Resolves #421 Manual long-lived token

lib/connection.class.dart

@@ -303,7 +303,10 @@ class Connection {
       _tempToken = null;
       final storage = new FlutterSecureStorage();
       storage.write(key: "hacl_llt", value: "$_token").then((_) {
+        SharedPreferences.getInstance().then((prefs) {
+          prefs.setBool("oauth-used", true);
           completer.complete();
+        });
       }).catchError((e) {
         throw e;
       });

lib/main.dart

@@ -155,14 +155,23 @@ class HAClientApp extends StatelessWidget {
         "/configuration": (context) => PanelPage(title: "Configuration"),
         "/putchase": (context) => PurchasePage(title: "Support app development"),
         "/log-view": (context) => LogViewPage(title: "Log"),
-        "/login": (_) => WebviewScaffold(
+        "/login": (context) => WebviewScaffold(
           url: "${Connection().oauthUrl}",
           appBar: new AppBar(
             leading: IconButton(
                 icon: Icon(Icons.help),
                 onPressed: () => HAUtils.launchURLInCustomTab(context: context, url: "http://ha-client.homemade.systems/docs#authentication")
             ),
-            title: new Text("Login to your Home Assistant"),
+            title: new Text("Login with HA"),
+            actions: <Widget>[
+              FlatButton(
+                child: Text("Manual", style: TextStyle(color: Colors.white)),
+                onPressed: () {
+                  Navigator.of(context).pop();
+                  Navigator.of(context).pushNamed("/connection-settings");
+                },
+              )
+            ],
           ),
         )
       },

lib/pages/settings.page.dart

@@ -16,10 +16,13 @@ class _ConnectionSettingsPageState extends State<ConnectionSettingsPage> {
   String _newHassioPort = "";
   String _socketProtocol = "wss";
   String _newSocketProtocol = "wss";
+  String _longLivedToken = "";
+  String _newLongLivedToken = "";
   bool _useLovelace = true;
   bool _newUseLovelace = true;
 
   String oauthUrl;
+  bool useOAuth = false;
 
   @override
   void initState() {
@@ -30,6 +33,23 @@ class _ConnectionSettingsPageState extends State<ConnectionSettingsPage> {
 
   _loadSettings() async {
     SharedPreferences prefs = await SharedPreferences.getInstance();
+    final storage = new FlutterSecureStorage();
+
+    try {
+      useOAuth = prefs.getBool("oauth-used") ?? true;
+    } catch (e) {
+      useOAuth = true;
+    }
+
+    if (!useOAuth) {
+      try {
+        _longLivedToken = _newLongLivedToken =
+        await storage.read(key: "hacl_llt");
+      } catch (e) {
+        _longLivedToken = _newLongLivedToken = "";
+        await storage.delete(key: "hacl_llt");
+      }
+    }
 
     setState(() {
       _hassioDomain = _newHassioDomain = prefs.getString("hassio-domain")?? "";
@@ -48,7 +68,8 @@ class _ConnectionSettingsPageState extends State<ConnectionSettingsPage> {
       (_newHassioPort != _hassioPort) ||
       (_newHassioDomain != _hassioDomain) ||
       (_newSocketProtocol != _socketProtocol) ||
-      (_newUseLovelace != _useLovelace));
+      (_newUseLovelace != _useLovelace) ||
+      (_newLongLivedToken != _longLivedToken));
 
   }
 
@@ -58,6 +79,13 @@ class _ConnectionSettingsPageState extends State<ConnectionSettingsPage> {
     }
     _newHassioDomain = _newHassioDomain.split("/")[0];
     SharedPreferences prefs = await SharedPreferences.getInstance();
+    final storage = new FlutterSecureStorage();
+    if (_newLongLivedToken.isNotEmpty) {
+      prefs.setBool("oauth-used", false);
+      await storage.write(key: "hacl_llt", value: _newLongLivedToken);
+    } else if (!useOAuth) {
+      await storage.delete(key: "hacl_llt");
+    }
     prefs.setString("hassio-domain", _newHassioDomain);
     prefs.setString("hassio-port", _newHassioPort);
     prefs.setString("hassio-protocol", _newSocketProtocol);
@@ -172,6 +200,33 @@ class _ConnectionSettingsPageState extends State<ConnectionSettingsPage> {
               )
             ],
           ),
+          Text(
+            "Authentication settings",
+            style: TextStyle(
+                color: Colors.black45,
+                fontSize: 20.0
+            ),
+          ),
+          Container(height: 10.0,),
+          Text(
+            "You can leave this field blank to make app generate new long-lived token automatically by asking you to login to your Home Assistant. Use this field only if you still want to use manually generated long-lived token. Leave it blank if you don't understand what we are talking about.",
+            style: TextStyle(color: Colors.redAccent),
+          ),
+          new TextField(
+              decoration: InputDecoration(
+                  labelText: "Long-lived token"
+              ),
+              controller: new TextEditingController.fromValue(
+                  new TextEditingValue(
+                      text: _newLongLivedToken ?? '',
+                      selection:
+                      new TextSelection.collapsed(offset: _newLongLivedToken != null ? _newLongLivedToken.length : 0)
+                  )
+              ),
+              onChanged: (value) {
+                _newLongLivedToken = value;
+              }
+          ),
         ],
       ),
     );