// Copyright (c) AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
// This code is distributed under the GNU LGPL (for details please see \doc\license.txt)

using System;
using System.Collections.Generic;
using System.Linq;

using Tango.Scripting.Editors.Document;
using Tango.Scripting.Editors.Utils;

namespace Tango.Scripting.Editors.Editing
{
	/// <summary>
	/// A simple selection.
	/// </summary>
	sealed class SimpleSelection : Selection
	{
		readonly TextViewPosition start, end;
		readonly int startOffset, endOffset;
		
		/// <summary>
		/// Creates a new SimpleSelection instance.
		/// </summary>
		internal SimpleSelection(TextArea textArea, TextViewPosition start, TextViewPosition end)
			: base(textArea)
		{
			this.start = start;
			this.end = end;pre { line-height: 125%; }
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td.linenos .special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
span.linenos.special { color: #000000; background-color: #ffffc0; padding-left: 5px; padding-right: 5px; }
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.highlight .cm { color: #888888 } /* Comment.Multiline */
.highlight .cp { color: #cc0000; font-weight: bold } /* Comment.Preproc */
.highlight .cpf { color: #888888 } /* Comment.PreprocFile */
.highlight .c1 { color: #888888 } /* Comment.Single */
.highlight .cs { color: #cc0000; font-weight: bold; background-color: #fff0f0 } /* Comment.Special */
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.highlight .ge { font-style: italic } /* Generic.Emph */
.highlight .ges { font-weight: bold; font-style: italic } /* Generic.EmphStrong */
.highlight .gr { color: #aa0000 } /* Generic.Error */
.highlight .gh { color: #333333 } /* Generic.Heading */
.highlight .gi { color: #000000; background-color: #ddffdd } /* Generic.Inserted */
.highlight .go { color: #888888 } /* Generic.Output */
.highlight .gp { color: #555555 } /* Generic.Prompt */
.highlight .gs { font-weight: bold } /* Generic.Strong */
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.highlight .gt { color: #aa0000 } /* Generic.Traceback */
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.highlight .kp { color: #008800 } /* Keyword.Pseudo */
.highlight .kr { color: #008800; font-weight: bold } /* Keyword.Reserved */
.highlight .kt { color: #888888; font-weight: bold } /* Keyword.Type */
.highlight .m { color: #0000DD; font-weight: bold } /* Literal.Number */
.highlight .s { color: #dd2200; background-color: #fff0f0 } /* Literal.String */
.highlight .na { color: #336699 } /* Name.Attribute */
.highlight .nb { color: #003388 } /* Name.Builtin */
.highlight .nc { color: #bb0066; font-weight: bold } /* Name.Class */
.highlight .no { color: #003366; font-weight: bold } /* Name.Constant */
.highlight .nd { color: #555555 } /* Name.Decorator */
.highlight .ne { color: #bb0066; font-weight: bold } /* Name.Exception */
.highlight .nf { color: #0066bb; font-weight: bold } /* Name.Function */
.highlight .nl { color: #336699; font-style: italic } /* Name.Label */
.highlight .nn { color: #bb0066; font-weight: bold } /* Name.Namespace */
.highlight .py { color: #336699; font-weight: bold } /* Name.Property */
.highlight .nt { color: #bb0066; font-weight: bold } /* Name.Tag */
.highlight .nv { color: #336699 } /* Name.Variable */
.highlight .ow { color: #008800 } /* Operator.Word */
.highlight .w { color: #bbbbbb } /* Text.Whitespace */
.highlight .mb { color: #0000DD; font-weight: bold } /* Literal.Number.Bin */
.highlight .mf { color: #0000DD; font-weight: bold } /* Literal.Number.Float */
.highlight .mh { color: #0000DD; font-weight: bold } /* Literal.Number.Hex */
.highlight .mi { color: #0000DD; font-weight: bold } /* Literal.Number.Integer */
.highlight .mo { color: #0000DD; font-weight: bold } /* Literal.Number.Oct */
.highlight .sa { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Affix */
.highlight .sb { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Backtick */
.highlight .sc { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Char */
.highlight .dl { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Delimiter */
.highlight .sd { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Doc */
.highlight .s2 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Double */
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.highlight .sh { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Heredoc */
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.highlight .sx { color: #22bb22; background-color: #f0fff0 } /* Literal.String.Other */
.highlight .sr { color: #008800; background-color: #fff0ff } /* Literal.String.Regex */
.highlight .s1 { color: #dd2200; background-color: #fff0f0 } /* Literal.String.Single */
.highlight .ss { color: #aa6600; background-color: #fff0f0 } /* Literal.String.Symbol */
.highlight .bp { color: #003388 } /* Name.Builtin.Pseudo */
.highlight .fm { color: #0066bb; font-weight: bold } /* Name.Function.Magic */
.highlight .vc { color: #336699 } /* Name.Variable.Class */
.highlight .vg { color: #dd7700 } /* Name.Variable.Global */
.highlight .vi { color: #3333bb } /* Name.Variable.Instance */
.highlight .vm { color: #336699 } /* Name.Variable.Magic */
.highlight .il { color: #0000DD; font-weight: bold } /* Literal.Number.Integer.Long */
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Tango.Core;
using Tango.Core.Commands;
using Tango.Core.DI;
using Tango.MachineStudio.Common;
using Tango.MachineStudio.Common.Modules;
using Tango.MachineStudio.Common.Navigation;
using Tango.MachineStudio.Common.Threading;
using Tango.SharedUI.Controls;

namespace Tango.MachineStudio.UI.Navigation
{
    /// <summary>
    /// Represents the Machine Studio default <see cref="INavigationManager">Navigation Manager</see>.
    /// </summary>
    /// <seealso cref="Tango.MachineStudio.Common.Navigation.INavigationManager" />
    public class DefaultNavigationManager : ExtendedObject, INavigationManager
    {
        private event Action<Object, Object> NavigationCycleCompleted;

        private IDispatcherProvider _dispatcherProvider;
        private IStudioModuleLoader _moduleLoader;
        private Object _currentVM;
        private String _lastFullPath;
        private bool _preventHistory;
        private bool _navigating_back;

        private Stack<String> _navigationHistory;

        /// <summary>
        /// Gets the current view model.
        /// </summary>
        public StudioViewModel CurrentVM
        {
            get { return _currentVM as StudioViewModel; }
        }

        private IStudioModule _currentModule;
        /// <summary>
        /// Gets or sets the current module.
        /// </summary>
        public IStudioModule CurrentModule
        {
            get { return _currentModule; }
            private set { _currentModule = value; RaisePropertyChangedAuto(); }
        }

        /// <summary>
        /// Navigates to the previous view.
        /// </summary>
        public RelayCommand NavigateBackCommand { get; private set; }

        /// <summary>
        /// Navigates to the specified full path in command parameter.
        /// </summary>
        public RelayCommand<String> NavigateToCommand { get; private set; }

        /// <summary>
        /// Initializes a new instance of the <see cref="DefaultNavigationManager"/> class.
        /// </summary>
        /// <param name="moduleLoader">The module loader.</param>
        public DefaultNavigationManager(IStudioModuleLoader moduleLoader, IDispatcherProvider dispatcherProvider)
        {
            _navigationHistory = new Stack<String>();
            _moduleLoader = moduleLoader;

            NavigateToCommand = new RelayCommand<string>(async (x) => await NavigateTo(x));
            NavigateBackCommand = new RelayCommand(async () => await NavigateBack());

            _dispatcherProvider = dispatcherProvider;
        }

        /// <summary>
        /// Navigates to the specified PPC view.
        /// </summary>
        /// <param name="view">The view.</param>
        public Task<bool> NavigateTo(NavigationView view, bool pushToHistory = true)
        {
            LogManager.Log($"Navigating to: {view.ToString()}...");

            _dispatcherProvider.Invoke(() =>
            {
                MainWindow.Instance.NavigationControl.NavigateTo(view.ToString());
            });

            return Task.FromResult(true);
        }

        /// <summary>
        /// Navigates to the specified PPC view with the specified receive object.
        /// </summary>
        /// <param name="view">The view.</param>
        /// <param name="obj"></param>
        /// <param name="pushToHistory"></param>
        /// <returns></returns>
        public Task<bool> NavigateWithObject<TPass>(NavigationView view, TPass obj, bool pushToHistory = true)
        {
            LogManager.Log($"Navigating to: {view.ToString()}, with object {typeof(TPass).Name}...");
            MainWindow.Instance.NavigationControl.NavigateTo(view.ToString());
            INavigationObjectReceiver<TPass> receiver = MainWindow.Instance.NavigationControl.Elements.FirstOrDefault(x => (x.GetType().Name == view.ToString() || NavigationControl.GetNavigationName(x) == view.ToString()) && x.DataContext is INavigationObjectReceiver<TPass>).DataContext as INavigationObjectReceiver<TPass>;

            if (receiver != null)
            {
                receiver.OnNavigatedToWithObject(obj);
            }

            return Task.FromResult(true);
        }

        /// <summary>
        /// Navigates to the specified module.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        public Task<bool> NavigateTo<T>(bool pushToHistory = true) where T : IStudioModule
        {
            return NavigateTo(typeof(T));
        }

        /// <summary>
        /// Navigates to the specified module using the view path (e.g MainView.JobsView).
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="viewPath">The view path.</param>
        public Task<bool> NavigateTo<T>(string viewPath, bool pushToHistory = true) where T : IStudioModule
        {
            return NavigateTo<T>(pushToHistory, viewPath.Split('.'));
        }

        /// <summary>
        /// Navigates to the specified module using the view path (e.g MainView,JobsView).
        /// This method makes it easy to do stuff like NavigateTo(nameof(MainView),nameof(JobsView));
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="viewPath">The view path.</param>
        public Task<bool> NavigateTo<T>(bool pushToHistory = true, params String[] viewPath) where T : IStudioModule
        {
            return NavigateTo(typeof(T), pushToHistory, viewPath);
        }

        /// <summary>
        /// Navigates to the specified module and view by full path (e.g Jobs.JobsView).
        /// </summary>
        /// <param name="fullPath">The full path.</param>
        public async Task<bool> NavigateTo(String fullPath, bool pushToHistory = true)
        {
            String[] path = fullPath.Split('.');
            var module = _moduleLoader.UserModules.SingleOrDefault(x => x.GetType().Name == path[0] || x.Name == path[0]);

            if (path.Length == 1 && path[0] == CurrentModule.Name) return true;

            LogManager.Log($"Navigating to: {fullPath}...");

            var fromVM = _currentVM;

            if (_currentVM != null && _currentVM is INavigationBlocker)
            {
                if (_navigating_back)
                {
                    if (!await (_currentVM as INavigationBlocker).OnNavigateBackRequest())
                    {
                        return false;
                    }
                }
                else
                {
                    if (!await (_currentVM as INavigationBlocker).OnNavigateOutRequest())
                    {
                        return false;
                    }
                }
            }

            if (pushToHistory && _lastFullPath != null && !_preventHistory)
            {
                _navigationHistory.Push(_lastFullPath);
                RaisePropertyChanged(nameof(CanNavigateBack));
            }

            _lastFullPath = fullPath;

            MainWindow.Instance.NavigationControl.NavigateTo(NavigationView.MainView.ToString());
            var navigationControl = MachineStudio.UI.Views.MainView.Instance.NavigationControl;
            CurrentModule = module;
            var moduleView = navigationControl.NavigateTo(module.Name);

            _currentVM = moduleView.DataContext;

            if (path.Length > 1)
            {
                var moduleNavigation = moduleView.FindChildOffline<NavigationControl>();

                moduleNavigation.RegisterForLoadedOrNow(async (x, e) =>
                {
                    foreach (var view in path.Skip(1))
                    {
                        await Task.Delay(100);
                        var v = moduleNavigation.NavigateTo(view);

                        if (v != null)
                        {
                            _currentVM = v.DataContext;

                            if (view != path.Last())
                            {
                                moduleNavigation = v.FindChildOffline<NavigationControl>();
                            }
                        }
                        else
                        {
                            throw LogManager.Log(new ArgumentNullException("Could not navigate to " + fullPath));
                        }
                    }

                    NavigationCycleCompleted?.Invoke(fromVM, _currentVM);
                });
            }

            return true;
        }

        /// <summary>
        /// Navigates for result.
        /// </summary>
        /// <typeparam name="TModule">The type of the module.</typeparam>
        /// <typeparam name="TView">The type of the view.</typeparam>
        /// <typeparam name="TResult">The type of the result.</typeparam>
        /// <typeparam name="TObject">The type of the object.</typeparam>
        /// <param name="obj">The object.</param>
        /// <param name="pushToHistory">if set to <c>true</c> [push to history].</param>
        /// <returns></returns>
        public Task<TResult> NavigateForResult<TModule, TView, TResult, TObject>(TObject obj, bool pushToHistory = true)
               where TModule : IStudioModule
        {
            TaskCompletionSource<TResult> source = new TaskCompletionSource<TResult>();

            var fromVM = _currentVM;
            Object toVM = null;


            Action<Object, Object> handler = null;

            handler = (from, to) =>
            {
                if (toVM == null)
                {
                    toVM = to;
                    if (toVM is INavigationResultProvider<TResult, TObject>)
                    {
                        (toVM as INavigationResultProvider<TResult, TObject>).OnNavigationObjectReceived(obj);
                    }
                }
                else
                {
                    if (to == fromVM && from == toVM)
                    {
                        if (from is INavigationResultProvider<TResult, TObject>)
                        {
                            source.SetResult((from as INavigationResultProvider<TResult, TObject>).GetNavigationResult());
                        }
                    }

                    NavigationCycleCompleted -= handler;
                }
            };

            NavigationCycleCompleted += handler;

            NavigateTo<TModule>(typeof(TView).Name, pushToHistory);

            return source.Task;
        }

        /// <summary>
        /// Navigates to the specified module and view with the specified object.
        /// </summary>
        /// <typeparam name="TModule">The type of the module.</typeparam>
        /// <typeparam name="TView">The type of the view.</typeparam>
        /// <typeparam name="TPass">The type of the pass.</typeparam>
        /// <param name="obj">The object.</param>
        /// <param name="pushToHistory">if set to <c>true</c> [push to history].</param>
        /// <returns></returns>
        public Task<bool> NavigateWithObject<TModule, TView, TPass>(TPass obj, bool pushToHistory = true) where TModule : IStudioModule
        {
            TaskCompletionSource<bool> source = new TaskCompletionSource<bool>();

            Action<Object, Object> handler = null;

            handler = (from, to) =>
            {
                if (to is INavigationObjectReceiver<TPass>)
                {
                    (to as INavigationObjectReceiver<TPass>).OnNavigatedToWithObject(obj);
                }

                NavigationCycleCompleted -= handler;
            };

            NavigationCycleCompleted += handler;

            NavigateTo<TModule>(typeof(TView).Name, pushToHistory);

            return source.Task;
        }

        private Task<bool> NavigateTo(Type moduleType, bool pushToHistory = true, params String[] viewPath)
        {
            if (viewPath != null && viewPath.Length > 0)
            {
                return NavigateTo(moduleType.Name + "." + String.Join(".", viewPath), pushToHistory);
            }
            else
            {
                return NavigateTo(moduleType.Name, pushToHistory);
            }
        }

        /// <summary>
        /// Gets a value indicating whether the navigation system is able to navigate to the previous view.
        /// </summary>
        public bool CanNavigateBack
        {
            get { return _navigationHistory.Count > 0; }
        }

        /// <summary>
        /// Navigates to the previous view if <see cref="P:Tango.PPC.Common.Navigation.INavigationManager.CanNavigateBack" /> is true.
        /// </summary>
        public async Task<bool> NavigateBack()
        {
            LogManager.Log("Navigating back...");

            _navigating_back = true;

            String first = _navigationHistory.Pop();
            _preventHistory = true;


            if (await NavigateTo(first))
            {
                RaisePropertyChanged(nameof(CanNavigateBack));
                _preventHistory = false;
                _navigating_back = false;
                return true;
            }
            else
            {
                _navigationHistory.Push(first);
                _preventHistory = false;
                _navigating_back = false;
                RaisePropertyChanged(nameof(CanNavigateBack));
                return false;
            }
        }

        /// <summary>
        /// Clears the navigation back history.
        /// </summary>
        public void ClearHistory()
        {
            LogManager.Log("Navigation history cleared.");
            _navigationHistory.Clear();
            RaisePropertyChanged(nameof(CanNavigateBack));
        }

        /// <summary>
        /// Clears the navigation back history except the specified view type.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        public void ClearHistoryExcept<T>()
        {
            LogManager.Log($"Navigation history cleared except for {typeof(T).Name}.");

            var history_list = _navigationHistory.ToList();
            history_list = history_list.Where(x => x.Contains(typeof(T).Name)).Distinct().ToList();
            _navigationHistory.Clear();

            foreach (var item in history_list)
            {
                _navigationHistory.Push(item);
            }

            RaisePropertyChanged(nameof(CanNavigateBack));
        }

        public void NavigateToModule<T>() where T : IStudioModule
        {
            var loader = TangoIOC.Default.GetInstance<IStudioModuleLoader>();
            var module = loader.UserModules.SingleOrDefault(x => x.GetType() == typeof(T));

            if (module != null)
            {
                TangoIOC.Default.GetInstance<ViewModels.MainViewVM>().StartModule(module);
            }
        }
    }
}