refactor: move auth models to better_networking package

packages/better_networking/lib/utils/auth_utils.dart

@@ -0,0 +1,94 @@
+import 'dart:convert';
+import 'dart:typed_data';
+import 'package:better_networking/models/auth/auth_jwt_model.dart';
+import 'package:crypto/crypto.dart';
+
+String generateJWT(AuthJwtModel jwtAuth) {
+  try {
+    Map<String, dynamic> header;
+    if (jwtAuth.header.isNotEmpty) {
+      try {
+        header = json.decode(jwtAuth.header) as Map<String, dynamic>;
+      } catch (e) {
+        header = {};
+      }
+    } else {
+      header = {};
+    }
+    header['typ'] = header['typ'] ?? 'JWT';
+    header['alg'] = jwtAuth.algorithm;
+    Map<String, dynamic> payload;
+    if (jwtAuth.payload.isNotEmpty) {
+      try {
+        payload = json.decode(jwtAuth.payload) as Map<String, dynamic>;
+      } catch (e) {
+        payload = {};
+      }
+    } else {
+      payload = {};
+    }
+    if (!payload.containsKey('iat')) {
+      payload['iat'] = DateTime.now().millisecondsSinceEpoch ~/ 1000;
+    }
+
+    // Encode header and payload
+    final encodedHeader = _base64UrlEncode(utf8.encode(json.encode(header)));
+    final encodedPayload = _base64UrlEncode(utf8.encode(json.encode(payload)));
+
+    // Create signature
+    final signature = _createSignature(
+      '$encodedHeader.$encodedPayload',
+      jwtAuth.secret,
+      jwtAuth.algorithm,
+      jwtAuth.isSecretBase64Encoded,
+    );
+
+    return '$encodedHeader.$encodedPayload.$signature';
+  } catch (e) {
+    throw Exception('Failed to generate JWT: $e');
+  }
+}
+
+String _createSignature(
+    String data, String secret, String algorithm, bool isSecretBase64Encoded) {
+  try {
+    Uint8List secretBytes;
+    if (isSecretBase64Encoded) {
+      secretBytes = base64.decode(secret);
+    } else {
+      secretBytes = utf8.encode(secret);
+    }
+
+    final dataBytes = utf8.encode(data);
+
+    switch (algorithm) {
+      case 'HS256':
+        final hmac = Hmac(sha256, secretBytes);
+        final digest = hmac.convert(dataBytes);
+        return _base64UrlEncode(digest.bytes);
+
+      case 'HS384':
+        final hmac = Hmac(sha384, secretBytes);
+        final digest = hmac.convert(dataBytes);
+        return _base64UrlEncode(digest.bytes);
+
+      case 'HS512':
+        final hmac = Hmac(sha512, secretBytes);
+        final digest = hmac.convert(dataBytes);
+        return _base64UrlEncode(digest.bytes);
+
+      default:
+        // Default to HS256
+        final hmac = Hmac(sha256, secretBytes);
+        final digest = hmac.convert(dataBytes);
+        return _base64UrlEncode(digest.bytes);
+    }
+  } catch (e) {
+    // Return placeholder signature if creation fails
+    return _base64UrlEncode(utf8.encode('signature_generation_failed'));
+  }
+}
+
+String _base64UrlEncode(List<int> bytes) {
+  return base64Url.encode(bytes).replaceAll('=', '');
+}