local ENTITY_NAME = "logistica:display_item"
local ENTITY_DIST_ADJ = 17 / 32
-- must be created with staticdata="id;texture"
minetest.register_entity(ENTITY_NAME, {
	initial_properties = {
		hp_max = 1,
		visual = "wielditem",
		visual_size = {x = 0.3, y = 0.3},
		collisionbox = {0, 0, 0, 0, 0, 0},
		physical = false,
		textures = {"air"},
		static_save = true
	},

	on_activate = function(self, staticdata)
    if staticdata and staticdata ~= "" then
      local data = staticdata:split(";")
      if data and data[1] and data[2] then
        self.id = data[1]
        self.texture = data[2]
      else
        self.object:remove()
      end
    end

		if self.texture then
      self.object:set_properties({textures = {self.texture}})
		end
	end,

	get_staticdata = function(self)
		if self.id and self.texture then return
      self.id..";"..self.texture
    else
		  return ""
    end
	end
})

-- public functions 

-- `optionalId` is optional
function logistica.remove_item_on_block_front(pos, optionalId)
  local id = optionalId or logistica.get_network_name_for(pos)
	local objs = minetest.get_objects_inside_radius({x = pos.x, y = pos.y, z = pos.z}, 1)
	if objs then
		for _, obj in pairs(objs) do
			if obj and obj:get_luaentity()
        and obj:get_luaentity().name == ENTITY_NAME
        and obj:get_luaentity().id == id then
				obj:remove()
			end
		end
	end
end

function logistica.display_item_on_block_front(pos, item)
	if item == nil or item == "" then return logistica.remove_item_on_block_front(pos) end
  local node = minetest.get_node(pos)
  if not node then return end
  local id = logistica.get_network_name_for(pos)

  logistica.remove_item_on_block_front(pos, id)

  local adjust = logistica.get_front_face_object_info(node.param2)
  if not adjust then return end

  pos.x = pos.x + adjust.x * ENTITY_DIST_ADJ
  pos.y = pos.y + adjust.y * ENTITY_DIST_ADJ
  pos.z = pos.z + adjust.z * ENTITY_DIST_ADJ
  local  pitch = adjust.pitch
  --local yaw = math.pi * 2 - adjust.yaw * math.pi / 2
  local yaw = 6.28 - adjust.yaw * 1.57
  --local roll = math.pi * 2 - adjust.roll * math.pi / 2
  local roll = 6.28 - adjust.roll * 1.57

	local texture = ItemStack(item):get_name()

	local entity = minetest.add_entity(pos, ENTITY_NAME, id..";"..texture)

  entity:set_rotation({x = pitch, y = yaw, z = roll})
end