<?php declare(strict_types = 1);

namespace MailPoet\Migrations\App;

if (!defined('ABSPATH')) exit;


use MailPoet\Doctrine\WPDB\Connection;
use MailPoet\Entities\NewsletterEntity;
use MailPoet\Entities\ScheduledTaskEntity;
use MailPoet\Entities\ScheduledTaskSubscriberEntity;
use MailPoet\Entities\SendingQueueEntity;
use MailPoet\Entities\StatisticsNewsletterEntity;
use MailPoet\Migrator\AppMigration;
use MailPoetVendor\Doctrine\DBAL\ArrayParameterType;

/**
 * We've had a set of bugs where campaign type newsletters (see NewsletterEntity::CAMPAIGN_TYPES),
 * such as post notifications, were getting stuck in the following state:
 * - The newsletter was in the "sending" state.
 * - The task failed to complete and ended up in the "invalid" state.
 *
 * This migration completes tasks that sent out all emails
 * and pauses those that have unprocessed subscribers.
 */
class Migration_20240207_105912_App extends AppMigration {
  public function run(): void {
    $this->pauseInvalidTasksWithUnprocessedSubscribers();
    $this->completeInvalidTasksWithAllSubscribersProcessed();
    $this->backfillMissingDataForMigratedNewsletters();
  }

  private function pauseInvalidTasksWithUnprocessedSubscribers(): void {
    $ids = $this->entityManager->createQueryBuilder()
      ->select('DISTINCT t.id')
      ->from(ScheduledTaskEntity::class, 't')
      ->join('t.subscribers', 's', 'WITH', 's.processed = :unprocessed')
      ->join('t.sendingQueue', 'q')
      ->join('q.newsletter', 'n')
      ->where('t.deletedAt IS NULL')
      ->andWhere('t.status = :invalid')
      ->andWhere('n.deletedAt IS NULL')
      ->andWhere('n.status = :sending')
      ->andWhere('n.type IN (:campaignTypes)')
      ->setParameter('unprocessed', ScheduledTaskSubscriberEntity::STATUS_UNPROCESSED)
      ->setParameter('invalid', ScheduledTaskEntity::STATUS_INVALID)
      ->setParameter('sending', NewsletterEntity::STATUS_SENDING)
      ->setParameter('campaignTypes', NewsletterEntity::CAMPAIGN_TYPES)
      ->getQuery()
      ->getSingleColumnResult();

    $this->entityManager->createQueryBuilder()
      ->update(ScheduledTaskEntity::class, 't')
      ->set('t.status', ':paused')
      ->where('t.id IN (:ids)')
      ->setParameter('paused', ScheduledTaskEntity::STATUS_PAUSED)
      ->setParameter('ids', $ids)
      ->getQuery()
      ->execute();
  }

  private function completeInvalidTasksWithAllSubscribersProcessed(): void {
    $ids = $this->entityManager->createQueryBuilder()
      ->select('DISTINCT t.id, n.id AS nid, t.updatedAt')
      ->from(ScheduledTaskEntity::class, 't')
      ->leftJoin('t.subscribers', 's', 'WITH', 's.processed = :unprocessed')
      ->join('t.sendingQueue', 'q')
      ->join('q.newsletter', 'n')
      ->where('t.deletedAt IS NULL')
      ->andWhere('t.status = :invalid')
      ->andWhere('s.task IS NULL')
      ->andWhere('n.deletedAt IS NULL')
      ->andWhere('n.status = :sending')
      ->andWhere('n.type IN (:campaignTypes)')
      ->setParameter('unprocessed', ScheduledTaskSubscriberEntity::STATUS_UNPROCESSED)
      ->setParameter('invalid', ScheduledTaskEntity::STATUS_INVALID)
      ->setParameter('sending', NewsletterEntity::STATUS_SENDING)
      ->setParameter('campaignTypes', NewsletterEntity::CAMPAIGN_TYPES)
      ->getQuery()
      ->getSingleColumnResult();

    // update sending queue counts
    $this->entityManager->createQueryBuilder()
      ->update(SendingQueueEntity::class, 'q')
      ->set('q.countProcessed', 'q.countTotal')
      ->set('q.countToProcess', 0)
      ->where('q.task IN (:ids)')
      ->setParameter('ids', $ids)
      ->getQuery()
      ->execute();

    // complete the invalid tasks
    $this->entityManager->createQueryBuilder()
      ->update(ScheduledTaskEntity::class, 't')
      ->set('t.status', ':completed')
      ->where('t.id IN (:ids)')
      ->setParameter('completed', ScheduledTaskEntity::STATUS_COMPLETED)
      ->setParameter('ids', $ids)
      ->getQuery()
      ->execute();

    // mark newsletters as sent, update "sentAt" (DBAL needed to be able to use JOIN)
    $newslettersTable = $this->entityManager->getClassMetadata(NewsletterEntity::class)->getTableName();
    $scheduledTasksTable = $this->entityManager->getClassMetadata(ScheduledTaskEntity::class)->getTableName();
    $scheduledTaskSubscribersTable = $this->entityManager->getClassMetadata(ScheduledTaskSubscriberEntity::class)->getTableName();
    $sendingQueuesTable = $this->entityManager->getClassMetadata(SendingQueueEntity::class)->getTableName();

    // Temporarily skip the query in WP Playground.
    // UPDATE with JOIN is not yet supported by the SQLite integration.
    if (Connection::isSQLite()) {
      return;
    }
    $this->entityManager->getConnection()->executeStatement(
      "
        UPDATE $newslettersTable n
        JOIN $sendingQueuesTable q ON n.id = q.newsletter_id
        JOIN $scheduledTasksTable t ON q.task_id = t.id
        SET
          n.status = :sent,
          n.sent_at = COALESCE(
            (
              -- use 'updated_at' of processed subscriber with the highest ID ('MAX(subscriber_id)' can use index)
              SELECT updated_at FROM $scheduledTaskSubscribersTable WHERE task_id = t.id AND subscriber_id = (
                SELECT MAX(subscriber_id) FROM $scheduledTaskSubscribersTable WHERE task_id = t.id
              )
            ),
            t.updated_at
          )
        WHERE t.id IN (:ids)
      ",
      ['sent' => NewsletterEntity::STATUS_SENT, 'ids' => $ids],
      ['ids' => ArrayParameterType::INTEGER]
    );
  }

  private function backfillMissingDataForMigratedNewsletters(): void {
    // In https://mailpoet.atlassian.net/browse/MAILPOET-5886 we fixed missing "sent" status
    // by https://github.com/mailpoet/mailpoet/pull/5416, but didn't backfill missing data.

    // get affected newsletter IDs
    $ids = $this->entityManager->createQueryBuilder()
      ->select('n.id')
      ->from(NewsletterEntity::class, 'n')
      ->where('n.status = :sent')
      ->andWhere('n.sentAt IS NULL')
      ->setParameter('sent', NewsletterEntity::STATUS_SENT)
      ->getQuery()
      ->getSingleColumnResult();

    // get missing newsletter statistics IDs
    $data = $this->entityManager->createQueryBuilder()
      ->select('IDENTITY(q.newsletter) AS nid, q.id AS qid, IDENTITY(s.subscriber) AS sid, s.updatedAt AS sentAt')
      ->from(SendingQueueEntity::class, 'q')
      ->join('q.task', 't')
      ->join('t.subscribers', 's')
      ->leftJoin(StatisticsNewsletterEntity::class, 'ns', 'WITH', 'ns.queue = q AND ns.subscriber = s.subscriber')
      ->where('q.newsletter IN (:ids)')
      ->andWhere('ns.id IS NULL')
      ->andWhere('s.processed = :processed')
      ->setParameter('ids', $ids)
      ->setParameter('processed', ScheduledTaskSubscriberEntity::STATUS_PROCESSED)
      ->getQuery()
      ->getResult();

    // insert missing newsletter statistics
    $newsletterStatisticsTable = $this->entityManager->getClassMetadata(StatisticsNewsletterEntity::class)->getTableName();
    foreach ($data as $row) {
      $this->entityManager->getConnection()->executeStatement("
        INSERT IGNORE INTO $newsletterStatisticsTable (newsletter_id, queue_id, subscriber_id, sent_at)
        VALUES (?, ?, ?, ?)
      ", [$row['nid'], $row['qid'], $row['sid'], $row['sentAt']->format('Y-m-d H:i:s')]);
    }

    // add missing "sentAt" (DBAL needed to be able to use JOIN)
    $newslettersTable = $this->entityManager->getClassMetadata(NewsletterEntity::class)->getTableName();
    $scheduledTasksTable = $this->entityManager->getClassMetadata(ScheduledTaskEntity::class)->getTableName();
    $scheduledTaskSubscribersTable = $this->entityManager->getClassMetadata(ScheduledTaskSubscriberEntity::class)->getTableName();
    $sendingQueuesTable = $this->entityManager->getClassMetadata(SendingQueueEntity::class)->getTableName();

    // Temporarily skip the query in WP Playground.
    // UPDATE with JOIN is not yet supported by the SQLite integration.
    if (Connection::isSQLite()) {
      return;
    }
    $this->entityManager->getConnection()->executeStatement(
      "
        UPDATE $newslettersTable n
        JOIN $sendingQueuesTable q ON n.id = q.newsletter_id
        JOIN $scheduledTasksTable t ON q.task_id = t.id
        SET n.sent_at = COALESCE(
          (
            -- use 'updated_at' of processed subscriber with the highest ID ('MAX(subscriber_id)' can use index)
            SELECT updated_at FROM $scheduledTaskSubscribersTable WHERE task_id = t.id AND subscriber_id = (
              SELECT MAX(subscriber_id) FROM $scheduledTaskSubscribersTable WHERE task_id = t.id
            )
          ),
          t.updated_at
        )
        WHERE q.newsletter_id IN (:ids)
      ",
      ['ids' => $ids],
      ['ids' => ArrayParameterType::INTEGER]
    );
  }
}