export_as_cgContext.sketchplugin

// (ctrl alt cmd p)
//doc, selection, scriptPath

main()

function main() {
  var loop = selection.objectEnumerator()
  while(item = loop.nextObject()) {
    parseSelection(item)
  }
}

function parseSelection(selection){
  var str = drawLayerGroup(selection, selection.frame(), 0, 0)

  var pasteBoard = NSPasteboard.generalPasteboard();
  pasteBoard.declareTypes_owner( [ NSPasteboardTypeString ], null );
  pasteBoard.setString_forType_(str, NSStringPboardType)
}

function drawLayerGroup(layer, boundingFrame, offsetX, offsetY) {
  if(!layer.isVisible()) return ""

  var str = "func " + safeName(layer) + "(rect:CGRect){\n"
  str += "\tlet ctx = UIGraphicsGetCurrentContext()\n"
  str += "\tlet width = rect.width\n"
  str += "\tlet height = rect.height\n"

  str += "\tvar pstyleRightAlign = NSMutableParagraphStyle()\n"
  str += "\tpstyleRightAlign.alignment = NSTextAlignment.Right\n"

  str += "\tvar pstyleLeftAlign = NSMutableParagraphStyle()\n"
  str += "\tpstyleLeftAlign.alignment = NSTextAlignment.Left\n"

  str += "\tvar pstyleCenterAlign = NSMutableParagraphStyle()\n"
  str += "\tpstyleCenterAlign.alignment = NSTextAlignment.Center\n"

  var count = layer.layers().count()
  var groupFunctions = ""

  for(var i=0; i<count; i++) {
    var item = layer.layers().objectAtIndex(i)
    var oX = offsetX + item.frame().x()
    var oY = offsetY + item.frame().y()

    if(!item.isVisible()) continue

    if(item.class() == MSLayerGroup) {
      groupFunctions += drawLayerGroup(item, boundingFrame, oX, oY)
      str += "\n " + safeName(item) + "(rect)\n"
    }
    else if(item.class() == MSShapeGroup) {
      str += "\n//" + safeName(item) + "\n"
      str += drawShapeGroup(item, boundingFrame, offsetX, offsetY)
    }
    else if(item.class() == MSTextLayer) {
      str += drawTextLayer(item, boundingFrame, offsetX, offsetY)
    }
  }

  str += "}\n"
  str += "\n" + groupFunctions
  return str
}

function drawShapeGroup(shapeGroup, boundingFrame, offsetX, offsetY) {
  if(shapeGroup.layers().count() > 1) {
    var alert = NSAlert.alloc().init()
    alert.setMessageText("warning: union, subtract, etc not supported")
    alert.addButtonWithTitle("OK")
    alert.runModal()
  } else if(shapeGroup.layers().count() == 1){
    var shape = shapeGroup.layers().objectAtIndex(0)
    var str = ""
    str += drawCGShapePath(shapeGroup, boundingFrame.width(), boundingFrame.height(), offsetX, offsetY)
    return str
  }
  return ""
}

/*
  generates swift code, using CGContext magic
  assumes we will have defined previously something like:
    let ctx = UIGraphicsGetCurrentContext()
    let width = ...
    let height = ...
*/
function drawCGShapePath(shapeGroup, boundingWidth, boundingHeight, offsetX, offsetY) {
  var str = ""
  var points = shapeGroup.layers().objectAtIndex(0).path().points()
  var count = points.count()
  var shapeFrame = shapeGroup.frame()

  var widthRatio = "*(width/" + boundingWidth + ")"
  var heightRatio = "*(height/" + boundingHeight + ")"

  for(var i = 0; i<count; i++) {
    var point = points.objectAtIndex(i)
    var p = point.point()
    var px = round(p.x*shapeFrame.width()) + round(shapeFrame.x()) + offsetX
    var py = p.y*shapeFrame.height() + shapeFrame.y() + offsetY

    var cp2 = point.curveTo()
    if(!point.hasCurveTo()) { cp2 = p }

    var cp2x = round(cp2.x*shapeFrame.width()) + round(shapeFrame.x()) + offsetX
    var cp2y = round(cp2.y*shapeFrame.height()) + round(shapeFrame.y()) + offsetY

    if(i == 0) {
      str += "\tCGContextMoveToPoint(ctx, " + px + widthRatio + ", " + py + heightRatio + ")\n"
    } else {
      var cp1 = points.objectAtIndex(i - 1).curveFrom()

      if(!points.objectAtIndex(i - 1).hasCurveFrom()) {
        cp1 = points.objectAtIndex(i - 1).point() 
      }

      var cp1x = round(cp1.x*shapeFrame.width()) + round(shapeFrame.x()) + offsetX
      var cp1y = round(cp1.y*shapeFrame.height()) + round(shapeFrame.y()) + offsetY


      str += "\tCGContextAddCurveToPoint(ctx, " + cp1x + widthRatio + ", " + cp1y + heightRatio + ", " + cp2x + widthRatio + ", " + cp2y + heightRatio + ", " + px + widthRatio + ", " + py + heightRatio + ")\n"
    }
  }

  var p0 = points.objectAtIndex(0).point()
  var p0x = round(p0.x*shapeFrame.width()) + round(shapeFrame.x()) + offsetX
  var p0y = round(p0.y*shapeFrame.height()) + round(shapeFrame.y()) + offsetY

  var cp2 = points.objectAtIndex(0).curveTo()
  if(!points.objectAtIndex(0).hasCurveTo()) {
    cp2 = points.objectAtIndex(0).point() 
  }
  var cp2x = round(cp2.x*shapeFrame.width()) + round(shapeFrame.x()) + offsetX
  var cp2y = round(cp2.y*shapeFrame.height()) + round(shapeFrame.y()) + offsetY

  var cp1 = points.objectAtIndex(points.count() - 1).curveFrom()
  if(!points.objectAtIndex(points.count() - 1).hasCurveFrom()) {
    cp1 = points.objectAtIndex(points.count() - 1).point() 
  }

  var cp1x = round(cp1.x*shapeFrame.width()) + round(shapeFrame.x()) + offsetX
  var cp1y = round(cp1.y*shapeFrame.height()) + round(shapeFrame.y()) + offsetY
  
  var p = points.objectAtIndex(points.count() - 1)
  var pp = p.point()

  log("(" + cp1x + ", " + cp1y + ")")
  log("(" + cp2x + ", " + cp2y + ")")
  log("(" + p0x + ", " + p0y + ")")

  //draw path back to first point
  str += "\tCGContextAddCurveToPoint(ctx, " + cp1x + widthRatio + ", " + cp1y + heightRatio + ", " + cp2x + widthRatio + ", " + cp2y + heightRatio + ", " + p0x + widthRatio + ", " + p0y + heightRatio + ")\n"

  var stroke = extractStroke(shapeGroup, boundingWidth, boundingHeight)
  var fill = extractFill(shapeGroup)

  str += stroke
  str += fill

  var mode = null
  if(stroke && fill) mode = "kCGPathFillStroke" 
  else if(stroke) mode = "kCGPathStroke"
  else if(fill) mode = "kCGPathFill"

  if(mode) {
    str += "\tCGContextDrawPath(ctx, " + mode + ")\n"
  }
  return "\tCGContextSaveGState(ctx)\n" + str + "\tCGContextRestoreGState(ctx)\n"
}

function drawTextLayer(textLayer, boundingFrame, offsetX, offsetY) {
  var str = ""
  
  var boundingWidth = boundingFrame.width()
  var boundingHeight = boundingFrame.height()

  var widthRatio = "*(width/" + boundingWidth + ")"
  var heightRatio = "*(height/" + boundingHeight + ")"

  var frame = textLayer.frame()
  var x = offsetX + frame.x()
  var y = offsetY + frame.y()
  var width = frame.width()
  var height = frame.height()

  var yHeightOffset = " + " + height + "*(1 - (height / " + boundingHeight + " ))/2"

  var name = textLayer.stringValue().stringByReplacingOccurrencesOfString_withString("\n", "\\n")

  str += "\"" + name + "\".drawInRect(CGRect(x:" + x + widthRatio + ", y:" + y + heightRatio + yHeightOffset + ", width:" + width + widthRatio + ", height:" + height + heightRatio + "), withAttributes: " + drawAttributes(textLayer, boundingFrame) + ")\n"

  return "\tCGContextSaveGState(ctx)\n" + str + "\tCGContextRestoreGState(ctx)\n"
}

function drawAttributes(textLayer, boundingFrame) {
  var boundingWidth = boundingFrame.width()
  var widthRatio = "*(width/" + boundingWidth + ")"

  var str = ""
  var color = textLayer.textColor()
  str += "NSFontAttributeName: UIFont(name: \"" + textLayer.fontPostscriptName() + "\", size: " + textLayer.fontSize() + widthRatio + ")!"
  str +=", NSForegroundColorAttributeName: UIColor(hue: " + color.hue() + ", saturation: " + color.saturation() + ", brightness: " + color.brightness() + ", alpha: " + color.alpha() + ")"

  if(textLayer.textAlignment() == 0) str +=", NSParagraphStyleAttributeName: pstyleLeftAlign"
  else if(textLayer.textAlignment() == 1) str +=", NSParagraphStyleAttributeName: pstyleRightAlign"
  else if(textLayer.textAlignment() == 2) str +=", NSParagraphStyleAttributeName: pstyleCenterAlign"

  return "[" + str + "]"
}

/*
  will grab the first available fill (has to be a solid color and enabled)
*/
function extractStroke(shapeGroup, boundingWidth, boundingHeight) {
  var stroke = ""
  var strokes = shapeGroup.style().borders()
  for(var i=0; i<strokes.count(); i++) {
    var item = strokes.objectAtIndex(i)
    if(item.isEnabled() && item.fillType() == 0 && item.position() == 0) {
      var thicknessMult = "*min(width/" + boundingWidth + ", height/" + boundingHeight + ")"
      var color = item.color()
      stroke = "\tCGContextSetStrokeColorWithColor(ctx, UIColor(hue: " + color.hue() + ", saturation: " + color.saturation() + ", brightness: " + color.brightness() + ", alpha: " + color.alpha() + ").CGColor)\n"
      stroke += "\tCGContextSetLineWidth(ctx, " + item.thickness() + thicknessMult + ")\n"
      break
    }
  }
  return stroke
}

function extractFill(shapeGroup) {
  var fill = ""
  var fills = shapeGroup.style().fills()
  for(var i=0; i<fills.count(); i++) {
    var item = fills.objectAtIndex(i)
    if(item.isEnabled() && item.fillType() == 0) {
      var color = item.color()
      fill = "\tCGContextSetFillColorWithColor(ctx, UIColor(hue: " + color.hue() + ", saturation: " + color.saturation() + ", brightness: " + color.brightness() + ", alpha: " + color.alpha() + ").CGColor)\n"
      break
    }
  }
  return fill
}

function safeName(layer) {
  var name = layer.name()
  return name.stringByReplacingOccurrencesOfString_withString_(" ", "_")
}

function round(value, decimals) {
  if(decimals == null) decimals = 2
  var power = Math.pow(10, decimals)
  return Math.round(value * power)/power
}