using Microsoft.Win32;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Timers;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using System.Windows.Threading;
using System.Windows.Ink;
using System.Windows.Media.Effects;

namespace SketchAssistantWPF
{
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window, MVP_View
    {
        public MainWindow()
        {
            bool InDebugMode = false;
            String[] commArgs = Environment.GetCommandLineArgs();
            InitializeComponent();
            if (commArgs.Length > 1)
            {
                if (commArgs[1].Equals("-debug"))
                {
                    InDebugMode = true;
                }
            }
            if(!InDebugMode)
            {
                DebugMode.Visibility = Visibility.Collapsed;
            }
            ProgramPresenter = new MVP_Presenter(this);
            //  DispatcherTimer setup
            dispatcherTimer = new DispatcherTimer(DispatcherPriority.Render);
            dispatcherTimer.Tick += new EventHandler(dispatcherTimer_Tick);
            dispatcherTimer.Interval = new TimeSpan(0, 0, 0, 0, 10);
            ProgramPresenter.Resize(new Tuple<int, int>((int)LeftCanvas.Width, (int)LeftCanvas.Height),
                new Tuple<int, int>((int)RightCanvas.Width, (int)RightCanvas.Height));
            //Setup overlay items
            SetupOverlay();
        }

        public enum ButtonState
        {
            Enabled,
            Disabled,
            Active
        }

        DispatcherTimer dispatcherTimer;
        /// <summary>
        /// Dialog to select a file.
        /// </summary>
        OpenFileDialog openFileDialog = new OpenFileDialog();
        /// <summary>
        /// All Lines in the current session
        /// </summary>
        List<Tuple<bool, InternalLine>> rightLineList = new List<Tuple<bool, InternalLine>>();
        /// <summary>
        /// Queue for the cursorPositions
        /// </summary>
        Queue<Point> cursorPositions = new Queue<Point>();
        /// <summary>
        /// The Presenter Component of the MVP-Model
        /// </summary>
        MVP_Presenter ProgramPresenter;
        /// <summary>
        /// The line currently being drawn
        /// </summary>
        Polyline currentLine;
        /// <summary>
        /// If the debug function is running.
        /// </summary>
        bool debugRunning = false;
        /// <summary>
        /// Point collections for debugging.
        /// </summary>
        DebugData debugDat = new DebugData();
        /// <summary>
        /// Stores Lines drawn on RightCanvas.
        /// </summary>
        public StrokeCollection strokeCollection = new StrokeCollection();
        /// <summary>
        /// Size of areas marking endpoints of lines in the redraw mode.
        /// </summary>
        public int markerRadius = 5;
        /// <summary>
        /// Dictionary containing the overlay elements
        /// </summary>
        public Dictionary<String, Shape> OverlayDictionary = new Dictionary<string, Shape>();

        /********************************************/
        /*** WINDOW SPECIFIC FUNCTIONS START HERE ***/
        /********************************************/

        /// <summary>
        /// Resize Function connected to the form resize event, will refresh the form when it is resized
        /// </summary>
        private void Window_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            ProgramPresenter.Resize(new Tuple<int, int>((int)LeftCanvas.ActualWidth, (int)LeftCanvas.ActualHeight),
                new Tuple<int, int>((int)RightCanvas.ActualWidth, (int)RightCanvas.ActualHeight));
        }

        /// <summary>
        /// Collects all Strokes on RightCanvas
        /// </summary>
        public void RightCanvas_StrokeCollection(object sender, InkCanvasStrokeCollectedEventArgs e)
        {
            strokeCollection.Add(e.Stroke);
        }

        /// <summary>
        /// Redo an Action.
        /// </summary>
        private void RedoButton_Click(object sender, RoutedEventArgs e)
        {
            if (!IsMousePressed()) ProgramPresenter.Redo();
        }

        /// <summary>
        /// Undo an Action.
        /// </summary>
        private void UndoButton_Click(object sender, RoutedEventArgs e)
        {
            if(!IsMousePressed()) ProgramPresenter.Undo();
        }

        /// <summary>
        /// Changes the state of the program to deletion
        /// </summary>
        private void DeleteButton_Click(object sender, RoutedEventArgs e)
        {
            ProgramPresenter.ChangeState(false);
            RightCanvas.EditingMode = InkCanvasEditingMode.EraseByStroke;
        }

        /// <summary>
        /// Changes the state of the program to drawing
        /// </summary>
        private void DrawButton_Click(object sender, RoutedEventArgs e)
        {
            ProgramPresenter.ChangeState(true);
            RightCanvas.EditingMode = InkCanvasEditingMode.Ink;
        }

        /// <summary>
        /// Hold left mouse button to start drawing.
        /// </summary>
        private void RightCanvas_MouseDown(object sender, MouseButtonEventArgs e)
        {
            ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Down, strokeCollection);
        }

        /// <summary>
        /// Lift left mouse button to stop drawing and add a new Line.
        /// </summary>
        private void RightCanvas_MouseUp(object sender, MouseButtonEventArgs e)
        {
            if(strokeCollection.Count == 0)
            {
                ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Up_Invalid, strokeCollection);
            }
            else
            {
                ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Up, strokeCollection);
                RightCanvas.Strokes.RemoveAt(0);
                strokeCollection.RemoveAt(0);
            }
        }

        /// <summary>
        /// Is called when a stylus is lifted, which has the same effect as releasing the mouse.
        /// Lifting the finger when using touch also toggles this, therfore this function is sufficient.
        /// </summary>
        private void RightCanvas_IsStylusCapturedChanged(object sender, DependencyPropertyChangedEventArgs e)
        {
            System.Diagnostics.Debug.WriteLine("Stylus Capture is now: {0}", RightCanvas.IsStylusCaptured);
            if (!RightCanvas.IsStylusCaptured)
            {
                if (strokeCollection.Count == 0)
                {
                    ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Up_Invalid,strokeCollection);
                }
                else
                {
                    ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Up, strokeCollection);
                    RightCanvas.Strokes.RemoveAt(0);
                    strokeCollection.RemoveAt(0);
                }
            }
        }

        /// <summary>
        /// Get current Mouse positon within the right picture box.
        /// </summary>
        private void RightCanvas_MouseMove(object sender, MouseEventArgs e)
        {
            ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Move, e.GetPosition(RightCanvas));
        }

        /// <summary>
        /// Button to create a new Canvas. Will create an empty image 
        /// which is the size of the left image, if there is one.
        /// If there is no image loaded the canvas will be the size of the right picture box
        /// </summary>
        private void CanvasButton_Click(object sender, RoutedEventArgs e)
        {
            ProgramPresenter.NewCanvas();
            RightCanvas.EditingMode = InkCanvasEditingMode.Ink;
            RightCanvas.Strokes.Clear();
        }

        /// <summary>
        /// Ticks the Presenter.
        /// </summary>
        private void dispatcherTimer_Tick(object sender, EventArgs e)
        {
            ProgramPresenter.Tick();
        }

        /// <summary>
        /// Import button for .svg file, will open an OpenFileDialog
        /// </summary>
        private void SVGMenuItem_Click(object sender, RoutedEventArgs e)
        {
            if(ProgramPresenter.SVGToolStripMenuItemClick())
                RightCanvas.EditingMode = InkCanvasEditingMode.Ink;
        }

        /*************************/
        /*** PRESENTER -> VIEW ***/
        /*************************/

        /// <summary>
        /// Returns the cursor position.
        /// </summary>
        /// <returns>The cursor Position</returns>
        public Point GetCursorPosition()
        {
            return Mouse.GetPosition(RightCanvas);
        }

        /// <summary>
        /// If the mouse is pressed or not.
        /// </summary>
        /// <returns>Whether or not the mouse is pressed.</returns>
        public bool IsMousePressed()
        {
            if (!debugRunning) {
                return (Mouse.LeftButton.Equals(MouseButtonState.Pressed) || Mouse.RightButton.Equals(MouseButtonState.Pressed)); }
            else return true;
        }

        /// <summary>
        /// Remove the current line.
        /// </summary>
        public void RemoveCurrLine()
        {
            RightCanvas.Children.Remove(currentLine);
        }

        /// <summary>
        /// Display the current line.
        /// </summary>
        /// <param name="line">The current line to display</param>
        public void DisplayCurrLine(Polyline line)
        {
            if (RightCanvas.Children.Contains(currentLine))
            {
                RemoveCurrLine();
            }
            RightCanvas.Children.Add(line);
            currentLine = line;
        }

        /// <summary>
        /// Removes all Lines from the left canvas.
        /// </summary>
        public void RemoveAllLeftLines()
        {
            LeftCanvas.Children.Clear();
        }

        /// <summary>
        /// Removes all lines in the right canvas.
        /// </summary>
        public void RemoveAllRightLines()
        {
            RightCanvas.Children.Clear();
        }

        /// <summary>
        /// Adds another Line that will be displayed in the left display.
        /// </summary>
        /// <param name="newLine">The new Polyline to be added displayed.</param>
        public void AddNewLineLeft(Polyline newLine)
        {
            newLine.Stroke = Brushes.Black;
            newLine.StrokeThickness = 2;
            LeftCanvas.Children.Add(newLine);
        }

        /// <summary>
        /// Adds another Line that will be displayed in the right display.
        /// </summary>
        /// <param name="newLine">The new Polyline to be added displayed.</param>
        public void AddNewLineRight(Polyline newLine)
        {
            newLine.Stroke = Brushes.Black;
            newLine.StrokeThickness = 2;
            RightCanvas.Children.Add(newLine);
        }

        /// <summary>
        /// Adds a point to the right canvas
        /// </summary>
        /// <param name="newPoint">The point</param>
        public void AddNewPointRight(Ellipse newPoint, InternalLine line)
        {
            newPoint.Height = 3; newPoint.Width = 3;
            newPoint.Fill = Brushes.Black;
            RightCanvas.Children.Add(newPoint);
            newPoint.Margin = new Thickness(line.point.X - 1.5, line.point.Y - 1.5, 0,0);
        }

        /// <summary>
        /// Adds a point to the left canvas
        /// </summary>
        /// <param name="newPoint">The point</param>
        public void AddNewPointLeft(Ellipse newPoint)
        {
            newPoint.Height = 3; newPoint.Width = 3;
            newPoint.Fill = Brushes.Black;
            LeftCanvas.Children.Add(newPoint);
        }

        /// <summary>
        /// Enables the timer of the View, which will tick the Presenter.
        /// </summary>
        public void EnableTimer()
        {
            dispatcherTimer.Start();
        }

        /// <summary>
        /// A function that opens a file dialog and returns the filename.
        /// </summary>
        /// <param name="Filter">The filter that should be applied to the new Dialog.</param>
        /// <returns>Returns the FileName and the SafeFileName if the user correctly selects a file, 
        /// else returns a tuple with empty strigns</returns>
        public Tuple<string, string> openNewDialog(string Filter)
        {
            openFileDialog.Filter = Filter;
            if (openFileDialog.ShowDialog() == true)
            {
                return new Tuple<string, string>(openFileDialog.FileName, openFileDialog.SafeFileName);
            }
            else
            {
                return new Tuple<string, string>("", "");
            }
        }

        /// <summary>
        /// Sets the contents of the last action taken indicator label.
        /// </summary>
        /// <param name="message">The new contents</param>
        public void SetLastActionTakenText(string message)
        {
            LastActionBox.Text = message;
        }

        /// <summary>
        /// Sets the contents of the status bar label containing
        /// the similarity score of the left and right image.
        /// </summary>
        /// <param name="message">The message to be set, 
        /// will be set to the default value if left empty.</param>
        public void SetImageSimilarityText(string message)
        {
            if (message.Count() > 0) LineSimilarityBox.Text = message;
            else LineSimilarityBox.Text = "-";
        }

        /// <summary>
        /// Changes the states of a tool strip button.
        /// </summary>
        /// <param name="buttonName">The name of the button.</param>
        /// <param name="state">The new state of the button.</param>
        public void SetToolStripButtonStatus(string buttonName, MainWindow.ButtonState state)
        {
            ButtonBase buttonToChange;
            bool isToggleable = false;
            switch (buttonName)
            {
                case "canvasButton":
                    buttonToChange = CanvasButton;
                    break;
                case "drawButton":
                    buttonToChange = DrawButton;
                    isToggleable = true;
                    break;
                case "deleteButton":
                    buttonToChange = DeleteButton;
                    isToggleable = true;
                    break;
                case "undoButton":
                    buttonToChange = UndoButton;
                    break;
                case "redoButton":
                    buttonToChange = RedoButton;
                    break;
                default:
                    Console.WriteLine("Invalid Button was given to SetToolStripButton. \nMaybe you forgot to add a case?");
                    return;
            }
            if (isToggleable)
            {
                switch (state)
                {
                    case ButtonState.Active:
                        ((ToggleButton)buttonToChange).IsEnabled = true;
                        ((ToggleButton)buttonToChange).IsChecked = true;
                        ((ToggleButton)buttonToChange).Opacity = 1;
                        ((ToggleButton)buttonToChange).Background = Brushes.SkyBlue;
                        break;
                    case ButtonState.Disabled:
                        ((ToggleButton)buttonToChange).IsEnabled = false;
                        ((ToggleButton)buttonToChange).IsChecked = false;
                        ((ToggleButton)buttonToChange).Opacity = 0.5;
                        ((ToggleButton)buttonToChange).Background = Brushes.LightGray;
                        break;
                    case ButtonState.Enabled:
                        ((ToggleButton)buttonToChange).IsEnabled = true;
                        ((ToggleButton)buttonToChange).IsChecked = false;
                        ((ToggleButton)buttonToChange).Opacity = 1;
                        ((ToggleButton)buttonToChange).Background = Brushes.LightGray;
                        break;
                }
            }
            else
            {
                switch (state)
                {
                    case ButtonState.Disabled:
                        ((Button)buttonToChange).IsEnabled = false;
                        ((Button)buttonToChange).Opacity = 0.5;
                        break;
                    default:
                        ((Button)buttonToChange).IsEnabled = true;
                        ((Button)buttonToChange).Opacity = 1;
                        break;
                }
            }
        }

        /// <summary>
        /// Sets the contents of the load status indicator label.
        /// </summary>
        /// <param name="message">The new contents</param>
        public void SetToolStripLoadStatus(string message)
        {
            LoadStatusBox.Text = message;
        }

        /// <summary>
        /// shows the given info message in a popup and asks the user to aknowledge it
        /// </summary>
        /// <param name="message">the message to show</param>
        public void ShowInfoMessage(string message)
        {
            MessageBox.Show(message);
        }

        /// <summary>
        /// Shows a warning box with the given message (Yes/No Buttons)and returns true if the user aknowledges it.
        /// </summary>
        /// <param name="message">The message of the warning.</param>
        /// <returns>True if the user confirms (Yes), negative if he doesn't (No)</returns>
        public bool ShowWarning(string message)
        {
            MessageBoxResult result = MessageBox.Show(message, "Warning", MessageBoxButton.YesNo, MessageBoxImage.Warning);
            return (result.Equals(MessageBoxResult.Yes));
        }

        /// <summary>
        /// Updates the colour of a canvas.
        /// </summary>
        /// <param name="canvasName">The name of the canvas to be updated.</param>
        /// <param name="active">Whether or not the canvas is active.</param>
        public void SetCanvasState(string canvasName, bool active)
        {
            switch (canvasName)
            {
                case ("LeftCanvas"):
                    if (active)
                    {
                        LeftCanvas.Background = Brushes.White;
                    }
                    else
                    {
                        LeftCanvas.Background = Brushes.SlateGray;
                    }
                    break;
                case ("RightCanvas"):
                    if (active)
                    {
                        RightCanvas.Background = Brushes.White;
                    }
                    else
                    {
                        RightCanvas.Background = Brushes.SlateGray;
                    }
                    break;
                default:
                    throw new InvalidOperationException("Unknown canvas name, Check that the canvas passed is either LeftCanvas or RightCanvas");
            }
        }

        /************************/
        /*** HELPING FUNCTION ***/
        /************************/

        /// <summary>
        /// A function that generates the overlay elements and sets all their values.
        /// </summary>
        private void SetupOverlay()
        {
            DropShadowEffect effect = new DropShadowEffect(); effect.ShadowDepth = 0;
            OverlayCanvas.Background = null;
            //Startpoint of a line to be redrawn
            Ellipse StartPointOverlay = new Ellipse();
            StartPointOverlay.Height = markerRadius * 2; StartPointOverlay.Width = markerRadius * 2;
            StartPointOverlay.Fill = Brushes.Green;
            StartPointOverlay.Effect = effect;
            OverlayDictionary.Add("startpoint", StartPointOverlay);
            //Pointer of the optitrack system
            Ellipse OptitrackMarker = new Ellipse(); OptitrackMarker.Height = 5; OptitrackMarker.Width = 5;
            OptitrackMarker.Fill = Brushes.LightGray;
            OptitrackMarker.Effect = effect;
            OverlayDictionary.Add("optipoint", OptitrackMarker);
            //10 Dotted Lines for debugging (if more are needed simply extend the for-loop
            for(int x = 0; x < 10; x++)
            {
                Line dotLine = new Line();
                dotLine.Stroke = Brushes.Red;
                dotLine.StrokeDashArray = new DoubleCollection { 2 + x, 2 + x };
                dotLine.StrokeThickness = 1;
                OverlayDictionary.Add("dotLine" + x.ToString(), dotLine);
            }

            //Common features of all overlay items
            foreach (KeyValuePair<String, Shape> s  in OverlayDictionary)
            {
                OverlayCanvas.Children.Add(s.Value);
                s.Value.Opacity = 0.00001;
                s.Value.IsHitTestVisible = false;
            }

            //Enable optipoint initially
            ProgramPresenter.SetOverlayStatus("optipoint", true, GetCursorPosition());
        }

        /// <summary>
        /// Sends inputs to the presenter simulating drawing, used for testing and debugging.
        /// Takes 7000ms
        /// </summary>
        private void DebugOne_Click(object sender, RoutedEventArgs e)
        {
            Debug(1);
        }

        /// <summary>
        /// Sends inputs to the presenter simulating drawing, used for testing and debugging.
        /// Takes 24000ms
        /// </summary>
        private void DebugTwo_Click(object sender, RoutedEventArgs e)
        {
            Debug(2);
        }

        /// <summary>
        /// Sends inputs to the presenter simulating drawing, used for testing and debugging.
        /// Takes 4000ms
        /// </summary>
        private void DebugThree_Click(object sender, RoutedEventArgs e)
        {
            Debug(3);
        }

        /// <summary>
        /// Sends inputs to the presenter simulating drawing, used for testing and debugging.
        /// Takes 
        /// </summary>
        private void DebugFour_Click(object sender, RoutedEventArgs e)
        {
            Debug(4);
        }

        /// <summary>
        /// A function which simulates canvas input for debugging.
        /// </summary>
        /// <param name="option"></param>
        private async void Debug(int option)
        {
            Point[] points;
            Point start = new Point(50, 50);
            switch (option)
            {
                case 1:
                    points = debugDat.debugPoints1;
                    break;
                case 2:
                    points = debugDat.debugPoints2;
                    break;
                case 3:
                    points = debugDat.debugPoints3;
                    break;
                case 4:
                    points = debugDat.debugPoints4;
                    start = new Point(284, 148);
                    break;
                default:
                    return;
            }
            dispatcherTimer.Stop();
            debugRunning = true;
            ProgramPresenter.Tick(); await Task.Delay(10);
            ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Move, start);
            ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Down, strokeCollection); await Task.Delay(10);
            for (int x = 0; x < points.Length; x++)
            {
                ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Move, points[x]);
                await Task.Delay(1);
                if (x % 5 == 0)
                {
                    ProgramPresenter.Tick();
                    await Task.Delay(1);
                }
            }
            ProgramPresenter.MouseEvent(MVP_Presenter.MouseAction.Up, strokeCollection); await Task.Delay(1);
            debugRunning = false;
            dispatcherTimer.Start();
        }
    }
}