feat: added authentification and redirection

lib/data/services/auth_client.dart

@@ -0,0 +1,77 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
+import 'package:flutter_secure_storage/flutter_secure_storage.dart';
+import 'package:seshat/config/constants.dart';
+import 'package:seshat/utils/result.dart';
+import "package:http/http.dart" as http;
+
+class AuthClient {
+  AuthClient();
+  FlutterSecureStorage? _secureStorage;
+
+  Future<void> _initStore() async {
+    _secureStorage ??= const FlutterSecureStorage(
+      aOptions: AndroidOptions(encryptedSharedPreferences: true),
+    );
+  }
+
+  Future<Result<bool>> hasValidToken() async {
+    try {
+      await _initStore();
+      bool hasToken = await _secureStorage!.containsKey(key: "token");
+      debugPrint("\n\n\n${hasToken == true} => HAS_TOKEN\n\n\n");
+      if (hasToken) {
+        var token = await _secureStorage!.read(key: "token");
+        var url = Uri.parse("https://$apiBasePath/token-check");
+        var response = await http.post(
+          url,
+          headers: {"Content-Type": "application/json"},
+          body: jsonEncode({"token": token}),
+        );
+        debugPrint(
+          "\n\n\n${response.body is String} => ${response.body}\n\n\n",
+        );
+
+        if (response.body == "true") {
+          return Result.ok(true);
+        }
+      }
+      return Result.ok(false);
+    } catch (e) {
+      debugPrint(e.toString());
+      return Result.error(Exception(e));
+    }
+  }
+
+  Future<Result<String>> login(String username, String password) async {
+    var client = http.Client();
+    try {
+      await _initStore();
+      var url = Uri.parse("https://$apiBasePath/auth");
+      var response = await client.post(
+        url,
+        headers: {
+          "Content-Type": "application/json",
+          "Accept": "application/json",
+        },
+        body: jsonEncode({"password": password, "username": username}),
+      );
+      if (response.statusCode == 200) {
+        var json = jsonDecode(response.body);
+        await _secureStorage!.write(key: "token", value: json["access_token"]);
+        return Result.ok(json["access_token"]);
+      } else if (response.statusCode == 401) {
+        return Result.error(Exception("Wrong credentials"));
+      } else {
+        return Result.error(Exception("Token creation error"));
+      }
+    } catch (e, stackTrace) {
+      debugPrint(e.toString());
+      debugPrintStack(stackTrace: stackTrace);
+      return Result.error(Exception(e));
+    } finally {
+      client.close();
+    }
+  }
+}