luanti-g1/init.lua

local MG_RATE = 10

local http = minetest.request_http_api()
if http == nil then
	error("Please add g1_bridge to secure.http_mods")
end

local mod_storage = core.get_mod_storage()
if mod_storage == nil then
	error("Cannot get mod storage")
end

function receive_debts()
	local block = mod_storage:get_int("block")
	http.fetch({url="http://127.0.0.1:30061/recv/"..block, method="GET"},
		function(res)
			if res.code == 200 then
				local data = minetest.parse_json(res.data)
				if data == nil or type(data.block) ~= "number" or data.block <= block or type(data.debts) ~= "table" then
					return
				end
				for i, debt in ipairs(data.debts) do
					if type(debt.name) == "string" and type(debt.amount) == "number" and core.player_exists(debt.name) then
						local player_debt = mod_storage:get_int("debt_"..debt.name)
						player_debt = player_debt + debt.amount
						mod_storage:set_int("debt_"..debt.name, player_debt)
					end
				end
				mod_storage:set_int("block", data.block + 1)
			end
		end
	)
end

minetest.register_chatcommand("g1_send", {
	params = "<address> <amount>",
	description = "Send MineGeld from your inventory to a G1 address. Fixed rate: 1G1=10MG.",
	func = function(name, param)
		local args = {}
		for arg in string.gmatch(param,"%S+") do
			if #args >= 2 then
				break
			end
			table.insert(args, arg)
		end
		if #args == 2 and string.find(args[1],"^[%da-zA-Z]+$") and string.find(args[2],"^%d+$") then
			local address = args[1]
			local amount_mg = tonumber(args[2])
			-- This version Lua does not have any way to check if a number is represented as an integer or a float,
			-- because it explicitely doesn't care.
			-- Hence, this program won't care if the player writes an invalid number,
			-- as there is no need to ensure arithmetic rules are respected. (as Lua's manual pretends)
			-- As the pattern excludes "." and nobody should have billions of items,
			-- it should still be safe. I hope.
			if type(amount_mg) ~= "number" then
				return
			end
			local inv = core.get_inventory({type="player", name=name})
			local wanted_stack = "currency:minegeld "..amount_mg
			local balanced = inv:contains_item("main", ItemStack(wanted_stack))
			if balanced then
				local amount = amount_mg * MG_RATE
				inv:remove_item("main", ItemStack(wanted_stack))
				http.fetch({url="http://127.0.0.1:30061/send/"..address.."/"..amount, method="GET"},
					function(res)
						if res ~= nil and res.code == 200 then
							minetest.log("action", "mt-g1 - "..name.." sent "..amount_mg.."MG to "..address)
							core.chat_send_player(name, "Transfer sent")
						else
							core.chat_send_player(name, "Error during transfer, giving your money back")
							inv:add_item("main", ItemStack(wanted_stack))
						end
					end
				)
			else
				core.chat_send_player(name, "Not enough money (please ensure it is available in 1MG banknotes)")
			end
		end
	end
})

minetest.register_chatcommand("g1_claim", {
	description = "Claim MineGeld from G1 sent to the server",
	func = function(name, param)
		receive_debts()
		local amount = mod_storage:get_int("debt_"..name)
		local amount_mg = amount / MG_RATE
		local inv = core.get_inventory({type="player", name=name})
		local stack = "currency:minegeld "..amount_mg
		if inv:room_for_item("main", ItemStack(stack)) then
			minetest.log("action", "mt-g1 - "..name.." claimed "..amount_mg.."MG")
			inv:add_item("main", ItemStack(stack))
			core.chat_send_player(name, "Claimed "..amount_mg.."MG")
			mod_storage:set_int("debt_"..name, 0)
		else
			core.chat_send_player(name, "No room in your inventory! Available: "..amount_mg.."MG")
		end
	end
})

minetest.register_chatcommand("g1_block", {
	description = "Get latest block number known by the server",
	func = function(name, param)
		local block = mod_storage:get_int("block")
		core.chat_send_player(name, "Current block: "..block)
	end
})

minetest.register_chatcommand("g1_setblock", {
	privs = {
		server = true
	},
	params = "<block number>",
	description = "(admin) Set latest block number",
	func = function(name, param)
		local new_block = tonumber(param)
		if type(new_block) == "number" then
			mod_storage:set_int("block", new_block)
		else
			core.chat_send_player("name", "Argument must be an integer.")
		end
	end
})