /// <param name="on">True to toggle on, false to toggle off (default)</param>
        public static void ToggleToolbarItem(string name, bool on)
        {
            Internal_ToggleToolbarItem(name, on);
        }

        /// <summary>
        /// Opens a folder in the default external application.
        /// </summary>
        /// <param name="path">Absolute path to the folder to open.</param>
        public static void OpenFolder(string path)
        {
            Internal_OpenFolder(path);
        }

        /// <summary>
        /// Marks a resource as dirty so that it may be saved the next time the project is saved. Optionally you may also
        /// call <see cref="ProjectLibrary.Save"/> to save it immediately.
        /// </summary>
        /// <param name="resource">Resource to mark as dirty</param>
        public static void SetDirty(Resource resource)
        {
            if (resource == null)
                return;

            SetStatusProject(true);
            persistentData.dirtyResources[resource.UUID] = resource;
        }

        /// <summary>
        /// Marks the current project dirty (requires saving in order for changes not to be lost).
        /// </summary>
        public static void SetProjectDirty()
        {
            SetStatusProject(true);
        }

        /// <summary>
        /// Marks the current scene as dirty.
        /// </summary>
        public static void SetSceneDirty()
        {
            SetSceneDirty(true);
        }

        /// <summary>
        /// Marks the current scene as clean or dirty.
        /// </summary>
        /// <param name="dirty">Should the scene be marked as clean or dirty.</param>
        internal static void SetSceneDirty(bool dirty)
        {
            sceneDirty = dirty;
            SetStatusScene(Scene.ActiveSceneName, dirty);

            if (!dirty && !Scene.ActiveSceneUUID.IsEmpty())
                persistentData.dirtyResources.Remove(Scene.ActiveSceneUUID);
        }

        /// <summary>
        /// Checks is the specific resource dirty and needs saving.
        /// </summary>
        /// <param name="resource">Resource to check.</param>
        /// <returns>True if the resource requires saving, false otherwise.</returns>
        public static bool IsDirty(Resource resource)
        {
            return persistentData.dirtyResources.ContainsKey(resource.UUID);
        }

        /// <summary>
        /// Checks does the path represent a native resource.
        /// </summary>
        /// <param name="path">Filename or path to check.</param>
        /// <returns>True if the path represents a native resource.</returns>
        public static bool IsNative(string path)
        {
            string extension = Path.GetExtension(path);

            return extension == ".asset" || extension == ".prefab";
        }

        /// <summary>
        /// Attempts to unload the currently loaded project. Offers the user a chance to save the current scene if it is
        /// modified. Automatically saves all project data before unloading.
        /// </summary>
        /// <param name="onDone">Callback to trigger when project project unload is done.</param>
        private static void TryUnloadProject(Action onDone)
        {
            if (delayUnloadProject)
                return;

            AskToSaveSceneAndContinue(
                    () =>
                {
                    if (ProjectLibrary.ImportInProgress)
                    {
                        ConfirmImportInProgressWindow.Show();
                        delayUnloadCallback = onDone;
                        delayUnloadProject = true;
                    }
                    else
                    {
                        UnloadProject();
                        onDone?.Invoke();
                    }
                });
        }

        /// <summary>
        /// Unloads the currently loaded project, without making any checks or requiring confirmation.
        /// </summary>
        private static void UnloadProject()
        {
            Scene.Clear();

            if (monitor != null)
            {
                monitor.Destroy();
                monitor = null;
            }

            LibraryWindow window = EditorWindow.GetWindow<LibraryWindow>();
            if (window != null)
                window.Reset();

            SetSceneDirty(false);
            Internal_UnloadProject();
            SetStatusProject(false);
        }

        /// <summary>
        /// Checks if the current scene is modified and asks the user to save the scene if it is. Triggers the
        /// <see cref="next"/> callback when done, unless user cancels the operation.
        /// </summary>
        /// <param name="next">Callback to trigger after this method finishes.</param>
        internal static void AskToSaveSceneAndContinue(Action next)
        {
            Action trySaveScene = null;
            trySaveScene = () =>
            {
                SaveScene(next, trySaveScene);
            };

            Action<DialogBox.ResultType> dialogCallback =
                (result) =>
                {
                    if (result == DialogBox.ResultType.Yes)
                        trySaveScene();
                    else if (result == DialogBox.ResultType.No)
                        next?.Invoke();
                };

            if (IsSceneModified())
            {
                DialogBox.Open("Warning", "You current scene has modifications. Do you wish to save them first?",
                    DialogBox.Type.YesNoCancel, dialogCallback);
            }
            else
                next?.Invoke();
        }

        /// <summary>
        /// Reloads all script assemblies in case they were modified. This action is delayed and will be executed
        /// at the beginning of the next frame.
        /// </summary>
        public static void ReloadAssemblies()
        {
            UpdateEditorSceneData();

            Internal_ReloadAssemblies();
        }

        /// <summary>
        /// Changes the scene displayed on the status bar.
        /// </summary>
        /// <param name="name">Name of the scene.</param>
        /// <param name="modified">Whether to display the scene as modified or not.</param>
        private static void SetStatusScene(string name, bool modified)
        {
            Internal_SetStatusScene(name, modified);
        }

        /// <summary>
        /// Changes the project state displayed on the status bar.
        /// </summary>
        /// <param name="modified">Whether to display the project as modified or not.</param>
        private static void SetStatusProject(bool modified)
        {
            Internal_SetStatusProject(modified);
        }

        /// <summary>
        /// Displays or hides the "compilation in progress" visual on the status bar.
        /// </summary>
        /// <param name="compiling">True to display the visual, false otherwise.</param>
        internal static void SetStatusCompiling(bool compiling)
        {
            Internal_SetStatusCompiling(compiling);
        }

        /// <summary>
        /// Displays or hides the "import in progress" visuals on the status bar and updates the related progress bar.
        /// </summary>
        /// <param name="importing">True to display the visual, false otherwise.</param>
        /// <param name="percent">Percent in range [0, 1] to display on the progress bar.</param>
        internal static void SetStatusImporting(bool importing, float percent)
        {
            Internal_SetStatusImporting(importing, percent);
        }

        /// <summary>
        /// Checks did we make any modifications to the scene since it was last saved.
        /// </summary>
        /// <returns>True if the scene was never saved, or was modified after last save.</returns>
        public static bool IsSceneModified()
        {
            return sceneDirty;
        }

        /// <summary>
        /// Runs a single frame of the game and pauses it. If the game is not currently running it will be started.
        /// </summary>
        public static void FrameStep()
        {
            if (IsStopped)
            {
                if (EditorSettings.GetBool(LogWindow.CLEAR_ON_PLAY_KEY, true))
                {
                    Debug.Clear();

                    LogWindow log = EditorWindow.GetWindow<LogWindow>();
                    if (log != null)
                        log.Refresh();
                }
            }

            ToggleToolbarItem("Play", false);
            ToggleToolbarItem("Pause", true);
            Internal_FrameStep();
        }

        /// <summary>
        /// Executes any editor-specific unit tests. This should be called after a project is loaded if possible.
        /// </summary>
        private static void RunUnitTests()
        {
#if DEBUG
            Internal_RunUnitTests();
#endif
        }

        /// <summary>
        /// Triggered by the runtime when <see cref="LoadProject"/> method completes.
        /// </summary>
        private static void Internal_OnProjectLoaded()
        {
            SetStatusProject(false);
            if (!unitTestsExecuted)
            {
                RunUnitTests();
                unitTestsExecuted = true;
            }

            if (!IsProjectLoaded)
            {
                ProjectWindow.Open();
                return;
            }

            string projectPath = ProjectPath;

            RecentProject[] recentProjects = EditorSettings.RecentProjects;
            bool foundPath = false;
            for (int i = 0; i < recentProjects.Length; i++)
            {
                if (PathEx.Compare(recentProjects[i].path, projectPath))
                {
                    recentProjects[i].accessTimestamp = (ulong)DateTime.Now.Ticks;
                    EditorSettings.RecentProjects = recentProjects;
                    foundPath = true;
                    break;
                }
            }

            if (!foundPath)
            {
                List<RecentProject> extendedRecentProjects = new List<RecentProject>();
                extendedRecentProjects.AddRange(recentProjects);

                RecentProject newProject = new RecentProject();
                newProject.path = projectPath;
                newProject.accessTimestamp = (ulong)DateTime.Now.Ticks;

                extendedRecentProjects.Add(newProject);

                EditorSettings.RecentProjects = extendedRecentProjects.ToArray();
            }

            EditorSettings.LastOpenProject = projectPath;
            EditorSettings.Save();

            ProjectLibrary.Refresh();

            if(monitor != null)
            {
                monitor.Destroy();
                monitor = null;
            }

            monitor = new FolderMonitor(ProjectLibrary.ResourceFolder);
            monitor.OnAdded += OnAssetModified;
            monitor.OnRemoved += OnAssetModified;
            monitor.OnModified += OnAssetModified;

            if (!string.IsNullOrWhiteSpace(ProjectSettings.LastOpenScene))
            {
                lastLoadedScene = Scene.LoadAsync(ProjectSettings.LastOpenScene);
                SetSceneDirty(false);
            }
        }

        /// <summary>
        /// Triggered by the runtime when the user clicks on the status bar.
        /// </summary>
        private static void Internal_OnStatusBarClicked()
        {
            EditorWindow.OpenWindow<LogWindow>();
        }

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SetStatusScene(string name, bool modified);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SetStatusProject(bool modified);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SetStatusCompiling(bool compiling);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SetStatusImporting(bool importing, float percent);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetProjectPath();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetProjectName();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern bool Internal_GetProjectLoaded();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetCompilerPath();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetMonoExecPath();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetBuiltinReleaseAssemblyPath();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetBuiltinDebugAssemblyPath();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetScriptAssemblyPath();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetFrameworkAssemblyPath();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetEngineAssemblyName();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetEditorAssemblyName();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetScriptGameAssemblyName();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern string Internal_GetScriptEditorAssemblyName();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern Prefab Internal_SaveScene(string path);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern bool Internal_IsValidProject(string path);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SaveProject();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_LoadProject(string path);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_UnloadProject();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_CreateProject(string path);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_ReloadAssemblies();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_OpenFolder(string path);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_RunUnitTests();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_Quit();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_ToggleToolbarItem(string name, bool on);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern bool Internal_GetIsPlaying();
        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SetIsPlaying(bool value);
        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern bool Internal_GetIsPaused();
        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SetIsPaused(bool value);
        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_FrameStep();

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern void Internal_SetMainRenderTarget(IntPtr rendertarget);

        [MethodImpl(MethodImplOptions.InternalCall)]
        private static extern bool Internal_HasFocus();
    }

    /** @} */
}