Aitapihikewin:Wikidata

La documentation pour ce module peut être créée à Aitapihikewin:Wikidata/doc

-- version 20170727

local p = {}

local wiki = 
{
	langcode = mw.language.getContentLanguage().code
}

-----------------------------------------------------------------------------
-- internationalisation at [[Module:Wikidata/i18n]]
local i18n = {
	["errors"] = {
		["property-not-found"] = "Property not found.",
		["entity-not-found"] = "Wikidata entity not found.",
		["unknown-claim-type"] = "Unknown claim type.",
		["unknown-entity-type"] = "Unknown entity type.",
		["qualifier-not-found"] = "Qualifier not found.",
		["site-not-found"] = "Wikimedia project not found.",
		["unknown-datetime-format"] = "Unknown datetime format.",
		["local-article-not-found"] = "Article is not yet available in this wiki.",
		['not-from-content-page'] = "Do not invoke from content page. Use a template or use a module subpage like /sandbox for testing ."
	},
	["datetime"] =
	{
		-- $1 is a placeholder for the actual number
		[0] = "$1 billion years",	-- precision: billion years
		[1] = "$100 million years",	-- precision: hundred million years
		[2] = "$10 million years",	-- precision: ten million years
		[3] = "$1 million years",	-- precision: million years
		[4] = "$100,000 years",		-- precision: hundred thousand years
		[5] = "$10,000 years",		-- precision: ten thousand years
		[6] = "$1 millennium",		-- precision: millennium
		[7] = "$1 century",			-- precision: century
		[8] = "$1s",				-- precision: decade
		-- the following use the format of #time parser function
		[9]  = "Y",					-- precision: year, 
		[10] = "F Y",				-- precision: month
		[11] = "F j, Y",			-- precision: day
		[12] = "F j, Y ga",			-- precision: hour
		[13] = "F j, Y g:ia",		-- precision: minute
		[14] = "F j, Y g:i:sa",		-- precision: second
		
		["beforenow"] = "$1 BCE",	-- how to format negative numbers for precisions 0 to 5
		["afternow"] = "$1 CE",		-- how to format positive numbers for precisions 0 to 5
		["bc"] = '$1 "BCE"',		-- how print negative years
		["ad"] = "$1",				-- how print positive years
		["bc-addon"] = " BC",		-- suffix for negative dates
		["ad-addon"] = ""			-- suffix for 1st century AD dates
	},
	["monolingualtext"] = '<span lang="%language">%text</span>',
	["warnDump"] = "[[Categoria:Funció Dump del mòdul Wikidata]]"
}


local cases = {} -- functions for local grammatical cases defined at [[Module:Wikidata/i18n]]

----------------------------------------------------------------------------
-- module local functions

-- Credit to http://stackoverflow.com/a/1283608/2644759
-- cc-by-sa 3.0
local function tableMerge(t1, t2)
	for k,v in pairs(t2) do
		if type(v) == "table" then
			if type(t1[k] or false) == "table" then
				tableMerge(t1[k] or {}, t2[k] or {})
			else
				t1[k] = v
			end
		else
			t1[k] = v
		end
	end
	return t1
end

local function loadI18n()
	local exist, res = pcall(require, "Module:Wikidata/i18n")
	if exist and next(res) ~= nil then
		tableMerge(i18n, res.i18n)
		cases = res.cases
	end
end

loadI18n()

local function case(word, localcase)
	if word == nil or word == '' or cases[localcase] == nil then
		return word
	end
	
	return cases[localcase](word)
end

local function expandBraces(text)
	if text == nil then return text end
	if type(text) ~= "string" then
		text = tostring(text)
	end
	
	for braces in mw.ustring.gmatch(text, "{{(.-)}}") do
		local parts = mw.text.split(braces, "|")
		local title = parts[1]
		local parameters = {}
		for i = 2, #parts do
			if mw.ustring.find(parts[i], "=") then
				local subparts = mw.text.split(parts[i], "=")
				parameters[subparts[1]] = subparts[2]
			else
				table.insert(parameters, parts[i])
			end
		end
		
		local braces_expanded
		if mw.ustring.find(title, ":") then
			braces_expanded = mw.getCurrentFrame():callParserFunction{name=title, args=parameters}
		else
			braces_expanded = mw.getCurrentFrame():expandTemplate{title=title, args=parameters}
		end
		title = mw.ustring.gsub(title, "([%^%$%(%)%%%.%[%]%*%+%-%?])", "%%%1") -- escape magic characters
		text = mw.ustring.gsub(text, "{{" .. title .. ".-}}", braces_expanded)
	end
	
	return text
end

local function printDatavalueString(data, parameter)
	if parameter == 'weblink' then 
		return '[' .. data ..  ' ' ..  mw.text.split(data, '//' )[2] .. ']'
	elseif mw.ustring.find((parameter or ''), '$1', 1, true) then -- formatting = a pattern
		return expandBraces(mw.ustring.gsub(parameter, '$1', data))
	else
		return data
	end
end

local function printDatavalueCoordinate(data, parameter)
	if parameter == 'latitude' then
		return data.latitude
	elseif parameter == 'longitude' then
		return data.longitude
	elseif parameter == 'dimension' then
		return data.dimension
	else --default formatting='globe'
		if data.globe == '' or data.globe == nil or data.globe == 'http://www.wikidata.org/entity/Q2' then
			return 'earth'
		else
			local globenum = mw.text.split(data.globe, 'entity/')[2] -- http://www.wikidata.org/wiki/Q2
			local globetable = mw.loadData('Module:Mapa cos celeste/dades')
			for _, globe in pairs(globetable.maps) do
				if globe.wikidata == globenum then
					return globe.coord_globe
				end
			end
			return globenum
		end
	end
end

local function printDatavalueQuantity(data, parameter)
	-- exemples: 277±1 Centímetre, 1,94 metre
	local amount = data.amount
	amount = mw.ustring.gsub(amount, "%+", "")
	local sortkey = string.format("%09d", amount)
	local lang = mw.language.new(wiki.langcode)
	amount = lang:formatNum(tonumber(amount))
	-- This is used to get the unit name for a numeric value
	local suffix = ""
	if parameter == "unit" or parameter == "unitcode" then
		-- get the url for the unit entry on Wikidata:
		local unitID = data.unit
		-- and just return the last bit from "Q" to the end (which is the QID):
		unitID = mw.ustring.sub(unitID, mw.ustring.find(unitID, "Q"), -1)
		if mw.ustring.sub(unitID, 1, 1) == "Q" then
			local unit_label = mw.wikibase.label(unitID)
			suffix = " " .. require("Module:Wikidata/Units").getUnit(amount, unit_label, unitID, parameter == "unitcode")
		end
	end
	return amount .. suffix, sortkey
end

local function printDatavalueTime(data, parameter)
	-- Dates and times are stored in ISO 8601 format
	local timestamp = data.time
	local sortkey = timestamp
	local addon = ""
	
	-- check for negative date, ex. "-0027-01-16T00:00:00Z"
	if string.sub(timestamp, 1, 1) == '-' then
		timestamp = '+' .. string.sub(timestamp, 2)
		addon = i18n.datetime["bc-addon"]
	elseif string.sub(timestamp, 2, 3) == '00' then
		addon = i18n.datetime["ad-addon"]
	end
	local function d(f, t)
		return mw.language.new(wiki.langcode):formatDate(f, t or timestamp) .. addon
	end
	local precision = data.precision or 11
	local intyear = tonumber(mw.ustring.match(timestamp, "^\+?%d+"))
	local ret = ""
	
	-- precision is 10000 years or more
	if precision <= 5 then
		local factor = 10 ^ ((5 - precision) + 4)
		local y2 = math.ceil(math.abs(intyear) / factor)
		local relative = mw.ustring.gsub(i18n.datetime[precision], "$1", tostring(y2))
		if addon == i18n.datetime["bc-addon"] then
			-- negative date
			ret = mw.ustring.gsub(i18n.datetime.beforenow, "$1", relative)
		else
			ret = mw.ustring.gsub(i18n.datetime.afternow, "$1", relative)
		end
	-- precision is millennia, centuries or decades
	elseif precision == 6 then
		local card = math.floor((intyear - 1) / 1000) + 1
		if mw.ustring.find(i18n.datetime[6], "$1") then
			ret = mw.ustring.gsub(i18n.datetime[6], "$1", tostring(card)) .. addon
		else
			ret = d(i18n.datetime[6], string.format("%04d", tostring(card)))
		end
	elseif precision == 7 then
		local card = math.floor((math.abs(intyear) - 1) / 100) + 1
		if mw.ustring.find(i18n.datetime[7], "$1") then
			ret = mw.ustring.gsub(i18n.datetime[7], "$1", tostring(card)) .. addon
		else
			ret = d(i18n.datetime[7], string.format("%04d", tostring(card)))
		end
	elseif precision == 8 then
		local card = math.floor(math.abs(intyear) / 10) * 10
		ret = mw.ustring.gsub(i18n.datetime[8], "$1", tostring(card)) .. addon
	-- precision is year
	elseif parameter == 'Y' or precision == 9 then
		ret = tostring(intyear) .. addon
	-- precision is month
	elseif precision == 10 then
		timestamp = timestamp .. " + 1 day" -- formatDate yyyy-mm-00 returns the previous month
		ret, _ = string.gsub(d(i18n.datetime[10]), " 0+", " ") -- supress leading zeros in year
	elseif parameter then
		ret, _ = string.gsub(d(parameter), "([ %[])0+", "%1") -- supress leading zeros in year optionally linked
	else
		ret, _ = string.gsub(d(i18n.datetime[11]), " 0+", " ")
	end
	return ret, sortkey
end

local function printDatavalueEntity(data, parameters)
	local entityId = "Q" .. tostring(data['numeric-id'])
	local label = mw.wikibase.label(entityId)
	local sitelink = mw.wikibase.sitelink(entityId)
	local parameter = parameters.formatting
	local labelcase = label or sitelink
	if parameters.case then
		labelcase = case(labelcase, parameters.case)
	end
	if parameter == 'raw' then 
		return entityId, entityId
	elseif parameter == 'label' then
		return (labelcase or entityId), (labelcase or entityId)
	elseif parameter == 'sitelink' then
		return (sitelink or 'wikidata:' .. entityId), (sitelink or entityId)
	elseif mw.ustring.find((parameter or ''), '$1', 1, true) then -- formatting = a pattern
		local ret = mw.ustring.gsub(parameter, '$1', labelcase or entityId)
		ret = expandBraces(ret)
		return ret, labelcase or entityId
	else
		if sitelink then
			return '[[' .. sitelink .. '|' .. labelcase .. ']]', labelcase
		elseif label and parameter == 'internallink' then
			return '[[' .. label .. '|' .. labelcase .. ']]', labelcase
		else
			return '[[wikidata:' .. entityId .. '|' .. (labelcase or entityId) .. ']]', labelcase or entityId
		end
	end
end

local function printDatavalueMonolingualText(data, parameter)
	-- data fields: language [string], text [string]
	local result = nil
	if parameter == "language" or parameter == "text" then
		result = data[parameter]
	elseif parameter then
		if data["language"] == wiki.langcode then
			result = data["text"]
		end
	else
		result = mw.ustring.gsub(mw.ustring.gsub(i18n.monolingualtext, "%%language", data["language"]), "%%text", data["text"])
	end
	return result
end

local function printDatatypeMath(data)
	return mw.getCurrentFrame():callParserFunction('#tag:math', data)
end

local function printError(key)
    return '<span class="error">' .. i18n.errors[key] .. '</span>'
end

local function findClaims(entity, property)
	if not property or not entity or not entity.claims then return end
	
	if mw.ustring.match(property, "^P%d+$") then
		-- if the property is given by an id (P..) access the claim list by this id
		return entity.claims[property]
	else
		property = mw.wikibase.resolvePropertyId(property)
		if not property then return end

		return entity.claims[property]
	end
end

local function getSnakValue(snak, parameters)
	local parameter = parameters.formatting
	if snak.snaktype == 'value' then
		-- call the respective snak parser
		if snak.datatype == 'math' then
			return printDatatypeMath(snak.datavalue.value)
		elseif snak.datavalue.type == "string" then
			return printDatavalueString(snak.datavalue.value, parameter)
		elseif snak.datavalue.type == "globecoordinate" then
			return printDatavalueCoordinate(snak.datavalue.value, parameter)
		elseif snak.datavalue.type == "quantity" then
			return printDatavalueQuantity(snak.datavalue.value, parameter)
		elseif snak.datavalue.type == "time" then
			return printDatavalueTime(snak.datavalue.value, parameter)
		elseif snak.datavalue.type == 'wikibase-entityid' then
			return printDatavalueEntity(snak.datavalue.value, parameters)
		elseif snak.datavalue.type == 'monolingualtext' then
			return printDatavalueMonolingualText(snak.datavalue.value, parameter)
		end
	end
	return mw.wikibase.renderSnak(snak)
end

local function getQualifierSnak(claim, qualifierId, parameters)
	-- a "snak" is Wikidata terminology for a typed key/value pair
	-- a claim consists of a main snak holding the main information of this claim,
	-- as well as a list of attribute snaks and a list of references snaks
	if qualifierId then
		-- search the attribute snak with the given qualifier as key
		if claim.qualifiers then
			local qualifier = claim.qualifiers[qualifierId]
			if qualifier then
				-- iterate over monolingualtext qualifiers to get local language
				for idx in pairs(qualifier) do
					if qualifier[idx].datavalue and qualifier[idx].datavalue.value and qualifier[idx].datavalue.value.language then
						if qualifier[idx].datavalue.value.language == wiki.langcode then
							return qualifier[idx]
						end
					end
				end
				if parameters.list then
					return qualifier
				else
					return qualifier[1]
				end
			end
		end
		return nil, printError("qualifier-not-found")
	else
		-- otherwise return the main snak
		return claim.mainsnak
	end
end

local function getValueOfClaim(claim, qualifierId, parameters)
	local error
	local snak
	snak, error = getQualifierSnak(claim, qualifierId, parameters)
	if not snak then
		return nil, nil, error
	elseif snak[1] then -- a multi qualifier
		local result = {}
		local sortkey = {}
		for idx in pairs(snak) do
			result[#result + 1], sortkey[#sortkey + 1] = getSnakValue(snak[idx], parameters)
		end
		return mw.text.listToText(result, parameters.qseparator, parameters.qconjunction), sortkey[1]
	else -- a property or a qualifier
		return getSnakValue(snak, parameters)
	end
end

-- Return the site link (for the current site) for a given data item.
function p.getSiteLink(frame)
    if frame.args[1] == nil then
        entity = mw.wikibase.getEntityObject()
        if not entity then
        	return nil
        end
        id = entity.id
    else
        id = frame.args[1]
    end
 
    return mw.wikibase.sitelink(id)
end

-- On debug console use: =p._debug({item="Q...", property="P...", ...})
function p._debug(args)
	return p._main(args)
end

function p.claim(frame)
	if mw.title.new(frame:getParent():getTitle()).isContentPage and not mw.title.new(frame:getTitle()).isSubpage then
		-- invoked from a content page and not invoking a module subpage
		return printError("not-from-content-page")
	end
	return p._main(frame.args)
end

function p._main(args)
	--If a value is already set, use it
	if args.value and args.value ~= '' then
		return args.value
	end
	
	-- arguments
	local property = args["property"] or ""
	local id = args["item"]; if id == "" then id = nil end
	local idgender = args["itemgender"]
	if idgender and not string.match(idgender, "^Q%d+$") then -- id malformed, maybe "unknown value"
		idgender = nil
	end
	local qualifierId = {}
	qualifierId[1] = args["qualifier"]
	for i = 2, 9 do
		qualifierId[i] = args["qualifier" .. i]
	end
	local parameter = args["formatting"] or ''; if parameter == "" then parameter = nil end
	local case = args.case
	local list = args["list"] or true; if list == "false" then list = false end
	local sorting_col = args.tablesort
	local sorting_up = (args.sorting or "") ~= "-1"
	local separator = args.separator
	local conjunction = args.conjunction or args.separator
	local rowformat = args.rowformat
	local showerrors = args["showerrors"]
	local default = args["default"]
	
	property = property:gsub("^p(%d)", "P%1")
	if qualifierId[1] then qualifierId[1] = qualifierId[1]:gsub("^p(%d)", "P%1") end
	local parameters = {["formatting"] = parameter, ["list"] = list, ["case"] = case,
		["separator"] = separator, ["conjunction"] = conjunction, ["qseparator"] = separator, ["qconjunction"] = conjunction}
	local preformat = ""
	local postformat = ""
	if parameters.formatting == "table" then
		parameters.separator = parameters.separator or "<br />"
		parameters.conjunction = parameters.conjunction or "<br />"
		parameters.qseparator = ", "
		parameters.qconjunction = ", "
		if not rowformat then
			rowformat = "$0 ($1"
			for i = 2, 9 do
				if qualifierId[i] then
					rowformat = rowformat .. ", $" .. i
				end
			end
			rowformat = rowformat .. ")"
		elseif mw.ustring.find(rowformat, "^[*#]") then
			parameters.separator = "</li><li>"
			parameters.conjunction = "</li><li>"
			if mw.ustring.match(rowformat, "^[*#]") == "*" then
				preformat = "<ul><li>"
				postformat = "</li></ul>"
			else
				preformat = "<ol><li>"
				postformat = "</li></ol>"
			end
			rowformat = mw.ustring.gsub(rowformat, "^[*#] ?", "")
		end
	end
	if default then showerrors = nil end
	
	-- get wikidata entity
	local entity = mw.wikibase.getEntityObject(id)
	if not entity then
		if showerrors then return printError("entity-not-found") else return default end
	end
	-- fetch the first claim of satisfying the given property
	local claims = findClaims(entity, property)
	if not claims or not claims[1] then
		if showerrors then return printError("property-not-found") else return default end
	end
	
	-- find feminine case if gender is requested
	local genderCase
	if parameters.case == "gender" or idgender or parameters.formatting == "table" then
		local genderEntity = idgender and mw.wikibase.getEntityObject(idgender) or entity
		local genderClaims = genderEntity.claims["P21"]
		if genderClaims then
			local genderId = getValueOfClaim(genderClaims[1], nil, {["formatting"]="raw"})
			if genderId == "Q6581072" or genderId == "Q1052281" or genderId == "Q43445" then -- female, transgender female, female organism
				genderCase = (parameters.case == "infoboxlabel") and "labelfeminine" or "feminine"
				if parameters.case == "gender" or idgender then
					parameters.case = genderCase
				end
			end
		end
	end
	
	-- get initial sort indices
	local sortindices = {}
	for idx in pairs(claims) do
		sortindices[#sortindices + 1] = idx
	end
	-- sort by claim rank
	local comparator = function(a, b)
		local rankmap = { deprecated = 2, normal = 1, preferred = 0 }
		local ranka = rankmap[claims[a].rank or "normal"] ..  string.format("%08d", a)
		local rankb = rankmap[claims[b].rank or "normal"] ..  string.format("%08d", b)
		return ranka < rankb
	end
	table.sort(sortindices, comparator)
	
	local result
	local error
	if parameters.list or parameters.formatting == "table" then
		-- convert LF to line feed, <br /> may not work on some cases
		parameters.separator = parameters.separator == "LF" and "\010" or parameters.separator
		parameters.conjunction = parameters.conjunction == "LF" and "\010" or parameters.conjunction
		-- iterate over all elements and return their value (if existing)
		local value, valueq
		local sortkey, sortkeyq
		local values = {}
		local sortkeys = {}
		local firstrank = parameters.list == "firstrank" and claims[sortindices[1]].rank or ''
		for idx in pairs(claims) do
			local claim = claims[sortindices[idx]]
			if firstrank ~= '' and firstrank ~= claim.rank then
				break
			end
			values[#values + 1] = {}
			sortkeys[#sortkeys + 1] = {}
			if parameters.formatting == "table" then
				local params = mw.clone(parameters)
				params.formatting = args["colformat0"]
				if args["case0"] then
					params.case = args["case0"] == "gender" and genderCase or args["case0"]
				end
				value, sortkey, error =  getValueOfClaim(claim, nil, params)
				for i, qual in ipairs(qualifierId) do
					params.formatting = args["colformat" .. i]
					if args["case" .. i] then
						params.case = args["case" .. i] == "gender" and genderCase or args["case" .. i]
					else
						params.case = parameters.case
					end
					valueq, sortkeyq, _ =  getValueOfClaim(claim, qual, params)
					values[#values]["col" .. i] = valueq
					sortkeys[#sortkeys]["col" .. i] = sortkeyq or valueq
				end
			else
				value, sortkey, error =  getValueOfClaim(claim, qualifierId[1], parameters)
			end
			if not value and showerrors then value = error end
			
			values[#values]["col0"] = value
			sortkeys[#sortkeys]["col0"] = sortkey or value
		end
		-- sort and format results
		sortindices = {}
		for idx in pairs(values) do
			sortindices[#sortindices + 1] = idx
		end
		if sorting_col then
			local comparator = function(a, b)
				local valuea = sortkeys[a]["col" .. sorting_col] or ''
				local valueb = sortkeys[b]["col" .. sorting_col] or ''
				if sorting_up then
					return valuea < valueb
				end
				return valuea > valueb
			end
			table.sort(sortindices, comparator)
		end
		result = {}
		for idx in pairs(values) do
			local valuerow = values[sortindices[idx]]
			value = valuerow["col0"]
			if parameters.formatting == "table" then
				value = mw.ustring.gsub(rowformat, "$0", value)
				for i, _ in ipairs(qualifierId) do
					valueq = valuerow["col" .. i]
					if args["rowsubformat" .. i] and valueq then
						valueq = mw.ustring.gsub(args["rowsubformat" .. i], "$" .. i, valueq)
					end
					value = mw.ustring.gsub(value, "$" .. i, valueq or '')
				end
			end
			value = expandBraces(value)
			result[#result + 1] = value
		end
		result = preformat .. mw.text.listToText(result, parameters.separator, parameters.conjunction) .. postformat
	else
		-- return first element	
		local claim = claims[sortindices[1]]
		result, _, error = getValueOfClaim(claim, qualifierId[1], parameters)
	end
	
	if result then return result else
		if showerrors then return error else return default end
	end
end

-- This is used to get the TA98 (Terminologia Anatomica first edition 1998) values like 'A01.1.00.005' (property P1323)
-- which are then linked to http://www.unifr.ch/ifaa/Public/EntryPage/TA98%20Tree/Entity%20TA98%20EN/01.1.00.005%20Entity%20TA98%20EN.htm
-- uses the newer mw.wikibase calls instead of directly using the snaks
-- formatPropertyValues returns a table with the P1323 values concatenated with ", " so we have to split them out into a table in order to construct the return string
p.getTAValue = function(frame)
    local ent = mw.wikibase.getEntityObject()
    local props = ent:formatPropertyValues('P1323')
    local out = {}
    local t = {}
    for k, v in pairs(props) do
        if k == 'value' then
            t = mw.text.split( v, ", ")
            for k2, v2 in pairs(t) do
                out[#out + 1] = "[http://www.unifr.ch/ifaa/Public/EntryPage/TA98%20Tree/Entity%20TA98%20EN/" .. string.sub(v2, 2) .. "%20Entity%20TA98%20EN.htm " .. v2 .. "]"
            end
        end
    end
    local ret = table.concat(out, "<br> ")
    if #ret == 0 then
        ret = "Invalid TA"
    end
    return ret
end

-- look into entity object
function p.ViewSomething(frame)
	local f = (frame.args[1] or frame.args.item) and frame or frame:getParent()
	local id = f.args.item
	if id and (#id == 0) then
		id = nil
	end
	local data = mw.wikibase.getEntityObject(id)
	if not data then
		return nil
	end

	local i = 1
	while true do
		local index = f.args[i]
		if not index then
			if type(data) == "table" then
				return frame:extensionTag('syntaxhighlight', mw.text.jsonEncode(data, mw.text.JSON_PRETTY), {lang = 'json'})
			else
				return tostring(data)
			end
		end
		
		data = data[index] or data[tonumber(index)]
		if not data then
			return
		end
		
		i = i + 1
	end
end

-- Dump data tree structure
-- From pl:Module:Wikidane, by User:Paweł Ziemian
-- Funció pensada com a eina d'ajuda en previsualització.
function p.Dump(frame)
	local data = mw.wikibase.getEntityObject()
	if not data then
		return i18n.warnDump
	end
	
	local f = frame.args[1] and frame or frame:getParent()

	local i = 1
	while true do
		local index = f.args[i]
		if not index then
			return frame:extensionTag('syntaxhighlight', mw.dumpObject(data), {lang = 'json'}) .. i18n.warnDump
		end
		
		data = data[index] or data[tonumber(index)]
		if not data then
			return i18n.warnDump
		end
		
		i = i + 1
	end
end

-- Look into entity object
-- From pl:Module:Wikidane, function V, by User:Paweł Ziemian
function p.getEntityFromTree(frame)
	local data = mw.wikibase.getEntityObject()
	if not data then
		return nil
	end
	
	local f = frame.args[1] and frame or frame:getParent()
	
	local i = 1
	while true do
		local index = f.args[i]
		if not index then
			return tostring(data)
		end
		
		data = data[index] or data[tonumber(index)]
		if not data then
			return
		end
		
		i = i + 1
	end
end

-- getParentValues: returns a property value with its instance label fetching a recursive tree

local function uc_first(word)
	return mw.ustring.upper(mw.ustring.sub(word, 1, 1)) .. mw.ustring.sub(word, 2)
end

local function getPropertyValue(id, property, parameter)
	local entity = mw.wikibase.getEntityObject(id)
	if not (entity and entity.claims) then return end
	
	local claims = entity.claims[property]
	if not claims then return end
	-- get initial sort indices
	local sortindices = {}
	for idx in pairs(claims) do
		sortindices[#sortindices + 1] = idx
	end
	-- sort by claim rank
	local comparator = function(a, b)
		local rankmap = { deprecated = 2, normal = 1, preferred = 0 }
		local ranka = rankmap[claims[a].rank or "normal"] ..  string.format("%08d", a)
		local rankb = rankmap[claims[b].rank or "normal"] ..  string.format("%08d", b)
		return ranka < rankb
	end
	table.sort(sortindices, comparator)
	
	local snak = claims[sortindices[1]].mainsnak
	
	local entityId
	local result = '-' -- default for 'no value'
	if snak.datavalue then
		entityId = "Q" .. tostring(snak.datavalue.value['numeric-id'])
		result, _ = getSnakValue(snak, {formatting=parameter})
	end
	
	return entityId, result
end

function p.getParentValues(frame)
	local args = frame.args
	local id = args["item"]; if id == "" then id = nil end
	local propertySup = args["property"]; if (propertySup == nil or propertySup == "") then propertySup = "P131" end --administrative entity
	local propertyLabel = args["label"]; if (propertyLabel == nil or propertyLabel == "") then propertyLabel = "P31" end --instance
	local propertyLink = args["valuetext"]; if propertyLink == "" then propertyLink = nil end --internallink
	local upto = args["upto"]; if upto == "" then upto = nil end
	local labelShow = args["labelshow"]; if labelShow == "" then labelShow = nil end
	local rowformat = args["rowformat"]; if (rowformat == nil or rowformat == "") then rowformat = "$0 = $1" end
	local separator = args["separator"]; if (separator == nil or separator == "") then separator = "<br />" end
	local sorting = args["sorting"]; if sorting == "" then sorting = nil end
	
	local lastlabel = uc_first(upto or '')
	local maxloop = tonumber(upto) or (lastlabel == '' and 10 or 50)
	
	local labelFilter = {}
	if labelShow then
		for i, v in ipairs(mw.text.split(labelShow, "/")) do
			labelFilter[uc_first(v)] = true
		end
	end
	
	local result = {}
	local label, link, linktext
	
	for iter = 1, maxloop do
		local label, link
		id, link = getPropertyValue(id, propertySup, "internallink")
		if id then
			_, label = getPropertyValue(id, propertyLabel, "label")
			if label and link then
				if propertyLink then
					_, linktext = getPropertyValue(id, propertyLink, "label")
					if linktext then
						link = mw.ustring.gsub(link, "%[%[(.*)%|.+%]%]", "[[%1|" .. linktext .. "]]")
					end
				end
				label = case(label, "infoboxlabel")
				if labelShow == nil or labelFilter[label] then
					result[#result + 1] = {label, link}
				end
				if label == lastlabel then
					break
				end
			else
				break
			end
		else
			break
		end
	end
	
	local ret = {}
	local first = 1
	local last = #result
	local iter = 1
	if sorting == "-1" then first = #result; last = 1; iter = -1 end

	for i = first, last, iter do
		local rowtext = mw.ustring.gsub(rowformat, "$[01]", {["$0"] = result[i][1], ["$1"] = result[i][2]})
		ret[#ret +1] = expandBraces(rowtext)
	end
	return mw.text.listToText(ret, separator, separator)
end

function p.linkWithParentLabel(frame)
	local args = {}
	for k, v in pairs(frame.args) do -- metatable
		args[k] = v
	end
	args.list = "false"
	args.formatting = "internallink"
	local link = p._main(args) -- get internal link of property/qualifier
	args.formatting = "raw"
	args.item = p._main(args) -- get item of property/qualifier
	args.property = args.parent
	args.qualifier = nil
	args.formatting = "label"
	local link_label = p._main(args) -- get label of parent property
	if link_label then
		link = mw.ustring.gsub(link or '', "%[%[(.*)%|.+%]%]", "[[%1|" .. link_label .. "]]")
	end
	return link
end

function p.years_old(frame)
	local args = frame.args
	local id = args.item; if id == '' then id = nil end
	local lang = mw.language.new('en')
	
	local function fetchsnak(id, snak)
		local ret = mw.wikibase.getEntityObject(id)
		for i, v in ipairs(snak) do
			if ret == nil then break end
			ret = ret[v]
		end
		return ret
	end
	
	local birth = fetchsnak(id, {'claims', 'P569', 1, 'mainsnak', 'datavalue', 'value'})
	if type(birth) ~= 'table' or birth.time == nil or birth.precision == nil or birth.precision < 8 then
		return
	end
	local death = fetchsnak(id, {'claims', 'P570', 1, 'mainsnak', 'datavalue', 'value'})
	if type(death) ~= 'table' or death.time == nil or death.precision == nil then
		death = {['time'] = lang:formatDate('c'), ['precision'] = 11} -- current date
	elseif death.precision < 8 then
		return
	end
	
	local dates = {}
	dates[1] = {['min'] = {}, ['max'] = {}, ['precision'] = birth.precision}
	dates[1].min.year = tonumber(mw.ustring.match(birth.time, "^[+-]?%d+"))
	dates[1].min.month = tonumber(mw.ustring.match(birth.time, "\-(%d%d)\-"))
	dates[1].min.day = tonumber(mw.ustring.match(birth.time, "\-(%d%d)T"))
	dates[1].max = mw.clone(dates[1].min)
	dates[2] = {['min'] = {}, ['max'] = {}, ['precision'] = death.precision}
	dates[2].min.year = tonumber(mw.ustring.match(death.time, "^[+-]?%d+"))
	dates[2].min.month = tonumber(mw.ustring.match(death.time, "\-(%d%d)\-"))
	dates[2].min.day = tonumber(mw.ustring.match(death.time, "\-(%d%d)T"))
	dates[2].max = mw.clone(dates[2].min)
	
	for i, d in ipairs(dates) do
		if d.precision == 10 then -- month
			d.min.day = 1
			local timestamp = string.format("%04d", tostring(math.abs(d.max.year)))
				.. string.format("%02d", tostring(d.max.month))
				.. "01"
			d.max.day = tonumber(lang:formatDate("j", timestamp .. " + 1 month - 1 day"))
		elseif d.precision < 10 then -- year or decade
			d.min.day = 1
			d.min.month = 1
			d.max.day = 31
			d.max.month = 12
			if d.precision == 8 then -- decade
				d.max.year = d.max.year + 9
			end
		end
	end
	
	local function age(d1, d2)
		local years = d2.year - d1.year
		if d2.month < d1.month or (d2.month == d1.month and d2.day < d1.day) then
			years = years - 1
		end
		if d2.year > 0 and d1.year < 0 then
			years = years - 1 -- no year 0
		end
		return years
	end
	
	local old_min = age(dates[1].max, dates[2].min)
	local old_max = age(dates[1].min, dates[2].max)
	local old = old_min == old_max and old_min or old_min .. "/" .. old_max
	if args.formatting then
		old = mw.ustring.gsub(args.formatting, '$1', old)
	end
	
	return old
end

return p