// 2x8 Lego Brick
// A standard Lego brick with 2 bumps wide and 8 bumps long.
// Define constants
const lbumps = 10 // number of bumps long
const wbumps = {{N}} // number of bumps wide
const pitch = 8.0
const clearance = 0.1
const bumpDiam = 4.8
const bumpHeight = 1.8
const height = 9.6
const t = (pitch - (2 * clearance) - bumpDiam) / 2.0
const totalLength = lbumps * pitch - (2.0 * clearance)
const totalWidth = wbumps * pitch - (2.0 * clearance)
// Create the plane for the pegs. This is a hack so that the pegs can be patterned along the face of the lego base.
const pegFace = {
  plane: {
    origin: { x: 0, y: 0, z: height },
    xAxis: { x: 1, y: 0, z: 0 },
    yAxis: { x: 0, y: 1, z: 0 },
    zAxis: { x: 0, y: 0, z: 1 }
  }
}
// Create the plane for the tubes underneath the lego. This is a hack so that the tubes can be patterned underneath the lego.
const tubeFace = {
    plane: {
    origin: { x: 0, y: 0, z: height - t },
    xAxis: { x: 1, y: 0, z: 0 },
    yAxis: { x: 0, y: 1, z: 0 },
    zAxis: { x: 0, y: 0, z: 1 }
  }
}
// Make the base
const s = startSketchOn('XY')
  |> startProfileAt([-totalWidth / 2, -totalLength / 2], %)
  |> line([totalWidth, 0], %)
  |> line([0, totalLength], %)
  |> line([-totalWidth, 0], %)
  |> close(%)
  |> extrude(height, %)

// Sketch and extrude a rectangular shape to create the shell underneath the lego. This is a hack until we have a shell function.
const shellExtrude = startSketchOn(s, "start")
  |> startProfileAt([
       -(totalWidth / 2 - t),
       -(totalLength / 2 - t)
     ], %)
  |> line([totalWidth - (2 * t), 0], %)
  |> line([0, totalLength - (2 * t)], %)
  |> line([-(totalWidth - (2 * t)), 0], %)
  |> close(%)
  |> extrude(-(height - t), %)

fn tr = (i) => {
  let j = i + 1
  let x = (j/wbumps) * pitch
  let y = (j % wbumps) * pitch
  return {
    translate: [x, y, 0],
  }
}

// Create the pegs on the top of the base
const totalBumps = (wbumps * lbumps)-1
const peg = startSketchOn(s, 'end')
  |> circle( center = [
       -(pitch*(wbumps-1)/2),
       -(pitch*(lbumps-1)/2)
     ], radius = bumpDiam / 2)
  |> patternLinear2d(
       axis = [1, 0],
       instances = wbumps,
       distance = pitch
     )
  |> patternLinear2d(
       axis = [0, 1],
       instances = lbumps,
       distance = pitch
     )
  |> extrude(bumpHeight, %)
  // |> patternTransform(instances = int(totalBumps-1), transform = tr)