namespace glarp {

  const create = vector.create2d

  const blockType = types.BlockType;
  const generate = formSpec.generate
  const FormSpec = formSpec.FormSpec
  const BackGround = formSpec.Background
  const BGColor = formSpec.BGColor
  const List = formSpec.List
  const ListColors = formSpec.ListColors
  const ListRing = formSpec.ListRing

  const color = utility.color
  const colorScalar = utility.colorScalar
  const colorRGB = utility.colorRGB

  const playerInventorySize = player.MAIN_INVENTORY_SIZE

  const WORKBENCH_INVENTORY_SIZE = create(3,3)
  

  const workBenchInventory: string = generate(new FormSpec({
    size: create(12,12),
    elements: [
      //! Nice background colors.
      new BGColor({
        bgColor: colorScalar(85),
        fullScreen: "both",
        fullScreenbgColor: colorScalar(0,40)
      }),
      //! Make these lists look nice as well.
      new ListColors({
        slotBGHover: colorScalar(70),
        slotBGNormal: colorScalar(55),
        slotBorder: colorScalar(0),
        toolTipBGColor: colorRGB(123,104,238),
        toolTipFontColor: colorScalar(100)
      }),
      //! Craft area.
      new List({
        location: "context",
        listName: "workBenchCraft",
        position: create(
          4,
          1.125
        ),
        size: WORKBENCH_INVENTORY_SIZE,
        startingIndex: 0
      }),
      //! Craft output
      new List({
        location: "context",
        listName: "output",
        position: create(
          9,
          2.375
        ),
        size: create(
          1,
          1
        ),
        startingIndex: 0
      }),
      //! Hot bar.
      new List({
        location: "current_player",
        listName: "main",
        position: create(
          0.5,
          6.5
        ),
        size: create(
          playerInventorySize.x,
          1
        ),
        startingIndex: 0
      }),
      //! Main inventory.
      new List({
        location: "current_player",
        listName: "main",
        position: create(
          0.5,
          8
        ),
        size: create(
          playerInventorySize.x,
          playerInventorySize.y - 1
        ),
        startingIndex: playerInventorySize.x
      }),
      //! List Rings.
      new ListRing({
        location: "current_player",
        listName: "main"
      }),
      new ListRing({
        location: "context",
        listName: "workBenchCraft"
      }),
      new ListRing({
        location: "current_player",
        listName: "main"
      }),
      new ListRing({
        location: "context",
        listName: "output"
      })
    ]
  }))

  function allowPut(
    position: Vec3,
    listName: string,
    index: number,
    stack: ItemStackObject,
    player: ObjectRef
  ): number {
    switch (listName) {
      case "output":
        return 0
      default:
        return stack.get_count()
    }
  }

  function workBenchLogic(position: Vec3, listName: string) {
    const meta = minetest.get_meta(position)
    const inventory = meta.get_inventory()
    const craftArea = inventory.get_list("workBenchCraft")
  
    const [result, leftOver] = minetest.get_craft_result({
      method: CraftCheckType.normal,
      width: WORKBENCH_INVENTORY_SIZE.x,
      items: craftArea
    })

    inventory.set_list("output", [result.item])

    // If user takes from the output, the craft has been finalized. Take the items.
    if (listName == "output") {
      inventory.set_list("workBenchCraft", leftOver.items)
      // Now recurse 1 deep to update the output slot.
      workBenchLogic(position, "")
    }
  }


  function workBenchPut(
    position: Vec3,
    listName: string,
    index: number,
    stack: ItemStackObject,
    player: ObjectRef
   ) {
    workBenchLogic(position, listName)
  }

  function workBenchMove(
    position: Vec3,
    fromList: string,
    fromIndex: number,
    toList: string,
    toIndex: number,
    count: number,
    player: ObjectRef
  ) {
    workBenchLogic(position, toList)
  }

  function workBenchTake(
    position: Vec3,
    listName: string,
    index: number,
    stack: ItemStackObject,
    player: ObjectRef
  ) {
    workBenchLogic(position, listName)
  }


  utility.registerNode("workbench", {
    drawtype: Drawtype.normal,
    tiles: [
      "crafting_workbench_top.png",
      "default_wood.png",
      "crafting_workbench_side.png"
    ],
    sounds: sounds.wood(),
    groups: {
      [blockType.wood]: 1
    },

    on_construct(position: Vec3) {
      const meta = minetest.get_meta(position)
      const inventory = meta.get_inventory()
      meta.set_string("formspec", workBenchInventory)
      inventory.set_size("workBenchCraft", WORKBENCH_INVENTORY_SIZE.x * WORKBENCH_INVENTORY_SIZE.y)
      inventory.set_width("workBenchCraft", WORKBENCH_INVENTORY_SIZE.x)
      inventory.set_size("output", 1)
      inventory.set_width("output", 1)
    },

    //! todo: These 3 functions can probably just be one. Look into this.
    on_metadata_inventory_put: workBenchPut,
    on_metadata_inventory_move: workBenchMove,
    on_metadata_inventory_take: workBenchTake,

    // All this does is stop a player from jamming items in the output slot.
    allow_metadata_inventory_put: allowPut,

    allow_metadata_inventory_take(position: Vec3, listName: string, index: number, stack: ItemStackObject, player: ObjectRef): number {
      if (listName != "output") return stack.get_count()
      const meta = minetest.get_meta(position)
      const inventory = meta.get_inventory()
      const list = inventory.get_list("output")
      const shouldGotten = list[0].get_count()
      const gotten = stack.get_count()

      print(shouldGotten, gotten)

      return (shouldGotten == gotten) ? gotten : 0
    }
  })
}