smouldering-beach-ball/SmoulderingBeachBall/ImageMaker.fs

namespace SmoulderingBeachBall

module ImageMaker =

    open System
    open System.IO
    open System.Drawing

    type OverlayType =
        | Border
        | Full

    type OverlaySpec =
        { colour: Brush;
          overlayType: OverlayType }

    type ImageSpec =
        { width: int;
          height: int;
          colour: Brush;
          filePath: string;
          overlay: OverlaySpec option }

    let private validateDimension dimension =
        match dimension with
        | dimension when dimension <= 0 -> invalidArg "dimension" "The width and height must be greater than 0."
        | _ -> ()

    let private validateDirectory filePath =
        let path = Path.GetDirectoryName filePath
        match (Directory.Exists path) with
        | false -> invalidArg "filePath" "Unable to save to the specified location because it does not exist."
        | true -> ()

    // This function is to be deleted.
    let makeImageBase width height colour filepath =
        async {
            try
                validateDimension width
                validateDimension height
                validateDirectory filepath
                use bitmap = new Bitmap(width, height)
                use graphics = Graphics.FromImage(bitmap)
                graphics.FillRectangle(colour, new Rectangle(0, 0, bitmap.Width, bitmap.Height))
                bitmap.Save(filepath)
                return "Image saved."
            with
            | :? ArgumentException as ex -> return ex.Message
            | _ as ex -> return ex.Message
        }

    let private createBorderPath penWidth spec =
        let penOffset = int (penWidth / (float32 2))
        [|Point (0, penOffset); // Essentially (0, 0)
          Point ((spec.width - penOffset), penOffset);
          Point ((spec.width - penOffset), (spec.height - penOffset));
          Point (penOffset, (spec.height - penOffset));
          Point (penOffset, 0)|]

    let private drawImageWithBorder (graphics: Graphics) (pen: Pen) spec =
        printfn "[INFO.] Adding border to image..."
        let penPath = createBorderPath pen.Width spec
        graphics.DrawLines (pen, penPath)


    let private drawImageWithFullOverlay graphics pen spec =
        printfn "[INFO.] Adding full overlay to image..."
        ()

    let private addOverlayToImage graphics spec =
        let overlay = spec.overlay.Value
        let pen = new Pen (overlay.colour, Width = 10.0f)
        match overlay.overlayType with
        | Border -> drawImageWithBorder graphics pen spec
        | Full -> drawImageWithFullOverlay graphics pen spec

    let private drawImage spec =
        let bitmap = new Bitmap (spec.width, spec.height)
        let graphics = Graphics.FromImage (bitmap)
        let rectangle = Rectangle (0, 0, spec.width, spec.height)
        graphics.FillRectangle (spec.colour, rectangle)
        match spec.overlay.IsSome with
        | true -> addOverlayToImage graphics spec
        | false -> printfn "[INFO.] No overlay specified. Creating image without one."
        bitmap.Save (spec.filePath)
        bitmap.Dispose()
        graphics.Dispose()

    let makeImage spec =
        async {
            try
                printfn "[INFO.] Attempting to make image..."
                validateDimension spec.width
                validateDimension spec.height
                validateDirectory spec.filePath
                drawImage spec
                printfn "[SUCCESS] Image creation attempt complete."
                return ()
            with
            | :? ArgumentException as ex -> printfn "%s" ex.Message
            | _ as ex -> printfn "%s" ex.Message
        }