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)
	if onlyOtherNames then
		return self._rawData.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 self._rawData.otherNames and not self._rawData.aliases and not self._rawData.varieties then
		return self._rawData.otherNames
	elseif self._rawData.aliases and not self._rawData.otherNames and not self._rawData.varieties then
		return self._rawData.aliases
	elseif self._rawData.varieties and not self._rawData.otherNames and not self._rawData.aliases then
		local saw_table = false
		for _, name in ipairs(self._rawData.varieties) do
			if type(name) == "table" then
				saw_table = true
				break
			end
		end
		if not saw_table then
			return self._rawData.varieties
		end
	end

	-- Have to do it the "hard way".
	local ret = {}
	if self._rawData.otherNames then
		for _, name in ipairs(self._rawData.otherNames) do
			table.insert(ret, name)
		end
	end
	if self._rawData.aliases then
		for _, name in ipairs(self._rawData.aliases) do
			table.insert(ret, name)
		end
	end
	if self._rawData.varieties then
		for _, name in ipairs(self._rawData.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)
	if self._rawData.varieties then
		-- If flattening not requested, just return them.
		if not flatten then
			return self._rawData.varieties
		end
		-- Check if no nested table; if so, just return the result.
		local saw_table = false
		for _, name in ipairs(self._rawData.varieties) do
			if type(name) == "table" then
				saw_table = true
				break
			end
		end
		if not saw_table then
			return self._rawData.varieties
		end
		-- At this point, we need to flatten the varieties.
		local ret = {}
		for _, name in ipairs(self._rawData.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