-- A geothermal EU generator
-- Using hot lava and water this device can create energy from steam
-- The machine is only producing LV EUs and can thus not drive more advanced equipment
-- The output is a little more than the coal burning generator (max 300EUs)

minetest.register_alias("geothermal", "technic:geothermal")

minetest.register_craft({
	output = 'technic:geothermal',
	recipe = {
		{'default:stone', 'default:stone', 'default:stone'},
		{'default:copper_ingot', 'default:diamond', 'default:copper_ingot'},
		{'default:stone', 'default:copper_ingot', 'default:stone'},
	}
})

minetest.register_craftitem("technic:geothermal", {
	description = "Geothermal Generator",
	stack_max = 99,
}) 

local geothermal_formspec =
	"invsize[8,4;]"..
	"label[0,0;Geothermal Generator]"..
	"list[current_player;main;0,5;8,4;]"
	

minetest.register_node("technic:geothermal", {
	description = "Geothermal Generator",
	tiles = {"technic_geothermal_top.png", "technic_machine_bottom.png", "technic_geothermal_side.png",
	         "technic_geothermal_side.png", "technic_geothermal_side.png", "technic_geothermal_side.png"},
	paramtype2 = "facedir",
	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2},
	legacy_facedir_simple = true,
	sounds = default.node_sound_wood_defaults(),
	on_construct = function(pos)
		local meta = minetest.get_meta(pos)
		meta:set_string("infotext", "Geothermal Generator")
		meta:set_float("technic_power_machine", 1)
		meta:set_int("LV_EU_supply", 0)
		meta:set_string("formspec", geothermal_formspec)	
	end,	
})

minetest.register_node("technic:geothermal_active", {
	description = "Geothermal Generator",
	tiles = {"technic_geothermal_top_active.png", "technic_machine_bottom.png", "technic_geothermal_side.png",
	         "technic_geothermal_side.png", "technic_geothermal_side.png", "technic_geothermal_side.png"},
	paramtype2 = "facedir",
	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2, not_in_creative_inventory=1},
	legacy_facedir_simple = true,
	sounds = default.node_sound_wood_defaults(),
	drop = "technic:geothermal",
})

local check_node_around = function(pos)
	local node = minetest.get_node(pos)
	if node.name == "default:water_source" or node.name == "default:water_flowing" then return 1 end
	if node.name == "default:lava_source"  or node.name == "default:lava_flowing"  then return 2 end	
	return 0
end

minetest.register_abm({
	nodenames = {"technic:geothermal","technic:geothermal_active"},
	interval = 1,
	chance   = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		local meta             = minetest.get_meta(pos)
		local water_nodes      = 0
		local lava_nodes       = 0
		local production_level = 0
		local eu_supply        = 0

		-- Correct positioning is water on one side and lava on the other.
		-- The two cannot be adjacent because the lava the turns into obsidian or rock.
		-- To get to 100% production stack the water and lava one extra block down as well:
		--    WGL (W=Water, L=Lava, G=the generator, |=an LV cable)
		--    W|L

		local positions = {
			{x=pos.x+1, y=pos.y,   z=pos.z},
			{x=pos.x+1, y=pos.y-1, z=pos.z},
			{x=pos.x-1, y=pos.y,   z=pos.z},
			{x=pos.x-1, y=pos.y-1, z=pos.z},
			{x=pos.x,   y=pos.y,   z=pos.z+1},
			{x=pos.x,   y=pos.y-1, z=pos.z+1},
			{x=pos.x,   y=pos.y,   z=pos.z-1},
			{x=pos.x,   y=pos.y-1, z=pos.z-1},
		}
		for _, p in pairs(positions) do
			local check = check_node_around(p)
			if check == 1 then water_nodes = water_nodes + 1 end
			if check == 2 then lava_nodes  = lava_nodes  + 1 end
		end

		if water_nodes == 1 and lava_nodes == 1 then production_level =  25; eu_supply = 50 end
		if water_nodes == 2 and lava_nodes == 1 then production_level =  50; eu_supply = 100 end
		if water_nodes == 1 and lava_nodes == 2 then production_level =  75; eu_supply = 200 end
		if water_nodes == 2 and lava_nodes == 2 then production_level = 100; eu_supply = 300 end

		if production_level > 0 then
			meta:set_int("LV_EU_supply", eu_supply)
		end

		meta:set_string("formspec",
			"invsize[8,4;]"..
			"label[0,0;Geothermal Generator]"..
			"label[4,0;Production at "..tostring(production_level).."%]")

		if production_level > 0 and minetest.get_node(pos).name == "technic:geothermal" then
			hacky_swap_node (pos, "technic:geothermal_active")
			return
		end
		if production_level == 0 then
			hacky_swap_node(pos, "technic:geothermal")
			meta:set_int("LV_EU_supply", 0)
		end
	end
}) 

technic.register_machine("LV", "technic:geothermal",        technic.producer)
technic.register_machine("LV", "technic:geothermal_active", technic.producer)