add structure

lib/model/employee_model.dart

@@ -0,0 +1,59 @@
+import 'package:cloud_firestore/cloud_firestore.dart';
+import 'package:logging/logging.dart';
+import 'package:fcs/vo/user.dart';
+
+import 'base_model.dart';
+import 'constants.dart';
+import 'firebase_helper.dart';
+
+class EmployeeModel extends BaseModel {
+  final log = Logger('EmployeeModel');
+
+  List<User> employees = [];
+
+  void initUser(user) async {
+    super.initUser(user);
+    _loadEmployees();
+  }
+
+  @override
+  logout() async {
+    employees = [];
+  }
+
+  Future<void> _loadEmployees() async {
+    if (!user.isOwnerAndAbove() && !user.hasAccount()) {
+      return;
+    }
+
+    try {
+      Firestore.instance
+          .collection("/$biz_collection/${setting.okEnergyId}/$user_collection")
+          .where("is_employee", isEqualTo: true)
+          .snapshots()
+          .listen((QuerySnapshot snapshot) {
+        employees.clear();
+        employees = snapshot.documents.map((documentSnapshot) {
+          var user =
+              User.fromMap(documentSnapshot.data, documentSnapshot.documentID);
+          return user;
+        }).toList();
+        notifyListeners();
+      }).onError((e) {
+        log.warning("Error! $e");
+      });
+    } catch (e) {
+      log.warning("Error!! $e");
+    }
+  }
+
+  Future<void> updatePrivileges(String userID, List<String> privileges) async {
+    try {
+      await request("/employee/privileges", "PUT",
+          payload: {"id": userID, "privileges": privileges},
+          token: await getToken());
+    } catch (e) {
+      throw Exception(e);
+    }
+  }
+}