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_';
  
  /**
   * {@inheritdoc}
   */
  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() : void {
    $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}'");
  }

}