class QueryBatchTest

class QueryBatchTest extends KernelTestBase {
    
    /**
     * The mocked migration.
     *
     * @var \Drupal\migrate\Plugin\MigrationInterface|\Prophecy\Prophecy\ObjectProphecy
     */
    protected $migration;
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'migrate',
        'migrate_query_batch_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Create a mock migration. This will be injected into the source plugin
        // under test.
        $this->migration = $this->prophesize(MigrationInterface::class);
        $this->migration
            ->id()
            ->willReturn($this->randomMachineName(16));
        // Prophesize a useless ID map plugin and an empty set of destination IDs.
        // Calling code can override these prophecies later and set up different
        // behaviors.
        $this->migration
            ->getIdMap()
            ->willReturn($this->prophesize(MigrateIdMapInterface::class)
            ->reveal());
        $this->migration
            ->getDestinationIds()
            ->willReturn([]);
    }
    
    /**
     * Tests a negative batch size throws an exception.
     */
    public function testBatchSizeNegative() : void {
        $this->expectException(MigrateException::class);
        $this->expectExceptionMessage('batch_size must be greater than or equal to zero');
        $plugin = $this->getPlugin([
            'batch_size' => -1,
        ]);
        $plugin->next();
    }
    
    /**
     * Tests a non integer batch size throws an exception.
     */
    public function testBatchSizeNonInteger() : void {
        $this->expectException(MigrateException::class);
        $this->expectExceptionMessage('batch_size must be greater than or equal to zero');
        $plugin = $this->getPlugin([
            'batch_size' => '1',
        ]);
        $plugin->next();
    }
    
    /**
     * {@inheritdoc}
     */
    public static function queryDataProvider() {
        // Define the parameters for building the data array. The first element is
        // the number of source data rows, the second is the batch size to set on
        // the plugin configuration.
        $test_parameters = [
            // Test when batch size is 0.
[
                200,
                0,
            ],
            // Test when rows mod batch size is 0.
[
                200,
                20,
            ],
            // Test when rows mod batch size is > 0.
[
                200,
                30,
            ],
            // Test when batch size = row count.
[
                200,
                200,
            ],
            // Test when batch size > row count.
[
                200,
                300,
            ],
        ];
        // Build the data provider array. The provider array consists of the source
        // data rows, the expected result data, the expected count, the plugin
        // configuration, the expected batch size and the expected batch count.
        $table = 'query_batch_test';
        $tests = [];
        $data_set = 0;
        foreach ($test_parameters as $data) {
            [
                $num_rows,
                $batch_size,
            ] = $data;
            for ($i = 0; $i < $num_rows; $i++) {
                $tests[$data_set]['source_data'][$table][] = [
                    'id' => $i,
                    'data' => Random::string(),
                ];
            }
            $tests[$data_set]['expected_data'] = $tests[$data_set]['source_data'][$table];
            $tests[$data_set][2] = $num_rows;
            // Plugin configuration array.
            $tests[$data_set][3] = [
                'batch_size' => $batch_size,
            ];
            // Expected batch size.
            $tests[$data_set][4] = $batch_size;
            // Expected batch count is 0 unless a batch size is set.
            $expected_batch_count = 0;
            if ($batch_size > 0) {
                $expected_batch_count = (int) ($num_rows / $batch_size);
                if ($num_rows % $batch_size) {
                    // If there is a remainder an extra batch is needed to get the
                    // remaining rows.
                    $expected_batch_count++;
                }
            }
            $tests[$data_set][5] = $expected_batch_count;
            $data_set++;
        }
        return $tests;
    }
    
    /**
     * Tests query batch size.
     *
     * @param array $source_data
     *   The source data, keyed by table name. Each table is an array containing
     *   the rows in that table.
     * @param array $expected_data
     *   The result rows the plugin is expected to return.
     * @param int $num_rows
     *   How many rows the source plugin is expected to return.
     * @param array $configuration
     *   Configuration for the source plugin specifying the batch size.
     * @param int $expected_batch_size
     *   The expected batch size, will be set to zero for invalid batch sizes.
     * @param int $expected_batch_count
     *   The total number of batches.
     *
     * @dataProvider queryDataProvider
     */
    public function testQueryBatch($source_data, $expected_data, $num_rows, $configuration, $expected_batch_size, $expected_batch_count) : void {
        $plugin = $this->getPlugin($configuration);
        // Since we don't yet inject the database connection, we need to use a
        // reflection hack to set it in the plugin instance.
        $reflector = new \ReflectionObject($plugin);
        $property = $reflector->getProperty('database');
        $connection = $this->getDatabase($source_data);
        $property->setValue($plugin, $connection);
        // Test the results.
        $i = 0;
        
        /** @var \Drupal\migrate\Row $row */
        foreach ($plugin as $row) {
            $expected = $expected_data[$i++];
            $actual = $row->getSource();
            foreach ($expected as $key => $value) {
                $this->assertArrayHasKey($key, $actual);
                $this->assertSame((string) $value, (string) $actual[$key]);
            }
        }
        // Test that all rows were retrieved.
        self::assertSame($num_rows, $i);
        // Test the batch size.
        if (is_null($expected_batch_size)) {
            $expected_batch_size = $configuration['batch_size'];
        }
        $property = $reflector->getProperty('batchSize');
        self::assertSame($expected_batch_size, $property->getValue($plugin));
        // Test the batch count.
        if (is_null($expected_batch_count)) {
            $expected_batch_count = intdiv($num_rows, $expected_batch_size);
            if ($num_rows % $configuration['batch_size']) {
                $expected_batch_count++;
            }
        }
        $property = $reflector->getProperty('batch');
        self::assertSame($expected_batch_count, $property->getValue($plugin));
    }
    
    /**
     * Instantiates the source plugin under test.
     *
     * @param array $configuration
     *   The source plugin configuration.
     *
     * @return \Drupal\migrate\Plugin\MigrateSourceInterface|object
     *   The fully configured source plugin.
     */
    protected function getPlugin($configuration) {
        
        /** @var \Drupal\migrate\Plugin\MigratePluginManager $plugin_manager */
        $plugin_manager = $this->container
            ->get('plugin.manager.migrate.source');
        $plugin = $plugin_manager->createInstance('query_batch_test', $configuration, $this->migration
            ->reveal());
        $this->migration
            ->getSourcePlugin()
            ->willReturn($plugin);
        return $plugin;
    }
    
    /**
     * Builds an in-memory SQLite database from a set of source data.
     *
     * @param array $source_data
     *   The source data, keyed by table name. Each table is an array containing
     *   the rows in that table.
     *
     * @return \Drupal\sqlite\Driver\Database\sqlite\Connection
     *   The SQLite database connection.
     */
    protected function getDatabase(array $source_data) {
        // Create an in-memory SQLite database. Plugins can interact with it like
        // any other database, and it will cease to exist when the connection is
        // closed.
        $connection_options = [
            'database' => ':memory:',
        ];
        $pdo = Connection::open($connection_options);
        $connection = new Connection($pdo, $connection_options);
        // Create the tables and fill them with data.
        foreach ($source_data as $table => $rows) {
            // Use the biggest row to build the table schema.
            $counts = array_map('count', $rows);
            asort($counts);
            $pilot = $rows[array_key_last($counts)];
            $connection->schema()
                ->createTable($table, [
                // SQLite uses loose affinity typing, so it's OK for every field to
                // be a text field.
'fields' => array_map(function () {
                    return [
                        'type' => 'text',
                    ];
                }, $pilot),
            ]);
            $fields = array_keys($pilot);
            $insert = $connection->insert($table)
                ->fields($fields);
            array_walk($rows, [
                $insert,
                'values',
            ]);
            $insert->execute();
        }
        return $connection;
    }

}