local max_charge         = 1500000
local max_charge_rate    = 3000
local max_discharge_rate = 5000

-- HV battery box
minetest.register_craft({
	output = 'technic:hv_battery_box 1',
	recipe = {
		{'technic:mv_battery_box', 'technic:mv_battery_box', 'technic:mv_battery_box'},
		{'technic:mv_battery_box', 'technic:hv_transformer', 'technic:mv_battery_box'},
		{'',                       'technic:hv_cable',       ''},
	}
})

local battery_box_formspec =
	"invsize[8,9;]"..
	"image[1,1;1,2;technic_power_meter_bg.png]"..
	"list[current_name;src;3,1;1,1;]"..
	"list[current_name;dst;5,1;1,1;]"..
	"label[0,0;HV Battery Box]"..
	"label[3,0;Charge]"..
	"label[5,0;Discharge]"..
	"label[1,3;Power level]"..
	"list[current_player;main;0,5;8,4;]"..
	"background[-0.19,-0.25;8.4,9.75;ui_form_bg.png]"..
	"background[0,0;8,4;ui_hv_battery_box.png]"..
	"background[0,5;8,4;ui_main_inventory.png]"

minetest.register_node("technic:hv_battery_box", {
	description = "HV Battery Box",
	tiles = {"technic_hv_battery_box_top.png",   "technic_hv_battery_box_bottom.png",
	         "technic_hv_battery_box_side0.png", "technic_hv_battery_box_side0.png",
	         "technic_hv_battery_box_side0.png", "technic_hv_battery_box_side0.png"},
	groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2},
	sounds = default.node_sound_wood_defaults(),
	drop = "technic:hv_battery_box",
	on_construct = function(pos)
		local meta = minetest.env:get_meta(pos)
		local inv = meta:get_inventory()
		meta:set_string("infotext", "HV Battery Box")
		meta:set_float("technic_hv_power_machine", 1)
		meta:set_string("formspec", battery_box_formspec)
		meta:set_int("HV_EU_demand", 0) -- How much this node can charge
		meta:set_int("HV_EU_supply", 0) -- How much this node can discharge
		meta:set_int("HV_EU_input",  0) -- How much power this machine is getting.
		meta:set_float("internal_EU_charge", 0)
		inv:set_size("src", 1)
		inv:set_size("dst", 1)
	end,
	can_dig = function(pos,player)
		local meta = minetest.env:get_meta(pos);
		local inv = meta:get_inventory()
		if not inv:is_empty("src") or not inv:is_empty("dst") then
			minetest.chat_send_player(player:get_player_name(), "Machine cannot be removed because it is not empty");
			return false
		else
			return true
		end
	end,
})

for i = 1,8,1 do
	minetest.register_node("technic:hv_battery_box"..i, {
		description = "HV Battery Box",
		tiles = {"technic_hv_battery_box_top.png", "technic_hv_battery_box_bottom.png",
		         "technic_hv_battery_box_side0.png^technic_power_meter"..i..".png",
		         "technic_hv_battery_box_side0.png^technic_power_meter"..i..".png",
		         "technic_hv_battery_box_side0.png^technic_power_meter"..i..".png",
		         "technic_hv_battery_box_side0.png^technic_power_meter"..i..".png"},
		groups = {snappy=2, choppy=2, oddly_breakable_by_hand=2, not_in_creative_inventory=1},
		sounds = default.node_sound_wood_defaults(),
		paramtype="light",
		light_source=9,
		drop="technic:hv_battery_box",
		can_dig = function(pos,player)
			local meta = minetest.env:get_meta(pos);
			local inv = meta:get_inventory()
			if not inv:is_empty("src") or not inv:is_empty("dst") then
				minetest.chat_send_player(player:get_player_name(), "Machine cannot be removed because it is not empty");
				return false
			else
				return true
			end
		end,
	})
end

minetest.register_abm({
	nodenames = {"technic:hv_battery_box",  "technic:hv_battery_box1", "technic:hv_battery_box2",
	             "technic:hv_battery_box3", "technic:hv_battery_box4", "technic:hv_battery_box5",
	             "technic:hv_battery_box6", "technic:hv_battery_box7", "technic:hv_battery_box8"},
	interval = 1,
	chance   = 1,
	action = function(pos, node, active_object_count, active_object_count_wider)
		local meta           = minetest.env:get_meta(pos)
		local eu_input       = meta:get_int("HV_EU_input")
		local current_charge = meta:get_int("internal_EU_charge") -- Battery charge right now

		-- Power off automatically if no longer connected to a switching station
		technic.switching_station_timeout_count(pos, "HV")

		-- Charge/discharge the battery with the input EUs
		if eu_input >= 0 then
			current_charge = math.min(current_charge + eu_input, max_charge)
		else
			current_charge = math.max(current_charge + eu_input, 0)
		end

		-- Charging/discharging tools here
		current_charge = charge_tools(meta, current_charge, 16000)
		current_charge = discharge_tools(meta, current_charge, max_charge, 16000)

		-- Set a demand (we allow batteries to charge on less than the demand though)
		meta:set_int("HV_EU_demand", math.min(max_charge_rate, max_charge-current_charge))

		-- Set how much we can supply
		meta:set_int("HV_EU_supply", math.min(max_discharge_rate, current_charge))

		meta:set_int("internal_EU_charge", current_charge)

		-- Select node textures
		local charge_count = math.ceil((current_charge / max_charge) * 8)
		if charge_count > 8 then
			charge_count = 8
		end
		local last_count = meta:get_float("last_side_shown")
		if charge_count ~= last_count then
			if charge_count > 0 then
				hacky_swap_node(pos,"technic:hv_battery_box"..charge_count)
			else
				hacky_swap_node(pos,"technic:hv_battery_box")
			end
			meta:set_float("last_side_shown", charge_count)
		end

		local charge_percent = math.floor(current_charge / max_charge * 100)
		meta:set_string("formspec",
			battery_box_formspec..
			"image[1,1;1,2;technic_power_meter_bg.png^[lowpart:"
			..charge_percent..":technic_power_meter_fg.png]")

		if eu_input == 0 then
			meta:set_string("infotext", "HV Battery box: "..current_charge.."/"..max_charge.." (idle)")
		else
			meta:set_string("infotext", "HV Battery box: "..current_charge.."/"..max_charge)
		end
	end
})

-- Register as a battery type
-- Battery type machines function as power reservoirs and can both receive and give back power
technic.register_HV_machine("technic:hv_battery_box","BA")
for i=1,8,1 do
	technic.register_HV_machine("technic:hv_battery_box"..i,"BA")
end