Added background notifications

src/components/BackgroundTask/BackgroundTask.tsx

@@ -0,0 +1,84 @@
+import React, { useEffect } from "react";
+import { View } from "react-native";
+import * as BackgroundFetch from "expo-background-fetch";
+import * as TaskManager from "expo-task-manager";
+import * as Notifications from "expo-notifications";
+import {
+  GetStudentStatus,
+  GetStudyGroupListFiltered,
+  GetUserInfo,
+} from "../Api/Api";
+import { StudyGroupType } from "../../interfaces/Interfaces";
+
+const FETCH_STUDENT_STATUS = "STUDENT_STATUS_TASK";
+
+TaskManager.defineTask(FETCH_STUDENT_STATUS, async () => {
+  const data = await GetStudyGroupListFiltered();
+  const student_status_data = await GetStudentStatus();
+  if (data[0] && data[1].length > -1) {
+    console.log("Background Fetch", data[1]);
+    const entryWithLeastDistance = data[1].reduce(
+      (prev: StudyGroupType, curr: StudyGroupType) => {
+        return prev.distance < curr.distance ? prev : curr;
+      }
+    );
+    // Only display a notification if a student isn't in a study group yet
+    if (
+      student_status_data[1].study_group == null ||
+      student_status_data[1].study_group == ""
+    ) {
+      Notifications.scheduleNotificationAsync({
+        content: {
+          title: "Students are studying nearby",
+          body: `Nearest study group is ${Math.round(
+            entryWithLeastDistance.distance * 1000
+          )}m away`,
+        },
+        trigger: {
+          seconds: 1,
+        },
+      });
+    }
+  } else {
+    console.log(data[1].response.data);
+  }
+
+  return BackgroundFetch.BackgroundFetchResult.NewData;
+});
+
+const BackgroundComponent = () => {
+  const [isRegistered, setIsRegistered] = React.useState(false);
+  const [status, setStatus] = React.useState<any>();
+  const checkStatusAsync = async () => {
+    const status = await BackgroundFetch.getStatusAsync();
+    const isRegistered = await TaskManager.isTaskRegisteredAsync(
+      FETCH_STUDENT_STATUS
+    );
+    setStatus(status);
+    setIsRegistered(isRegistered);
+  };
+
+  useEffect(() => {
+    const registerTask = async () => {
+      try {
+        await checkStatusAsync();
+        if (!isRegistered) {
+          await BackgroundFetch.registerTaskAsync(FETCH_STUDENT_STATUS, {
+            minimumInterval: 5, // seconds,
+          });
+          console.log("Task registered");
+        } else {
+          console.log("Task already registered");
+        }
+      } catch (err) {
+        console.log("Task Register failed:", err);
+      }
+    };
+
+    registerTask();
+  }, []);
+
+  return <View />;
+};
+
+export default BackgroundComponent;