Issue #3485276: Add complete task functionality

src/Form/CloseTaskForm.php

+<?php
+
+namespace Drupal\todoist_api\Form;
+
+use Drupal\Core\Form\ConfirmFormBase;
+use Drupal\Core\Form\FormStateInterface;
+use Drupal\Core\Url;
+use GuzzleHttp\Exception\RequestException;
+use Drupal\Component\Serialization\Json;
+
+/**
+ * Defines a confirmation form to confirm deletion of something by id.
+ */
+class CloseTaskForm extends ConfirmFormBase {
+
+  /**
+   * ID of the item to delete.
+   *
+   * @var int
+   */
+  protected $id;
+
+  /**
+   * ID of the item to delete.
+   *
+   * @var object
+   */
+  protected $todoistclient;
+
+  /**
+   * {@inheritdoc}
+   */
+  public function buildForm(array $form, FormStateInterface $form_state, string $id = NULL) {
+    $this->id = $id;
+    return parent::buildForm($form, $form_state);
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function submitForm(array &$form, FormStateInterface $form_state) {
+    // @todo: Do the deletion.
+    $uri = 'tasks';
+    $content_id = $this->id;
+    try{
+      $response = \Drupal::service('todoist_api.client')->post($uri, null, $content_id);
+      if($response):
+        $this->messenger()->addStatus($this->t('One task has been completed.'));
+        $form_state->setRedirect('todoist_api.taskscontroller');
+      endif;
+    } catch( RequestException $exception) {
+      \Drupal::logger('error_rest_client')->notice($exception->getMessage());
+      $form_state->setErrorByName('task', $this->t('Application error. Please try again later.'));
+    }
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getFormId() : string {
+    return "task_close_form";
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getCancelUrl() {
+    return new Url('todoist_api.taskscontroller');
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public function getQuestion() {
+    $uri = 'tasks';
+    $content_id = $this->id;
+    return $this->t('Do you want to close the %id?', ['%id' => $this->id]);
+  }
+
+}

todoist_api.routing.yml

@@ -26,3 +26,12 @@ todoist_api.deletetask:
   requirements:
     _permission: 'user todoist access'
     id: ^\d+$
+
+todoist_api.closetask:
+  path: '/admin/content/todoist/{id}/close'
+  defaults:
+    _form: '\Drupal\todoist_api\Form\CloseTaskForm'
+    _title: 'Complete Task'
+  requirements:
+    _permission: 'user todoist access'
+    id: ^\d+$