class Migration

class Migration extends PluginBase implements MigrationInterface, RequirementsInterface, ContainerFactoryPluginInterface {
    
    /**
     * The migration ID (machine name).
     *
     * @var string
     */
    protected $id;
    
    /**
     * The human-readable label for the migration.
     *
     * @var string
     */
    protected $label;
    
    /**
     * The plugin ID for the row.
     *
     * @var string
     */
    protected $row;
    
    /**
     * The source configuration, with at least a 'plugin' key.
     *
     * Used to initialize the $sourcePlugin.
     *
     * @var array
     */
    protected $source;
    
    /**
     * The source plugin.
     *
     * @var \Drupal\migrate\Plugin\MigrateSourceInterface
     */
    protected $sourcePlugin;
    
    /**
     * The configuration describing the process plugins.
     *
     * This is a strictly internal property and should not returned to calling
     * code, use getProcess() instead.
     *
     * @var array
     */
    protected $process = [];
    
    /**
     * The cached process plugins.
     *
     * @var array
     */
    protected $processPlugins = [];
    
    /**
     * The destination configuration, with at least a 'plugin' key.
     *
     * Used to initialize $destinationPlugin.
     *
     * @var array
     */
    protected $destination;
    
    /**
     * The destination plugin.
     *
     * @var \Drupal\migrate\Plugin\MigrateDestinationInterface
     */
    protected $destinationPlugin;
    
    /**
     * The identifier map data.
     *
     * Used to initialize $idMapPlugin.
     *
     * @var array
     */
    protected $idMap = [];
    
    /**
     * The identifier map.
     *
     * @var \Drupal\migrate\Plugin\MigrateIdMapInterface
     */
    protected $idMapPlugin;
    
    /**
     * The source identifiers.
     *
     * An array of source identifiers: the keys are the name of the properties,
     * the values are dependent on the ID map plugin.
     *
     * @var array
     */
    protected $sourceIds = [];
    
    /**
     * The destination identifiers.
     *
     * An array of destination identifiers: the keys are the name of the
     * properties, the values are dependent on the ID map plugin.
     *
     * @var array
     */
    protected $destinationIds = [];
    
    /**
     * The source_row_status for the current map row.
     *
     * @var int
     */
    protected $sourceRowStatus = MigrateIdMapInterface::STATUS_IMPORTED;
    
    /**
     * Track time of last import if TRUE.
     *
     * @var bool
     */
    protected $trackLastImported = FALSE;
    
    /**
     * These migrations must be already executed before this migration can run.
     *
     * @var array
     */
    protected $requirements = [];
    
    /**
     * An optional list of tags, used by the plugin manager for filtering.
     *
     * @var array
     */
    protected $migration_tags = [];
    
    /**
     * Whether the migration is auditable.
     *
     * If set to TRUE, the migration's IDs will be audited. This means that, if
     * the highest destination ID is greater than the highest source ID, a warning
     * will be displayed that entities might be overwritten.
     *
     * @var bool
     */
    protected $audit = FALSE;
    
    /**
     * These migrations, if run, must be executed before this migration.
     *
     * These are different from the configuration dependencies. Migration
     * dependencies are only used to store relationships between migrations.
     *
     * The migration_dependencies value is structured like this:
     * @code
     * array(
     *   'required' => array(
     *     // An array of migration IDs that must be run before this migration.
     *   ),
     *   'optional' => array(
     *     // An array of migration IDs that, if they exist, must be run before
     *     // this migration.
     *   ),
     * );
     * @endcode
     *
     * @var array
     */
    protected $migration_dependencies = [];
    
    /**
     * The migration's configuration dependencies.
     *
     * These store any dependencies on modules or other configuration (including
     * other migrations) that must be available before the migration can be
     * created.
     *
     * @see \Drupal\Core\Config\Entity\ConfigDependencyManager
     *
     * @var array
     */
    protected $dependencies = [];
    
    /**
     * The migration plugin manager for loading other migration plugins.
     *
     * @var \Drupal\migrate\Plugin\MigrationPluginManagerInterface
     */
    protected $migrationPluginManager;
    
    /**
     * The source plugin manager.
     *
     * @var \Drupal\migrate\Plugin\MigratePluginManager
     */
    protected $sourcePluginManager;
    
    /**
     * The process plugin manager.
     *
     * @var \Drupal\migrate\Plugin\MigratePluginManager
     */
    protected $processPluginManager;
    
    /**
     * The destination plugin manager.
     *
     * @var \Drupal\migrate\Plugin\MigrateDestinationPluginManager
     */
    protected $destinationPluginManager;
    
    /**
     * The ID map plugin manager.
     *
     * @var \Drupal\migrate\Plugin\MigratePluginManager
     */
    protected $idMapPluginManager;
    
    /**
     * Labels corresponding to each defined status.
     *
     * @var array
     */
    protected $statusLabels = [
        self::STATUS_IDLE => 'Idle',
        self::STATUS_IMPORTING => 'Importing',
        self::STATUS_ROLLING_BACK => 'Rolling back',
        self::STATUS_STOPPING => 'Stopping',
        self::STATUS_DISABLED => 'Disabled',
    ];
    
    /**
     * Constructs a Migration.
     *
     * @param array $configuration
     *   Plugin configuration.
     * @param string $plugin_id
     *   The plugin ID.
     * @param mixed $plugin_definition
     *   The plugin definition.
     * @param \Drupal\migrate\Plugin\MigrationPluginManagerInterface $migration_plugin_manager
     *   The migration plugin manager.
     * @param \Drupal\migrate\Plugin\MigratePluginManagerInterface $source_plugin_manager
     *   The source migration plugin manager.
     * @param \Drupal\migrate\Plugin\MigratePluginManagerInterface $process_plugin_manager
     *   The process migration plugin manager.
     * @param \Drupal\migrate\Plugin\MigrateDestinationPluginManager $destination_plugin_manager
     *   The destination migration plugin manager.
     * @param \Drupal\migrate\Plugin\MigratePluginManagerInterface $id_map_plugin_manager
     *   The ID map migration plugin manager.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationPluginManagerInterface $migration_plugin_manager, MigratePluginManagerInterface $source_plugin_manager, MigratePluginManagerInterface $process_plugin_manager, MigrateDestinationPluginManager $destination_plugin_manager, MigratePluginManagerInterface $id_map_plugin_manager) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->migrationPluginManager = $migration_plugin_manager;
        $this->sourcePluginManager = $source_plugin_manager;
        $this->processPluginManager = $process_plugin_manager;
        $this->destinationPluginManager = $destination_plugin_manager;
        $this->idMapPluginManager = $id_map_plugin_manager;
        foreach (NestedArray::mergeDeepArray([
            $plugin_definition,
            $configuration,
        ], TRUE) as $key => $value) {
            $this->{$key} = $value;
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('plugin.manager.migration'), $container->get('plugin.manager.migrate.source'), $container->get('plugin.manager.migrate.process'), $container->get('plugin.manager.migrate.destination'), $container->get('plugin.manager.migrate.id_map'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function id() {
        return $this->pluginId;
    }
    
    /**
     * {@inheritdoc}
     */
    public function label() {
        return $this->label;
    }
    
    /**
     * Retrieves the ID map plugin.
     *
     * @return \Drupal\migrate\Plugin\MigrateIdMapInterface
     *   The ID map plugin.
     */
    public function getIdMapPlugin() {
        return $this->idMapPlugin;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSourcePlugin() {
        if (!isset($this->sourcePlugin)) {
            $this->sourcePlugin = $this->sourcePluginManager
                ->createInstance($this->source['plugin'], $this->source, $this);
        }
        return $this->sourcePlugin;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getProcessPlugins(array $process = NULL) {
        if (!isset($process)) {
            $process = $this->getProcess();
        }
        $index = serialize($process);
        if (!isset($this->processPlugins[$index])) {
            $this->processPlugins[$index] = [];
            foreach ($this->getProcessNormalized($process) as $property => $configurations) {
                $this->processPlugins[$index][$property] = [];
                foreach ($configurations as $configuration) {
                    if (isset($configuration['source'])) {
                        $this->processPlugins[$index][$property][] = $this->processPluginManager
                            ->createInstance('get', $configuration, $this);
                    }
                    // Get is already handled.
                    if ($configuration['plugin'] != 'get') {
                        $this->processPlugins[$index][$property][] = $this->processPluginManager
                            ->createInstance($configuration['plugin'], $configuration, $this);
                    }
                    if (!$this->processPlugins[$index][$property]) {
                        throw new MigrateException("Invalid process configuration for {$property}");
                    }
                }
            }
        }
        return $this->processPlugins[$index];
    }
    
    /**
     * Resolve shorthands into a list of plugin configurations.
     *
     * @param array $process
     *   A process configuration array.
     *
     * @return array
     *   The normalized process configuration.
     */
    protected function getProcessNormalized(array $process) {
        $normalized_configurations = [];
        foreach ($process as $destination => $configuration) {
            if (is_string($configuration)) {
                $configuration = [
                    'plugin' => 'get',
                    'source' => $configuration,
                ];
            }
            if (isset($configuration['plugin'])) {
                $configuration = [
                    $configuration,
                ];
            }
            if (!is_array($configuration)) {
                $migration_id = $this->getPluginId();
                throw new MigrateException("Invalid process for destination '{$destination}' in migration '{$migration_id}'");
            }
            $normalized_configurations[$destination] = $configuration;
        }
        return $normalized_configurations;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDestinationPlugin($stub_being_requested = FALSE) {
        if ($stub_being_requested && !empty($this->destination['no_stub'])) {
            throw new MigrateSkipRowException('Stub requested but not made because no_stub configuration is set.');
        }
        if (!isset($this->destinationPlugin)) {
            $this->destinationPlugin = $this->destinationPluginManager
                ->createInstance($this->destination['plugin'], $this->destination, $this);
        }
        return $this->destinationPlugin;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getIdMap() {
        if (!isset($this->idMapPlugin)) {
            $configuration = $this->idMap;
            $plugin = $configuration['plugin'] ?? 'sql';
            $this->idMapPlugin = $this->idMapPluginManager
                ->createInstance($plugin, $configuration, $this);
        }
        return $this->idMapPlugin;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getRequirements() : array {
        return $this->requirements;
    }
    
    /**
     * {@inheritdoc}
     */
    public function checkRequirements() {
        // Check whether the current migration source and destination plugin
        // requirements are met or not.
        if ($this->getSourcePlugin() instanceof RequirementsInterface) {
            $this->getSourcePlugin()
                ->checkRequirements();
        }
        if ($this->getDestinationPlugin() instanceof RequirementsInterface) {
            $this->getDestinationPlugin()
                ->checkRequirements();
        }
        if (empty($this->requirements)) {
            // There are no requirements to check.
            return;
        }
        
        /** @var \Drupal\migrate\Plugin\MigrationInterface[] $required_migrations */
        $required_migrations = $this->getMigrationPluginManager()
            ->createInstances($this->requirements);
        $missing_migrations = array_diff($this->requirements, array_keys($required_migrations));
        // Check if the dependencies are in good shape.
        foreach ($required_migrations as $migration_id => $required_migration) {
            if (!$required_migration->allRowsProcessed()) {
                $missing_migrations[] = $migration_id;
            }
        }
        if ($missing_migrations) {
            throw new RequirementsException('Missing migrations ' . implode(', ', $missing_migrations) . '.', [
                'requirements' => $missing_migrations,
            ]);
        }
    }
    
    /**
     * Gets the migration plugin manager.
     *
     * @return \Drupal\migrate\Plugin\MigrationPluginManagerInterface
     *   The migration plugin manager.
     */
    protected function getMigrationPluginManager() {
        return $this->migrationPluginManager;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setStatus($status) {
        \Drupal::keyValue('migrate_status')->set($this->id(), $status);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getStatus() {
        return \Drupal::keyValue('migrate_status')->get($this->id(), static::STATUS_IDLE);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getStatusLabel() {
        $status = $this->getStatus();
        if (isset($this->statusLabels[$status])) {
            return $this->statusLabels[$status];
        }
        else {
            return '';
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getInterruptionResult() {
        return \Drupal::keyValue('migrate_interruption_result')->get($this->id(), static::RESULT_INCOMPLETE);
    }
    
    /**
     * {@inheritdoc}
     */
    public function clearInterruptionResult() {
        \Drupal::keyValue('migrate_interruption_result')->delete($this->id());
    }
    
    /**
     * {@inheritdoc}
     */
    public function interruptMigration($result) {
        $this->setStatus(MigrationInterface::STATUS_STOPPING);
        \Drupal::keyValue('migrate_interruption_result')->set($this->id(), $result);
    }
    
    /**
     * {@inheritdoc}
     */
    public function allRowsProcessed() {
        $source_count = $this->getSourcePlugin()
            ->count();
        // If the source is uncountable, we have no way of knowing if it's
        // complete, so stipulate that it is.
        if ($source_count < 0) {
            return TRUE;
        }
        $processed_count = $this->getIdMap()
            ->processedCount();
        // We don't use == because in some circumstances (like unresolved stubs
        // being created), the processed count may be higher than the available
        // source rows.
        return $source_count <= $processed_count;
    }
    
    /**
     * {@inheritdoc}
     */
    public function set($property_name, $value) {
        if ($property_name == 'source') {
            // Invalidate the source plugin.
            unset($this->sourcePlugin);
        }
        elseif ($property_name === 'destination') {
            // Invalidate the destination plugin.
            unset($this->destinationPlugin);
        }
        $this->{$property_name} = $value;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getProcess() {
        return $this->getProcessNormalized($this->process);
    }
    
    /**
     * {@inheritdoc}
     */
    public function setProcess(array $process) {
        $this->process = $process;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setProcessOfProperty($property, $process_of_property) {
        $this->process[$property] = $process_of_property;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function mergeProcessOfProperty($property, array $process_of_property) {
        // If we already have a process value then merge the incoming process array
        // otherwise simply set it.
        $current_process = $this->getProcess();
        if (isset($current_process[$property])) {
            $this->process = NestedArray::mergeDeepArray([
                $current_process,
                $this->getProcessNormalized([
                    $property => $process_of_property,
                ]),
            ], TRUE);
        }
        else {
            $this->setProcessOfProperty($property, $process_of_property);
        }
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isTrackLastImported() {
        return $this->trackLastImported;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setTrackLastImported($track_last_imported) {
        $this->trackLastImported = (bool) $track_last_imported;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getMigrationDependencies() {
        $this->migration_dependencies = ($this->migration_dependencies ?: []) + [
            'required' => [],
            'optional' => [],
        ];
        if (count($this->migration_dependencies) !== 2 || !is_array($this->migration_dependencies['required']) || !is_array($this->migration_dependencies['optional'])) {
            throw new InvalidPluginDefinitionException($this->id(), "Invalid migration dependencies configuration for migration {$this->id()}");
        }
        $this->migration_dependencies['optional'] = array_unique(array_merge($this->migration_dependencies['optional'], $this->findMigrationDependencies($this->process)));
        return $this->migration_dependencies;
    }
    
    /**
     * Find migration dependencies from migration_lookup and sub_process plugins.
     *
     * @param array $process
     *   A process configuration array.
     *
     * @return array
     *   The migration dependencies.
     */
    protected function findMigrationDependencies($process) {
        $return = [];
        foreach ($this->getProcessNormalized($process) as $process_pipeline) {
            foreach ($process_pipeline as $plugin_configuration) {
                // If the migration uses a deriver and has a migration_lookup with
                // itself as the source migration, then skip adding dependencies.
                // Otherwise the migration will depend on all the variations of itself.
                // See d7_taxonomy_term for an example.
                if (isset($this->deriver) && $plugin_configuration['plugin'] === 'migration_lookup' && $plugin_configuration['migration'] == $this->getBaseId()) {
                    continue;
                }
                if (in_array($plugin_configuration['plugin'], [
                    'migration',
                    'migration_lookup',
                ], TRUE)) {
                    $return = array_merge($return, (array) $plugin_configuration['migration']);
                }
                if (in_array($plugin_configuration['plugin'], [
                    'iterator',
                    'sub_process',
                ], TRUE)) {
                    $return = array_merge($return, $this->findMigrationDependencies($plugin_configuration['process']));
                }
            }
        }
        return $return;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getPluginDefinition() {
        $definition = [];
        // While normal plugins do not change their definitions on the fly, this
        // one does so accommodate for that.
        foreach (parent::getPluginDefinition() as $key => $value) {
            $definition[$key] = $this->{$key} ?? $value;
        }
        return $definition;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDestinationConfiguration() {
        return $this->destination;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getSourceConfiguration() {
        return $this->source;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getTrackLastImported() {
        return $this->trackLastImported;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDestinationIds() {
        return $this->destinationIds;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getMigrationTags() {
        return $this->migration_tags;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isAuditable() {
        return (bool) $this->audit;
    }

}