Документация
local categorizeByPlaceOfBirthAndDeath = true;

local WDS = require( 'Module:WikidataSelectors' );
local p = {};
local project = 'ruwiki';

local function min( prev, next )
	if ( prev == nil ) then return next;
	elseif ( prev > next ) then return next;
	else return prev; end
end

local function max( prev, next )
	if ( prev == nil ) then return next;
	elseif ( prev < next ) then return next;
	else return prev; end
end

local function getTimeBoundariesFromProperty( context, propertyId )
	mw.log( 'Get time boundaries for ' .. propertyId .. '...');

	local dateClaims = WDS.filter( context.entity.claims, propertyId );
	if ( not dateClaims or #dateClaims == 0 ) then return nil; end
	mw.log( 'Get time boundaries for ' .. propertyId .. '... Got ' .. #dateClaims .. ' date claim(s)');

	-- only support exact date so far, but need improvment
	local left = nil;
	local right = nil;
	for _, claim in pairs( dateClaims ) do
		if ( not claim.mainsnak ) then return nil; end
		local boundaries = context.parseTimeBoundariesFromSnak( claim.mainsnak );
		if ( not boundaries ) then return nil; end
		left = min( left, boundaries[1] );
		right = max( right, boundaries[2] );
	end

	if ( not left or not right ) then return nil; end

	mw.log( 'Time boundaries for ' .. propertyId .. ' are ' .. left .. ' and ' .. right );
	return { left, right };
end

local function getTimeBoundariesFromProperties( context, propertyIds )
	for _, propertyId in ipairs( propertyIds ) do
		local result = getTimeBoundariesFromProperty( context, propertyId );
		if result then
			return result;
		end
	end

	return nil;
end

local function getTimeBoundariesFromQualifiers( context, statement, qualifierId )
	-- only support exact date so far, but need improvment
	local left = nil;
	local right = nil;
	if ( statement.qualifiers and statement.qualifiers[qualifierId] ) then
		for _, qualifier in pairs( statement.qualifiers[qualifierId] ) do
			local boundaries = context.parseTimeBoundariesFromSnak( qualifier );
			if ( not boundaries ) then return nil; end
			left = min( left, boundaries[1] );
			right = max( right, boundaries[2] );
		end
	end

	if ( not left or not right ) then
		return nil;
	end

	return { left, right };
end

local function getParentsInBoundariesSnakImpl( context, entity, boundaries, propertyIds )
	local results = {};

	if entity.claims and boundaries then
		for _, propertyId in ipairs( propertyIds ) do
			local filteredClaims = WDS.filter( entity.claims, propertyId .. '[rank:preferred, rank:normal]' );
			if filteredClaims then
				for _, claim in pairs( filteredClaims ) do
					local startBoundaries = getTimeBoundariesFromQualifiers( context, claim, 'P580' );
					local endBoundaries = getTimeBoundariesFromQualifiers( context, claim, 'P582' );
					if ( (startBoundaries == nil or ( startBoundaries[2] <= boundaries[1]))
							and (endBoundaries == nil or ( endBoundaries[1] >= boundaries[2]))) then
						table.insert( results, claim.mainsnak );
					end 
				end
			end

			if #results > 0 then
				break;
			end
		end
	end

	return results;
end

local function getParentsInBoundariesSnak( context, entity, boundaries )
	if ( not entity ) then error('entity must be specified'); end
	if ( type(entity) ~= 'table' ) then error('entity must be table'); end
	if ( not boundaries ) then error('boundaries must be specified'); end
	if ( type(boundaries) ~= 'table' ) then error('boundaries must be table'); end

	local results = getParentsInBoundariesSnakImpl( context, entity, boundaries, {'P131'} )
	if not results or #results == 0 then
		results = getParentsInBoundariesSnakImpl( context, entity, boundaries, {'P17'} )
	end
	for r, result in pairs( results ) do
		if result.snaktype ~= 'value' then
			return nil;
		end
		local resultId = 'Q' .. result.datavalue.value['numeric-id'];
		if ( resultId == entity.id ) then
			return nil;
		end
	end
	return results;
end

local unions = { 
	Q1140229 = true, -- political union
	Q3623811 = true, -- Экономический союз
	Q4120211 = true -- региональная организация
}

local countries = { 
	Q6256 = true, -- страна
	Q7275 = true, -- государство
	Q3624078 = true -- суверенное государство
}

local function isSkipTopLevel( entity )
	local isCountry = false;
	local isUnion = false;
	if ( entity
			and entity.claims
			and entity.claims.P31 ) then
		for c, claim in pairs( entity.claims.P31 ) do
			if ( claim
					and claim.mainsnak
					and claim.mainsnak.datavalue
					and claim.mainsnak.datavalue.value
					and claim.mainsnak.datavalue.value['numeric-id'] ) then
				local typeId = 'Q' .. claim.mainsnak.datavalue.value['numeric-id'];
				isCountry = isCountry or countries[typeId];
				isUnion = isUnion or unions[typeId];
			end
		end
	end
	return isUnion and not isCountry;
end

local function isPartOfNext(prevLabel, nextLabel)
	return (mw.ustring.len(prevLabel) > mw.ustring.len(nextLabel))
		and (mw.ustring.sub( prevLabel, mw.ustring.len(prevLabel) - mw.ustring.len(nextLabel) + 1 ) == nextLabel);
end

--Property:P19, Property:P20, Property:P119
function p.formatPlaceWithQualifiers( context, options, statement )
	local property = mw.ustring.upper( options.property );
	mw.log( 'formatPlaceWithQualifiers(..., ' .. property .. ')');

	local entriesToLookupCategory = {};

	local circumstances = context.getSourcingCircumstances( statement );
	local result = '';
	local baseResult = context.formatSnak( options, statement.mainsnak, circumstances );
	insertFromSnak( statement.mainsnak, entriesToLookupCategory )

	local hasAdditionalQualifiers = false;
	if ( statement.qualifiers ) then
		--parent divisions
		if ( statement.qualifiers.P131 ) then
			for i, qualifier in ipairs( statement.qualifiers.P131 ) do
				local parentOptions = options;
				-- local parentOptions = mw.clone( options );
				parentOptions['text'] = getLabel( context, qualifier, boundaries );

				result = result .. ', ' .. context.formatSnak( parentOptions, qualifier );
				insertFromSnak( qualifier, entriesToLookupCategory )
				hasAdditionalQualifiers = true;
			end
		end

		--country
		if ( statement.qualifiers.P17 ) then
			for i, qualifier in ipairs( statement.qualifiers.P17 ) do
				result = result .. ', ' .. context.formatSnak( options, qualifier );
				insertFromSnak( qualifier, entriesToLookupCategory )
				hasAdditionalQualifiers = true;
			end
		end
	end

	if ( statement.mainsnak
			and statement.mainsnak.datavalue
			and statement.mainsnak.datavalue.value
			and statement.mainsnak.datavalue.value['numeric-id'] ) then
		local entity = mw.wikibase.getEntity( 'Q' .. statement.mainsnak.datavalue.value['numeric-id'] );
		local parentSnaks = { statement.mainsnak };
		local parentEntities = { entity };

		local actualDateBoundariesProperty = nil;
		if ( property == 'P19' ) then actualDateBoundariesProperty = 'P569'; end
		if ( property == 'P20' ) then actualDateBoundariesProperty = 'P570'; end
		if ( actualDateBoundariesProperty ~= nil ) then
			local boundaries = getTimeBoundariesFromProperty( context, actualDateBoundariesProperty );
			if ( boundaries ) then
				local entityOptions = options;
				-- local entityOptions = mw.clone( options );
				entityOptions['text'] = getLabel( context, entity, boundaries );
				baseResult = context.formatSnak( entityOptions, statement.mainsnak, circumstances );

				local parent = entity;
				while ( parent ~= nil ) do
					-- get parent
					local newParentSnaks = getParentsInBoundariesSnak( context, parent, boundaries );
					if ( not newParentSnaks or #newParentSnaks == 0 ) then
						parent = nil;
					elseif ( #newParentSnaks == 1 ) then
						local parentSnak = newParentSnaks[1];
						parent = mw.wikibase.getEntity( 'Q' .. parentSnak.datavalue.value['numeric-id'] );
						table.insert( parentSnaks, parentSnak );
						table.insert( parentEntities, parent );
					else
						parent = nil;
						result = result .. '[[Категория:Википедия:Страницы с неоднозначными геоцепочками]]';
					end
				end

				if ( not hasAdditionalQualifiers ) then
					for i=2,#parentSnaks,1 do
						local parentSnak = parentSnaks[i];
						insertFromSnak( parentSnak, entriesToLookupCategory )
					end
				end

				-- mw.logObject( parentSnaks );
				do
					local i = #parentSnaks;
					while ( i > 1 ) do
						local prevEntity = parentEntities[i - 1];
						-- TODO: use English labels, if there is no current language labels
						local prevLabel = getLabel( context, prevEntity, boundaries ) or '';
						local nextEntity = parentEntities[i];
						local nextLabel = getLabel( context, nextEntity, boundaries ) or '';
						if ( prevLabel == nextLabel ) then
							-- do not output same label twice (NY, NY, USA)
							table.remove( parentSnaks, i );
							table.remove( parentEntities, i );
						elseif ( isPartOfNext( prevLabel, ' ' .. nextLabel) ) then
							-- do not output same label if it's part of previos
							table.remove( parentSnaks, i - 1 );
							table.remove( parentEntities, i - 1 );
						end
						i = i - 1;
					end
				end

				if ( isSkipTopLevel( parentEntities[ #parentEntities ] ) ) then
					table.remove( parentSnaks, #parentEntities );
					table.remove( parentEntities, #parentEntities );
				end

				if ( not hasAdditionalQualifiers ) then
					for i=2,#parentSnaks,1 do
						local parentSnak = parentSnaks[i];

						local parentOptions = options;
						-- local parentOptions = mw.clone( options );
						parentOptions['text'] = getLabel( context, parentEntities[i], boundaries );

						result = result .. ', ' .. context.formatSnak( parentOptions, parentSnak );
					end
				end
			end
		end
	end

	result =  baseResult .. result .. context.formatRefs( options, statement );

	if ( categorizeByPlaceOfBirthAndDeath ) then
		if ( property == 'P19' ) then result = result .. getCategory( 'P1464', entriesToLookupCategory ); end
		if ( property == 'P20' ) then result = result .. getCategory( 'P1465', entriesToLookupCategory ); end
		if ( property == 'P119' ) then result = result .. getCategory( 'P1791', entriesToLookupCategory ); end
	end

	return result;
end

-- append entity id from snak to result
function insertFromSnak( snak, result )
	if ( not categorizeByPlaceOfBirthAndDeath ) then
		return;
	end
	if ( snak 
			and snak.datavalue
			and snak.datavalue.type == 'wikibase-entityid'
			and snak.datavalue.value
			and snak.datavalue.value['entity-type'] == 'item' ) then
		table.insert( result, 'Q' .. snak.datavalue.value['numeric-id'] );
	end
end

function getCategory( propertyToSearch, entriesToLookupCategoryFor )
	for _, placeId in pairs( entriesToLookupCategoryFor ) do
		local placeEntity = mw.wikibase.getEntity( placeId );
		local claims = WDS.filter( placeEntity.claims, propertyToSearch );

		if ( claims ) then
			for _, claim in pairs( claims ) do
				if ( claim.mainsnak
						and claim.mainsnak
						and claim.mainsnak.datavalue
						and claim.mainsnak.datavalue.type == "wikibase-entityid" ) then
					local catEntityId =  'Q' .. claim.mainsnak.datavalue.value["numeric-id"];
					local catEntity = mw.wikibase.getEntity( catEntityId );
					if ( catEntity and catEntity.sitelinks and catEntity.sitelinks[project] and catEntity.sitelinks[project].title ) then
						return '[[' .. catEntity.sitelinks[project].title .. ']]';
					end
				end
			end
		end
	end
	return '';
end

-- get current of historic name of place
function getLabel( context, entity, boundaries )
	if not entity then
		return nil;
	end

	local lang = mw.language.getContentLanguage();
	local langCode = lang:getCode();

	-- name from label
	-- TODO: lang:getFallbackLanguages()
	local label = nil;
	if entity.labels then
		if entity.labels[langCode] and entity.labels[langCode].value then
			label = entity.labels[langCode].value;
		elseif entity.labels.en and entity.labels.en.value then
			label = entity.labels.en.value;
		end
	end

	-- name from properties
	local results = getParentsInBoundariesSnakImpl( context, entity, boundaries, {
		'P1813[language:' .. langCode .. ']',
		'P1448[language:' .. langCode .. ']',
		'P1705[language:' .. langCode .. ']'
	} );

	for r, result in pairs( results ) do
		if result.datavalue
				and result.datavalue.value
				and result.datavalue.value.text then
			label = result.datavalue.value.text;
			break;
		end
	end

	return label;
end

local function calculateEndDateTimestamp( context, options, statement )
	if (not context) then error('context not specified') end;
	if (not options) then error('options not specified') end;
	if (not options.entity) then error('options.entity missing') end;
	if (not statement) then error('statement not specified') end;

	if ( statement.qualifiers and statement.qualifiers.P582 ) then
		for i, qualifier in ipairs(statement.qualifiers.P582 ) do
			local parsedTime = context.parseTimeFromSnak( qualifier );
			if ( parsedTime ) then
				return parsedTime;
			end
		end
	end

	-- check death day... do we have it at all?
	for h, propertyId in pairs( { "P570", "P577", "P571" } ) do
		local dateClaims = context.selectClaims( options, propertyId );
		if ( dateClaims ) then
			for i, statement in ipairs( dateClaims ) do
				local parsedTime = context.parseTimeFromSnak( statement.mainsnak );
				if ( parsedTime ) then
					return parsedTime;
				end
			end
		end
	end

	-- TODO: check other "end" properties

	-- no death day
	return os.time() * 1000;
end

function getFlag( context, countryEntityId, actualDate )

	local countryEntity = mw.wikibase.getEntity( countryEntityId );
	if ( not countryEntity or not countryEntity.claims or not countryEntity.claims.P41 ) then
		return nil;
	end

	local countryFlags = {};
	local flagImageStatements = countryEntity.claims.P41;
	for _, flagImageStatement in pairs( countryEntity.claims.P41 ) do
		if ( flagImageStatement.rank ~= 'deprecated' ) then
			local flagImage;
			if ( flagImageStatement and flagImageStatement.mainsnak and flagImageStatement.mainsnak.datavalue and flagImageStatement.mainsnak.datavalue.value ) then
				flagImage = flagImageStatement.mainsnak.datavalue.value;
			end
			local flagStartTime = -9223372036854775808;
			if ( flagImageStatement.qualifiers
					and flagImageStatement.qualifiers.P580
					and flagImageStatement.qualifiers.P580[1] ) then
				 local parsedFlagStartTime = context.parseTimeFromSnak( flagImageStatement.qualifiers.P580[1] );
				 if ( parsedFlagStartTime ) then
				 	flagStartTime = parsedFlagStartTime;
				 end
			end
			if ( flagImage ) then
				countryFlags[ flagStartTime ] = flagImage;
			end
		end
	end

	local goodFlag = nil;
	if ( countryFlags ) then
		local ordered_dates = {}
		for flagBeginDate in pairs(countryFlags) do
			table.insert(ordered_dates, flagBeginDate)
		end
		table.sort(ordered_dates)

		for i = 1, #ordered_dates do
			local flagBeginDate, flag = ordered_dates[i], countryFlags[ ordered_dates[i] ];
			if ( actualDate >= flagBeginDate ) then
				goodFlag = flag;
			end
		end
	end
	if ( goodFlag ) then
		return '[[File:' .. goodFlag .. '|20x15px|border]]';
	end
	return nil;
end

function p.formatCountryClaimWithFlag( context, options, statement )
	if (not context) then error('context not specified') end;
	if (not options) then error('options not specified') end;
	if (not options.entity) then error('options.entity is missing') end;
	if (not statement) then error('statement not specified') end;

	local countryEntityId = nil;
	local countryEntity = nil;
	if ( statement.mainsnak and statement.mainsnak.datavalue and statement.mainsnak.datavalue.value and statement.mainsnak.datavalue.value["numeric-id"] ) then
		countryEntityId = 'Q' .. statement.mainsnak.datavalue.value["numeric-id"];
		countryEntity = mw.wikibase.getEntity( countryEntityId );
	end
	
	if not countryEntity then
		return '<span class="country-name">' .. context.formatStatementDefault( context, options, statement ) .. '</span>';
	end

	local endDateTimestamp = calculateEndDateTimestamp( context, options, statement );
	local boundaries = getTimeBoundariesFromProperties( context, {'P570', 'P577', 'P571'} );

	local countryOptions = mw.clone( options );
	if not countryOptions['text'] or countryOptions['text'] == '' then
		countryOptions['text'] = getLabel( context, countryEntity, boundaries );
	end

	local flag = getFlag( context, countryEntityId, endDateTimestamp );

	if ( flag ) then
		return flag .. '&nbsp;<span class="country-name">' .. context.formatStatementDefault( context, countryOptions, statement ) .. '</span>';
	end

	return '<span class="country-name">' .. context.formatStatementDefault( context, countryOptions, statement ) .. '</span>';
end

return p;