Add compat lib

packages/host/lua/clusterio_lib/info.json

@@ -19,6 +19,7 @@
 	"homepage": "https://github.com/clusterio/clusterio",
 	"description": "Library for interfacing with Clusterio.  Warning: work in progress alpha.",
 	"additional_files": {
+		"compat.lua": ["..", "..", "modules", "clusterio", "compat.lua"],
 		"serialize.lua": ["..", "..", "modules", "clusterio", "serialize.lua"]
 	}
 }

packages/host/modules/clusterio/compat.lua

@@ -0,0 +1,148 @@
+--[[
+Adds various functions used to ensure compatibly between version including some polyfills
+]]
+
+--- @class LibCompat
+local compat = {}
+
+--- @alias VersionTable { [1]: number, [2]: number, [3]: number }
+
+--- Concert a version string into a version table
+--- @param version string
+--- @return VersionTable
+local function version_to_table(version)
+	local index = 0
+	local rtn = { 0, 0, 0 }
+	for part in version:gmatch("%d+") do
+		index = index + 1
+		rtn[index] = tonumber(part)
+	end
+	return rtn
+end
+
+--- The current version of factorio, the earliest supported is 0.17.69
+local current_version_str = "0.17.69"
+local current_version = version_to_table(current_version_str)
+do
+	local success, base_version = pcall(function()
+		return script.active_mods.base
+	end)
+	if success then
+		current_version_str = base_version
+		current_version = version_to_table(current_version_str)
+	end
+end
+
+--- Raise an error because the current version is unsupported
+--- @return any
+local function unsupported_version()
+	error("Unsupported version: " .. current_version_str, 3)
+end
+
+--- Returns true if the current version is equal to the provided version
+--- @param version string Version to compare against
+--- @return boolean # True if versions are equal
+function compat.version_eq(version)
+	local version_tbl = version_to_table(version)
+	for i = 1, 3 do
+		if version_tbl[i] ~= current_version[i] then
+			return false
+		end
+	end
+	return true
+end
+
+--- Returns true if the current version is greater than or equal to the the provided version
+--- @param version string Version to compare against
+--- @return boolean # True if the version is greater or equal to provided
+function compat.version_ge(version)
+	local version_tbl = version_to_table(version)
+	for i = 1, 3 do
+		if version_tbl[i] > current_version[i] then
+			return false
+		elseif version_tbl[i] < current_version[i] then
+			return true
+		end
+	end
+	return true
+end
+
+--- Returns true if the current version is less than or equal to the the provided version
+--- @param version string Version to compare against
+--- @return boolean # True if the version is less or equal to provided
+function compat.version_le(version)
+	return not compat.version_ge(version)
+end
+
+--- The major versions of factorio we support
+local major_v2 = compat.version_ge("2.0.0")
+local major_v1_1 = not major_v2 and compat.version_ge("1.1.0")
+-- local major_v1 = not major_v1_1 and compat.version_ge("1.0.0")
+
+--- Returns the table reference used to store script data
+--- @return table script_data
+function compat.script_data()
+	if major_v1_1 then
+		return global
+	elseif major_v2 then
+		return storage
+	end
+	return unsupported_version()
+end
+
+--- Returns the table reference used to store prototypes
+--- @param category string Category of prototype to access, eg "item", "fluid", "recipe"
+--- @return table # Table of prototype data
+function compat.prototype_data(category)
+	if major_v1_1 then
+		return game[category .. "_prototypes"]
+	elseif major_v2 then
+		return prototypes[category]
+	end
+	return unsupported_version()
+end
+
+--- Returns the table reference used to list active mods
+--- @return table # Table of active mods
+function compat.active_mods()
+	if major_v1_1 or major_v2 then
+		return script.active_mods
+	end
+	return unsupported_version()
+end
+
+--- Converts a table into a json string
+--- @param tbl table Table to convert to json
+--- @return string # Json string representing the table
+function compat.table_to_json(tbl)
+	return unsupported_version()
+end
+
+--- Converts a json string into a table
+--- @param json string Json string representing a table
+--- @return table # Table created from the string
+function compat.json_to_table(tbl)
+	return unsupported_version()
+end
+
+--- Write a file to script output directory
+--- @param filename string The name of the file.
+--- @param data LocalisedString The content to write to the file.
+--- @param append boolean? True if the data will be appended, false will overwrite existing data
+--- @param for_player uint? If given, file is only written for this player index, 0 represents the server
+--- @return table # Table created from the string
+function compat.write_file(filename, data, append, for_player)
+	return unsupported_version()
+end
+
+if major_v1_1 then
+	-- Game is not always available so it needs to be called within another function
+	-- TODO maybe include a version that does not require game?
+	compat.table_to_json = function(...) return game.table_to_json(...) end
+	compat.json_to_table = function(...) return game.json_to_table(...) end
+	compat.write_file = function(...) return game.write_file(...) end
+elseif major_v2 then
+	compat.table_to_json = helpers.table_to_json
+	compat.json_to_table = helpers.json_to_table
+	compat.write_file = helpers.write_file
+end