module internal Validation

    open System.IO

    let validateFilePath path =
        match File.Exists path with
        | true -> ()
        | false -> raise (new FileNotFoundException (path + " could not be found."))

    let validateSaveFileType file =
        match Path.GetExtension file with
        | ".jpg" -> ()
        | ".JPG" -> ()
        | ".png" -> ()
        | ".PNG" -> ()
        | _ -> invalidArg "savePath" "The file type must be a .jpg or .png file."

    let validateIO iPath oPath =
        validateFilePath iPath
        validateSaveFileType oPath