local function growth_timer(pos)
  minetest.get_node_timer(pos):start(3)
  local meta = minetest.get_meta(pos)
  meta:mark_as_private("ebiometrees:age")
  meta:set_int("ebiometrees:age", 0)
end

function ebiometrees.register_tree_leaves(modname, basename, data)
  local S = minetest.get_translator(modname)
  local leaves_groups = table.copy(data.groups)
  leaves_groups.leaves = 1
  leaves_groups.leafdecay = 3
  leaves_groups.snappy = 3
  minetest.register_node(modname..":"..basename.."_leaves", {
    description = S(data.description.." leaves"),
    drawtype = "allfaces_optional",
    waving = 1,
    tiles = { modname.."_"..basename.."_leaves.png" },
    special_tiles = { modname.."_"..basename.."_leaves_simple.png" },
    paramtype = "light",
    is_ground_content = false,
    groups = leaves_groups
  })
end

function ebiometrees.register_tree_sapling(modname, basename, data)
  -- register saplings
  local S = minetest.get_translator(modname)
  local sapling_groups = table.copy(data.groups)
  sapling_groups.sapling = 1
  sapling_groups.snappy = 2
  sapling_groups.dig_immediate = 3
  minetest.register_node(modname..":"..basename.."_sapling", {
    description = S(data.description.." sapling"),
    drawtype = "plantlike",
    tiles = { modname.."_"..basename.."_sapling.png"},
    paramtype = "light",
    on_timer = ebiometrees.grow_closure(
      modname..":"..basename.."_sprout"
    ),
    sunlight_propagates = true,
    walkable = false,
    groups = sapling_groups,
    on_construct = growth_timer
  })
end

function ebiometrees.register_tree_sprout(modname, basename, data)
  -- register tree leaves
  local S = minetest.get_translator(modname)
  local sprout_groups = table.copy(data.groups)
  sprout_groups.sapling = 1
  sprout_groups.snappy = 2
  minetest.register_node(modname..":"..basename.."_sprout", {
    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.grow_closure(
      modname..":"..basename.."_trunk_growing_terminal"
    ),
    groups = sprout_groups,
    on_construct = growth_timer
  })
end

function ebiometrees.register_tree_trunks(modname, basename, data)
  local S = minetest.get_translator(modname)
  -- registers corresponding trunk nodes
  local trunk_groups = table.copy(data.groups)
  trunk_groups.choppy = 2 -- TODO: customizations
  trunk_groups.treetrunk = 1
  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.."top.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
      local nodespec = {
          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_construct = growth_timer
      }
      if trunk_type == "growing"
        then
          nodespec.on_timer = ebiometrees.tree_grower(
            modname..":"..basename.."_leaves",
            {
              {ebiometrees.directions.up},
              {
                ebiometrees.directions.north,
                ebiometrees.directions.east,
                ebiometrees.directions.south,
                ebiometrees.directions.west
              }
            },
            modname..":"..basename.."_trunk_growing_terminal",
            modname..":"..basename.."_trunk_normal_"..trunk_subtype,
            20,
            10
          )
      end
      minetest.register_node(
        modname..":"..basename.."_trunk_"..trunk_type.."_"..trunk_subtype,
        nodespec)
    end
  end
end