Module:External links/sandbox

require('strict')
-- local genitive = require('Module:Genitive')._genitive
local contLangCode = mw.language.getContentLanguage():getCode()

local cmodule = {}
local conf = require 'Module:External links/conf'(contLangCode)
local hasdatafromwikidata = false
local hasdatafromlocal = false
local haswikidatalink = true -- we assume it's connected

local p = {}

local function getLabel(entity, use_genitive, pagetitle)
	local label = (pagetitle ~= '') and pagetitle or nil
	if not label and not entity then
		label = mw.title.getCurrentTitle().text
	elseif not label then
		label = mw.wikibase.label(entity.id) or mw.title.getCurrentTitle().text
	end
--	return use_genitive and genitive(label, 'sitt') or label
	return use_genitive and label .. "'s" or label
end

-- @todo cleanup, this is in production, use the console
local function dump(obj)
	return "<pre>" .. mw.dumpObject(obj) .. "</pre>"
end


local function stringFormatter( datavalue )
	if datavalue == nil or datavalue.type ~= 'string' then
		return nil
	end
	return datavalue.value
end

-- This is a really makeshift crappy converter, but it'll do some basic
-- conversion from PCRE to Lua-style patterns (note that this only work
-- in very few cases)
local function regexConverterTest( regex, str )
	regex = regex:gsub("\\d{(%d)}", function(num) return string.rep("%d", num) end)
	
	return string.find(str, '^' .. regex .. '$')
end


local function getFormatterUrl( prop, value )
	local fUrl = ""
	local statements = mw.wikibase.getBestStatements(prop, "P1630")
	-- to avoid deep tests
	if #statements == 0 then
		return ""
	end
	-- let's go through the claims
	for _, claim in ipairs( statements ) do
		local mainsnak = claim.mainsnak or {}
		-- get any qualifiers for this claim (we are interested in P1793 for
		-- indication of which claim is correct) 
		local qualifiers = claim.qualifiers or {}
		-- now let's check the qualifier we are interested in
		local qualid = 'P1793' -- format as a regular expression
		-- if the claim has this qualifier
		if qualifiers[qualid] then
			-- it's here, let's check it out!
			-- traverse all snaks in this qualifier
			for _, qualsnak in ipairs( qualifiers[qualid] ) do
				if qualsnak.snaktype == 'value'
					and regexConverterTest(qualsnak.datavalue.value, value) 
				then
					-- it matched, this is correct and overrides any other.
					fUrl = mainsnak.datavalue.value
					break
				end
			end
		elseif fUrl == '' then -- if we don't have any other, use this one
			fUrl = mainsnak.datavalue.value
		end
	end
	return fUrl
end



local function getLanguageData(prop, qid, separator)
	-- Formerly outputted a table, but this function was always run through table.concat() when invoked, so it has been simplified to yield a string
	separator = separator or ''
	local output = ''
	if not mw.wikibase.entityExists(qid) then -- yield error, which would originally happen because table.concat(nil) errors
		error("getLanguageData was given a nonexistent entity")
	end
	-- get claims
	local statements = mw.wikibase.getBestStatements(qid, prop)
	-- to avoid deep tests
	if #statements == 0 then
		return ''
	end
	-- mw.log("getLanguageData going through claims="..dump(statements))
	-- let's go through the claims
	for _, claim in ipairs( statements ) do
		local mainsnak = claim.mainsnak
		if mainsnak.snaktype == 'value' then
			-- if this is the correct P-value, dive into it and get P218 (ISO 639-1)
			if prop == 'P364' then -- original language of work
				output = output .. separator .. getLanguageData('P218', mainsnak.datavalue.value.id, conf:a('mod-filter-separator'))
			elseif prop == 'P218' or prop == 'P305' then -- ISO 639-1 code or IETF language tag
				output = output .. separator .. stringFormatter(mainsnak.datavalue)
			end
		end
	end
	return output
end

local langqvalorder = {'P407','P364'} -- check `language of work or name` first, `original language of film or TV show` second
local otherqvalorder = {'P582'}

local function getValuesFromWikidata(linkTemplate)
	local output = {}
	-- mw.log("getValuesFromWikidata, linkTemplate="..dump(linkTemplate))
	-- get statements
	local entity = mw.wikibase.getEntity()
	-- check if the entity exists
	-- TODO: check if we can skip distinguishing between no entity vs. no statements
	if not entity then -- check if the entity exists
		return nil
	end
	local statements = entity:getBestStatements(linkTemplate.prop)
	-- to avoid deep tests
	if #statements == 0 then
		return {}
	end
	-- let's go through the claims
	for _, claim in ipairs( statements ) do
		local qualifiers = claim.qualifiers or {}
		-- get the content of the claim (the identifier)
		local langcode = linkTemplate.langcode
		if langcode
			and langcode ~= ''
			and string.find(langcode, "[pP]%d+") 
		then
			-- this is a P-value for language-code, so we'll check qualifiers for languagedata
			-- first get any qualifiers
			for _, qualid in ipairs( langqvalorder ) do
				-- if the claim has this qualifier
				if qualifiers[qualid] then
					-- it's here, let's check it out!
					-- traverse all snaks in this qualifier
					for _, qualsnak in ipairs( qualifiers[qualid] ) do
						if qualsnak.snaktype == 'value' then
							-- now get the actual data
							langcode = getLanguageData('P305', qualsnak.datavalue.value.id)
						end
					end
				end
				-- mw.log("langcode is now="..dump(langcode))
			end
			if string.find(langcode, "[pP]%d+") then
				-- we still don't have any langcode, so we default to "en"
				langcode = nil
			end
		end
		--[[ EDITOR'S NOTE: 
			I trimmed the `stillvalid` check thinking it was just doing stuff already handled by Wikibase's built-in input constraints.
			However, it would've also aborted the loop iteration if "end time" was provided with `no value` or `unknown valuee`.
			I'm not sure if that functionality would've had any purpose, given how cryptic this function is.
		]]
		output[#output+1] = { value=stringFormatter(claim.mainsnak.datavalue) }
		if langcode and langcode ~= '' then
			output[#output]['langcode'] = langcode
		end
	end
	-- mw.log("getValuesFromWikidata returning head="..dump(head).." tail="..dump(tail))
	return output
end

local function findMainLinksOnWikidata(linkTemplate, pagetitle, short_links)
	local output = {}
	-- get the entity we are checking
	local entity = mw.wikibase.getEntity()
	-- to avoid deep tests
	if not entity then
		return nil
	end
	local values = getValuesFromWikidata(linkTemplate)
	for _, value in ipairs( values ) do
		local verified_value = value.value
		if not (linkTemplate.regex and
			regexConverterTest(linkTemplate.regex, value.value))
		then
			local url = ''
			output[#output+1] = {
				langcode = value.langcode,
				category = {}
			}
			-- Search for a url formatter
			if linkTemplate.url_f then
				-- we have a locally defined url-formatter function from the config, use it as first priority
				url = linkTemplate.url_f(verified_value)
				if linkTemplate.track and not string.find(linkTemplate.langcode, "[pP]%d+") then 
					output[#output].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-local-wd'), linkTemplate.prop):plain()
				elseif linkTemplate.track then 
					output[#output].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-wd-wd'), linkTemplate.prop):plain()
				end
			elseif linkTemplate.url then
				-- we have a locally defined url-formatter string from the config, use it as second priority
				url = mw.message.newRawMessage(linkTemplate.url, verified_value):plain()
				if linkTemplate.track and not string.find(linkTemplate.langcode, "[pP]%d+") then 
					output[#output].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-local-wd'), linkTemplate.prop):plain()
				elseif linkTemplate.track then 
					output[#output].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-wd-wd'), linkTemplate.prop):plain()
				end
			else
				-- config has no url formatter; check if Wikidata has one on the property
				local formatterUrl = getFormatterUrl(linkTemplate.prop, verified_value)
				if formatterUrl ~= '' then
					url = mw.message.newRawMessage(formatterUrl, verified_value):plain()
					if linkTemplate.track then 
						output[#output].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-wd-wd'), linkTemplate.prop):plain()
					end
				end
			end
			if url ~= '' then
				local langlink = (value.langcode and value.langcode ~= '' and value.langcode ~= contLangCode) and mw.message.newRawMessage(conf:g('msg-langcode'), value.langcode, mw.language.fetchLanguageName(value.langcode, contLangCode)) or ""
				output[#output].text =
					mw.message.newRawMessage(short_links and linkTemplate.short or linkTemplate.message,
						getLabel(entity, linkTemplate.genitive, pagetitle),
						url,
						langlink,
						verified_value,
						mw.uri.encode(verified_value, 'PATH'))
					:plain()
			end
		end
	end
	--mw.log("findMainLinksOnWikidata returning="..dump(output))
	return output
end

local function getSitelinkFromWikidata(linkTemplate, entity)
	-- to avoid deep tests
	if not entity then
		entity = mw.wikibase.getEntity()
		if not entity then
			--mw.log("getSitelinkFromWikidata no entity")
			return nil
		end
	end
	local requested_sitelink = string.match(linkTemplate.prop, "SL(%l+)") -- a specific wiki to be linked to can be specified by config; otherwise, default to this wiki
	local sitelink = entity:getSitelink(requested_sitelink)
	return sitelink or nil
end

-- This function has a bug: :getSitelink does not return an object - only a string; yet this function tries to access sitelink.langcode
local function findSiteLinksOnWikidata(linkTemplate, pagetitle, short_links)
	local output = {}
	
	local sitelink = getSitelinkFromWikidata(linkTemplate)
	-- verify existence of sitelink
	if not sitelink then
		return nil
	end
	if not (linkTemplate.regex and
		regexConverterTest(linkTemplate.regex, sitelink))
	then
		--mw.log("it's verified..")
		local url = ''
		output[1] = {
			langcode = sitelink.langcode,
			category = {}
		}
		-- Search for a url-formatter
		if linkTemplate.url_f then
			-- we have a locally defined url-formatter function from the config, use it as first priority
			url = linkTemplate.url_f(sitelink)
		elseif linkTemplate.url then
			-- we have a locally defined url-formatter string from the config, use it as second priority
			url = mw.message.newRawMessage(linkTemplate.url, sitelink):plain()
		else
			url = sitelink:gsub(' ','_')
		end
		
		if linkTemplate.track and not string.find(linkTemplate.langcode, "SL%l+") and (linkTemplate.url_f or linkTemplate.url) then
			output[1].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-local-wd'), linkTemplate.prop):plain()
		elseif linkTemplate.track then
			output[1].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-wd-wd'), linkTemplate.prop):plain()
		end
		
		if url ~= '' then
			local langlink = (sitelink.langcode and sitelink.langcode ~= '' and sitelink.langcode ~= contLangCode) and mw.message.newRawMessage(conf:g('msg-langcode'), sitelink.langcode, mw.language.fetchLanguageName(sitelink.langcode, contLangCode)) or ""
			output[1].text =
				mw.message.newRawMessage(short_links and linkTemplate.short or linkTemplate.message,
					getLabel(entity, linkTemplate.genitive, pagetitle),
					url,
					langlink,
					sitelink,
					mw.uri.encode(sitelink, 'PATH'))
				:plain()
		end
	end
	--mw.log("findSiteLinksOnWikidata returning="..dump(output))
	return output
end


local function findMainLinksLocal(linkTemplate, pagetitle, short_links, local_value)
	local output = {}
	-- to avoid deep tests
	if not local_value or local_value == '' -- bail out if no value is present
		or (linkTemplate.regex and linkTemplate.regex ~= ''
			and not regexConverterTest(linkTemplate.regex, local_value))
	then
		return {}
	end
	local wikidata_property = string.find(linkTemplate.prop, "[pP]%d+")
	local wikidata_values = nil
	if wikidata_property then
		-- get any wikidata values to see if they are equal to local values
		wikidata_values = getValuesFromWikidata(linkTemplate)
	end
	if wikidata_property or (linkTemplate.url and linkTemplate.url ~= '') or (linkTemplate.url_f) then
		output[1] = {
			langcode = string.find(linkTemplate.langcode, "[pP]%d+") and "" or linkTemplate.langcode,
			category = {}
		}
		local url = ''
		assert(not wikidata_values or type(wikidata_values) == 'table', "Something went wrong: wikidata_values is neither a table nor nil")
		if linkTemplate.track and wikidata_values then
			local local_value_in_wikidata = false
			for _,value in ipairs( wikidata_values ) do
				if value.value == local_value then
					local_value_in_wikidata = true
					break
				end
			end
			output[1].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, (local_value_in_wikidata and 'track-cat-local-wd-equal' or 'track-cat-local-wd-unequal')), linkTemplate.prop):plain()
		end
		if wikidata_values then
			hasdatafromwikidata = true -- signal up the chain this article has a wikidata claim
		end
		-- Search for a url-formatter
		if linkTemplate.url_f then
			-- we have a locally defined url-formatter function from the config, use it as first priority
			url = linkTemplate.url_f(local_value)
			if linkTemplate.track then 
				output[1].category[#output[1].category+1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-local-local'), linkTemplate.prop):plain()
			end
		elseif linkTemplate.url then
			-- we have a locally defined url-formatter string from the config, use it as second priority
			url = mw.message.newRawMessage(linkTemplate.url, local_value):plain()
			if linkTemplate.track then 
				output[1].category[#output[1].category+1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-local-local'), linkTemplate.prop):plain()
			end
		else -- we know wikidata_property exists
			-- config has no url formatter; check if Wikidata has one on the property
			local formatterUrl = getFormatterUrl(linkTemplate.prop, local_value)
			if formatterUrl ~= '' then
				url = mw.message.newRawMessage(formatterUrl, local_value):plain()
				if linkTemplate.track then
					output[1].category[#output[1].category+1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-wd-local'), linkTemplate.prop):plain()
				end
			end
		end
		local langlink = (output[1].langcode and output[1].langcode ~= '' and output[1].langcode ~= contLangCode) and mw.message.newRawMessage(conf:g('msg-langcode'), linkTemplate.langcode, mw.language.fetchLanguageName(linkTemplate.langcode, contLangCode)) or ""
		output[1].text =
			mw.message.newRawMessage(short_links and linkTemplate.short or linkTemplate.message,
				getLabel(nil, linkTemplate.genitive, pagetitle),
				url,
				langlink,
				local_value,
				mw.uri.encode(local_value, 'PATH'))
			:plain()
	end
	--mw.log("findMainLinksLocal returning="..dump(output))
	return output
end

local function findSiteLinksLocal(linkTemplate, pagetitle, short_links, local_value)
	local output = {}
	-- to avoid deep tests
	if not local_value or local_value == '' -- bail out if no value is present
		or (linkTemplate.regex and linkTemplate.regex ~= ''
			and not regexConverterTest(linkTemplate.regex, local_value))
	then
		return {}
	end
	local wikidata_property = string.find(linkTemplate.prop, "SL.+")
	local wikidata_sitelink = nil
	if wikidata_property then
		-- get any wikidata values to see if they are equal to local values
		wikidata_sitelink = getSitelinkFromWikidata(linkTemplate)
	end
	if wikidata_property or (linkTemplate.url and linkTemplate.url ~= '') or (linkTemplate.url_f) then
		output[1] = {
			langcode = string.find(linkTemplate.langcode, "SL.+") and "" or linkTemplate.langcode,
			category = {}
		}
		--mw.log("findSiteLinksLocal - linkTemplate="..dump(linkTemplate).." langcode="..output[#output].langcode .." wikidata_values="..dump(wikidata_values))
		local url = ''
		if linkTemplate.track and wikidata_sitelink then
			local local_value_in_wikidata = (wikidata_sitelink == local_value)
			output[1].category[1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, (local_value_in_wikidata and 'track-cat-local-wd-equal' or 'track-cat-local-wd-unequal')), linkTemplate.prop):plain()
		end
		if wikidata_sitelink then
			hasdatafromwikidata = true -- signal up the chain this article has a wikidata claim
		end
		-- Search for a url formatter
		if linkTemplate.url_f then
			-- we have a locally defined url-formatter function from the config, use it as first priority
			url = linkTemplate.url_f(local_value)
			if linkTemplate.track then 
				output[1].category[#output[1].category+1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-local-local'), linkTemplate.prop):plain()
			end
		elseif linkTemplate.url then
			-- we have a locally defined url-formatter string from the config, use it as second priority
			url = mw.message.newRawMessage(linkTemplate.url, local_value):plain()
			if linkTemplate.track then 
				output[1].category[#output[1].category+1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-local-local'), linkTemplate.prop):plain()
			end
		else -- we know wikidata_property exists
			url = local_value:gsub(' ','_')
			if linkTemplate.track then 
				output[1].category[#output[1].category+1] = mw.message.newRawMessage(cmodule:getMessage(contLangCode, 'track-cat-wd-local'), linkTemplate.prop):plain()
			end
		end
		local langlink = (output[1].langcode and output[1].langcode ~= '' and output[1].langcode ~= contLangCode) and mw.message.newRawMessage(conf:g('msg-langcode'), linkTemplate.langcode, mw.language.fetchLanguageName(linkTemplate.langcode, contLangCode)) or ""
		output[1].text =
			mw.message.newRawMessage(short_links and linkTemplate.short or linkTemplate.message,
				getLabel(nil, linkTemplate.genitive, pagetitle),
				url,
				langlink,
				local_value,
				mw.uri.encode(local_value, 'PATH'))
			:plain()
	end
	--mw.log("findSiteLinksLocal returning="..dump(output))
	return output
end


local function addLinkback(str, property)
	local id = mw.wikibase.getEntityIdForCurrentPage()
	if not id then
		return str
	end
	
	local class = ''
	local url = ''
	if property then
		class = 'wd_' .. string.lower(property)
		url = mw.uri.fullUrl('d:' .. id .. '#' .. property)
		url.fragment = property
	else
		url = mw.uri.fullUrl('d:' .. id )
	end
	
	local title = conf:g('wikidata-linkback-edit')
	local icon = '[%s [[File:Blue pencil.svg|%s|10px|text-top|link=]] ]'
	url = tostring(url)
	local v = mw.html.create('span')
		:addClass(class)
		:wikitext(str)
		:tag('span')
			:addClass('noprint plainlinks wikidata-linkback')
			:css('padding-left', '.3em')
			:wikitext(icon:format(url, title))
		:allDone()
	return tostring(v)
end


local function getArgument(frame, argument)
	local args = frame.args
	if args[1] == nil then
		local pFrame = frame:getParent();
		args = pFrame.args;
		for k,v in pairs( frame.args ) do
			args[k] = v;
		end
	end
	return args[argument]
end


local function removeEntry(conf_claims, identifier, property)
	for i, linkTemplate in ipairs(conf_claims) do
		if linkTemplate[identifier] == property then
			table.remove(conf_claims, i)
		end
	end
	return conf_claims
end

function p.getLinks(frame, customClaims) --customClaims is a backdoor for testcases
	local configured_conf = getArgument(frame, conf:a('arg-conf'))
	if configured_conf then
		cmodule = require ('Module:External_links/conf/'..configured_conf)
	else
		error(mw.message.newRawMessage(conf:g('missing-conf'), configured_conf):plain())
	end
	local conf_claims = customClaims or cmodule:getConfiguredClaims(contLangCode)
	
	local limits = cmodule:getLimits()
	assert(limits, mw.message.newRawMessage(conf:g('missing-limits'), configured_conf):plain())
	local links_shown = tonumber(getArgument(frame, conf:a('arg-maxlink'))) or limits['links-shown'] or 10 -- maximum links to display
	
	local pagetitle = getArgument(frame, conf:a('arg-title'))
	-- get a list of tracked properties from the article itself
	local requested_tracking = getArgument(frame, conf:a('arg-track'))
	if requested_tracking and requested_tracking ~= '' then
		-- the properties should be written as P1234, P2345 and other 
		-- version corresponding to the applicable property-identifiers in the config
		for track_prop in string.gmatch(requested_tracking,"[^ ,;:]+") do
			-- get the requested properties and be able to access them
			-- like req_prop['P345'] to verify if it was requested
			local remove_track = string.match(track_prop, "^%-(.*)")
			for i,claim in ipairs ( conf_claims )  do
				if remove_track == claim.prop or remove_track == conf:a('mod-filter-all') then
					-- if a property starts with "-", then we'll simply remove that 
					-- property from the conf_claims
					conf_claims[i].track = false
				elseif track_prop == claim.prop or track_prop == conf:a('mod-filter-all') then
					conf_claims[i].track = true
				end
			end
		end
	end
	-- get a list of "approved" properties from the article itself
	local requested_properties = getArgument(frame, conf:a('arg-properties'))
	--mw.log("requested_properties="..dump(requested_properties))
	-- assume all properties are allowed
	local req_prop = {}
	local no_req_prop = false  -- we'll allow properties to be filtered for now 
	if requested_properties and requested_properties ~= '' then
		-- the properties should be written as P1234, P2345 and other 
		-- version corresponding to the applicable property-identifiers in the config
		for i in string.gmatch(requested_properties,"[^ ,;:]+") do
			-- get the requested properties and be able to access them
			-- like req_prop['P345'] to verify if it was requested
			if i == conf:a('mod-filter-all') then
				-- this is a special modifier, saying we should ignore 
				-- all previous and future positive filters and remove the
				-- filter (with exception of negative filters)
				req_prop = {}
				no_req_prop = true
			end
			local remove_prop = string.match(i, "^%-(.*)")
			if remove_prop then
				-- if a property starts with "-", then we'll simply remove that 
				-- property from the conf_claims
				conf_claims = removeEntry(conf_claims, 'prop', remove_prop)
			elseif not no_req_prop then -- only if we are allowing properties to be filtered 
				req_prop[i] = true
				-- cheat to make #req_prop indicate populated table
				req_prop[1] = true
			end
		end
	end
	local requested_langs = getArgument(frame, conf:a('arg-languages'))
	--mw.log("requested_langs="..dump(requested_langs))
	-- assume all languages are allowed
	local req_lang = {}
	local no_req_lang = false  -- we'll allow languages to be filtered for now
	if requested_langs and requested_langs ~= '' then
		-- the languages should be written as langcodes as used in the conf_claims
		for i in string.gmatch(requested_langs,"[^ ,;:]+") do
			-- get the requested languages and be able to access them
			if i == conf:a('mod-filter-all') then
				-- this is a special modifier, saying we should ignore 
				-- all previous and future positive filters and remove the
				-- filter (with exception of negative filters)
				req_lang = {}
				no_req_lang = true
			end
			-- like req_lang['en'] to verify if it was requested
			local remove_lang = string.match(i, "^%-(.*)")
			if remove_lang then
				-- if a language starts with "-", then we'll simply remove that 
				-- language from the conf_claims
				conf_claims = removeEntry(conf_claims, 'langcode', remove_lang)
			elseif not no_req_lang then -- only if we are allowing languages to be filtered 
				req_lang[i] = true
				-- cheat to make #req_lang indicate populated table
				req_lang[1] = true
			end
		end
	end
	local short_links = getArgument(frame, conf:a('arg-short'))
	short_links = (short_links and short_links ~= '' or false)
	
	local showinline = getArgument(frame, conf:a('arg-inline'))
	showinline = (showinline and showinline ~= '' or false)
	
	local somedataonwikidata = not short_links
	--mw.log("conf_claims="..dump(conf_claims))
	--mw.log("req_prop="..dump(req_prop))
	--mw.log("req_lang="..dump(req_lang))
	--mw.log("short_links="..dump(short_links))
	
	local output = {}
	local category = {}
	for _, linkTemplate in ipairs(conf_claims) do
		-- if we're called with a list of approved properties or languages, check if this one is "approved"
		if (#req_prop==0 or req_prop[linkTemplate.prop]) and (#req_lang==0 or req_lang[linkTemplate.langcode] or string.find(linkTemplate.langcode, "[pP]%d+")) then
			-- Error if linkTemplate.prop is nonexistent, as it is required
			assert(linkTemplate.prop, "malformed linkTemplate from config (no .prop given): " .. dump(linkTemplate))
			
			local links = {}
			local checkedonwikidata = false
			-- get the any local overriding value from the call
			local wikivalue = getArgument(frame, linkTemplate.prop)
			if (not wikivalue or wikivalue == "") and string.find(linkTemplate.prop, "[pP]%d+") then
				-- the property is a Pnnn type, and therefore on Wikidata
				links = findMainLinksOnWikidata(linkTemplate, pagetitle, short_links)
				if links == nil then
					-- a nil-value indicated no wikidata-link
					haswikidatalink = false
					links = {}
				else
					checkedonwikidata = true
				end
			elseif (not wikivalue or wikivalue == "") and string.find(linkTemplate.prop, "SL%l+") then
				-- this is a sitelink-type (SLspecieswiki)
				--mw.log("finding sitelinks..")
				links = findSiteLinksOnWikidata(linkTemplate, pagetitle, short_links)
				if links == nil then
					-- a nil-value indicated no wikidata-link
					haswikidatalink = false
					links = {}
				else
					checkedonwikidata = true
				end
			elseif string.find(linkTemplate.prop, "SL%l+") then -- we know that wikivalue is set if this is true
				-- this is a sitelink-type (SLspecieswiki)
				links = findSiteLinksLocal(linkTemplate, pagetitle, short_links, wikivalue)
			elseif wikivalue and wikivalue ~= '' then
				-- the property is of another annotation, and therefore a local construct
				links = findMainLinksLocal(linkTemplate, pagetitle, short_links, wikivalue)
			end
			--mw.log("links="..dump(links))
			for _,v in ipairs(links) do
				-- we'll have to check langcodes again as they may have come from wikidata
				if (#req_lang==0 or req_lang[v.langcode]) then
					if checkedonwikidata and not hasdatafromwikidata then
						-- add a general tracking category for articles with data from wikidata
						hasdatafromwikidata = true
						category[#category+1] = cmodule:getMessage(contLangCode, 'with-data-cat')
					elseif not checkedonwikidata and not hasdatafromlocal then -- not checkonwikidata
						-- add a general tracking category for articles with data from template-calls in local articles
						hasdatafromlocal = true
						category[#category+1] = cmodule:getMessage(contLangCode, 'with-local-cat')
					end
					if short_links and linkTemplate.short and v.text and v.text ~= '' then
						-- if short links were requested, and a short definition exists for this property, let's use it
						if #output==0 then
							output[1] = v.text
						else
							output[#output] = output[#output] .. cmodule:getMessage(contLangCode,'short-list-separator') .. v.text
						end
						somedataonwikidata = true
					elseif not short_links and not showinline and v.text and v.text ~= '' then
						-- only if short links were not requested
						output[#output+1] = (#output ~= 0 and conf:g('msg-ul-prepend') or '')			-- if this is the first link, we won't output a list-element (msg-ul-prepend) 
							.. (checkedonwikidata and addLinkback(v.text, linkTemplate.prop) or v.text)	-- if the link comes from wikidata, also output a linkback.
					elseif not short_links and v.text and v.text ~= '' then -- and showinline
						-- only if short links were not requested
						output[#output+1] = v.text
					end
					if linkTemplate.track then
						-- add category if tracking is on for this property and a category exists in the link-result.
						for _,cats in ipairs( v.category ) do
							category[#category+1] = cats
						end
					end
					if links_shown == 0 then -- abort if we've hit the maximum for number of links
						break
					end
					links_shown = links_shown - 1
				end
			end
			if links_shown==0 then
				break
			end
		end
	end
	local outtext = "" 
	if short_links and #output>0 then
		-- if these are short links, output the whole thing with linkback to wikidata
		--mw.log("somedataonwikidata="..dump(somedataonwikidata).." and output="..dump(output).." and #output="..dump(#output))
		outtext = (somedataonwikidata 
			and addLinkback(table.concat(output,cmodule:getMessage(contLangCode,'short-list-separator')), nil)
			or table.concat(output,cmodule:getMessage(contLangCode,'short-list-separator')))
	elseif not showinline and #output>0 then -- and not shortlinks
		outtext = table.concat(output,"\n")
	elseif #output>0 then -- and not short_links and showinline
		outtext = table.concat(output,conf:g('msg-inline-separator'))
	end
	if not hasdatafromwikidata then
		category[#category+1] = cmodule:getMessage(contLangCode, 'no-data-cat')
		if not hasdatafromlocal and not short_links then
			outtext = cmodule:getMessage(contLangCode, 'no-data-text')
		end
	end
	if not haswikidatalink then
		category[#category+1] = cmodule:getMessage(contLangCode, 'no-wikilink-cat')
		if not hasdatafromlocal and not short_links then
			outtext = cmodule:getMessage(contLangCode, 'no-wikilink')
		end
	end
	local nocategory = getArgument(frame, conf:a('arg-no-categories'))
	category = #category>0 and "\n" .. table.concat(category,"\n") or ""
	--mw.log("nocategory="..dump(nocategory).." and outtext="..dump(outtext).." and category="..dump(category))
	outtext = outtext .. (nocategory and '' or category)
	return outtext
end

function p.getLanguageCode(frame)
	local prop = getArgument(frame, conf:a('arg-properties'))
	return getLanguageData(prop, nil, conf:a(mod-filter-separator))
end

return p