Fix background task + socket in services + cleaning

mobile/traque-app/services/backgroundLocationTask.js

@@ -0,0 +1,48 @@
+// Expo
+import { defineTask, isTaskRegisteredAsync } from "expo-task-manager";
+import * as Location from 'expo-location';
+// Services
+import { emitUpdatePosition } from "./socketEmitter";
+// Constants
+import { TASKS, LOCATION_PARAMETERS } from "../constants";
+
+
+// Task
+    
+defineTask(TASKS.BACKGROUND_LOCATION, async ({ data, error }) => {
+    if (error) {
+        console.error(error);
+        return;
+    }
+    if (data) {
+        const { locations } = data;
+        if (locations.length == 0) {
+            console.log("No location measured.");
+            return;
+        }
+        const { latitude, longitude } = locations[0].coords;
+        emitUpdatePosition([latitude, longitude]);
+    }
+});
+
+
+// Functions
+
+export const getLocationAuthorization = async () => {
+    const { status : statusForeground } = await Location.requestForegroundPermissionsAsync();
+    const { status : statusBackground } = await Location.requestBackgroundPermissionsAsync();
+    return statusForeground == "granted" && statusBackground == "granted";
+};
+
+export const startLocationTracking = async () => {
+    if (!(await getLocationAuthorization())) return;
+    if (await isTaskRegisteredAsync(TASKS.BACKGROUND_LOCATION)) return;
+    console.log("Location tracking started.");
+    await Location.startLocationUpdatesAsync(TASKS.BACKGROUND_LOCATION, LOCATION_PARAMETERS.SERVER);
+};
+
+export const stopLocationTracking = async () => {
+    if (!await isTaskRegisteredAsync(TASKS.BACKGROUND_LOCATION)) return;
+    console.log("Location tracking stopped.");
+    await Location.stopLocationUpdatesAsync(TASKS.BACKGROUND_LOCATION);
+};