import "Simantics/Variables"
include "Simantics/Diagram/SVGNode"

import "http://www.simantics.org/Diagram-2.2" as DIA
import "http://www.simantics.org/G2D-1.1" as G2D

textFontValueAccessor =
  createValueAccessor
    (\self -> decodeFont self)
    (\self binding -> decodeFont self)
    (\self value -> encodeFont self value)
    (\self value binding -> encodeFont self value)
    standardGetDatatype
  
decodeFont :: Variable -> <ReadGraph> String
decodeFont self = do
  element = represents $ parent $ parent self
  match possibleObject element DIA.TextElement.font with
    Nothing -> ""
    Just font -> do
      family = match possibleRelatedValue font G2D.HasFontFamily with
        Nothing -> "Arial"
        Just f -> f
      size = match possibleRelatedValue font G2D.HasFontSize with
        Nothing -> 12
        Just s -> s
      style = match possibleObject font G2D.HasFontStyle with
        Just G2D.FontStyle.normal_font_style -> "Normal"
        Just G2D.FontStyle.bold_font_style -> "Bold"
        Just G2D.FontStyle.italic_font_style -> "Italic"
        Just G2D.FontStyle.bold_italic_style -> "BoldItalic"
        Nothing -> "Normal"
      family + "," + (show size) + "," + style

encodeFont :: Variable -> String -> <WriteGraph> ()
encodeFont self value = do
  parts = split "," value
  match length parts with
    3 -> do
      element = represents $ parent $ parent self
      denyByPredicate element DIA.TextElement.font
      font = newResource ()
      family = parts!0
      size = read (parts!1) :: Integer
      style = match parts!2 with
        "Normal" -> G2D.FontStyle.normal_font_style
        "Bold" -> G2D.FontStyle.bold_font_style
        "Italic" -> G2D.FontStyle.italic_font_style
        "BoldItalic" -> G2D.FontStyle.bold_italic_style
      claim font L0.InstanceOf G2D.Font
      claimRelatedValue font G2D.HasFontFamily (parts!0)
      claimRelatedValue font G2D.HasFontSize size
      claim font G2D.HasFontStyle style
      claim element DIA.TextElement.font font
  ()