export default function (part) {
  let { sa, Point, points, Path, paths, snippets, options, complete, paperless, macro } =
    part.shorthand()

  // Don't bother of we're not drafting back pockets
  if (!options.backPockets) {
    part.render = false
    return part
  }

  // Clean up
  for (const path in paths) delete paths[path]
  for (const snippet in snippets) delete snippets[snippet]

  let welt = points.pocketLeft.dist(points.pocketRight) * options.weltFactor
  points.topLeft = new Point(points.pocketBagWaistLeft.x, points.pocketLeft.y)
  points.topRight = new Point(points.pocketBagWaistRight.x, points.topLeft.y)
  points.bottomLeft = points.topLeft.shift(-90, welt * 2)
  points.bottomRight = points.topRight.shift(-90, welt * 2)

  paths.seam = new Path()
    .move(points.topLeft)
    .line(points.bottomLeft)
    .line(points.bottomRight)
    .line(points.topRight)
    .line(points.topLeft)
    .close()
    .attr('class', 'fabric')

  if (complete) {
    points.title = points.topLeft.shiftFractionTowards(points.bottomRight, 0.4)
    macro('title', {
      at: points.title,
      nr: 7,
      title: 'pocketWelt',
    })
    macro('grainline', {
      from: points.topLeft.shift(0, 15),
      to: points.bottomLeft.shift(0, 15),
    })
    macro('sprinkle', {
      snippet: 'bnotch',
      on: ['pocketLeft', 'pocketRight', 'pocketBagWaistLeft', 'pocketBagWaistRight'],
    })

    if (sa) {
      paths.sa = paths.seam.offset(sa).attr('class', 'fabric sa')
    }

    if (paperless) {
      macro('hd', {
        from: points.bottomLeft,
        to: points.bottomRight,
        y: points.bottomLeft.y + 15 + sa,
      })
      macro('hd', {
        from: points.pocketLeft,
        to: points.pocketRight,
        y: points.topLeft.y - 15 - sa,
      })
      macro('vd', {
        from: points.bottomRight,
        to: points.topLeft,
        x: points.topRight.x + 15 + sa,
      })
    }
  }

  return part
}