<?php

namespace MediaWiki\Tests\Rest\Handler;

use HashConfig;
use InvalidArgumentException;
use Language;
use MediaWiki\HookContainer\HookContainer;
use MediaWiki\Linker\LinkTarget;
use MediaWiki\MainConfigNames;
use MediaWiki\Page\PageIdentity;
use MediaWiki\Page\PageIdentityValue;
use MediaWiki\Page\PageStore;
use MediaWiki\Page\ProperPageIdentity;
use MediaWiki\Page\RedirectLookup;
use MediaWiki\Permissions\PermissionManager;
use MediaWiki\Rest\Handler\SearchHandler;
use MediaWiki\Rest\LocalizedHttpException;
use MediaWiki\Rest\RequestData;
use MediaWiki\Search\Entity\SearchResultThumbnail;
use MediaWiki\Search\SearchResultThumbnailProvider;
use MediaWiki\Tests\Unit\DummyServicesTrait;
use MediaWiki\User\UserOptionsLookup;
use MockSearchResultSet;
use PHPUnit\Framework\MockObject\MockObject;
use SearchEngine;
use SearchEngineFactory;
use SearchResult;
use SearchResultSet;
use SearchSuggestion;
use SearchSuggestionSet;
use Status;
use TitleFormatter;
use TitleValue;
use Wikimedia\Message\MessageValue;

/**
 * @covers \MediaWiki\Rest\Handler\SearchHandler
 */
class SearchHandlerTest extends \MediaWikiUnitTestCase {

	use DummyServicesTrait;
	use MediaTestTrait;

	/**
	 * @var SearchEngine|MockObject|null
	 */
	private $searchEngine = null;

	/**
	 * @param string $query
	 * @param SearchResultSet|Status $titleResult
	 * @param SearchResultSet|Status $textResult
	 * @param SearchSuggestionSet|null $completionResult
	 * @param PermissionManager|null $permissionManager
	 * @param RedirectLookup|null $redirectLookup
	 * @param PageStore|null $pageStore
	 * @param TitleFormatter|null $mockTitleFormatter
	 * @param HookContainer|null $hookContainer
	 *
	 * @return SearchHandler
	 */
	private function newHandler(
		$query,
		$titleResult,
		$textResult,
		$completionResult = null,
		$permissionManager = null,
		$redirectLookup = null,
		$pageStore = null,
		$mockTitleFormatter = null,
		HookContainer $hookContainer = null
	) {
		$config = new HashConfig( [
			MainConfigNames::SearchType => 'test',
			MainConfigNames::SearchTypeAlternatives => [],
			MainConfigNames::NamespacesToBeSearchedDefault => [ NS_MAIN => true ],
			MainConfigNames::SearchSuggestCacheExpiry => 1200,
		] );

		/** @var Language|MockObject $language */
		$language = $this->createNoOpMock( Language::class );
		$hookContainer ??= $this->createHookContainer();
		/** @var UserOptionsLookup|MockObject $userOptionsLookup */
		$userOptionsLookup = $this->createMock( UserOptionsLookup::class );
		$searchEngineConfig = new \SearchEngineConfig(
			$config,
			$language,
			$hookContainer,
			[],
			$userOptionsLookup
		);

		if ( !$permissionManager ) {
			$permissionManager = $this->createMock( PermissionManager::class );
			$permissionManager->method( 'isEveryoneAllowed' )
				->with( 'read' )
				->willReturn( true );
		}
		if ( !$pageStore ) {
			$pageStore = $this->createMock( PageStore::class );
		}

		// Our mock RedirectLookup defaults to not finding a redirect for our given page
		if ( !$redirectLookup ) {
			$redirectLookup = $this->createMock( RedirectLookup::class );
			$redirectLookup->method( 'getRedirectTarget' )
				->willReturn( null );
		}

		if ( !$mockTitleFormatter ) {
			$mockTitleFormatter = $this->getDummyTitleFormatter();
		}

		/** @var SearchEngine|MockObject $searchEngine */
		$this->searchEngine = $this->createMock( SearchEngine::class );
		$this->searchEngine->method( 'searchTitle' )
			->with( $query )
			->willReturn( $titleResult );
		$this->searchEngine->method( 'searchText' )
			->with( $query )
			->willReturn( $textResult );

		if ( $completionResult ) {
			$this->searchEngine->method( 'completionSearchWithVariants' )
				->with( $query )
				->willReturn( $completionResult );
		}

		/** @var SearchEngineFactory|MockObject $searchEngineFactory */
		$searchEngineFactory = $this->createNoOpMock( SearchEngineFactory::class, [ 'create' ] );
		$searchEngineFactory->method( 'create' )
			->willReturn( $this->searchEngine );

		$searchResultThumbnailProvider = new SearchResultThumbnailProvider(
			$this->makeMockRepoGroup( [] ),
			$hookContainer
		);

		return new SearchHandler(
			$config,
			$searchEngineFactory,
			$searchEngineConfig,
			$searchResultThumbnailProvider,
			$permissionManager,
			$redirectLookup,
			$pageStore,
			$mockTitleFormatter
		);
	}

	/**
	 * @param string $pageName
	 * @param string $textSnippet
	 * @param bool $broken
	 * @param bool $missing
	 *
	 * @return SearchResult
	 */
	private function makeMockSearchResult(
		$pageName,
		$textSnippet = 'Lorem Ipsum',
		$broken = false,
		$missing = false
	) {
		$title = $this->makeMockTitle( $pageName );

		/** @var SearchResult|MockObject $result */
		$result = $this->createNoOpMock( SearchResult::class, [
			'getTitle', 'isBrokenTitle', 'isMissingRevision', 'getTextSnippet'
		] );
		$result->method( 'getTitle' )->willReturn( $title );
		$result->method( 'getTextSnippet' )->willReturn( $textSnippet );
		$result->method( 'isBrokenTitle' )->willReturn( $broken );
		$result->method( 'isMissingRevision' )->willReturn( $missing );

		return $result;
	}

	/**
	 * @param string $pageName
	 * @param MockObject|null $title
	 *
	 * @return SearchSuggestion
	 */
	private function makeMockSearchSuggestion( $pageName, $title = null ) {
		if ( !$title ) {
			$title = $this->makeMockTitle( $pageName );
		}

		/** @var SearchSuggestion|MockObject $suggestion */
		$suggestion = $this->createNoOpMock(
			SearchSuggestion::class,
			[ 'getSuggestedTitle', 'getSuggestedTitleID', 'getText' ]
		);
		$suggestion->method( 'getSuggestedTitle' )->willReturn( $title );
		$suggestion->method( 'getSuggestedTitleID' )->willReturn( $title->getArticleID() );
		$suggestion->method( 'getText' )->willReturn( $title->getPrefixedText() );

		return $suggestion;
	}

	public function testExecuteFulltextSearch() {
		$titleResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo', 'one' ),
			$this->makeMockSearchResult( 'Forbidden Foo', 'two' ), // forbidden
			$this->makeMockSearchResult( 'FooBar', 'three' ),
			$this->makeMockSearchResult( 'Foo Moo', 'four', true, false ), // missing
		] );
		$textResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Quux', 'one' ),
			$this->makeMockSearchResult( 'Forbidden Quux', 'two' ), // forbidden
			$this->makeMockSearchResult( 'Xyzzy', 'three' ),
			$this->makeMockSearchResult( 'Yookoo', 'four', false, true ), // broken
		] );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );
		$handler = $this->newHandler( $query, $titleResults, $textResults );
		$config = [ 'mode' => SearchHandler::FULLTEXT_MODE ];
		$data = $this->executeHandlerAndGetBodyData( $handler, $request, $config, [], [], [],
			$this->mockAnonAuthority( static function ( string $permission, ?PageIdentity $target ) {
				return $target && !preg_match( '/Forbidden/', $target->getDBkey() );
			} ) );

		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 4, $data['pages'] );
		$this->assertSame( 'Foo', $data['pages'][0]['title'] );
		$this->assertSame( 'one', $data['pages'][0]['excerpt'] );
		$this->assertSame( 'FooBar', $data['pages'][1]['title'] );
		$this->assertSame( 'three', $data['pages'][1]['excerpt'] );
		$this->assertSame( 'Quux', $data['pages'][2]['title'] );
		$this->assertSame( 'one', $data['pages'][2]['excerpt'] );
		$this->assertSame( 'Xyzzy', $data['pages'][3]['title'] );
		$this->assertSame( 'three', $data['pages'][3]['excerpt'] );
	}

	public function testExecuteCompletionSearch() {
		$titleResults = new MockSearchResultSet( [] );
		$textResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Quux', 'one' ),
		] );
		$completionResults = new SearchSuggestionSet( [
			$this->makeMockSearchSuggestion( 'Frob' ),
			$this->makeMockSearchSuggestion( 'Frobnitz' ),
		] );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$handler = $this->newHandler(
			$query, $titleResults, $textResults, $completionResults );
		$config = [ 'mode' => SearchHandler::COMPLETION_MODE ];
		$response = $this->executeHandler( $handler, $request, $config );

		$this->assertSame( 200, $response->getStatusCode() );
		$this->assertSame( 'application/json', $response->getHeaderLine( 'Content-Type' ) );
		$this->assertSame( 'public, max-age=1200', $response->getHeaderLine( 'Cache-Control' ) );

		$data = json_decode( $response->getBody(), true );
		$this->assertIsArray( $data, 'Body must be a JSON array' );

		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 2, $data['pages'] );
		$this->assertSame( 'Frob', $data['pages'][0]['title'] );
		$this->assertSame( 'Frob', $data['pages'][0]['excerpt'] );
		$this->assertSame( 'Frobnitz', $data['pages'][1]['title'] );
		$this->assertSame( 'Frobnitz', $data['pages'][1]['excerpt'] );
	}

	public function testCompletionSearchNotCachedForPublicPages() {
		$titleResults = new MockSearchResultSet( [] );
		$textResults = new MockSearchResultSet( [] );
		$completionResults = new SearchSuggestionSet( [] );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$permissionManager = $this->createMock( PermissionManager::class );
		$permissionManager->method( 'isEveryoneAllowed' )
			->with( 'read' )
			->willReturn( false );

		$handler = $this->newHandler( $query, $titleResults, $textResults, $completionResults, $permissionManager );
		$config = [ 'mode' => SearchHandler::COMPLETION_MODE ];

		$response = $this->executeHandler( $handler, $request, $config );
		$this->assertSame( 'no-store, max-age=0', $response->getHeaderLine( 'Cache-Control' ) );
		$this->assertSame( 200, $response->getStatusCode() );
	}

	public function testExecute_limit() {
		$titleResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo' ),
			$this->makeMockSearchResult( 'FooBar' ),
		] );
		$textResults = new MockSearchResultSet( [] );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query, 'limit' => 7 ] ] );

		$handler = $this->newHandler( $query, $titleResults, $textResults );

		// Limits are enforced by the SearchEngine, which we mock.
		// So we have to do assertions on the mock, not on the result data.
		$this->searchEngine
			->expects( $this->atLeastOnce() )
			->method( 'setLimitOffset' )
			->with( 7, 0 );

		$this->executeHandler( $handler, $request );
	}

	public function testExecute_limit_default() {
		$titleResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo' ),
			$this->makeMockSearchResult( 'FooBar' ),
		] );
		$textResults = new MockSearchResultSet( [] );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$handler = $this->newHandler( $query, $titleResults, $textResults );

		// Limits are enforced by the SearchEngine, which we mock.
		// So we have to do assertions on the mock, not on the result data.
		$this->searchEngine
			->expects( $this->atLeastOnce() )
			->method( 'setLimitOffset' )
			->with( 50, 0 );

		$this->executeHandler( $handler, $request );
	}

	public function provideExecute_limit_error() {
		yield [ 0, 'paramvalidator-outofrange-minmax' ];
		yield [ 123, 'paramvalidator-outofrange-minmax' ];
		yield [ 'xyz', 'paramvalidator-badinteger' ];
	}

	/**
	 * @dataProvider provideExecute_limit_error
	 * @param int $requestedLimit
	 * @param string $error
	 */
	public function testExecute_limit_error( $requestedLimit, $error ) {
		$titleResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo' ),
			$this->makeMockSearchResult( 'FooBar' ),
		] );
		$textResults = new MockSearchResultSet( [] );

		$query = 'foo';
		$request =
			new RequestData( [ 'queryParams' => [ 'q' => $query, 'limit' => $requestedLimit ] ] );

		$handler = $this->newHandler( $query, $titleResults, $textResults );

		$this->expectExceptionObject(
			new LocalizedHttpException( new MessageValue( $error ), 400 )
		);

		$this->executeHandler( $handler, $request );
	}

	public function testExecute_status() {
		$titleResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo', 'one' ),
			$this->makeMockSearchResult( 'FooBar', 'three' ),
		] ) );
		$textResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Quux', 'one' ),
			$this->makeMockSearchResult( 'Xyzzy', 'three' ),
		] ) );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$handler = $this->newHandler( $query, $titleResults, $textResults );
		$data = $this->executeHandlerAndGetBodyData( $handler, $request );

		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 4, $data['pages'] );
	}

	public function testExecute_missingparam() {
		$titleResults = Status::newFatal( 'testing' );
		$textResults = new MockSearchResultSet( [] );

		$query = '';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$this->expectExceptionObject(
			new LocalizedHttpException(
				new MessageValue( "paramvalidator-missingparam", [ 'q' ] ),
				400
			)
		);

		$handler = $this->newHandler( $query, $titleResults, $textResults );
		$this->executeHandler( $handler, $request );
	}

	public function testExecute_error() {
		$titleResults = Status::newFatal( 'testing' );
		$textResults = new MockSearchResultSet( [] );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$this->expectExceptionObject(
			new LocalizedHttpException( new MessageValue( "rest-search-error", [ 'testing' ] ) )
		);

		$handler = $this->newHandler( $query, $titleResults, $textResults );
		$this->executeHandler( $handler, $request );
	}

	public function testNeedsWriteWriteAccess() {
		$titleResults = new MockSearchResultSet( [] );
		$textResults = new MockSearchResultSet( [] );

		$handler = $this->newHandler( '', $titleResults, $textResults );
		$this->assertTrue( $handler->needsReadAccess() );
		$this->assertFalse( $handler->needsWriteAccess() );
	}

	public function testExecute_augmentedFields() {
		$titleResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo', 'one' ),
			$this->makeMockSearchResult( 'FooBar', 'three' ),
		] ) );
		$textResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Quux', 'one' ),
			$this->makeMockSearchResult( 'Xyzzy', 'three' ),
		] ) );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$handler = $this->newHandler( $query, $titleResults, $textResults );
		$data = $this->executeHandlerAndGetBodyData( $handler, $request );

		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 4, $data['pages'] );
		$this->assertArrayHasKey( 'thumbnail', $data['pages'][0] );
		$this->assertNull( $data['pages'][0][ 'thumbnail' ] );

		$this->assertArrayHasKey( 'description', $data['pages'][0] );
		$this->assertNull( $data['pages'][0][ 'description' ] );

		$this->assertArrayHasKey( 'matched_title', $data['pages'][0] );
		$this->assertNull( $data['pages'][0][ 'matched_title' ] );
	}

	public function testExecute_augmentedFieldsDescriptionAndThumbnailProvided() {
		$titleResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo', 'one' ),
		] ) );
		$textResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Quux', 'one' ),
		] ) );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$hookContainer = $this->createHookContainer( [
			'SearchResultProvideDescription' =>
				static function ( array $pageIdentities, array &$result ) {
					foreach ( $pageIdentities as $pageId => $pageIdentity ) {
						$result[ $pageId ] = 'Description_' . $pageIdentity->getId();
					}
				},
			'SearchResultProvideThumbnail' =>
				static function ( array $pageIdentities, array &$result ) {
					foreach ( $pageIdentities as $pageId => $pageIdentity ) {
						$result[ $pageId ] = new SearchResultThumbnail(
							'image/png',
							2250,
							100,
							125,
							500,
							'http:/example.org/url_' . $pageIdentity->getId(),
							null
						);
					}
				}
		] );

		$handler = $this->newHandler(
			$query, $titleResults, $textResults, null, null, null, null, null, $hookContainer
		);

		$data = $this->executeHandlerAndGetBodyData( $handler, $request, [], $hookContainer );

		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 2, $data['pages'] );
		$this->assertArrayHasKey( 'thumbnail', $data['pages'][0] );

		$this->assertSame( 'http:/example.org/url_1', $data['pages'][0][ 'thumbnail' ]['url'] );
		$this->assertSame( 125, $data['pages'][0][ 'thumbnail' ]['height'] );
		$this->assertSame( 100, $data['pages'][0][ 'thumbnail' ]['width'] );
		$this->assertSame( 'image/png', $data['pages'][0][ 'thumbnail' ]['mimetype'] );
		$this->assertSame( 2250, $data['pages'][0][ 'thumbnail' ]['size'] );
		$this->assertSame( 500, $data['pages'][0][ 'thumbnail' ]['duration'] );
		$this->assertArrayHasKey( 'description', $data['pages'][0] );
		$this->assertSame( 'Description_1', $data['pages'][0][ 'description' ] );
	}

	/**
	 * Tests the case where a search term matches a page with a redirect.
	 */
	public function testExecute_ResolvesRedirect() {
		$textResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo Redirect Source' ),
			$this->makeMockSearchResult( 'FooBarBaz' ),
		] );

		$pageTarget = new PageIdentityValue( 1, NS_MAIN, 'Foo_Redirect_Target', PageIdentityValue::LOCAL );

		$mockRedirectLinkTarget = $this->createMock( LinkTarget::class );
		$mockPageStore = $this->createMock( PageStore::class );
		$mockPageStore->method( 'getPageForLink' )->willReturn( $pageTarget );
		$mockRedirectLookup = $this->createMock( RedirectLookup::class );

		// first call has a redirect, second call does not
		$mockRedirectLookup
			->method( 'getRedirectTarget' )
			->willReturnOnConsecutiveCalls( $mockRedirectLinkTarget, null );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );
		$config = [];
		$handler = $this->newHandler(
			$query, null, $textResults, null, null,
			$mockRedirectLookup, $mockPageStore
		);

		$data = $this->executeHandlerAndGetBodyData( $handler, $request, $config, [] );

		$this->assertCount( 2, $data['pages'] );
		$this->assertArrayHasKey( 'matched_title', $data['pages'][0] );
		$this->assertArrayHasKey( 'matched_title', $data['pages'][1] );

		$this->assertSame( 'Foo Redirect Source', $data['pages'][0]['matched_title'] );
		$this->assertSame( 'Foo Redirect Target', $data['pages'][0]['title'] );
		$this->assertSame( null, $data['pages'][1]['matched_title'] );
	}

	/**
	 * Tests the case where a search term matches both the redirect source and the redirect target page.
	 * We expect to remove the redirect source, and keep the redirect target.
	 */
	public function testExecute_RemovesDuplicateRedirectAndSource() {
		$pageTarget = $this->createMock( ProperPageIdentity::class );
		$pageTarget->method( 'getID' )->willReturn( 10 );
		$pageTarget->method( 'getDBKey' )->willReturn( 'Foo_Redirect_Target' );

		$mockRedirectLinkTarget = $this->createMock( LinkTarget::class );
		$mockPageStore = $this->createMock( PageStore::class );
		$mockPageStore->method( 'getPageForLink' )->willReturn( $pageTarget );
		$mockRedirectLookup = $this->createMock( RedirectLookup::class );

		// first call has a redirect, second call does not
		$mockRedirectLookup
			->method( 'getRedirectTarget' )
			->willReturnOnConsecutiveCalls( $mockRedirectLinkTarget, null );

		$mockTitle = $this->makeMockTitle( 'Foo Redirect Target', [ 'id' => 10 ] );
		$completionConfig = [ 'mode' => SearchHandler::COMPLETION_MODE ];
		$completionResults = new SearchSuggestionSet( [
			$this->makeMockSearchSuggestion( 'Foo Redirect Source', $mockTitle ),
			$this->makeMockSearchSuggestion( 'Foo Redirect Target', $mockTitle ),
		] );
		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$handler = $this->newHandler(
			$query, null, null, $completionResults, null,
			$mockRedirectLookup, $mockPageStore
		);

		$data = $this->executeHandlerAndGetBodyData( $handler, $request, $completionConfig, [] );

		$this->assertCount( 1, $data['pages'] );
		$this->assertArrayHasKey( 'matched_title', $data['pages'][0] );

		$this->assertSame( 'Foo Redirect Target', $data['pages'][0]['title'] );
	}

	public function testExecute_NonProperPage() {
		$page = $this->makeMockTitle( 'Blankpage', [ 'namespace' => NS_SPECIAL ] );
		$result = $this->createNoOpMock(
			SearchResult::class,
			[ 'getTitle', 'isBrokenTitle', 'isMissingRevision', 'getTextSnippet' ]
		);
		$result->method( 'getTitle' )->willReturn( $page );
		$textResults = new MockSearchResultSet( [ $result ] );

		$query = 'foo';

		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );
		$handler = $this->newHandler(
			$query,
			null,
			$textResults
		);

		$data = $this->executeHandlerAndGetBodyData( $handler, $request );
		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 1, $data['pages'] );
	}

	/**
	 * When a page in a real namespace redirects to a Special Page, it should come back in results
	 */
	public function testExecute_NonProperPageAsRedirect() {
		$textResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Special Page Redirect Source' ),
		] );

		$mockRedirectLinkTarget = new TitleValue( NS_SPECIAL, 'MyPage' );
		$mockRedirectLookup = $this->createMock( RedirectLookup::class );
		$mockRedirectLookup->method( 'getRedirectTarget' )
			->willReturn( $mockRedirectLinkTarget );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$config = [];
		$handler = $this->newHandler(
			$query, null, $textResults, null, null,
			$mockRedirectLookup
		);

		$data = $this->executeHandlerAndGetBodyData( $handler, $request, $config, [] );
		$this->assertCount( 1, $data['pages'] );
		$this->assertEquals( 'Special Page Redirect Source', $data['pages'][0]['title'] );
		$this->assertNull( $data['pages'][0]['matched_title'] );
	}

	/**
	 * When a page in a real namespace redirects to an interwiki, it should come back in results
	 */
	public function testExecute_InterwikiLinkAsRedirect() {
		$textResults = new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Interwiki Redirect Source' ),
		] );

		$mockRedirectLinkTarget = $this->createMock( LinkTarget::class );
		$mockRedirectLinkTarget->method( 'getNamespace' )->willReturn( 0 );
		$mockRedirectLinkTarget->method( 'isExternal' )->willReturn( true );
		$mockRedirectLinkTarget->method( 'getDBkey' )->willReturn( 'Interwiki_Redirect_Target' );

		$mockRedirectLookup = $this->createMock( RedirectLookup::class );
		$mockRedirectLookup->method( 'getRedirectTarget' )
			->willReturn( $mockRedirectLinkTarget );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$config = [];
		$handler = $this->newHandler(
			$query, null, $textResults, null, null,
			$mockRedirectLookup
		);

		$data = $this->executeHandlerAndGetBodyData( $handler, $request, $config, [] );

		$this->assertCount( 1, $data['pages'] );
		$this->assertNull( $data['pages'][0]['matched_title'] );
		$this->assertEquals( 'Interwiki Redirect Source', $data['pages'][0]['title'] );
	}

	public function testExecute_NullResults() {
		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$handler = $this->newHandler( $query, null, null );
		$data = $this->executeHandlerAndGetBodyData( $handler, $request );

		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 0, $data['pages'] );
	}

	public function testInitWrongConfig() {
		$titleResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Foo', 'one' ),
			$this->makeMockSearchResult( 'FooBar', 'three' ),
		] ) );
		$textResults = Status::newGood( new MockSearchResultSet( [
			$this->makeMockSearchResult( 'Quux', 'one' ),
			$this->makeMockSearchResult( 'Xyzzy', 'three' ),
		] ) );

		$query = 'foo';
		$request = new RequestData( [ 'queryParams' => [ 'q' => $query ] ] );

		$this->expectException( InvalidArgumentException::class );

		$handler = $this->newHandler( $query, $titleResults, $textResults );
		$data = $this->executeHandlerAndGetBodyData(
			$handler,
			$request,
			[
				'mode' => 'SomethingWrong'
			] );

		$this->assertArrayHasKey( 'pages', $data );
		$this->assertCount( 0, $data['pages'] );
	}
}