وحدة:Arguments with aliases

-- This module is forked from [[:en:Module:Arguments]] to support aliases
-- main idea of aliases is from [[:en:Citaion/CS1]]

-- This module provides easy processing of arguments passed to Scribunto from
-- #invoke. It is intended for use by other Lua modules, and should not be
-- called from #invoke directly.

local libraryUtil = require('libraryUtil')
local checkType = libraryUtil.checkType

local arguments = {}

-- Generate four different tidyVal functions, so that we don't have to check the
-- options every time we call it.

local function tidyValDefault(key, val)
	if type(val) == 'string' then
		val = mw.ustring.match(val, '^%s*(.-)%s*$')
		if val == '' then
			return nil
		else
			return val
		end
	else
		return val
	end
end

local function tidyValTrimOnly(key, val)
	if type(val) == 'string' then
		return mw.ustring.match(val, '^%s*(.-)%s*$')
	else
		return val
	end
end

local function tidyValRemoveBlanksOnly(key, val)
	if type(val) == 'string' then
		if mw.ustring.find(val, '%S') then
			return val
		else
			return nil
		end
	else
		return val
	end
end

local function tidyValNoChange(key, val)
	return val
end

local function matchesTitle(given, title)
	local tp = type( given )
	return (tp == 'string' or tp == 'number') and mw.title.new( given ).prefixedText == title
end

local function tableClone(t)
	checkType('tableClone', 1, t, 'table')
	if getmetatable(t) and getmetatable(t).mw_loadData then
		local ret = {}
		for k, v in pairs(t) do
			ret[k] = v
		end
		return ret
	else
		return t
	end
end

function arguments.getArgs(frame, options)
	checkType('getArgs', 1, frame, 'table', true)
	checkType('getArgs', 2, options, 'table', true)
	frame = frame or {}
	options = options or {}
	local aliases = options.aliases and tableClone(options.aliases) or {}
	local numbered_aliases = options.numbered_aliases and tableClone(options.numbered_aliases) or nil
	local backtranslate = options.backtranslate and tableClone(options.backtranslate) or nil
	local numbered_backtranslate = options.numbered_backtranslate and tableClone(options.numbered_backtranslate) or nil
	local origin = {}

	--[[
	-- Set up argument translation.
	--]]
	local translate_mt = { __index = function(t, k)
			local order_num = mw.ustring.match(k,'%d+')
			if order_num and numbered_aliases then
				local plist =  numbered_aliases[mw.ustring.gsub(k,order_num,"#")]
				if plist then
					local ret
					if type(plist) == 'table' then
						ret = {}
						for _,v in ipairs(plist) do
							local numarg = mw.ustring.gsub(v, '#', order_num )
							table.insert(ret, numarg)
						end
					else
						ret= mw.ustring.gsub(plist, '#', order_num )
					end
					return ret
				end
			end
			return k
		end
	}

	if getmetatable(aliases) == nil then
		setmetatable(aliases, translate_mt)
	end

	if backtranslate == nil then
		backtranslate = {}
		for k, list in pairs(aliases) do
			if type(list) == 'table' then
				for _, v in pairs(list) do
					backtranslate[v] = k
				end
			else
				backtranslate[list] = k
			end
		end
	end

	if numbered_aliases and numbered_backtranslate == nil then
		numbered_backtranslate = {}
		for k, list in pairs(numbered_aliases) do
			if type(list) == 'table' then
				for _, v in pairs(list) do
					numbered_backtranslate[v] = k
				end
			else
				numbered_backtranslate[list] = k
			end
		end
	end

	if backtranslate and getmetatable(backtranslate) == nil then
		setmetatable(backtranslate, {
			__index = function(t, k)
				local order_num = mw.ustring.match(k,'%d+')
				if order_num and numbered_backtranslate then
					local plist =  numbered_backtranslate[mw.ustring.gsub(k,order_num,"#")]
					if plist then
						return mw.ustring.gsub(plist, '#', order_num )
					end
				end
				return k
			end
		})
	end

	--[[
	-- Get the argument tables. If we were passed a valid frame object, get the
	-- frame arguments (fargs) and the parent frame arguments (pargs), depending
	-- on the options set and on the parent frame's availability. If we weren't
	-- passed a valid frame object, we are being called from another Lua module
	-- or from the debug console, so assume that we were passed a table of args
	-- directly, and assign it to a new variable (luaArgs).
	--]]
	local fargs, pargs, luaArgs
	if type(frame.args) == 'table' and type(frame.getParent) == 'function' then
		if options.wrappers then
			--[[
			-- The wrappers option makes Module:Arguments look up arguments in
			-- either the frame argument table or the parent argument table, but
			-- not both. This means that users can use either the #invoke syntax
			-- or a wrapper template without the loss of performance associated
			-- with looking arguments up in both the frame and the parent frame.
			-- Module:Arguments will look up arguments in the parent frame
			-- if it finds the parent frame's title in options.wrapper;
			-- otherwise it will look up arguments in the frame object passed
			-- to getArgs.
			--]]
			local parent = frame:getParent()
			if not parent then
				fargs = frame.args
			else
				local title = mw.ustring.gsub(mw.ustring.gsub(parent:getTitle(), '/sandbox$', ''), '/ملعب$', '')
				local found = false
				if matchesTitle(options.wrappers, title) then
					found = true
				elseif type(options.wrappers) == 'table' then
					for _,v in pairs(options.wrappers) do
						if matchesTitle(v, title) then
							found = true
							break
						end
					end
				end

				-- We test for false specifically here so that nil (the default) acts like true.
				if found or options.frameOnly == false then
					pargs = parent.args
				end
				if not found or options.parentOnly == false then
					fargs = frame.args
				end
			end
		else
			-- options.wrapper isn't set, so check the other options.
			if not options.parentOnly then
				fargs = frame.args
			end
			if not options.frameOnly then
				local parent = frame:getParent()
				pargs = parent and parent.args or nil
			end
		end
		if options.parentFirst then
			fargs, pargs = pargs, fargs
		end
	else
		luaArgs = frame
	end

	-- Set the order of precedence of the argument tables. If the variables are
	-- nil, nothing will be added to the table, which is how we avoid clashes
	-- between the frame/parent args and the Lua args.
	local argTables = {fargs}
	argTables[#argTables + 1] = pargs
	argTables[#argTables + 1] = luaArgs

	--[[
	-- Generate the tidyVal function. If it has been specified by the user, we
	-- use that; if not, we choose one of four functions depending on the
	-- options chosen. This is so that we don't have to call the options table
	-- every time the function is called.
	--]]
	local tidyVal = options.valueFunc
	if tidyVal then
		if type(tidyVal) ~= 'function' then
			error(
				"bad value assigned to option 'valueFunc'"
					.. '(function expected, got '
					.. type(tidyVal)
					.. ')',
				2
			)
		end
	elseif options.trim ~= false then
		if options.removeBlanks ~= false then
			tidyVal = tidyValDefault
		else
			tidyVal = tidyValTrimOnly
		end
	else
		if options.removeBlanks ~= false then
			tidyVal = tidyValRemoveBlanksOnly
		else
			tidyVal = tidyValNoChange
		end
	end

	--[[
	-- Set up the args, metaArgs and nilArgs tables. args will be the one
	-- accessed from functions, and metaArgs will hold the actual arguments. Nil
	-- arguments are memoized in nilArgs, and the metatable connects all of them
	-- together.
	--]]
	local args, metaArgs, nilArgs, metatable = {}, {}, {}, {}
	setmetatable(args, metatable)

	local function mergeArgs(tables)
		--[[
		-- Accepts multiple tables as input and merges their keys and values
		-- into one table. If a value is already present it is not overwritten;
		-- tables listed earlier have precedence. We are also memoizing nil
		-- values, which can be overwritten if they are 's' (soft).
		--]]
		for _, t in ipairs(tables) do
			for akey, val in pairs(t) do
				local key = backtranslate[akey]
				if metaArgs[key] == nil and nilArgs[key] ~= 'h' then
					local tidiedVal = tidyVal(key, val)
					if tidiedVal == nil then
						nilArgs[key] = 's'
					else
						metaArgs[key] = tidiedVal
						origin[key] = akey
					end
				end
			end
		end
	end

	--[[
	-- Define metatable behaviour. Arguments are memoized in the metaArgs table,
	-- and are only fetched from the argument tables once. Fetching arguments
	-- from the argument tables is the most resource-intensive step in this
	-- module, so we try and avoid it where possible. For this reason, nil
	-- arguments are also memoized, in the nilArgs table. Also, we keep a record
	-- in the metatable of when pairs and ipairs have been called, so we do not
	-- run pairs and ipairs on the argument tables more than once. We also do
	-- not run ipairs on fargs and pargs if pairs has already been run, as all
	-- the arguments will already have been copied over.
	--]]

	metatable.__index = function (t, key)
		--[[
		-- Fetches an argument when the args table is indexed. First we check
		-- to see if the value is memoized, and if not we try and fetch it from
		-- the argument tables. When we check memoization, we need to check
		-- metaArgs before nilArgs, as both can be non-nil at the same time.
		-- If the argument is not present in metaArgs, we also check whether
		-- pairs has been run yet. If pairs has already been run, we return nil.
		-- This is because all the arguments will have already been copied into
		-- metaArgs by the mergeArgs function, meaning that any other arguments
		-- must be nil.
		--]]
		local val = metaArgs[key]
		if val ~= nil then
			return val
		elseif  metatable.donePairs or nilArgs[key] then
			return nil
		end
		
		local list = (type(key) == "number") and key or aliases[key];
		for _,argTable in ipairs(argTables) do
			if type( list ) == 'table' then
				for _, alias_key in pairs( list ) do
					local argTableVal = tidyVal(key, argTable[alias_key])
					if argTableVal ~= nil then
						metaArgs[key] = argTableVal
						origin[key] = alias_key
						return argTableVal
					end
				end
			elseif list ~= nil then
				local argTableVal = tidyVal(key, argTable[list])
				if argTableVal ~= nil then
					metaArgs[key] = argTableVal
					origin[key] = list
					return argTableVal
				end
			end

			if argTable[key] then
				local argTableVal = tidyVal(key, argTable[key])
				if argTableVal ~= nil then
					metaArgs[key] = argTableVal
					origin[key] = key
					return argTableVal
				end
			end
		end

		nilArgs[key] = 'h'
		return nil
	end

	metatable.__newindex = function (t, key, val)
		-- This function is called when a module tries to add a new value to the
		-- args table, or tries to change an existing value.
		if options.readOnly then
			error(
				'could not write to argument table key "'
					.. tostring(key)
					.. '"; the table is read-only',
				2
			)
		elseif options.noOverwrite and args[key] ~= nil then
			error(
				'could not write to argument table key "'
					.. tostring(key)
					.. '"; overwriting existing arguments is not permitted',
				2
			)
		elseif val == nil then
			--[[
			-- If the argument is to be overwritten with nil, we need to erase
			-- the value in metaArgs, so that __index, __pairs and __ipairs do
			-- not use a previous existing value, if present; and we also need
			-- to memoize the nil in nilArgs, so that the value isn't looked
			-- up in the argument tables if it is accessed again.
			--]]
			metaArgs[key] = nil
			nilArgs[key] = 'h'
		else
			metaArgs[key] = val
		end
	end

	args._ORIGIN = function ( self, k )
		-- تعطي الوسيط الأصلي الذي كتبه المستخدم مهمة في رسائل الخطأ
		local dummy = self[k];												-- force the variable to be loaded.
		return origin[k];
	end

	local function translatenext(invariant)
		local k, v = next(invariant.t, invariant.k)
		invariant.k = k
		if k == nil then
			return nil
		elseif k == '_ORIGIN' then
			return translatenext(invariant)
		elseif type(k) ~= 'string' or not backtranslate then
			return k, v
		else
			local k_backtranslate = backtranslate[k]
			if k_backtranslate == nil then
				-- Skip this one. This is a tail call, so this won't cause stack overflow
				return translatenext(invariant)
			else
				return k_backtranslate, v
			end
		end
	end

	metatable.__pairs = function ()
		-- Called when pairs is run on the args table.
		if not metatable.donePairs then
			mergeArgs(argTables)
			metatable.donePairs = true
		end
		return translatenext, { t = metaArgs }
	end

	local function inext(t, i)
		-- This uses our __index metamethod
		local v = t[i + 1]
		if v ~= nil then
			return i + 1, v
		end
	end

	metatable.__ipairs = function (t)
		-- Called when ipairs is run on the args table.
		return inext, t, 0
	end

	return args
end

return arguments