add api, docs

frontend/modules/api/controllers/TaskUserController.php

@@ -0,0 +1,73 @@
+<?php
+
+namespace frontend\modules\api\controllers;
+
+use common\models\TaskUser;
+use Yii;
+use yii\filters\auth\HttpBearerAuth;
+use yii\rest\Controller;
+use yii\web\BadRequestHttpException;
+use yii\web\NotFoundHttpException;
+
+class TaskUserController extends Controller
+{
+    public function behaviors(): array
+    {
+        $behaviors = parent::behaviors();
+
+        $behaviors['authenticator']['authMethods'] = [
+            HttpBearerAuth::className(),
+        ];
+
+        return $behaviors;
+    }
+
+    public function verbs(): array
+    {
+        return [
+            'get-task-users' => ['get'],
+            'set-task-user' => ['post', 'patch'],
+        ];
+    }
+
+    public function actionSetTaskUser()
+    {
+        $taskUserModel = new TaskUser();
+
+        $params = Yii::$app->request->post();
+        $taskUserModel->attributes = $params;
+
+        if(!$taskUserModel->validate()){
+            throw new BadRequestHttpException(json_encode($taskUserModel->errors));
+        }
+
+        $taskUserModel->save();
+
+        return $taskUserModel->toArray();
+    }
+
+    /**
+     * @throws NotFoundHttpException
+     */
+    public function actionGetTaskUsers()
+    {
+        $task_id = Yii::$app->request->get('task_id');
+        if(empty($task_id) or !is_numeric($task_id))
+        {
+            throw new NotFoundHttpException('Incorrect task ID');
+        }
+
+        $tasks = $this->findUsers($task_id);
+
+        if(empty($tasks)) {
+            throw new NotFoundHttpException('The task does not exist or there are no employees for it');
+        }
+
+        return $tasks;
+    }
+
+    private function findUsers($project_id): array
+    {
+        return TaskUser::find()->where(['task_id' => $project_id])->all();
+    }
+}