local function growth_timer(pos)
  minetest.get_node_timer(pos):start(3)
end


local S = minetest.get_translator("ebiometrees")
function ebiometrees.register_tree(modname, basename, data)
  -- register saplings
  local sapling_name = modname..":"..basename.."_sapling"
  local sprout_name = modname..":"..basename.."_sprout"

  local sapling_groups = table.copy(data.groups)
  local sprout_groups = table.copy(data.groups)
  sapling_groups.sapling = 1
  sapling_groups.snappy = 2
  sapling_groups.dig_immediate = 3
  sprout_groups.sapling = 1
  sprout_groups.snappy = 2
  minetest.register_node(sapling_name, {
    description = S(data.description.." sapling"),
    drawtype = "plantlike",
    tiles = { modname.."_"..basename.."_sapling.png"},
    paramtype = "light",
    on_timer = ebiometrees.get_sapling_grower(sprout_name),
    sunlight_propagates = true,
    walkable = false,
    groups = sapling_groups,
    on_construct = growth_timer
  })
  minetest.register_node(sprout_name, {
    description = S(data.description.." sprout"),
    drawtype = "plantlike",
    visual_scale = 1.4,
    tiles = { modname.."_"..basename.."_sprout.png" },
    paramtype = "light",
    sunlight_propagates = true,
    walkable = false,
    on_timer = ebiometrees.get_sprout_grower(
      modname..":"..basename.."_trunk_growing_straight",
      modname..":"..basename.."_trunk_growing_terminal"),
    groups = sprout_groups,
    on_construct = growth_timer
  })
  -- registers tree and corresponding nodes
  local trunk_groups = table.copy(data.groups)
  trunk_groups.choppy = 2 -- TODO: customizations
  local trunk_types = {"growing", "normal"}
  local trunk_subtypes = {"terminal", "straight", "corner",
    "tjunction", "t2junction", "xjunction",
    "xtjunction", "x2junction"}

  for _, trunk_type in ipairs(trunk_types)
  do
    local texture_basename = modname.."_"..basename.."_trunk_"..trunk_type.."_"
    local subtype_tiles = {
      terminal = {
        texture_basename.."terminal.png",
        texture_basename.."slice.png",
        texture_basename.."terminal.png"
      },
      straight = {
        texture_basename.."slice.png",
        texture_basename.."slice.png",
        texture_basename.."normal.png"
      },
      corner = {
        texture_basename.."normal.png",
        texture_basename.."slice.png",
        texture_basename.."corner.png^[transformFX",
        texture_basename.."corner.png",
        texture_basename.."normal.png",
        texture_basename.."slice.png",
      },
      tjunction = {
        texture_basename.."slice.png",
        texture_basename.."slice.png",
        texture_basename.."tjunction.png^[transformFX",
        texture_basename.."tjunction.png",
        texture_basename.."normal.png",
        texture_basename.."slice.png",
      },
      t2junction = {
        texture_basename.."slice.png",
        texture_basename.."slice.png",
        texture_basename.."tjunction.png^[transformFX",
        texture_basename.."slice.png",
        texture_basename.."tjunction.png",
        texture_basename.."slice.png",
      },
      xjunction = {
        texture_basename.."slice.png",
        texture_basename.."slice.png",
        texture_basename.."xjunction.png^[transformFX",
        texture_basename.."xjunction.png",
        texture_basename.."slice.png",
        texture_basename.."slice.png",
      },
      xtjunction = {
        texture_basename.."slice.png",
        texture_basename.."slice.png",
        texture_basename.."xjunction.png",
        texture_basename.."slice.png",
        texture_basename.."slice.png",
        texture_basename.."slice.png",
      },
      x2junction = {
        texture_basename.."slice.png"
      }
    }
    for _, trunk_subtype in ipairs(trunk_subtypes)
    do
      minetest.register_node(
        modname..":"..basename.."_trunk_"..trunk_type.."_"..trunk_subtype, {
          description = S(data.description.." "..trunk_type.." "..trunk_subtype),
          groups = trunk_groups,
          tiles = subtype_tiles[trunk_subtype],
          paramtype2 = "facedir",
          is_ground_content = false,
          on_place = minetest.rotate_node,
          on_timer = function(pos)
            return true
          end,
          on_construct = growth_timer
      })
    end
  end
end