<?php

namespace MailPoet\API\JSON\v1;

use MailPoet\API\JSON\Endpoint as APIEndpoint;
use MailPoet\API\JSON\Error as APIError;
use MailPoet\API\JSON\Response;
use MailPoet\Config\AccessControl;
use MailPoet\Cron\Triggers\WordPress;
use MailPoet\Models\Newsletter;
use MailPoet\Models\SendingQueue as SendingQueueModel;
use MailPoet\Newsletter\Scheduler\Scheduler;
use MailPoet\Segments\SubscribersFinder;
use MailPoet\Tasks\Sending as SendingTask;
use MailPoet\Util\License\Features\Subscribers as SubscribersFeature;
use MailPoet\WP\Functions as WPFunctions;

class SendingQueue extends APIEndpoint {
  public $permissions = [
    'global' => AccessControl::PERMISSION_MANAGE_EMAILS,
  ];

  /** @var SubscribersFeature */
  private $subscribersFeature;

  public function __construct(SubscribersFeature $subscribersFeature) {
    $this->subscribersFeature = $subscribersFeature;
  }

  public function add($data = []) {
    if ($this->subscribersFeature->check()) {
      return $this->errorResponse([
        APIError::FORBIDDEN => __('Subscribers limit reached.', 'mailpoet'),
      ], [], Response::STATUS_FORBIDDEN);
    }
    $newsletterId = (isset($data['newsletter_id'])
      ? (int)$data['newsletter_id']
      : false
    );

    // check that the newsletter exists
    $newsletter = Newsletter::findOneWithOptions($newsletterId);

    if (!$newsletter instanceof Newsletter) {
      return $this->errorResponse([
        APIError::NOT_FOUND => __('This newsletter does not exist.', 'mailpoet'),
      ]);
    }

    // check that the sending method has been configured properly
    try {
      $mailer = new \MailPoet\Mailer\Mailer();
      $mailer->init();
    } catch (\Exception $e) {
      return $this->errorResponse([
        $e->getCode() => $e->getMessage(),
      ]);
    }

    // add newsletter to the sending queue
    $queue = SendingQueueModel::joinWithTasks()
      ->where('queues.newsletter_id', $newsletter->id)
      ->whereNull('tasks.status')
      ->findOne();

    if (!empty($queue)) {
      return $this->errorResponse([
        APIError::NOT_FOUND => __('This newsletter is already being sent.', 'mailpoet'),
      ]);
    }

    $scheduledQueue = SendingQueueModel::joinWithTasks()
      ->where('queues.newsletter_id', $newsletter->id)
      ->where('tasks.status', SendingQueueModel::STATUS_SCHEDULED)
      ->findOne();
    if ($scheduledQueue instanceof SendingQueueModel) {
      $queue = SendingTask::createFromQueue($scheduledQueue);
    } else {
      $queue = SendingTask::create();
      $queue->newsletterId = $newsletter->id;
    }

    WordPress::resetRunInterval();

    if ((bool)$newsletter->isScheduled) {
      // set newsletter status
      $newsletter->setStatus(Newsletter::STATUS_SCHEDULED);

      // set queue status
      $queue->status = SendingQueueModel::STATUS_SCHEDULED;
      $queue->scheduledAt = Scheduler::formatDatetimeString($newsletter->scheduledAt);
    } else {
      $segments = $newsletter->segments()->findMany();
      $finder = new SubscribersFinder();
      $subscribersCount = $finder->addSubscribersToTaskFromSegments($queue->task(), $segments);
      if (!$subscribersCount) {
        return $this->errorResponse([
          APIError::UNKNOWN => __('There are no subscribers in that list!', 'mailpoet'),
        ]);
      }
      $queue->updateCount();
      $queue->status = null;
      $queue->scheduledAt = null;

      // set newsletter status
      $newsletter->setStatus(Newsletter::STATUS_SENDING);
    }
    $queue->save();

    $errors = $queue->getErrors();
    if (!empty($errors)) {
      return $this->errorResponse($errors);
    } else {
      return $this->successResponse(
        $newsletter->getQueue()->asArray()
      );
    }
  }

  public function pause($data = []) {
    $newsletterId = (isset($data['newsletter_id'])
      ? (int)$data['newsletter_id']
      : false
    );
    $newsletter = Newsletter::findOne($newsletterId);

    if ($newsletter instanceof Newsletter) {
      $queue = $newsletter->getQueue();

      if ($queue === false) {
        return $this->errorResponse([
          APIError::UNKNOWN => __('This newsletter has not been sent yet.', 'mailpoet'),
        ]);
      } else {
        $queue->pause();
        return $this->successResponse(
          $newsletter->getQueue()->asArray()
        );
      }
    } else {
      return $this->errorResponse([
        APIError::NOT_FOUND => __('This newsletter does not exist.', 'mailpoet'),
      ]);
    }
  }

  public function resume($data = []) {
    if ($this->subscribersFeature->check()) {
      return $this->errorResponse([
        APIError::FORBIDDEN => __('Subscribers limit reached.', 'mailpoet'),
      ], [], Response::STATUS_FORBIDDEN);
    }
    $newsletterId = (isset($data['newsletter_id'])
      ? (int)$data['newsletter_id']
      : false
    );
    $newsletter = Newsletter::findOne($newsletterId);
    if ($newsletter instanceof Newsletter) {
      $queue = $newsletter->getQueue();

      if ($queue === false) {
        return $this->errorResponse([
          APIError::UNKNOWN => __('This newsletter has not been sent yet.', 'mailpoet'),
        ]);
      } else {
        $queue->resume();
        return $this->successResponse(
          $newsletter->getQueue()->asArray()
        );
      }
    } else {
      return $this->errorResponse([
        APIError::NOT_FOUND => __('This newsletter does not exist.', 'mailpoet'),
      ]);
    }
  }
}