Module:language-like

local export = {}

-- Implementation of getOtherNames() for languages, etymology languages,
-- families and scripts. If `onlyOtherNames` is passed in, only return
-- the names in the `otherNames` field, otherwise combine `otherNames`,
-- `aliases` and `varieties`.
function export.getOtherNames(self, onlyOtherNames)
	local data
	if self._extraData then
		data = self._extraData
	else
		data = self._rawData
	end
	if onlyOtherNames then
		return data.otherNames or {}
	end
	-- Combine otherNames, aliases and varieties. First try to optimize and not create any
	-- new memory. This is possible if exactly one of the three exist, and if it's `varieties`,
	-- there are no nested lists in `varieties`.
	if data.otherNames and not data.aliases and not data.varieties then
		return data.otherNames
	elseif data.aliases and not data.otherNames and not data.varieties then
		return data.aliases
	elseif data.varieties and not data.otherNames and not data.aliases then
		local saw_table = false
		for _, name in ipairs(data.varieties) do
			if type(name) == "table" then
				saw_table = true
				break
			end
		end
		if not saw_table then
			return data.varieties
		end
	end

	-- Have to do it the "hard way".
	local ret = {}
	if data.otherNames then
		for _, name in ipairs(data.otherNames) do
			table.insert(ret, name)
		end
	end
	if data.aliases then
		for _, name in ipairs(data.aliases) do
			table.insert(ret, name)
		end
	end
	if data.varieties then
		for _, name in ipairs(data.varieties) do
			if type(name) == "table" then
				for _, n in ipairs(name) do
					table.insert(ret, n)
				end
			else
				table.insert(ret, name)
			end
		end
	end
	return ret
end


-- Implementation of getVarieties() for languages, etymology languages,
-- families and scripts. If `flatten` is passed in, flatten down to a
-- list of stings; otherwise, keep the structure.
function export.getVarieties(self, flatten)
	local data
	if self._extraData then
		data = self._extraData
	else
		data = self._rawData
	end
	if data.varieties then
		-- If flattening not requested, just return them.
		if not flatten then
			return data.varieties
		end
		-- Check if no nested table; if so, just return the result.
		local saw_table = false
		for _, name in ipairs(data.varieties) do
			if type(name) == "table" then
				saw_table = true
				break
			end
		end
		if not saw_table then
			return data.varieties
		end
		-- At this point, we need to flatten the varieties.
		local ret = {}
		for _, name in ipairs(data.varieties) do
			if type(name) == "table" then
				for _, n in ipairs(name) do
					table.insert(ret, n)
				end
			else
				table.insert(ret, name)
			end
		end
		return ret
	else
		return {}
	end
end


-- Implementation of template-callable getByCode() function for languages,
-- etymology languages, families and scripts. `item` is the language,
-- family or script in question; `args` is the arguments passed in by the
-- module invocation; `extra_processing`, if specified, is a function of
-- one argument (the requested property) and should return the value to
-- be returned to the caller, or nil if the property isn't recognized.
-- `extra_processing` is called after special-cased properties are handled
-- and before general-purpose processing code that works for all string
-- properties.
function export.templateGetByCode(item, args, extra_processing)
	-- The item that the caller wanted to look up
	local itemname = args[2] or error("Function to call (parameter 2) has not been specified.")
	local list
	if itemname == "getOtherNames" then
		list = item:getOtherNames()
	elseif itemname == "getOnlyOtherNames" then
		list = item:getOtherNames(true)
	elseif itemname == "getAliases" then
		list = item:getAliases()
	elseif itemname == "getVarieties" then
		list = item:getVarieties(true)
	end
	if list then
		local index = args[3]; if index == "" then index = nil end
		index = tonumber(index or error("Numeric index of the desired item in the list (parameter 3) has not been specified."))
		return list[index] or ""
	end

	if itemname == "getFamily" and item.getFamily then
		return item:getFamily():getCode()
	end

	if extra_processing then
		local retval = extra_processing(itemname)
		if retval then
			return retval
		end
	end

	if item[itemname] then
		local ret = item[itemname](item)
		
		if type(ret) == "string" then
			return ret
		else
			error("The function \"" .. itemname .. "\" did not return a string value.")
		end
	end

	error("Requested invalid item name \"" .. itemname .. "\".")
end

return export