From d8e84a6fd69f332081452ad9d47a389e4f9a8b64 Mon Sep 17 00:00:00 2001
From: Kha Truong <64438356+khatruong2009@users.noreply.github.com>
Date: Mon, 28 Aug 2023 15:51:36 -0700
Subject: [PATCH] feat(logging): default remote config

---
 .../lib/src/plugin_config.dart                |  9 ++
 .../lib/src/remote_constraint_provider.dart   | 82 ++++++++++++++++++-
 .../aws_logging_cloudwatch/pubspec.yaml       |  1 +
 3 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/plugin_config.dart b/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/plugin_config.dart
index 9fd10d18d0..6a1e9e5838 100644
--- a/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/plugin_config.dart
+++ b/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/plugin_config.dart
@@ -48,6 +48,15 @@ class CloudWatchLoggerPluginConfiguration with AWSDebuggable {
 /// The logging constraint for sending logs to CloudWatch.
 /// {@endtemplate}
 class LoggingConstraint with AWSDebuggable {
+  factory LoggingConstraint.fromJson(Map<String, dynamic> json) {
+    return LoggingConstraint(
+      defaultLogLevel: LogLevel.values.firstWhere(
+        (e) => e.toString() == 'LogLevel.${json['defaultLogLevel']}',
+        orElse: () => LogLevel.error, // Default value if not found
+      ),
+    );
+  }
+
   /// {@macro aws_logging_cloudwatch.logging_constraint}
   const LoggingConstraint({this.defaultLogLevel = LogLevel.error});
 
diff --git a/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/remote_constraint_provider.dart b/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/remote_constraint_provider.dart
index 7a8a36332f..076efaba25 100644
--- a/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/remote_constraint_provider.dart
+++ b/packages/logging_cloudwatch/aws_logging_cloudwatch/lib/src/remote_constraint_provider.dart
@@ -1,11 +1,15 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+import 'dart:convert';
+import 'dart:io';
+
 // TODO(nikahsn): remove after implementing the get loggingConstraint.
 // ignore_for_file: unused_field
 
 import 'package:aws_common/aws_common.dart';
 import 'package:aws_logging_cloudwatch/aws_logging_cloudwatch.dart';
+import 'package:http/http.dart' as http;
 
 /// {@template aws_logging_cloudwatch.remote_logging_constraint_provider}
 /// An Interface to provide custom implementation for
@@ -33,9 +37,83 @@ class DefaultRemoteLoggingConstraintProvider
   final DefaultRemoteConfiguration _config;
   final AWSCredentialsProvider _credentialsProvider;
 
+  LoggingConstraint? _loggingConstraint;
+  DateTime? _lastUpdated;
+
+  Future<void> _saveConstraintLocally(LoggingConstraint constraint) async {
+    final file = File('logging_constraint.json');
+    await file.writeAsString(jsonEncode(constraint));
+  }
+
+  Future<LoggingConstraint?> _getConstraintFromLocalStorage() async {
+    final file = File('logging_constraint.json');
+    if (await file.exists()) {
+      final content = await file.readAsString();
+      return LoggingConstraint.fromJson(
+        jsonDecode(content) as Map<String, dynamic>,
+      );
+    }
+    return null;
+  }
+
+  Future<void> _fetchAndCacheConstraintFromEndpoint() async {
+    try {
+      final constraint = await _fetchConstraintFromEndpoint();
+      if (constraint != null) {
+        _loggingConstraint = constraint;
+        _lastUpdated = DateTime.now();
+      }
+    } catch (error) {
+      print('Error fetching constraints: $error');
+    }
+  }
+
+  Future<LoggingConstraint?> _fetchConstraintFromEndpoint() async {
+    final response = await http.get(Uri.parse(_config.endpoint));
+    if (response.statusCode == 200) {
+      final fetchedConstraint = LoggingConstraint.fromJson(
+        jsonDecode(response.body) as Map<String, dynamic>,
+      );
+      await _saveConstraintLocally(fetchedConstraint);
+      return fetchedConstraint;
+    }
+    throw Exception(
+      'Failed to fetch logging constraint from ${_config.endpoint}',
+    );
+  }
+
   @override
-  // TODO(nikahsn): add implementation.
-  LoggingConstraint get loggingConstraint => throw UnimplementedError();
+  LoggingConstraint? get loggingConstraint {
+    if (_loggingConstraint != null &&
+        _lastUpdated != null &&
+        DateTime.now().difference(_lastUpdated!).inSeconds <=
+            _config.refreshIntervalInSeconds.inSeconds) {
+      return _loggingConstraint;
+    }
+    // Load from local storage synchronously
+    final file = File('logging_constraint.json');
+    if (file.existsSync()) {
+      final content = file.readAsStringSync();
+      return LoggingConstraint.fromJson(
+        jsonDecode(content) as Map<String, dynamic>,
+      );
+    }
+    return null;
+  }
+
+  /// Initializes and starts the periodic fetch.
+  void initialize() {
+    _fetchAndCacheConstraintFromEndpoint(); // Fetch once immediately on initialize
+    _refreshConstraintPeriodically();
+  }
+
+  /// Refreshes the constraint from the endpoint periodically.
+  Future<void> _refreshConstraintPeriodically() async {
+    while (true) {
+      await Future<void>.delayed(_config.refreshIntervalInSeconds);
+      await _fetchAndCacheConstraintFromEndpoint();
+    }
+  }
 }
 
 /// {@template aws_logging_cloudwatch.default_remote_configuration}
diff --git a/packages/logging_cloudwatch/aws_logging_cloudwatch/pubspec.yaml b/packages/logging_cloudwatch/aws_logging_cloudwatch/pubspec.yaml
index fa470e56ba..0e3d86fdf6 100644
--- a/packages/logging_cloudwatch/aws_logging_cloudwatch/pubspec.yaml
+++ b/packages/logging_cloudwatch/aws_logging_cloudwatch/pubspec.yaml
@@ -15,6 +15,7 @@ dependencies:
   built_collection: ^5.1.1
   built_value: ">=8.6.0 <8.7.0"
   fixnum: ^1.1.0
+  http: ^1.0.0
   intl: ">=0.18.0 <1.0.0"
   meta: ^1.9.1
   smithy: ^0.5.0+3