minetest.register_abm({
  label = "Water freezing/evaporating",
  nodenames = {"group:water"},
  interval = 3,
  chance = 2.5,
  catch_up = true,
  action = function (pos)
    local def = PyuTest.get_biome_def(pos)
    if not def then return end

    local heat = def.heat_point or 50
    local found = minetest.find_node_near(pos, 2, {"group:emits_heat"}) ~= nil

    if heat <= 12 and not found then
      minetest.set_node(pos, {name = "pyutest_blocks:ice_block"})
    end
  end
})

minetest.register_abm({
  label = "Water evaporating",
  nodenames = {"group:water"},
  interval = 0.1,
  chance = 1,
  action = function (pos)
    local def = PyuTest.get_biome_def(pos)
    if not def then return end

    local heat = def.heat_point or 50

    if heat >= 100  then
      minetest.remove_node(pos)
    end
  end
})

minetest.register_abm({
  label = "Ice thawing",
  nodenames = {"group:thawable"},
  neighbors = {"group:emits_heat"},
  interval = 3,
  chance = 2.5,
  catch_up = true,
  action = function (pos, node)
      local def = minetest.registered_nodes[node.name]
      local thaw_into = def.__thaw_into or "pyutest_blocks:water_source"
      minetest.set_node(pos, { name = thaw_into })
  end
})