local stair_oxidation = {
	{ "stair", "cut", "exposed_cut" },
	{ "stair", "cut_inner", "exposed_cut_inner" },
	{ "stair", "cut_outer", "exposed_cut_outer" },
	{ "stair", "exposed_cut", "weathered_cut" },
	{ "stair", "exposed_cut_inner", "weathered_cut_inner" },
	{ "stair", "exposed_cut_outer", "weathered_cut_outer" },
	{ "stair", "weathered_cut", "oxidized_cut" },
	{ "stair", "weathered_cut_inner", "oxidized_cut_inner" },
	{ "stair", "weathered_cut_outer", "oxidized_cut_outer" }
}

local slab_oxidization = {
	{ "slab", "cut", "exposed_cut" },
	{ "slab", "cut_top", "exposed_cut_top" },
	{ "slab", "cut_double", "exposed_cut_double" },
	{ "slab", "exposed_cut", "weathered_cut" },
	{ "slab", "exposed_cut_top", "weathered_cut_top" },
	{ "slab", "exposed_cut_double", "weathered_cut_double" },
	{ "slab", "weathered_cut", "oxidized_cut" },
	{ "slab", "weathered_cut_top", "oxidized_cut_double" },
	{ "slab", "weathered_cut_double", "oxidized_cut_double" },
}

local def
local def_variant_oxidized
local def_variant_waxed
local def_variant_scraped

-- register abm, then set up oxidized and waxed variants.
for _, s in pairs(stair_oxidation) do
	def = "mcl_stairs:" .. s[1] .. "_copper_" .. s[2]
	def_variant_oxidized = "mcl_stairs:" .. s[1] .. "_copper_" .. s[3]
	minetest.override_item(def, { _mcl_oxidized_variant = def_variant_oxidized })

	def_variant_waxed = "mcl_stairs:" .. s[1] .. "_copper_" .. s[2] .. "_waxed"
	minetest.override_item(def, { _mcl_copper_waxed_variant = def_variant_waxed })
	def = "mcl_stairs:" .. s[1] .. "_copper_" .. s[2]
	def_variant_oxidized = "mcl_stairs:" .. s[1] .. "_copper_" .. s[3]
	minetest.override_item(def, { _mcl_oxidized_variant = def_variant_oxidized })

	def_variant_waxed = "mcl_stairs:" .. s[1] .. "_copper_" .. s[2] .. "_waxed"
	minetest.override_item(def, { _mcl_copper_waxed_variant = def_variant_waxed })
end

-- Set up scraped variants.
for i=1, #stair_oxidation do
	if i > 3 then
		def = "mcl_stairs:" .. stair_oxidation[i][1] .. "_copper_" .. stair_oxidation[i][2]
		def_variant_scraped="mcl_stairs:" .. stair_oxidation[i-3][1] .. "_copper_" .. stair_oxidation[i-3][2]
		minetest.override_item(def, { _mcl_stripped_variant = def_variant_scraped })
		def = "mcl_stairs:" .. slab_oxidization[i][1] .. "_copper_" .. slab_oxidization[i][2]
		def_variant_scraped="mcl_stairs:" .. slab_oxidization[i-3][1] .. "_copper_" .. slab_oxidization[i-3][2]
		minetest.override_item(def, { _mcl_stripped_variant = def_variant_scraped })
	end
	if i>6 then
		def = "mcl_stairs:" .. stair_oxidation[i][1] .. "_copper_" .. stair_oxidation[i][3]
		def_variant_scraped="mcl_stairs:" .. stair_oxidation[i][1] .. "_copper_" .. stair_oxidation[i][2]
		minetest.override_item(def, { _mcl_stripped_variant = def_variant_scraped })
		def = "mcl_stairs:" .. slab_oxidization[i][1] .. "_copper_" .. slab_oxidization[i][3]
		def_variant_scraped="mcl_stairs:" .. slab_oxidization[i][1] .. "_copper_" .. slab_oxidization[i][2]
		minetest.override_item(def, { _mcl_stripped_variant = def_variant_scraped })
	end
end