From a7a10eee3367a99c1bfe9a91c6362a61bb2b6645 Mon Sep 17 00:00:00 2001
From: Leszek Manicki <leszek.manicki@wikimedia.de>
Date: Wed, 9 Nov 2016 14:54:59 +0100
Subject: [PATCH] Add ForeignEntityRevisionLookupFactory providing a
 WikiPageEntityMetaDataLookup for the given foreign repository

Bug: T150330
Change-Id: Iac2de8d73fbc7e49ad2de358d69cc29456da25a5
---
 composer.json                                 |   2 +-
 .../ForeignEntityRevisionLookupFactory.php    | 145 ++++++++++++++++++
 ...ForeignEntityRevisionLookupFactoryTest.php | 138 +++++++++++++++++
 3 files changed, 284 insertions(+), 1 deletion(-)
 create mode 100644 lib/includes/Store/ForeignEntityRevisionLookupFactory.php
 create mode 100644 lib/tests/phpunit/Store/ForeignEntityRevisionLookupFactoryTest.php

diff --git a/composer.json b/composer.json
index 8d37538ce9..eeabaaa503 100644
--- a/composer.json
+++ b/composer.json
@@ -36,7 +36,7 @@
 		"wikibase/data-model": "~6.3",
 		"wikibase/data-model-serialization": "~2.2",
 		"wikibase/internal-serialization": "~2.3",
-		"wikibase/data-model-services": "~3.5",
+		"wikibase/data-model-services": "~3.7",
 		"wikibase/data-model-javascript": "~3.0.0",
 		"wikibase/javascript-api": "~2.2.0",
 		"wikibase/serialization-javascript": "~2.0.6",
diff --git a/lib/includes/Store/ForeignEntityRevisionLookupFactory.php b/lib/includes/Store/ForeignEntityRevisionLookupFactory.php
new file mode 100644
index 0000000000..27364a0220
--- /dev/null
+++ b/lib/includes/Store/ForeignEntityRevisionLookupFactory.php
@@ -0,0 +1,145 @@
+<?php
+
+namespace Wikibase\Lib\Store;
+
+use DataValues\Deserializers\DataValueDeserializer;
+use Serializers\Serializer;
+use Wikibase\DataModel\Assert\RepositoryNameAssert;
+use Wikibase\DataModel\Entity\EntityIdParser;
+use Wikibase\DataModel\Services\EntityId\PrefixMappingEntityIdParserFactory;
+use Wikibase\DataModel\Services\Lookup\UnknownForeignRepositoryException;
+use Wikibase\InternalSerialization\DeserializerFactory;
+use Wikibase\Lib\Store\Sql\PrefetchingWikiPageEntityMetaDataAccessor;
+use Wikibase\Lib\Store\Sql\WikiPageEntityMetaDataLookup;
+use Wikimedia\Assert\Assert;
+use Wikimedia\Assert\ParameterAssertionException;
+
+/**
+ * A factory providing the WikiPageEntityMetaDataLookup instance configured for the given foreign repository.
+ *
+ * @license GPL-2.0+
+ */
+class ForeignEntityRevisionLookupFactory {
+
+	/**
+	 * @var PrefixMappingEntityIdParserFactory
+	 */
+	private $parserFactory;
+
+	/**
+	 * @var Serializer
+	 */
+	private $entitySerializer;
+
+	/**
+	 * @var DataValueDeserializer
+	 */
+	private $dataValueDeserializer;
+
+	/**
+	 * @var EntityNamespaceLookup
+	 */
+	private $entityNamespaceLookup;
+
+	/**
+	 * @var int
+	 */
+	private $maxBlobSize;
+
+	/**
+	 * @var string[]
+	 */
+	private $databaseNames;
+
+	/**
+	 * @var WikiPageEntityRevisionLookup[]
+	 */
+	private $lookups = [];
+
+	/**
+	 * @param PrefixMappingEntityIdParserFactory $parserFactory
+	 * @param DataValueDeserializer $dataValueDeserializer
+	 * @param EntityIdParser $idParser Parser used to create an EntityId with a foreign repository prefix stripped
+	 * @param EntityNamespaceLookup $entityNamespaceLookup
+	 * @param int $maxBlobSize The maximum size of a blob allowed in serialization/deserialization,
+	 *            @see EntityContentDataCodec
+	 * @param string[] $databaseNames Associative array mapping repository names (prefixes) to database names
+	 *
+	 * @throws ParameterAssertionException
+	 */
+	public function __construct(
+		PrefixMappingEntityIdParserFactory $parserFactory,
+		Serializer $entitySerializer,
+		DataValueDeserializer $dataValueDeserializer,
+		EntityNamespaceLookup $entityNamespaceLookup,
+		$maxBlobSize,
+		array $databaseNames
+	) {
+		RepositoryNameAssert::assertParameterKeysAreValidRepositoryNames( $databaseNames, '$databaseNames' );
+		Assert::parameterElementType( 'string', $databaseNames, '$databaseNames' );
+		Assert::parameter( !array_key_exists( '', $databaseNames ), '$databaseNames', 'must not contain an empty string key' );
+
+		$this->parserFactory = $parserFactory;
+		$this->entitySerializer = $entitySerializer;
+		$this->dataValueDeserializer = $dataValueDeserializer;
+		$this->entityNamespaceLookup = $entityNamespaceLookup;
+		$this->maxBlobSize = $maxBlobSize;
+		$this->databaseNames = $databaseNames;
+	}
+
+	/**
+	 * @param string $repositoryName
+	 *
+	 * @return WikiPageEntityRevisionLookup
+	 *
+	 * @throws UnknownForeignRepositoryException
+	 */
+	public function getLookup( $repositoryName ) {
+		if ( !isset( $this->lookups[$repositoryName] ) ) {
+			$this->lookups[$repositoryName] = $this->newLookupForRepository( $repositoryName );
+
+		}
+		return $this->lookups[$repositoryName];
+	}
+
+	/**
+	 * @param string $repositoryName
+	 *
+	 * @return WikiPageEntityRevisionLookup
+	 *
+	 * @throws UnknownForeignRepositoryException
+	 */
+	private function newLookupForRepository( $repositoryName ) {
+		if ( !array_key_exists( $repositoryName, $this->databaseNames ) ) {
+			throw new UnknownForeignRepositoryException( 'No database configured for repository: ' . $repositoryName );
+		}
+
+		$prefixMappingIdParser = $this->parserFactory->getIdParser( $repositoryName );
+		$entityDeserializerFactory = new DeserializerFactory(
+			$this->dataValueDeserializer,
+			$prefixMappingIdParser,
+			null
+		);
+		$codec = new EntityContentDataCodec(
+			$prefixMappingIdParser,
+			$this->entitySerializer,
+			$entityDeserializerFactory->newEntityDeserializer(),
+			$this->maxBlobSize
+		);
+
+		$metaDataLookup = new PrefetchingWikiPageEntityMetaDataAccessor(
+			new WikiPageEntityMetaDataLookup(
+				$this->entityNamespaceLookup,
+				$this->databaseNames[$repositoryName],
+				$repositoryName
+			)
+		);
+
+		return new WikiPageEntityRevisionLookup(
+			$codec,
+			$metaDataLookup,
+			$this->databaseNames[$repositoryName]
+		);
+	}
+
+}
diff --git a/lib/tests/phpunit/Store/ForeignEntityRevisionLookupFactoryTest.php b/lib/tests/phpunit/Store/ForeignEntityRevisionLookupFactoryTest.php
new file mode 100644
index 0000000000..deebb5b0ff
--- /dev/null
+++ b/lib/tests/phpunit/Store/ForeignEntityRevisionLookupFactoryTest.php
@@ -0,0 +1,138 @@
+<?php
+
+namespace Wikibase\Lib\Tests\Store;
+
+use DataValues\Deserializers\DataValueDeserializer;
+use Serializers\Serializer;
+use Wikibase\DataModel\Entity\EntityIdParser;
+use Wikibase\DataModel\Services\EntityId\PrefixMappingEntityIdParserFactory;
+use Wikibase\DataModel\Services\Lookup\UnknownForeignRepositoryException;
+use Wikibase\Lib\Store\EntityNamespaceLookup;
+use Wikibase\Lib\Store\ForeignEntityRevisionLookupFactory;
+use Wikibase\Lib\Store\WikiPageEntityRevisionLookup;
+use Wikimedia\Assert\ParameterAssertionException;
+
+/**
+ * @covers Wikibase\Lib\Store\ForeignEntityRevisionLookupFactory
+ *
+ * @group Wikibase
+ * @group WikibaseLib
+ *
+ * @license GPL-2.0+
+ */
+class ForeignEntityRevisionLookupFactoryTest extends \PHPUnit_Framework_TestCase {
+
+	/**
+	 * @return EntityIdParser
+	 */
+	private function getEntityIdParser() {
+		return $this->getMock( EntityIdParser::class );
+	}
+
+	/**
+	 * @return PrefixMappingEntityIdParserFactory
+	 */
+	private function getPrefixMappingEntityIdParserFactory() {
+		$factory = $this->getMockBuilder( PrefixMappingEntityIdParserFactory::class )
+			->disableOriginalConstructor()
+			->getMock();
+		$factory->expects( $this->any() )
+			->method( 'getIdParser' )
+			->will( $this->returnValue( $this->getEntityIdParser() ) );
+		return $factory;
+	}
+
+	/**
+	 * @return Serializer
+	 */
+	private function getEntitySerializer() {
+		return $this->getMock( Serializer::class );
+	}
+
+	/**
+	 * @return DataValueDeserializer
+	 */
+	private function getDataValueDeserializer() {
+		return $this->getMock( DataValueDeserializer::class );
+	}
+
+	/**
+	 * @return EntityNamespaceLookup
+	 */
+	private function getEntityNamespaceLookup() {
+		return new EntityNamespaceLookup( [ 'item' => 100 ] );
+	}
+
+	public function testGivenKnownRepository_getLookupReturnsInstanceOfWikiPageEntityRevisionLookup() {
+		$factory = new ForeignEntityRevisionLookupFactory(
+			$this->getPrefixMappingEntityIdParserFactory(),
+			$this->getEntitySerializer(),
+			$this->getDataValueDeserializer(),
+			$this->getEntityNamespaceLookup(),
+			0,
+			[ 'foo' => 'foodb' ]
+		);
+
+		$this->assertInstanceOf( WikiPageEntityRevisionLookup::class, $factory->getLookup( 'foo' ) );
+	}
+
+	public function testGivenUnknownRepository_getLookupThrowsException() {
+		$factory = new ForeignEntityRevisionLookupFactory(
+			$this->getPrefixMappingEntityIdParserFactory(),
+			$this->getEntitySerializer(),
+			$this->getDataValueDeserializer(),
+			$this->getEntityNamespaceLookup(),
+			0,
+			[ 'foo' => 'foodb' ]
+		);
+
+		$this->setExpectedException( UnknownForeignRepositoryException::class );
+
+		$this->assertInstanceOf( WikiPageEntityRevisionLookup::class, $factory->getLookup( 'bar' ) );
+	}
+
+	public function testGetLookupReusesTheInstanceOverMultipleCalls() {
+		$factory = new ForeignEntityRevisionLookupFactory(
+			$this->getPrefixMappingEntityIdParserFactory(),
+			$this->getEntitySerializer(),
+			$this->getDataValueDeserializer(),
+			$this->getEntityNamespaceLookup(),
+			0,
+			[ 'foo' => 'foodb' ]
+		);
+
+		$lookupOne = $factory->getLookup( 'foo' );
+		$lookupTwo = $factory->getLookup( 'foo' );
+
+		$this->assertSame( $lookupOne, $lookupTwo );
+	}
+
+	public function provideInvalidDatabaseNamesValue() {
+		return [
+			'repository name containing a colon' => [ [ 'fo:o' => 'foodb' ] ],
+			'providing database name for local repository' => [ [ '' => 'foodb' ] ],
+			'non-string key' => [ [ 0 => 'foodb' ] ],
+			'not a string as a database name (false)' => [ [ 'foo' => false ] ],
+			'not a string as a database name (true)' => [ [ 'foo' => true ] ],
+			'not a string as a database name (null)' => [ [ 'foo' => null ] ],
+			'not a string as a database name (int)' => [ [ 'foo' => 100 ] ],
+		];
+	}
+
+	/**
+	 * @dataProvider provideInvalidDatabaseNamesValue
+	 */
+	public function testGivenInvalidDatabaseNamesValue_exceptionIsThrown( array $databaseNames ) {
+		$this->setExpectedException( ParameterAssertionException::class );
+
+		new ForeignEntityRevisionLookupFactory(
+			$this->getPrefixMappingEntityIdParserFactory(),
+			$this->getEntitySerializer(),
+			$this->getDataValueDeserializer(),
+			$this->getEntityNamespaceLookup(),
+			0,
+			$databaseNames
+		);
+	}
+
+}