feat: server conn statistics (#888)

lib/data/model/server/connection_stat.dart

@@ -0,0 +1,79 @@
+import 'package:fl_lib/fl_lib.dart';
+import 'package:freezed_annotation/freezed_annotation.dart';
+import 'package:hive_ce/hive.dart';
+
+part 'connection_stat.freezed.dart';
+part 'connection_stat.g.dart';
+
+@freezed
+@HiveType(typeId: 100)
+abstract class ConnectionStat with _$ConnectionStat {
+  const factory ConnectionStat({
+    @HiveField(0) required String serverId,
+    @HiveField(1) required String serverName,
+    @HiveField(2) required DateTime timestamp,
+    @HiveField(3) required ConnectionResult result,
+    @HiveField(4) @Default('') String errorMessage,
+    @HiveField(5) required int durationMs,
+  }) = _ConnectionStat;
+
+  factory ConnectionStat.fromJson(Map<String, dynamic> json) =>
+      _$ConnectionStatFromJson(json);
+}
+
+@freezed
+@HiveType(typeId: 101)
+abstract class ServerConnectionStats with _$ServerConnectionStats {
+  const factory ServerConnectionStats({
+    @HiveField(0) required String serverId,
+    @HiveField(1) required String serverName,
+    @HiveField(2) required int totalAttempts,
+    @HiveField(3) required int successCount,
+    @HiveField(4) required int failureCount,
+    @HiveField(5) @Default(null) DateTime? lastSuccessTime,
+    @HiveField(6) @Default(null) DateTime? lastFailureTime,
+    @HiveField(7) @Default([]) List<ConnectionStat> recentConnections,
+    @HiveField(8) required double successRate,
+  }) = _ServerConnectionStats;
+
+  factory ServerConnectionStats.fromJson(Map<String, dynamic> json) =>
+      _$ServerConnectionStatsFromJson(json);
+}
+
+@HiveType(typeId: 102)
+enum ConnectionResult {
+  @HiveField(0)
+  @JsonValue('success')
+  success,
+  @HiveField(1)
+  @JsonValue('timeout')
+  timeout,
+  @HiveField(2)
+  @JsonValue('auth_failed')
+  authFailed,
+  @HiveField(3)
+  @JsonValue('network_error')
+  networkError,
+  @HiveField(4)
+  @JsonValue('unknown_error')
+  unknownError,
+}
+
+extension ConnectionResultExtension on ConnectionResult {
+  String get displayName {
+    switch (this) {
+      case ConnectionResult.success:
+        return libL10n.success;
+      case ConnectionResult.timeout:
+        return '${libL10n.error}(timeout)';
+      case ConnectionResult.authFailed:
+        return '${libL10n.error}(auth)';
+      case ConnectionResult.networkError:
+        return '${libL10n.error}(${libL10n.network})';
+      case ConnectionResult.unknownError:
+        return '${libL10n.error}(${libL10n.unknown})';
+    }
+  }
+
+  bool get isSuccess => this == ConnectionResult.success;
+}