From dfab55d70e5afccecd3f21fdb96c960d76bda792 Mon Sep 17 00:00:00 2001
From: Jeremy Kescher <jeremy@kescher.at>
Date: Wed, 29 Jan 2020 14:26:10 +0100
Subject: [PATCH] Server persistence added

---
 android/app/build.gradle |  1 -
 lib/server.dart          | 27 ++++++++++++++++
 lib/serverlist.dart      | 70 +++++++++++++++++++++++++---------------
 pubspec.yaml             |  2 +-
 4 files changed, 72 insertions(+), 28 deletions(-)

diff --git a/android/app/build.gradle b/android/app/build.gradle
index 6b0543a..696afba 100644
--- a/android/app/build.gradle
+++ b/android/app/build.gradle
@@ -37,7 +37,6 @@ android {
     }
 
     defaultConfig {
-        // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "at.htldonaustadt.server_pinger"
         minSdkVersion 16
         targetSdkVersion 28
diff --git a/lib/server.dart b/lib/server.dart
index 05cba87..ee0db44 100644
--- a/lib/server.dart
+++ b/lib/server.dart
@@ -16,4 +16,31 @@ class Server {
     this.displayName,
     this.uri,
   );
+
+  static Server fromPrefs(PrefsServer prefsServer) {
+    return Server(prefsServer.displayName, prefsServer.uri);
+  }
+}
+
+class PrefsServer {
+  String displayName;
+  String uri;
+
+  PrefsServer(
+      this.displayName,
+      this.uri,
+      );
+
+  static PrefsServer fromServer(Server server) {
+    return PrefsServer(server.displayName, server.uri);
+  }
+
+  Map<String, dynamic> toJson() => {
+    'displayName': displayName,
+    'uri': uri,
+  };
+
+  PrefsServer.fromJson(Map<String, dynamic> json)
+      : displayName = json['displayName'],
+        uri = json['uri'];
 }
diff --git a/lib/serverlist.dart b/lib/serverlist.dart
index 407e2f5..ece22e8 100644
--- a/lib/serverlist.dart
+++ b/lib/serverlist.dart
@@ -1,10 +1,12 @@
 import 'dart:async';
+import 'dart:convert';
 import 'dart:io';
 import 'dart:math';
 
 import 'package:basic_utils/basic_utils.dart';
 import 'package:flutter/material.dart';
 import 'package:server_pinger/server.dart';
+import 'package:shared_preferences/shared_preferences.dart';
 
 import 'server.dart';
 
@@ -18,26 +20,12 @@ class ServerList extends StatefulWidget {
 }
 
 class _ServerListState extends State<ServerList> {
+  _ServerListState() {
+    _initServersFromPreferences();
+  }
   // Currently expanded server list entry, -1 = no field is expanded
   int selectedServer = -1;
-  List<Server> servers = [
-    new Server(
-      "example.com",
-      "http://example.com",
-    ),
-    new Server(
-      "youtube.com",
-      "https://youtube.com",
-    ),
-    new Server(
-      "My VPS",
-      "http://kescher.at",
-    ),
-    new Server(
-      "Raspberry Pi",
-      "https://pi.kescher.at/isup",
-    ),
-  ];
+  List<Server> servers;
 
   Timer timer;
   Random rnd = new Random();
@@ -46,9 +34,6 @@ class _ServerListState extends State<ServerList> {
   void initState() {
     super.initState();
 
-    // TODO: load shared preferences
-
-    _updateAllServers();
     timer = new Timer.periodic(
         new Duration(seconds: 30), (_) => _updateAllServers());
   }
@@ -138,18 +123,18 @@ class _ServerListState extends State<ServerList> {
   }
 
   void _addServer(String customName, String uri) {
-    // TODO: add to shared preferences
     Server server = Server(customName, uri);
     servers.add(server);
+    _saveServersToPreferences();
     _updateServerStatus(server);
     Navigator.of(context).pop();
   }
 
   void _removeServer(int index) {
-    // TODO: remove from shared preferences
     setState(() {
       servers.removeAt(index);
     });
+    _saveServersToPreferences();
   }
 
   void _modifyServerForm(Server server) {
@@ -218,7 +203,7 @@ class _ServerListState extends State<ServerList> {
   }
 
   List<Widget> _createChildren() {
-    List<Widget> list = new List<Widget>.generate(servers.length, (int index) {
+    List<Widget> entries = new List<Widget>.generate(servers.length, (int index) {
       Widget info = Row(children: [
         Expanded(
           child: Align(
@@ -341,7 +326,7 @@ class _ServerListState extends State<ServerList> {
             child: info),
       );
     });
-    list.add(
+    entries.add(
       GestureDetector(
         onTap: _addServerForm,
         child: Container(
@@ -360,7 +345,7 @@ class _ServerListState extends State<ServerList> {
         ),
       ),
     );
-    return list;
+    return entries;
   }
 
   static Future<ServerStatus> _checkStatus(String uri) async {
@@ -469,4 +454,37 @@ class _ServerListState extends State<ServerList> {
     if (uri.length < 100) return uri;
     return uri.substring(0, 100) + "...";
   }
+
+  void _initServersFromPreferences() {
+    servers = [];
+    SharedPreferences.getInstance().then((prefs) {
+      List<String> serverStrings = prefs.getStringList('servers');
+      if (serverStrings == null) {
+        prefs.setStringList('servers', []).then((_) {
+          serverStrings = prefs.getStringList('servers');
+        });
+      }
+      serverStrings.forEach((str) {
+        Server server = Server.fromPrefs(
+          PrefsServer.fromJson(
+            json.decode(str),
+          ),
+        );
+        _updateServerStatus(server);
+        servers.add(server);
+      });
+    });
+  }
+
+  void _saveServersToPreferences() {
+    SharedPreferences.getInstance().then((prefs) {
+      prefs
+          .setStringList(
+              'servers',
+              new List<String>.generate(servers.length, (int i) {
+                return json.encode(PrefsServer.fromServer(servers[i]).toJson());
+              }))
+          .then((set) {});
+    });
+  }
 }
diff --git a/pubspec.yaml b/pubspec.yaml
index 9853b57..2afb138 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -14,7 +14,7 @@ description: A new Flutter application.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
+  sdk: ">=2.4.0 <3.0.0"
 
 dependencies:
   flutter:
-- 
2.47.0