Module:Wikibase

-- Module:Wikibase
local p = {}

-- Return the item ID of the item connected to the current page or connected to a page title via a sitelink.
-- mw.wikibase.getEntityIdForCurrentPage, mw.wikibase.getEntityIdForTitle
function p.id(frame)
	local page_title = frame.args[1] and mw.text.trim(frame.args[1])
	if page_title == nil or page_title == '' then
		return mw.wikibase.getEntityIdForCurrentPage()
	end
	return mw.wikibase.getEntityIdForTitle(page_title)
end

-- Return the label of a given data item, optionally in a given language.
-- mw.wikibase.getLabel, mw.wikibase.getLabelByLang
function p.label(frame)
	local id
	if frame.args[1] == nil then
		id = mw.wikibase.getEntityIdForCurrentPage()
		if not id then return nil end
	else
		id = mw.text.trim(frame.args[1])
	end
	if frame.args[2] then
		return mw.wikibase.getLabelByLang(id, mw.text.trim(frame.args[2]))
	end
	return mw.wikibase.getLabel(id)
end

-- Return the description of a given data entity, optionally in a given language.
-- mw.wikibase.getDescription
function p.description(frame)
	local id = frame.args[1] and mw.text.trim(frame.args[1]) or nil
	local lang = frame.args[2] and mw.text.trim(frame.args[2]) or nil
	local entity = mw.wikibase.getEntity(id)
	if not entity then return nil end
	return entity:getDescription(lang)
end

-- Return the local page about a given data item, optionary in a given wiki.
-- mw.wikibase.getSitelink
function p.getSiteLink(frame)
	local id = frame.args[1] and mw.text.trim(frame.args[1])
	if id == nil or id == '' then
		id = mw.wikibase.getEntityIdForCurrentPage()
		if not id then return nil end
	end
	return mw.wikibase.getSitelink(id, mw.text.trim(frame.args[2] or ''))
end

-- Return first lemma and language for a lexeme
-- entity:getLemmas()
function p.getLemma(frame) -- simple for simple templates like {{Q|}}}
	local entity = mw.wikibase.getEntity(frame.args[1])
	if not entity then
		return
	end
	local lemmas = entity:getLemmas()
	return lemmas[1][1] .. " <sup>(" .. lemmas[1][2] .. ")</sup>"
end

return p