class TestDatabase

class TestDatabase {
    
    /**
     * The test lock ID.
     *
     * A random number used to ensure that test fixtures are unique to each test
     * method.
     *
     * @var int
     */
    protected $lockId;
    
    /**
     * The test database prefix.
     *
     * @var string
     */
    protected $databasePrefix;
    
    /**
     * Returns the database connection to the site running Simpletest.
     *
     * @return \Drupal\Core\Database\Connection
     *   The database connection to use for inserting assertions.
     *
     * @see \Drupal\simpletest\TestBase::prepareEnvironment()
     */
    public static function getConnection() {
        // Check whether there is a test runner connection.
        // @see run-tests.sh
        // @todo Convert Simpletest UI runner to create + use this connection, too.
        try {
            $connection = Database::getConnection('default', 'test-runner');
        } catch (ConnectionNotDefinedException $e) {
            // Check whether there is a backup of the original default connection.
            // @see TestBase::prepareEnvironment()
            try {
                $connection = Database::getConnection('default', 'simpletest_original_default');
            } catch (ConnectionNotDefinedException $e) {
                // If TestBase::prepareEnvironment() or TestBase::restoreEnvironment()
                // failed, the test-specific database connection does not exist
                // yet/anymore, so fall back to the default of the (UI) test runner.
                $connection = Database::getConnection('default', 'default');
            }
        }
        return $connection;
    }
    
    /**
     * TestDatabase constructor.
     *
     * @param string|null $db_prefix
     *   If not provided a new test lock is generated.
     * @param bool $create_lock
     *   (optional) Whether or not to create a lock file. Defaults to FALSE. If
     *   the environment variable RUN_TESTS_CONCURRENCY is greater than 1 it will
     *   be overridden to TRUE regardless of its initial value.
     *
     * @throws \InvalidArgumentException
     *   Thrown when $db_prefix does not match the regular expression.
     */
    public function __construct($db_prefix = NULL, $create_lock = FALSE) {
        if ($db_prefix === NULL) {
            $this->lockId = $this->getTestLock($create_lock);
            $this->databasePrefix = 'test' . $this->lockId;
        }
        else {
            $this->databasePrefix = $db_prefix;
            // It is possible that we're running a test inside a test. In which case
            // $db_prefix will be something like test12345678test90123456 and the
            // generated lock ID for the running test method would be 90123456.
            preg_match('/test(\\d+)$/', $db_prefix, $matches);
            if (!isset($matches[1])) {
                throw new \InvalidArgumentException("Invalid database prefix: {$db_prefix}");
            }
            $this->lockId = $matches[1];
        }
    }
    
    /**
     * Gets the relative path to the test site directory.
     *
     * @return string
     *   The relative path to the test site directory.
     */
    public function getTestSitePath() {
        return 'sites/simpletest/' . $this->lockId;
    }
    
    /**
     * Gets the test database prefix.
     *
     * @return string
     *   The test database prefix.
     */
    public function getDatabasePrefix() {
        return $this->databasePrefix;
    }
    
    /**
     * Generates a unique lock ID for the test method.
     *
     * @param bool $create_lock
     *   (optional) Whether or not to create a lock file. Defaults to FALSE.
     *
     * @return int
     *   The unique lock ID for the test method.
     */
    protected function getTestLock($create_lock = FALSE) {
        // There is a risk that the generated random number is a duplicate. This
        // would cause different tests to try to use the same database prefix.
        // Therefore, if running with a concurrency of greater than 1, we need to
        // create a lock.
        if (getenv('RUN_TESTS_CONCURRENCY') > 1) {
            $create_lock = TRUE;
        }
        do {
            $lock_id = mt_rand(10000000, 99999999);
            if ($create_lock && @symlink(__FILE__, $this->getLockFile($lock_id)) === FALSE) {
                // If we can't create a symlink, the lock ID is in use. Generate another
                // one. Symlinks are used because they are atomic and reliable.
                $lock_id = NULL;
            }
        } while ($lock_id === NULL);
        return $lock_id;
    }
    
    /**
     * Releases a lock.
     *
     * @return bool
     *   TRUE if successful, FALSE if not.
     */
    public function releaseLock() {
        return unlink($this->getLockFile($this->lockId));
    }
    
    /**
     * Releases all test locks.
     *
     * This should only be called once all the test fixtures have been cleaned up.
     */
    public static function releaseAllTestLocks() {
        $tmp = FileSystem::getOsTemporaryDirectory();
        $dir = dir($tmp);
        while (($entry = $dir->read()) !== FALSE) {
            if ($entry === '.' || $entry === '..') {
                continue;
            }
            $entry_path = $tmp . '/' . $entry;
            if (preg_match('/^test_\\d+/', $entry) && is_link($entry_path)) {
                unlink($entry_path);
            }
        }
    }
    
    /**
     * Gets the lock file path.
     *
     * @param int $lock_id
     *   The test method lock ID.
     *
     * @return string
     *   A file path to the symbolic link that prevents the lock ID being re-used.
     */
    protected function getLockFile($lock_id) {
        return FileSystem::getOsTemporaryDirectory() . '/test_' . $lock_id;
    }
    
    /**
     * Store an assertion from outside the testing context.
     *
     * This is useful for inserting assertions that can only be recorded after
     * the test case has been destroyed, such as PHP fatal errors. The caller
     * information is not automatically gathered since the caller is most likely
     * inserting the assertion on behalf of other code. In all other respects
     * the method behaves just like \Drupal\simpletest\TestBase::assert() in terms
     * of storing the assertion.
     *
     * @param string $test_id
     *   The test ID to which the assertion relates.
     * @param string $test_class
     *   The test class to store an assertion for.
     * @param bool|string $status
     *   A boolean or a string of 'pass' or 'fail'. TRUE means 'pass'.
     * @param string $message
     *   The assertion message.
     * @param string $group
     *   The assertion message group.
     * @param array $caller
     *   The an array containing the keys 'file' and 'line' that represent the
     *   file and line number of that file that is responsible for the assertion.
     *
     * @return int
     *   Message ID of the stored assertion.
     *
     * @internal
     */
    public static function insertAssert($test_id, $test_class, $status, $message = '', $group = 'Other', array $caller = []) {
        // Convert boolean status to string status.
        if (is_bool($status)) {
            $status = $status ? 'pass' : 'fail';
        }
        $caller += [
            'function' => 'Unknown',
            'line' => 0,
            'file' => 'Unknown',
        ];
        $assertion = [
            'test_id' => $test_id,
            'test_class' => $test_class,
            'status' => $status,
            'message' => $message,
            'message_group' => $group,
            'function' => $caller['function'],
            'line' => $caller['line'],
            'file' => $caller['file'],
        ];
        return static::getConnection()->insert('simpletest')
            ->fields($assertion)
            ->execute();
    }
    
    /**
     * Get information about the last test that ran given a test ID.
     *
     * @param int $test_id
     *   The test ID to get the last test from.
     *
     * @return array
     *   Associative array containing the last database prefix used and the
     *   last test class that ran.
     *
     * @internal
     */
    public static function lastTestGet($test_id) {
        $connection = static::getConnection();
        // Define a subquery to identify the latest 'message_id' given the
        // $test_id.
        $max_message_id_subquery = $connection->select('simpletest', 'sub')
            ->condition('test_id', $test_id);
        $max_message_id_subquery->addExpression('MAX([message_id])', 'max_message_id');
        // Run a select query to return 'last_prefix' from {simpletest_test_id} and
        // 'test_class' from {simpletest}.
        $select = $connection->select($max_message_id_subquery, 'st_sub');
        $select->join('simpletest', 'st', '[st].[message_id] = [st_sub].[max_message_id]');
        $select->join('simpletest_test_id', 'sttid', '[st].[test_id] = [sttid].[test_id]');
        $select->addField('sttid', 'last_prefix');
        $select->addField('st', 'test_class');
        return $select->execute()
            ->fetchAssoc();
    }
    
    /**
     * Reads the error log and reports any errors as assertion failures.
     *
     * The errors in the log should only be fatal errors since any other errors
     * will have been recorded by the error handler.
     *
     * @param int $test_id
     *   The test ID to which the log relates.
     * @param string $test_class
     *   The test class to which the log relates.
     *
     * @return bool
     *   Whether any fatal errors were found.
     *
     * @internal
     */
    public function logRead($test_id, $test_class) {
        $log = DRUPAL_ROOT . '/' . $this->getTestSitePath() . '/error.log';
        $found = FALSE;
        if (file_exists($log)) {
            foreach (file($log) as $line) {
                if (preg_match('/\\[.*?\\] (.*?): (.*?) in (.*) on line (\\d+)/', $line, $match)) {
                    // Parse PHP fatal errors for example: PHP Fatal error: Call to
                    // undefined function break_me() in /path/to/file.php on line 17
                    $caller = [
                        'line' => $match[4],
                        'file' => $match[3],
                    ];
                    static::insertAssert($test_id, $test_class, FALSE, $match[2], $match[1], $caller);
                }
                else {
                    // Unknown format, place the entire message in the log.
                    static::insertAssert($test_id, $test_class, FALSE, $line, 'Fatal error');
                }
                $found = TRUE;
            }
        }
        return $found;
    }
    
    /**
     * Defines the database schema for run-tests.sh and simpletest module.
     *
     * @return array
     *   Array suitable for use in a hook_schema() implementation.
     *
     * @internal
     */
    public static function testingSchema() {
        $schema['simpletest'] = [
            'description' => 'Stores simpletest messages',
            'fields' => [
                'message_id' => [
                    'type' => 'serial',
                    'not null' => TRUE,
                    'description' => 'Primary Key: Unique simpletest message ID.',
                ],
                'test_id' => [
                    'type' => 'int',
                    'not null' => TRUE,
                    'default' => 0,
                    'description' => 'Test ID, messages belonging to the same ID are reported together',
                ],
                'test_class' => [
                    'type' => 'varchar_ascii',
                    'length' => 255,
                    'not null' => TRUE,
                    'default' => '',
                    'description' => 'The name of the class that created this message.',
                ],
                'status' => [
                    'type' => 'varchar',
                    'length' => 9,
                    'not null' => TRUE,
                    'default' => '',
                    'description' => 'Message status. Core understands pass, fail, exception.',
                ],
                'message' => [
                    'type' => 'text',
                    'not null' => TRUE,
                    'description' => 'The message itself.',
                ],
                'message_group' => [
                    'type' => 'varchar_ascii',
                    'length' => 255,
                    'not null' => TRUE,
                    'default' => '',
                    'description' => 'The message group this message belongs to. For example: warning, browser, user.',
                ],
                'function' => [
                    'type' => 'varchar_ascii',
                    'length' => 255,
                    'not null' => TRUE,
                    'default' => '',
                    'description' => 'Name of the assertion function or method that created this message.',
                ],
                'line' => [
                    'type' => 'int',
                    'not null' => TRUE,
                    'default' => 0,
                    'description' => 'Line number on which the function is called.',
                ],
                'file' => [
                    'type' => 'varchar',
                    'length' => 255,
                    'not null' => TRUE,
                    'default' => '',
                    'description' => 'Name of the file where the function is called.',
                ],
            ],
            'primary key' => [
                'message_id',
            ],
            'indexes' => [
                'reporter' => [
                    'test_class',
                    'message_id',
                ],
            ],
        ];
        $schema['simpletest_test_id'] = [
            'description' => 'Stores simpletest test IDs, used to auto-increment the test ID so that a fresh test ID is used.',
            'fields' => [
                'test_id' => [
                    'type' => 'serial',
                    'not null' => TRUE,
                    'description' => 'Primary Key: Unique simpletest ID used to group test results together. Each time a set of tests
                            are run a new test ID is used.',
                ],
                'last_prefix' => [
                    'type' => 'varchar',
                    'length' => 60,
                    'not null' => FALSE,
                    'default' => '',
                    'description' => 'The last database prefix used during testing.',
                ],
            ],
            'primary key' => [
                'test_id',
            ],
        ];
        return $schema;
    }
    
    /**
     * Inserts the parsed PHPUnit results into {simpletest}.
     *
     * @param array[] $phpunit_results
     *   An array of test results, as returned from
     *   \Drupal\Core\Test\JUnitConverter::xmlToRows(). These results are in a
     *   form suitable for inserting into the {simpletest} table of the test
     *   results database.
     *
     * @internal
     */
    public static function processPhpUnitResults($phpunit_results) {
        if ($phpunit_results) {
            $query = static::getConnection()->insert('simpletest')
                ->fields(array_keys($phpunit_results[0]));
            foreach ($phpunit_results as $result) {
                $query->values($result);
            }
            $query->execute();
        }
    }

}