musttest_game/mods/barter_table/barter.lua

if not minetest.global_exists("barter") then barter = {} end
barter.chest = barter.chest or {}
barter.reset_delay = 60*20 -- Number of seconds to reset after pressing start.
barter.long_delay = 60*60*3
barter.enable_logging = false

-- Localize for performance.
local math_floor = math.floor

function barter.report(msg)
	if barter.enable_logging then
		local pref = utility.get_first_available_admin()
		if pref then
			minetest.chat_send_player(pref:get_player_name(), msg)
		end
	end
end

barter.chest.formspec = {
	main = "size[8,9]"..
		default.gui_bg ..
		default.gui_bg_img ..
		default.gui_slots ..
		"list[context;pl1;0,0;3,4;]"..
		"list[context;pl2;5,0;3,4;]"..
		"list[current_player;main;0,5;8,4;]",

	pl1 = {
		start = "button[3,1;1,1;pl1_start;Start]",
		player = function(name) return "label[3,0;" .. rename.gpn(name) .. "]" end,
		accept1 = "button[3,1;1,1;pl1_accept1;Confirm]"..
				"button[3,2;1,1;pl1_cancel;Cancel]",
		accept2 = "button[3,1;1,1;pl1_accept2;Exchange]"..
				"button[3,2;1,1;pl1_cancel;Cancel]",
	},

	pl2 = {
		start = "button[4,1;1,1;pl2_start;Start]",
		player = function(name) return "label[4,0;" .. rename.gpn(name) .. "]" end,
		accept1 = "button[4,1;1,1;pl2_accept1;Confirm]"..
				"button[4,2;1,1;pl2_cancel;Cancel]",
		accept2 = "button[4,1;1,1;pl2_accept2;Exchange]"..
				"button[4,2;1,1;pl2_cancel;Cancel]",
	},
}

barter.chest.check_privilege = function(listname,playername,meta)
	if listname == "pl1" then
		if playername ~= meta:get_string("pl1") then
			return false
		elseif meta:get_int("pl1step") ~= 1 then
			return false
		end
	end
	if listname == "pl2" then
		if playername ~= meta:get_string("pl2") then
			return false
		elseif meta:get_int("pl2step") ~= 1 then
			return false
		end
	end
	return true
end

barter.chest.update_formspec = function(meta)
	local formspec = barter.chest.formspec.main

	local pl_formspec = function(n)
		if meta:get_int(n.."step")==0 then
			formspec = formspec .. barter.chest.formspec[n].start
		else
			formspec = formspec .. barter.chest.formspec[n].player(meta:get_string(n))
			if meta:get_int(n.."step") == 1 then
				formspec = formspec .. barter.chest.formspec[n].accept1
			elseif meta:get_int(n.."step") == 2 then
				formspec = formspec .. barter.chest.formspec[n].accept2
			end
		end
	end

	pl_formspec("pl1")
	pl_formspec("pl2")
	meta:set_string("formspec", formspec)
end

barter.chest.give_inventory = function(inv, list, playername)
	barter.report("Giving list " .. list .. " to <" .. playername .. ">.")
	player = minetest.get_player_by_name(playername)
	if inv and player then
		local pinv = player:get_inventory()
		if pinv then
			barter.report("Moving items!")
			local from_list = inv:get_list(list)
			for k, v in ipairs(from_list) do
				pinv:add_item("main", v)
				inv:remove_item(list, v)
			end
		else
			barter.report("Couldn't get player inv!")
		end
	else
		barter.report("Missing inv or player!")
	end
end

barter.chest.cancel = function(meta)
	barter.chest.give_inventory(meta:get_inventory(),"pl1",meta:get_string("pl1"))
	barter.chest.give_inventory(meta:get_inventory(),"pl2",meta:get_string("pl2"))
	meta:set_string("pl1","")
	meta:set_string("pl2","")
	meta:set_int("pl1step",0)
	meta:set_int("pl2step",0)
end

-- This function expects to be called from minetest.after().
-- Added by MustTest, to prevent players from locking these tables up so other players can't use them.
barter.chest.hard_reset = function(pos, side, name)
	local node = minetest.get_node(pos)
	if node.name == "barter_table:barter" then
		local meta = minetest.get_meta(pos)
		if meta and meta:get_string(side) == name then
			barter.chest.give_inventory(meta:get_inventory(), side, meta:get_string(side))
			meta:set_string(side, "")
			meta:set_int(side .. "step", 0)
			barter.chest.update_formspec(meta)
		end
	end
end

-- Also need an hourly (or so) reset function, in case the server crashes before minetest.after() is run.
barter.chest.reset2 = function(pos, elapsed)
	local node = minetest.get_node(pos)
	if node.name == "barter_table:barter" then
		local meta = minetest.get_meta(pos)
		barter.chest.give_inventory(meta:get_inventory(), "pl1", meta:get_string("pl1"))
		barter.chest.give_inventory(meta:get_inventory(), "pl2", meta:get_string("pl2"))
		meta:set_string("pl1", "")
		meta:set_string("pl2", "")
		meta:set_int("pl1step", 0)
		meta:set_int("pl2step", 0)
		barter.chest.update_formspec(meta)
		return true
	end
end

barter.chest.exchange = function(meta)
	barter.chest.give_inventory(meta:get_inventory(), "pl1", meta:get_string("pl2"))
	barter.chest.give_inventory(meta:get_inventory(), "pl2", meta:get_string("pl1"))
	meta:set_string("pl1","")
	meta:set_string("pl2","")
	meta:set_int("pl1step",0)
	meta:set_int("pl2step",0)
end



minetest.register_node("barter_table:barter", {
	drawtype = "nodebox",
	description = "Barter Table",
	paramtype = "light",
	paramtype2 = "facedir",
	tiles = {
		"barter_top.png",
		"barter_base.png",
		"barter_side.png",
	},

	inventory_image = "barter_top.png",
	node_box = {
		type = "fixed",
		fixed = {
			{-0.500000,0.312500,-0.500000,0.500000,0.500000,0.500000},
			{-0.437500,-0.500000,-0.437500,-0.250000,0.500000,-0.250000},
			{-0.437500,-0.500000,0.250000,-0.250000,0.500000,0.437500},
			{0.250000,-0.500000,-0.437500,0.437500,0.500000,-0.250000},
			{0.250000,-0.500000,0.250000,0.437500,0.500000,0.447500},
		},
	},
	groups = utility.dig_groups("furniture"),
	sounds = default.node_sound_wood_defaults(),
	on_timer = barter.chest.reset2,


	on_construct = function(pos)
		local meta = minetest.get_meta(pos)
		meta:set_string("infotext", "Trade/Barter Table")
		meta:set_string("pl1","")
		meta:set_string("pl2","")
		barter.chest.update_formspec(meta)
		local inv = meta:get_inventory()
		inv:set_size("pl1", 3*4)
		inv:set_size("pl2", 3*4)
		local timer = minetest.get_node_timer(pos)
		timer:start(barter.long_delay)
	end,



	on_receive_fields = function(pos, formname, fields, sender)
		local meta = minetest.get_meta(pos)

		local pl_receive_fields = function(n)
			if fields[n.."_start"] and meta:get_string(n) == "" then
				meta:set_string(n,sender:get_player_name())
				minetest.chat_send_player(sender:get_player_name(),
					"# Server: This barter table will reset in " ..
					barter.reset_delay/60 .. " minutes. Please complete your transaction before then.")
				minetest.after(barter.reset_delay, barter.chest.hard_reset, pos, n, sender:get_player_name())

				-- Make sure the janitor timer is running.
				local timer = minetest.get_node_timer(pos)
				if timer then
					if not timer:is_started() then
						timer:start(barter.long_delay)
					end

					-- Alert players how much time is left.
					local elasped = timer:get_elapsed()
					minetest.chat_send_player(sender:get_player_name(), "# Server: The periodic reset for this table is scheduled to occure in " .. math_floor((barter.long_delay - elasped)/60) .. " minutes.")
          minetest.chat_send_player(sender:get_player_name(), "# Server: WARNING: make sure you have enough space in your inventory to receive bartered goods.")
				end
			end
			if meta:get_string(n) == "" then
				meta:set_int(n.."step",0)
			elseif meta:get_int(n.."step")==0 then
				meta:set_int(n.."step",1)
			end
			if sender:get_player_name() == meta:get_string(n) then
				if meta:get_int(n.."step")==1 and fields[n.."_accept1"] then
					meta:set_int(n.."step",2)
				end
				if meta:get_int(n.."step")==2 and fields[n.."_accept2"] then
					meta:set_int(n.."step",3)
					if n == "pl1" and meta:get_int("pl2step") == 3 then barter.chest.exchange(meta) end
					if n == "pl2" and meta:get_int("pl1step") == 3 then barter.chest.exchange(meta) end
				end
				if fields[n.."_cancel"] then barter.chest.cancel(meta) end
			end
		end

		pl_receive_fields("pl1")
		pl_receive_fields("pl2")

		-- End
		barter.chest.update_formspec(meta)
	end,



	allow_metadata_inventory_move = function(pos, from_list, from_index, to_list, to_index, count, player)
		local meta = minetest.get_meta(pos)
		if not barter.chest.check_privilege(from_list,player:get_player_name(),meta) then return 0 end
		if not barter.chest.check_privilege(to_list,player:get_player_name(),meta) then return 0 end
		return count
	end,



	allow_metadata_inventory_put = function(pos, listname, index, stack, player)
		local meta = minetest.get_meta(pos)
		if not barter.chest.check_privilege(listname,player:get_player_name(),meta) then return 0 end
		return stack:get_count()
	end,



	allow_metadata_inventory_take = function(pos, listname, index, stack, player)
		local meta = minetest.get_meta(pos)
		if not barter.chest.check_privilege(listname,player:get_player_name(),meta) then return 0 end
		return stack:get_count()
	end,
})