First version 🐈

shop_functions.lua

@@ -0,0 +1,162 @@
+function exchange_shop.has_access(meta, player_name)
+	local owner = meta:get_string("owner")
+	if player_name == owner or owner == "" then
+		return true
+	end
+	local privs = minetest.get_player_privs(player_name)
+	return privs.server or privs.protection_bypass
+end
+
+
+-- Tool wear aware replacement for contains_item.
+function exchange_shop.list_contains_item(inv, listname, stack)
+	local count = stack:get_count()
+	if count == 0 then
+		return true
+	end
+
+	local list = inv:get_list(listname)
+	local name = stack:get_name()
+	local wear = stack:get_wear()
+	for _, list_stack in pairs(list) do
+		if list_stack:get_name() == name and
+		   list_stack:get_wear() <= wear then
+			if list_stack:get_count() >= count then
+				return true
+			else
+				count = count - list_stack:get_count()
+			end
+		end
+	end
+end
+
+-- Tool wear aware replacement for remove_item.
+function exchange_shop.list_remove_item(inv, listname, stack)
+	local wanted = stack:get_count()
+	if wanted == 0 then
+		return stack
+	end
+
+	local list = inv:get_list(listname)
+	local name = stack:get_name()
+	local wear = stack:get_wear()
+	local remaining = wanted
+	local removed_wear = 0
+
+	for index, list_stack in pairs(list) do
+		if list_stack:get_name() == name and
+		   list_stack:get_wear() <= wear then
+			local taken_stack = list_stack:take_item(remaining)
+			inv:set_stack(listname, index, list_stack)
+
+			removed_wear = math.max(removed_wear, taken_stack:get_wear())
+			remaining = remaining - taken_stack:get_count()
+			if remaining == 0 then
+				break
+			end
+		end
+	end
+
+	-- Todo: Also remove kebab
+	local removed_stack = ItemStack(name)
+	removed_stack:set_count(wanted - remaining)
+	removed_stack:set_wear(removed_wear)
+	return removed_stack
+end
+
+function exchange_shop.exchange_action(player_inv, shop_inv)
+	if not shop_inv:is_empty("cust_ej")
+			or not shop_inv:is_empty("custm_ej") then
+		return "One or multiple ejection fields are filled. "..
+			"Please empty them or contact the shop owner."
+	end
+	local owner_wants = shop_inv:get_list("cust_ow")
+	local owner_gives = shop_inv:get_list("cust_og")
+
+	-- Check validness of stack "owner wants"
+	for i1, item1 in pairs(owner_wants) do
+		local name1 = item1:get_name()
+		for i2, item2 in pairs(owner_wants) do
+			if name1 == "" then
+				break
+			end
+			if i1 ~= i2 and name1 == item2:get_name() then
+				return "The field 'Owner needs' can not contain multiple "..
+					"times the same items. Please contact the shop owner."
+			end
+		end
+	end
+
+	-- Check validness of stack "owner gives"
+	for i1, item1 in pairs(owner_gives) do
+		local name1 = item1:get_name()
+		for i2, item2 in pairs(owner_gives) do
+			if name1 == "" then
+				break
+			end
+			if i1 ~= i2 and name1 == item2:get_name() then
+				return "The field 'Owner gives' can not contain multiple "..
+					"times the same items. Please contact the shop owner."
+			end
+		end
+	end
+
+	-- Check for space in the shop
+	for i, item in pairs(owner_wants) do
+		if not shop_inv:room_for_item("custm", item) then
+			return "The stock in this shop is full. "..
+				"Please contact the shop owner."
+		end
+	end
+
+	local list_contains_item = exchange_shop.list_contains_item
+
+	-- Check availability of the shop's items
+	for i, item in pairs(owner_gives) do
+		if not list_contains_item(shop_inv, "stock", item) then
+			return "This shop is sold out."
+		end
+	end
+
+	-- Check for space in the player's inventory
+	for i, item in pairs(owner_gives) do
+		if not player_inv:room_for_item("main", item) then
+			return "You do not have enough space in your inventory."
+		end
+	end
+
+	-- Check availability of the player's items
+	for i, item in pairs(owner_wants) do
+		if not list_contains_item(player_inv, "main", item) then
+			return "You do not have the required items."
+		end
+	end
+
+	local list_remove_item = exchange_shop.list_remove_item
+
+	-- Conditions are ok: (try to) exchange now
+	local fully_exchanged = true
+	for i, item in pairs(owner_wants) do
+		local stack = list_remove_item(player_inv, "main", item)
+		if shop_inv:room_for_item("custm", stack) then
+			shop_inv:add_item("custm", stack)
+		else
+			-- Move to ejection field
+			shop_inv:add_item("custm_ej", stack)
+			fully_exchanged = false
+		end
+	end
+	for i, item in pairs(owner_gives) do
+		local stack = list_remove_item(shop_inv, "stock", item)
+		if player_inv:room_for_item("main", stack) then
+			player_inv:add_item("main", stack)
+		else
+			-- Move to ejection field
+			shop_inv:add_item("cust_ej", stack)
+			fully_exchanged = false
+		end
+	end
+	if not fully_exchanged then
+		return "Warning! Stacks are overflowing somewhere!"
+	end
+end