module ParasitemiaUI.GUI

open System
open System.IO
open System.Linq
open System.Windows
open System.Windows.Media
open System.Windows.Controls
open Microsoft.Win32 // For the common dialogs.

open Logger

open ParasitemiaUIControls
open ParasitemiaCore.Config
open ParasitemiaCore.Utils
open Types

let run (defaultConfig : Config) (fileToOpen : string option) =
    let app = new Application ()
    let win = MainWindow ()

    let state = State.State defaultConfig
    let mutable currentScale = 1.
    let mutable displayHealthy = false
    let warningBelowNumberOfRBC = 1000

    // Initializations.
    let canvasCurrentImageColor = win.canvasCurrentImage.Background
    win.menuHightlightRBC.IsChecked <- displayHealthy

    // Utils.
    let extractRBCPreview (img : Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte>) (rbc : RBC) : Emgu.CV.Image<Emgu.CV.Structure.Bgr, byte> =
        let rbcWidth = rbc.size.Width
        let rbcHeight = rbc.size.Height
        let x = rbc.center.X - rbcWidth / 2. |> roundInt
        let y = rbc.center.Y - rbcHeight / 2. |> roundInt
        let w = roundInt rbcWidth
        let h = roundInt rbcHeight
        img.GetSubRect (
            System.Drawing.Rectangle (
                System.Drawing.Point ((if x < 0 then 0 else x), (if y < 0 then 0 else y)),
                System.Drawing.Size ((if x + w >= img.Width then img.Width - x else w), (if y + h >= img.Height then img.Height - y else h))
            )
        )

    let setRBCFrameStyle (srcImg : SourceImage) (rbc : RBC) (frame : RBCFrame) =
        frame.Opacity <- if displayHealthy || rbc.setManually || rbc.infected then 1. else 0.
        let color = if rbc.infected then srcImg.InfectedRBCColor else srcImg.HealthyRBCColor
        frame.manuallyAdded.Visibility <- if rbc.setManually then Visibility.Visible else Visibility.Hidden
        frame.manuallyAdded.Fill <- color
        frame.border.Stroke <- color

    let frameStrokeThickness (averageRBCSize : float) =
        max 1. (averageRBCSize / 60.)

    let frameFontSize (averageRBCSize : float) =
        max 1. (averageRBCSize / 8.)

    let createRBCFrameFromExisting (srcImg : SourceImage) (rbc : RBC) (frame : RBCFrame) (frameThickness : float) (fontSize : float) : RBCFrame =
        frame.Visibility <- Visibility.Visible
        frame.Width <- rbc.size.Width
        frame.Height <- rbc.size.Height
        frame.Tag <- rbc
        setRBCFrameStyle srcImg rbc frame
        frame.border.StrokeThickness <- frameThickness
        frame.txtRBCNumber.Text <- string rbc.num
        frame.txtRBCNumber.FontSize <- fontSize
        frame

    let updateDocumentStatus () =
        win.txtDocumentStatus.Text <- if state.FilePath = "" then "<New document>" else state.FilePath

    let statusMessageTimer = Threading.DispatcherTimer ()
    statusMessageTimer.Tick.AddHandler (fun obj args -> statusMessageTimer.Stop (); win.txtMessageStatus.Text <- "")
    statusMessageTimer.Interval <- TimeSpan (0, 0, 2)

    // To show a use message while a short period of time.
    let displayStatusMessage (message : string) =
        win.txtMessageStatus.Text <- message
        statusMessageTimer.Stop ()
        statusMessageTimer.Start ()

    let highlightRBCFrame (frame : RBCFrame) (highlight : bool) =
        let rbc = frame.Tag :?> RBC
        if highlight then
            frame.border.StrokeThickness <- 3. * frame.border.StrokeThickness
            if not rbc.infected && not rbc.setManually && not displayHealthy then frame.Opacity <- 1.
        else
            frame.border.StrokeThickness <- frame.border.StrokeThickness / 3.
            if not rbc.infected && not rbc.setManually && not displayHealthy then frame.Opacity <- 0.

    let zoomToRBC (rbc : RBC) =
        win.scrollViewCurrentImage.ScrollToHorizontalOffset (rbc.center.X * currentScale - win.scrollViewCurrentImage.ViewportWidth / 2. + win.borderCurrentImage.BorderThickness.Left)
        win.scrollViewCurrentImage.ScrollToVerticalOffset (rbc.center.Y * currentScale - win.scrollViewCurrentImage.ViewportHeight / 2. + win.borderCurrentImage.BorderThickness.Top)

    let txtImageName_TextChanged =
        TextChangedEventHandler (fun obj args -> state.CurrentImage |> Option.iter (fun srcImg -> state.SetName srcImg win.txtImageName.Text))

    let updateCurrentImageInformation () =
        win.txtImageName.TextChanged.RemoveHandler (txtImageName_TextChanged)
        win.txtImageInformation1.Inlines.Clear ()
        win.txtImageInformation2.Inlines.Clear ()
        win.txtImageName.Text <- ""

        match state.CurrentImage with
        | Some srcImg ->
            win.gridImageInformation.Visibility <- Visibility.Visible
            win.txtImageName.Text <- srcImg.Name
            win.txtImageName.TextChanged.AddHandler txtImageName_TextChanged

            // The left part.
            let parasitemiaStr = Utils.percentText srcImg.ImageParasitemia
            win.txtImageInformation1.Inlines.Add (Documents.Run ("Parasitemia: ", FontWeight = FontWeights.Bold))
            win.txtImageInformation1.Inlines.Add parasitemiaStr
            win.txtImageInformation1.Inlines.Add (Documents.LineBreak ())

            win.txtImageInformation1.Inlines.Add (Documents.Run ("Last analysis: ", FontWeight = FontWeights.Bold))
            win.txtImageInformation1.Inlines.Add (Documents.Run (if srcImg.DateLastAnalysis.Ticks = 0L then "<Never>" else string (srcImg.DateLastAnalysis.ToLocalTime())))

            // The right part part.
            win.txtImageInformation2.Inlines.Add (Documents.Run ("Added infected erythrocyte: ", FontWeight = FontWeights.Bold))
            win.txtImageInformation2.Inlines.Add (Documents.Run ((srcImg.ImageNbManuallyChangedRBCStr true) + " " + (srcImg.ImageManuallyChangedRBCStr true)))
            win.txtImageInformation2.Inlines.Add (Documents.LineBreak ())
            win.txtImageInformation2.Inlines.Add (Documents.Run ("Removed infected erythrocyte: ", FontWeight = FontWeights.Bold))
            win.txtImageInformation2.Inlines.Add (Documents.Run ((srcImg.ImageNbManuallyChangedRBCStr false) + " " + (srcImg.ImageManuallyChangedRBCStr false)))

        | _ ->
            win.gridImageInformation.Visibility <- Visibility.Hidden

    let updateGlobalParasitemia () =
        win.txtGlobalParasitemia.Inlines.Clear ()
        let total, infected = state.GlobalParasitemia
        win.txtGlobalParasitemia.Inlines.Add (Documents.Run (Utils.percentText (total, infected), FontWeight = FontWeights.Bold))
        if total > 0 && total < warningBelowNumberOfRBC then
            win.txtGlobalParasitemia.Inlines.Add (
                Documents.Run (
                    sprintf " Warning: the number of erythrocytes should be above %d" warningBelowNumberOfRBC,
                    FontWeight = FontWeights.Bold,
                    Foreground = Brushes.Red
                )
            )

    let updateViewportPreview () =
        for preview in win.stackPreviews.Children |> Seq.cast<ImageSourcePreview> do
            let srcImg = preview.Tag :?> SourceImage
            if Some srcImg = state.CurrentImage then
                preview.viewport.Visibility <- Visibility.Visible

                let canvasWidth = win.canvasCurrentImage.ActualWidth * currentScale
                let canvasHeight = win.canvasCurrentImage.ActualHeight * currentScale
                let previewWidth = (preview.ActualWidth - preview.BorderThickness.Left - preview.BorderThickness.Right)
                let previewHeight = (preview.ActualHeight - preview.BorderThickness.Top - preview.BorderThickness.Bottom)

                let marginLeft = previewWidth * (win.scrollViewCurrentImage.HorizontalOffset - win.borderCurrentImage.BorderThickness.Left) / canvasWidth - 2.
                let marginRight = previewWidth * (canvasWidth - (win.scrollViewCurrentImage.HorizontalOffset - win.borderCurrentImage.BorderThickness.Right) - win.scrollViewCurrentImage.ViewportWidth) / canvasWidth - 2.
                let marginTop = previewHeight * (win.scrollViewCurrentImage.VerticalOffset - win.borderCurrentImage.BorderThickness.Top) / canvasHeight - 2.
                let marginBottom = previewHeight * (canvasHeight - (win.scrollViewCurrentImage.VerticalOffset - win.borderCurrentImage.BorderThickness.Bottom) - win.scrollViewCurrentImage.ViewportHeight) / canvasHeight - 2.

                preview.viewport.Margin <-
                    Thickness (
                        marginLeft,
                        marginTop,
                        marginRight,
                        marginBottom
                    )
            else
                preview.viewport.Visibility <- Visibility.Hidden

    let rec setAsInfected (srcImg : SourceImage) (rbc : RBC) (infected : bool) =
        state.SetAsInfected rbc infected
        win.canvasCurrentImage.Children
        |> Seq.cast<RBCFrame>
        |> Seq.iter (
            fun frame ->
                if (frame.Tag :?> RBC) = rbc then
                    setRBCFrameStyle srcImg rbc frame
        )
        updateRBCFramesPreview ()
        updateCurrentImageInformation ()
        updateGlobalParasitemia ()

    and createRBCFrame (srcImg : SourceImage) (rbc : RBC) (frameThickness : float) (fontSize : float) : RBCFrame =
        let frame = createRBCFrameFromExisting srcImg rbc (RBCFrame ()) frameThickness fontSize
        frame.SetValue (Panel.ZIndexProperty, Int32.MaxValue - rbc.num) // To be sure the
        frame.menuRBCSetAsHealthy.Click.AddHandler (fun obj args -> setAsInfected srcImg (frame.Tag :?> RBC) false)
        frame.menuRBCSetAsInfected.Click.AddHandler (fun obj args -> setAsInfected srcImg (frame.Tag :?> RBC) true)
        frame.ContextMenuOpening.AddHandler (
            fun obj args ->
                if (frame.Tag :?> RBC).infected then
                    frame.menuRBCSetAsHealthy.Visibility <- Visibility.Visible
                    frame.menuRBCSetAsInfected.Visibility <- Visibility.Collapsed
                else
                    frame.menuRBCSetAsHealthy.Visibility <- Visibility.Collapsed
                    frame.menuRBCSetAsInfected.Visibility <- Visibility.Visible
        )
        frame.ContextMenuClosing.AddHandler (fun obj args -> if not frame.IsMouseOver then highlightRBCFrame frame false )
        frame.MouseEnter.AddHandler (fun obj args -> highlightRBCFrame frame true)
        frame.MouseLeave.AddHandler (fun obj args -> if not frame.grid.ContextMenu.IsOpen then highlightRBCFrame frame false)
        frame

    and updateRBCFramesPreview () =
        match state.CurrentImage with
        | Some srcImg ->
            let mutable currentPreview = 0
            for rbc in srcImg.RBCs |> List.filter (fun rbc -> displayHealthy || rbc.infected) do
                let previewInfected =
                    if currentPreview < win.stackRBC.Children.Count then
                        createRBCFrameFromExisting srcImg rbc (win.stackRBC.Children.[currentPreview] :?> RBCFrame) 1. 12.
                    else
                        let f = createRBCFrame srcImg rbc 1. 12.
                        f.MouseLeftButtonUp.AddHandler (fun obj args -> zoomToRBC (f.Tag :?> RBC))
                        win.stackRBC.Children.Add f |> ignore
                        f

                currentPreview <- currentPreview + 1

                previewInfected.Height <- win.stackRBC.ActualHeight
                previewInfected.Width <- win.stackRBC.ActualHeight * rbc.size.Width / rbc.size.Height
                previewInfected.border.Fill <- ImageBrush (BitmapSourceConvert.ToBitmapSource (extractRBCPreview srcImg.Img rbc))

            win.stackRBC.Children.RemoveRange (currentPreview, win.stackRBC.Children.Count - currentPreview)
        | _ -> ()

        updateViewportPreview ()

    let updateRBCFramesCurrent () =
        match state.CurrentImage with
        | Some srcImg ->
            let mutable currentCanvas = 0
            let strokeThickness = frameStrokeThickness srcImg.AverageRBCSize
            let fontSize = frameFontSize srcImg.AverageRBCSize
            for rbc in srcImg.RBCs do
                let frame =
                    if currentCanvas < win.canvasCurrentImage.Children.Count then
                        createRBCFrameFromExisting srcImg rbc (win.canvasCurrentImage.Children.[currentCanvas] :?> RBCFrame) strokeThickness fontSize
                    else
                        let f = createRBCFrame srcImg rbc strokeThickness fontSize
                        win.canvasCurrentImage.Children.Add f |> ignore
                        f

                currentCanvas <- currentCanvas + 1

                Canvas.SetLeft (frame, rbc.center.X - rbc.size.Width / 2.)
                Canvas.SetTop (frame, rbc.center.Y - rbc.size.Height / 2.)

            for i in currentCanvas .. win.canvasCurrentImage.Children.Count - 1 do
                win.canvasCurrentImage.Children.[i].Visibility <- Visibility.Hidden
        | _ -> ()

    let askDocumentPathToSave () : string option =
        let dialog = SaveFileDialog (AddExtension = true, DefaultExt = PiaZ.extension, Filter = PiaZ.filter)

        if state.FilePath <> "" then
            dialog.FileName <- FileInfo(state.FilePath).Name
        elif state.PatientID <> "" then
            dialog.FileName <- state.PatientID + PiaZ.extension

        let res = dialog.ShowDialog ()
        if res.HasValue && res.Value then
            Some dialog.FileName
        else
            None

    let saveCurrentDocument () =
        try
            if state.FilePath = "" then
                match askDocumentPathToSave () with
                | Some filepath ->
                    state.FilePath <- filepath
                    state.Save ()
                | _ -> ()
            else
                state.Save ()
            updateDocumentStatus ()
            displayStatusMessage "Document saved"
        with
        | :? IOException as ex ->
            Log.Error "%O" ex
            MessageBox.Show (sprintf "The document cannot be save in \"%s\"" state.FilePath, "Error saving the document", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore

    let saveCurrentDocumentAsNewFile () =
        match askDocumentPathToSave () with
        | Some filepath ->
            state.FilePath <- filepath
            saveCurrentDocument ()
        | _ -> ()

    // Ask the use to save the current document if neccessary.
    let askSaveCurrent () =
        if state.AlteredSinceLastSave then
            match MessageBox.Show ("Would you like to save the current document?", "Saving the current document", MessageBoxButton.YesNo, MessageBoxImage.Question) with
            | MessageBoxResult.Yes -> saveCurrentDocument ()
            | _ -> ()

    let updateCurrentImage () =
        match state.CurrentImage with
        | Some srcImg ->
            win.imgLogos.Visibility <- Visibility.Collapsed

            // Highlight the preview.
            win.stackPreviews.Children
            |> Seq.cast<ImageSourcePreview>
            |> Seq.iter (fun preview -> preview.border.BorderThickness <- Thickness (if preview.Tag = (srcImg :> Object) then 3. else 0.))

            win.canvasCurrentImage.Height <- float srcImg.Img.Height
            win.canvasCurrentImage.Width <- float srcImg.Img.Width
            win.canvasCurrentImage.Background <- ImageBrush (BitmapSourceConvert.ToBitmapSource (srcImg.Img))

            updateRBCFramesCurrent ()
            updateRBCFramesPreview ()

        | None ->
            win.imgLogos.Visibility <- Visibility.Visible

            win.stackRBC.Children.Clear ()
            win.canvasCurrentImage.Children.Clear ()
            win.canvasCurrentImage.Background <- canvasCurrentImageColor

        updateCurrentImageInformation ()

    let setCurrentImage (srcImg : SourceImage) =
        if state.CurrentImage.IsNone || state.CurrentImage.Value <> srcImg then
            state.CurrentImage <- Some srcImg
            updateCurrentImage ()

    let addPreview (srcImg : SourceImage) =
        let imgCtrl = ImageSourcePreview (Margin = Thickness 3.)

        imgCtrl.menuRemoveImage.Click.AddHandler (
            fun obj args ->
                win.stackPreviews.Children.Remove (imgCtrl)
                let srcImg = imgCtrl.Tag :?> SourceImage
                let currentRemoved = Some srcImg = state.CurrentImage
                state.RemoveSourceImage srcImg
                if currentRemoved then
                    updateCurrentImage ()

                updateGlobalParasitemia ()

                // Update image numbers.
                win.stackPreviews.Children |> Seq.cast<ImageSourcePreview> |> Seq.iter (fun imgPreview -> imgPreview.txtImageNumber.Text <- (imgPreview.Tag :?> SourceImage).RomanNum)
        )

        imgCtrl.Tag <- srcImg
        imgCtrl.txtImageNumber.Text <- string srcImg.RomanNum
        let width = 200
        let height = srcImg.Img.Height * width / srcImg.Img.Width
        imgCtrl.imagePreview.Source <- BitmapSourceConvert.ToBitmapSource (srcImg.Img.Resize (width, height, Emgu.CV.CvEnum.Inter.Cubic))
        win.stackPreviews.Children.Add imgCtrl |> ignore

        // Zoom to a mouse position into the control 'imgCtrl'.
        let zoomTo (mousePos : Point) =
            let canvasW = win.canvasCurrentImage.ActualWidth * currentScale
            let canvasH = win.canvasCurrentImage.ActualHeight * currentScale
            let centerX = (mousePos.X - imgCtrl.BorderThickness.Left) / (imgCtrl.ActualWidth - imgCtrl.BorderThickness.Left) * canvasW
            let centerY = (mousePos.Y - imgCtrl.BorderThickness.Top) / (imgCtrl.ActualHeight - imgCtrl.BorderThickness.Top) * canvasH
            win.scrollViewCurrentImage.ScrollToHorizontalOffset (centerX - win.scrollViewCurrentImage.ViewportWidth / 2. + win.borderCurrentImage.BorderThickness.Left)
            win.scrollViewCurrentImage.ScrollToVerticalOffset (centerY - win.scrollViewCurrentImage.ViewportHeight / 2. + win.borderCurrentImage.BorderThickness.Top)

        imgCtrl.MouseLeftButtonDown.AddHandler (
            fun obj args ->
                setCurrentImage (state.SourceImages |> Seq.find (fun srcImg -> (srcImg :> Object) = imgCtrl.Tag))
                imgCtrl.UpdateLayout ()
                zoomTo (args.GetPosition (imgCtrl))
                imgCtrl.CaptureMouse () |> ignore
        )

        imgCtrl.MouseMove.AddHandler (
            fun obj args ->
                if imgCtrl.IsMouseCaptured then
                    zoomTo (args.GetPosition imgCtrl)
        )

        imgCtrl.MouseLeftButtonUp.AddHandler (
            fun obj args ->
                if imgCtrl.IsMouseCaptured then
                    imgCtrl.ReleaseMouseCapture ()
        )

    let updatePreviews () =
        win.stackPreviews.Children.Clear ()
        for srcImg in state.SourceImages do
            addPreview srcImg
        updateCurrentImage ()

    let updateGUI () =
        win.txtPatient.Text <- state.PatientID
        updatePreviews ()
        updateGlobalParasitemia ()
        updateDocumentStatus ()

    let loadFile (filepath : string) =
        askSaveCurrent ()
        let previousFilePath = state.FilePath
        try
            state.FilePath <- filepath
            state.Load ()
            updateGUI ()
        with
        | :? IOException as ex ->
            Log.Error "%O" ex
            state.FilePath <- previousFilePath
            MessageBox.Show (sprintf "The document cannot be loaded from \"%s\"" filepath, "Error loading the document", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore

    let askLoadFile () =
        let dialog = OpenFileDialog (Filter = PiaZ.filter)
        let res = dialog.ShowDialog ()
        if res.HasValue && res.Value then
            loadFile dialog.FileName

    let newFile () =
        askSaveCurrent ()
        state.Reset ()
        updateGUI ()

    let exportResults () =
        let extension = ".txt"
        let dialog = SaveFileDialog (AddExtension = true, DefaultExt = extension)

        if state.FilePath <> "" then
            dialog.FileName <- Path.GetFileNameWithoutExtension state.FilePath + extension
        elif state.PatientID <> "" then
            dialog.FileName <- state.PatientID + extension

        let res = dialog.ShowDialog ()
        if res.HasValue && res.Value then
            try
                Export.exportResults state dialog.FileName
            with
            | :? IOException as ex ->
                Log.Error "%O" ex
                MessageBox.Show (sprintf "The results cannot be exported in \"%s\"" state.FilePath, "Error exporting the files", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore

    let importImage () =
        let dialog = OpenFileDialog (Filter = "Image Files|*.png;*.jpg;*.tif;*.tiff", Multiselect = true)
        let res = dialog.ShowDialog ()
        if res.HasValue && res.Value then
            let noSourceImage = state.SourceImages.Count () = 0

            for filename in dialog.FileNames do
                try
                    let srcImg = state.AddSourceImage filename defaultConfig
                    addPreview srcImg
                with
                | _ as ex ->
                    Log.Error "%O" ex
                    MessageBox.Show (sprintf "Unable to read the image from \"%s\"" filename, "Error adding an image", MessageBoxButton.OK, MessageBoxImage.Error) |> ignore

            updateGlobalParasitemia ()

            if noSourceImage then
                updateCurrentImage ()

    let showAnalysisWindow () =
        if Analysis.showWindow win state then
            updateGlobalParasitemia ()
            updateCurrentImage ()

    let setHighlightRBC (highlight : bool) =
        displayHealthy <- highlight
        updateRBCFramesPreview ()
        updateRBCFramesCurrent ()

    win.txtPatient.TextChanged.AddHandler (fun obj args -> state.PatientID <- win.txtPatient.Text)

    win.menuExit.Click.AddHandler (fun obj args -> win.Close ())
    win.menuSave.Click.AddHandler (fun obj args -> saveCurrentDocument ())
    win.menuSaveAs.Click.AddHandler (fun obj args -> saveCurrentDocumentAsNewFile ())
    win.menuOpen.Click.AddHandler (fun obj args -> askLoadFile ())
    win.menuNew.Click.AddHandler (fun obj args -> newFile ())
    win.menuExportResults.Click.AddHandler (fun obj args -> exportResults ())

    win.menuAddSourceImage.Click.AddHandler (fun obj args -> importImage ())

    win.menuAnalysis.SubmenuOpened.AddHandler (fun obj args -> win.menuStartAnalysis.IsEnabled <- state.SourceImages.Count () > 0)

    win.menuStartAnalysis.Click.AddHandler (fun obj args -> showAnalysisWindow ())

    win.menuHightlightRBC.Click.AddHandler (fun obj args -> setHighlightRBC win.menuHightlightRBC.IsChecked)

    win.menuAbout.Click.AddHandler (fun obj args -> About.showWindow win)

    win.menuCommandLineArguments.Click.AddHandler (fun obj args -> CommandLineArguments.showWindow win)

    win.Closing.AddHandler (fun obj args -> askSaveCurrent ())

    // Zoom on the current image.
    let adjustCurrentImageBorders (deltaX : float) (deltaY : float) =
        win.borderCurrentImage.BorderThickness <-
            Thickness (
                (win.scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
                (win.scrollViewCurrentImage.ViewportHeight + deltaY) / 2.,
                (win.scrollViewCurrentImage.ViewportWidth + deltaX) / 2.,
                (win.scrollViewCurrentImage.ViewportHeight + deltaY) / 2.
            )

    win.canvasCurrentImage.SizeChanged.AddHandler (
        fun obj args ->
            let deltaX = args.NewSize.Width - args.PreviousSize.Width
            let deltaY = args.NewSize.Height - args.PreviousSize.Height
            if deltaX > 0.5 || deltaY > 0.5 then
                adjustCurrentImageBorders 0.0 0.0
                // Center the view at the center of the image initialy.
                win.scrollViewCurrentImage.UpdateLayout ()
                win.scrollViewCurrentImage.ScrollToHorizontalOffset (win.borderCurrentImage.ActualWidth / 2. - win.scrollViewCurrentImage.ViewportWidth / 2.)
                win.scrollViewCurrentImage.ScrollToVerticalOffset (win.borderCurrentImage.ActualHeight / 2. - win.scrollViewCurrentImage.ViewportHeight / 2.)
    )

    win.scrollViewCurrentImage.SizeChanged.AddHandler (
        fun obj args ->
            let deltaX = args.NewSize.Width - args.PreviousSize.Width
            let deltaY = args.NewSize.Height - args.PreviousSize.Height
            adjustCurrentImageBorders deltaX deltaY
            win.scrollViewCurrentImage.ScrollToHorizontalOffset (win.scrollViewCurrentImage.HorizontalOffset + deltaX / 8.)
            win.scrollViewCurrentImage.ScrollToVerticalOffset (win.scrollViewCurrentImage.VerticalOffset + deltaY / 8.)
    )

    let mutable maxScale = 4.
    let mutable minScale = 0.25
    let currentImageScaleTransform = ScaleTransform ()
    win.canvasCurrentImage.LayoutTransform <- currentImageScaleTransform
    win.borderCurrentImage.PreviewMouseWheel.AddHandler (
        fun _obj args ->
            let scaleFactor = if args.Delta > 0 then 2.0 else 0.5
            if scaleFactor > 1. && currentScale < maxScale || scaleFactor < 1. && currentScale > minScale then
                let previousScale = currentScale
                currentScale <-
                    let newScale = currentScale * scaleFactor
                    if newScale > maxScale then maxScale elif newScale < minScale then minScale else newScale
                let realScaleFactor = currentScale / previousScale

                let centerX = win.scrollViewCurrentImage.HorizontalOffset + win.scrollViewCurrentImage.ViewportWidth / 2. - win.borderCurrentImage.BorderThickness.Left
                let centerY = win.scrollViewCurrentImage.VerticalOffset + win.scrollViewCurrentImage.ViewportHeight / 2. - win.borderCurrentImage.BorderThickness.Top

                currentImageScaleTransform.ScaleX <- currentScale
                currentImageScaleTransform.ScaleY <- currentScale

                win.scrollViewCurrentImage.ScrollToHorizontalOffset (centerX * realScaleFactor - win.scrollViewCurrentImage.ViewportWidth / 2. + win.borderCurrentImage.BorderThickness.Left)
                win.scrollViewCurrentImage.ScrollToVerticalOffset (centerY * realScaleFactor - win.scrollViewCurrentImage.ViewportHeight / 2. + win.borderCurrentImage.BorderThickness.Top)

            args.Handled <- true
    )

    // Pan on the current image.
    let mutable scrollStartPosition = Point (0., 0.)
    let mutable scrollStartOffsetX = 0.
    let mutable scrollStartOffsetY = 0.
    win.borderCurrentImage.PreviewMouseLeftButtonDown.AddHandler (
        fun _obj args ->
            scrollStartPosition <- args.GetPosition win.scrollViewCurrentImage
            scrollStartOffsetX <- win.scrollViewCurrentImage.HorizontalOffset
            scrollStartOffsetY <- win.scrollViewCurrentImage.VerticalOffset
            win.borderCurrentImage.Cursor <- Input.Cursors.ScrollAll
            win.borderCurrentImage.CaptureMouse () |> ignore
            args.Handled <- true
    )

    win.borderCurrentImage.PreviewMouseMove.AddHandler (
        fun _obj args ->
            if win.borderCurrentImage.IsMouseCaptured then
                let position = args.GetPosition win.scrollViewCurrentImage
                let deltaX = scrollStartPosition.X - position.X
                let deltaY = scrollStartPosition.Y - position.Y
                win.scrollViewCurrentImage.ScrollToHorizontalOffset (deltaX + scrollStartOffsetX)
                win.scrollViewCurrentImage.ScrollToVerticalOffset (deltaY + scrollStartOffsetY)

                args.Handled <- true
    )

    win.borderCurrentImage.PreviewMouseLeftButtonUp.AddHandler (
        fun _obj args ->
            if win.borderCurrentImage.IsMouseCaptured then
                win.borderCurrentImage.Cursor <- Input.Cursors.Arrow
                win.borderCurrentImage.ReleaseMouseCapture ()
                args.Handled <- true
    )

    // Shortcuts.
    // Save.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand ((fun obj -> saveCurrentDocument ()), (fun obj -> true)),
            Input.KeyGesture (Input.Key.S, Input.ModifierKeys.Control)
        )
    ) |> ignore

    // Save as.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand ((fun obj -> saveCurrentDocumentAsNewFile ()), (fun obj -> true)),
            Input.KeyGesture (Input.Key.S, Input.ModifierKeys.Control ||| Input.ModifierKeys.Shift)
        )
    ) |> ignore

    // Open.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand ((fun obj -> askLoadFile ()), (fun obj -> true)),
            Input.KeyGesture (Input.Key.O, Input.ModifierKeys.Control)
        )
    ) |> ignore

    // New file.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand ((fun obj -> newFile ()), (fun obj -> true)),
            Input.KeyGesture (Input.Key.N, Input.ModifierKeys.Control)
        )
    ) |> ignore

    // Export results.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand ((fun obj -> exportResults ()), (fun obj -> true)),
            Input.KeyGesture (Input.Key.E, Input.ModifierKeys.Control)
        )
    ) |> ignore

    // Import an image.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand ((fun obj -> importImage ()), (fun obj -> true)),
            Input.KeyGesture (Input.Key.A, Input.ModifierKeys.Control)
        )
    ) |> ignore

    // Show analysis dialog.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand ((fun obj -> showAnalysisWindow ()), (fun obj -> state.SourceImages.Count () > 0)),
            Input.KeyGesture (Input.Key.Y, Input.ModifierKeys.Control)
        )
    ) |> ignore

    // Toggle RBC highlight.
    win.InputBindings.Add (
        Input.KeyBinding (
            ViewModule.FunCommand (
                (
                    fun obj ->
                        win.menuHightlightRBC.IsChecked <- not win.menuHightlightRBC.IsChecked
                        setHighlightRBC win.menuHightlightRBC.IsChecked
                ),
                (fun obj -> true)
            ),
            Input.KeyGesture (Input.Key.H, Input.ModifierKeys.Control)
        )
    ) |> ignore

    // Viewport preview.
    win.scrollViewCurrentImage.ScrollChanged.AddHandler (fun obj args -> updateViewportPreview ())

    updateDocumentStatus ()
    win.gridImageInformation.Visibility <- Visibility.Hidden

    win.Show ()

    match fileToOpen with
    | Some filepath -> loadFile filepath
    | None -> ()

    app.Run ()