class SearchMatchTest

class SearchMatchTest extends KernelTestBase {
    // The search index can contain different types of content. Typically the type
    // is 'node'. Here we test with _test_ and _test2_ as the type.
    const SEARCH_TYPE = '_test_';
    const SEARCH_TYPE_2 = '_test2_';
    const SEARCH_TYPE_JPN = '_test3_';
    
    /**
     * Modules to enable.
     *
     * @var array
     */
    protected static $modules = [
        'search',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        $this->installSchema('search', [
            'search_index',
            'search_dataset',
            'search_total',
        ]);
        $this->installConfig([
            'search',
        ]);
    }
    
    /**
     * Tests search indexing.
     */
    public function testMatching() {
        $this->_setup();
        $this->_testQueries();
    }
    
    /**
     * Set up a small index of items to test against.
     */
    public function _setup() {
        $this->config('search.settings')
            ->set('index.minimum_word_size', 3)
            ->save();
        $search_index = \Drupal::service('search.index');
        assert($search_index instanceof SearchIndexInterface);
        for ($i = 1; $i <= 7; ++$i) {
            $search_index->index(static::SEARCH_TYPE, $i, LanguageInterface::LANGCODE_NOT_SPECIFIED, $this->getText($i));
        }
        for ($i = 1; $i <= 5; ++$i) {
            $search_index->index(static::SEARCH_TYPE_2, $i + 7, LanguageInterface::LANGCODE_NOT_SPECIFIED, $this->getText2($i));
        }
        // No getText builder function for Japanese text; just a simple array.
        foreach ([
            13 => '以呂波耳・ほへとち。リヌルヲ。',
            14 => 'ドルーパルが大好きよ！',
            15 => 'コーヒーとケーキ',
        ] as $i => $jpn) {
            $search_index->index(static::SEARCH_TYPE_JPN, $i, LanguageInterface::LANGCODE_NOT_SPECIFIED, $jpn);
        }
    }
    
    /**
     * _test_: Helper method for generating snippets of content.
     *
     * Generated items to test against:
     *   1  ipsum
     *   2  dolore sit
     *   3  sit am ut
     *   4  am ut enim am
     *   5  ut enim am minim veniam
     *   6  enim am minim veniam es cillum
     *   7  am minim veniam es cillum dolore eu
     */
    public function getText($n) {
        $words = explode(' ', "Ipsum dolore sit am. Ut enim am minim veniam. Es cillum dolore eu.");
        return implode(' ', array_slice($words, $n - 1, $n));
    }
    
    /**
     * _test2_: Helper method for generating snippets of content.
     *
     * Generated items to test against:
     *   8  dear
     *   9  king philip
     *   10 philip came over
     *   11 came over from germany
     *   12 over from germany swimming
     */
    public function getText2($n) {
        $words = explode(' ', "Dear King Philip came over from Germany swimming.");
        return implode(' ', array_slice($words, $n - 1, $n));
    }
    
    /**
     * Run predefine queries looking for indexed terms.
     */
    public function _testQueries() {
        // Note: OR queries that include short words in OR groups are only accepted
        // if the ORed terms are ANDed with at least one long word in the rest of
        // the query. Examples:
        // -  enim dolore OR ut = enim (dolore OR ut) = (enim dolor) OR (enim ut)
        // is good, and
        // -  dolore OR ut = (dolore) OR (ut)
        // is bad. This is a design limitation to avoid full table scans.
        $queries = [
            // Simple AND queries.
'ipsum' => [
                1,
            ],
            'enim' => [
                4,
                5,
                6,
            ],
            'xxxxx' => [],
            'enim minim' => [
                5,
                6,
            ],
            'enim xxxxx' => [],
            'dolore eu' => [
                7,
            ],
            'dolore xx' => [],
            'ut minim' => [
                5,
            ],
            'xx minim' => [],
            'enim veniam am minim ut' => [
                5,
            ],
            // Simple OR and AND/OR queries.
'dolore OR ipsum' => [
                1,
                2,
                7,
            ],
            'dolore OR xxxxx' => [
                2,
                7,
            ],
            'dolore OR ipsum OR enim' => [
                1,
                2,
                4,
                5,
                6,
                7,
            ],
            'ipsum OR dolore sit OR cillum' => [
                2,
                7,
            ],
            'minim dolore OR ipsum' => [
                7,
            ],
            'dolore OR ipsum veniam' => [
                7,
            ],
            'minim dolore OR ipsum OR enim' => [
                5,
                6,
                7,
            ],
            'dolore xx OR yy' => [],
            'xxxxx dolore OR ipsum' => [],
            // Sequence of OR queries.
'minim' => [
                5,
                6,
                7,
            ],
            'minim OR xxxx' => [
                5,
                6,
                7,
            ],
            'minim OR xxxx OR minim' => [
                5,
                6,
                7,
            ],
            'minim OR xxxx minim' => [
                5,
                6,
                7,
            ],
            'minim OR xxxx minim OR yyyy' => [
                5,
                6,
                7,
            ],
            'minim OR xxxx minim OR cillum' => [
                6,
                7,
                5,
            ],
            'minim OR xxxx minim OR xxxx' => [
                5,
                6,
                7,
            ],
            // Negative queries.
'dolore -sit' => [
                7,
            ],
            'dolore -eu' => [
                2,
            ],
            'dolore -xxxxx' => [
                2,
                7,
            ],
            'dolore -xx' => [
                2,
                7,
            ],
            // Phrase queries.
'"dolore sit"' => [
                2,
            ],
            '"sit dolore"' => [],
            '"am minim veniam es"' => [
                6,
                7,
            ],
            '"minim am veniam es"' => [],
            // Mixed queries.
'"am minim veniam es" OR dolore' => [
                2,
                6,
                7,
            ],
            '"minim am veniam es" OR "dolore sit"' => [
                2,
            ],
            '"minim am veniam es" OR "sit dolore"' => [],
            '"am minim veniam es" -eu' => [
                6,
            ],
            '"am minim veniam" -"cillum dolore"' => [
                5,
                6,
            ],
            '"am minim veniam" -"dolore cillum"' => [
                5,
                6,
                7,
            ],
            'xxxxx "minim am veniam es" OR dolore' => [],
            'xx "minim am veniam es" OR dolore' => [],
        ];
        $connection = Database::getConnection();
        foreach ($queries as $query => $results) {
            $result = $connection->select('search_index', 'i')
                ->extend(SearchQuery::class)
                ->searchExpression($query, static::SEARCH_TYPE)
                ->execute();
            $set = $result ? $result->fetchAll() : [];
            $this->_testQueryMatching($query, $set, $results);
            $this->_testQueryScores($query, $set, $results);
        }
        // These queries are run against the second index type, SEARCH_TYPE_2.
        $queries = [
            // Simple AND queries.
'ipsum' => [],
            'enim' => [],
            'enim minim' => [],
            'dear' => [
                8,
            ],
            'germany' => [
                11,
                12,
            ],
        ];
        foreach ($queries as $query => $results) {
            $result = $connection->select('search_index', 'i')
                ->extend(SearchQuery::class)
                ->searchExpression($query, static::SEARCH_TYPE_2)
                ->execute();
            $set = $result ? $result->fetchAll() : [];
            $this->_testQueryMatching($query, $set, $results);
            $this->_testQueryScores($query, $set, $results);
        }
        // These queries are run against the third index type, SEARCH_TYPE_JPN.
        $queries = [
            // Simple AND queries.
'呂波耳' => [
                13,
            ],
            '以呂波耳' => [
                13,
            ],
            'ほへと　ヌルヲ' => [
                13,
            ],
            'とちリ' => [],
            'ドルーパル' => [
                14,
            ],
            'パルが大' => [
                14,
            ],
            'コーヒー' => [
                15,
            ],
            'ヒーキ' => [],
        ];
        foreach ($queries as $query => $results) {
            $result = $connection->select('search_index', 'i')
                ->extend(SearchQuery::class)
                ->searchExpression($query, static::SEARCH_TYPE_JPN)
                ->execute();
            $set = $result ? $result->fetchAll() : [];
            $this->_testQueryMatching($query, $set, $results);
            $this->_testQueryScores($query, $set, $results);
        }
    }
    
    /**
     * Tests the matching abilities of the engine.
     *
     * Verify if a query produces the correct results.
     */
    public function _testQueryMatching($query, $set, $results) {
        // Get result IDs.
        $found = [];
        foreach ($set as $item) {
            $found[] = $item->sid;
        }
        // Compare $results and $found.
        sort($found);
        sort($results);
        $this->assertEquals($found, $results, "Query matching '{$query}'");
    }
    
    /**
     * Tests the scoring abilities of the engine.
     *
     * Verify if a query produces normalized, monotonous scores.
     */
    public function _testQueryScores($query, $set, $results) {
        // Get result scores.
        $scores = [];
        foreach ($set as $item) {
            $scores[] = $item->calculated_score;
        }
        // Check order.
        $sorted = $scores;
        sort($sorted);
        $this->assertEquals($scores, array_reverse($sorted), "Query order '{$query}'");
        // Check range.
        $this->assertTrue(!count($scores) || min($scores) > 0.0 && max($scores) <= 1.0001, "Query scoring '{$query}'");
    }

}