Feature: Relay beacon to new leader (#122)

* initial

* user online missing

* added more fields in mutation

* feat: relay beacon to new leader

* small fix

* snackbar message improvement

* fix: moved code to viewmodel

Author: ItsAdityaKSingh

lib/components/hike_screen_widget.dart

@@ -18,7 +18,7 @@ import 'package:share_plus/share_plus.dart';
 
 import 'package:sizer/sizer.dart';
 
-class HikeScreenWidget {
+class HikeScreenWidget extends ChangeNotifier {
   static copyPasskey(String passkey) {
     Clipboard.setData(ClipboardData(text: passkey));
     Fluttertoast.showToast(msg: 'PASSKEY: $passkey  COPIED');
@@ -200,12 +200,6 @@ class HikeScreenWidget {
                                 text:
                                     'Long Press on any hiker to hand over the beacon\n',
                                 style: TextStyle(fontSize: 16)),
-                            //TODO: enable this once backend has updated.
-                            //Commented, since we dont have the neccessary mutation atm on backend to change the duration.
-                            // TextSpan(
-                            //     text:
-                            //         'Double tap on beacon to change the duration\n',
-                            //     style: TextStyle(fontSize: 14)),
                           ],
                         ),
                       ),
@@ -223,25 +217,21 @@ class HikeScreenWidget {
                   itemCount: model.hikers.length,
                   itemBuilder: (BuildContext context, int index) {
                     return ListTile(
-                      onTap: () {
-                        model.hikers[index].id == userConfig.currentUser.id
-                            ? Fluttertoast.showToast(msg: 'Yeah, that\'s you')
-                            : model.beacon.leader.id ==
-                                    userConfig.currentUser.id
-                                ? model.relayBeacon(model.hikers[index])
-                                : Fluttertoast.showToast(
-                                    msg: 'You dont have beacon to relay');
+                      onLongPress: () async {
+                        model.relayBeacon(
+                            model.hikers[index].name, model.hikers[index].id);
                       },
                       leading: CircleAvatar(
                         backgroundColor:
                             model.isBeaconExpired ? Colors.grey : kYellow,
                         radius: 18,
                         child: ClipRRect(
-                            borderRadius: BorderRadius.circular(50),
-                            child: Icon(
-                              Icons.person_outline,
-                              color: Colors.white,
-                            )),
+                          borderRadius: BorderRadius.circular(50),
+                          child: Icon(
+                            Icons.person_outline,
+                            color: Colors.white,
+                          ),
+                        ),
                       ),
                       title: Text(
                         model.hikers[index].name,

lib/queries/beacon.dart

@@ -1,6 +1,41 @@
 import 'package:graphql_flutter/graphql_flutter.dart';
 
 class BeaconQueries {
+  String changeLeader(String beaconID, String newLeaderID) {
+    return '''
+        mutation{
+           changeLeader (beaconID:"$beaconID" ,newLeaderID: "$newLeaderID")
+          {
+            _id
+             title
+             shortcode
+             leader {
+               _id
+               name
+             }
+             location{
+               lat
+               lon
+             }
+             followers {
+               _id
+               name
+             }
+             startsAt
+             expiresAt
+             landmarks {
+               title
+               location {
+                 lat
+                 lon
+               }
+             }
+           }
+          }
+        }
+    ''';
+  }
+
   String createBeacon(
       String title, int startsAt, int expiresAt, String lat, String lon) {
     return '''
@@ -188,7 +223,7 @@ class BeaconQueries {
     }
   ''');
 
-  // Gql for oreder updated subscription.
+  // Gql for order updated subscription.
   final beaconJoinedSubGql = gql(r'''
     subscription StreamNewlyJoinedBeacons($id: ID!){
       beaconJoined(id: $id){

lib/services/database_mutation_functions.dart

@@ -370,4 +370,23 @@ class DataBaseMutationFunctions {
     }
     return _nearbyBeacons;
   }
+
+  Future<Beacon> changeLeader(String beaconID, String newLeaderID) async {
+    await clientAuth
+        .mutate(MutationOptions(
+            document: gql(_beaconQuery.changeLeader(beaconID, newLeaderID))))
+        .then((value) {
+      if (value.hasException) {
+        navigationService.showSnackBar(
+            "Something went wrong: ${value.exception.graphqlErrors.first.message}");
+        print("Something went wrong: ${value.exception}");
+      } else if (value.data != null && value.isConcrete) {
+        final Beacon changedLeader =
+            Beacon.fromJson(value.data['changeLeader'] as Map<String, dynamic>);
+        return changedLeader;
+      }
+      return null;
+    });
+    return null;
+  }
 }

lib/view_model/hike_screen_model.dart

@@ -49,8 +49,22 @@ class HikeScreenViewModel extends BaseModel {
   final List<StreamSubscription> mergedStreamSubscriptions = [];
   bool isLeader = false;
 
-  void relayBeacon(User newHolder) {
-    Fluttertoast.showToast(msg: 'Beacon handed over to $newHolder');
+  void relayBeacon(String newLeaderName, String newLeaderID) async {
+    print(newLeaderID);
+    if (newLeaderID == userConfig.currentUser.id)
+      Fluttertoast.showToast(msg: 'Yeah, that\'s you');
+    else {
+      if (beacon.leader.id == userConfig.currentUser.id) {
+        await databaseFunctions.init();
+        final changedLeader =
+            databaseFunctions.changeLeader(beacon.id, newLeaderID);
+        if (changedLeader != null) beacon.leader.id = newLeaderID;
+        Fluttertoast.showToast(msg: 'Beacon handed over to $newLeaderName');
+        notifyListeners();
+      } else {
+        Fluttertoast.showToast(msg: 'You dont have beacon to relay');
+      }
+    }
   }
 
   Future<bool> onWillPop(context) async {