implement avg buildtime field in header

frontend/lib/components/dashboard/quick_info_banner.dart

@@ -1,5 +1,6 @@
 import 'package:aurcache/components/dashboard/quick_info_tile.dart';
 import 'package:aurcache/utils/file_formatter.dart';
+import 'package:aurcache/utils/time_formatter.dart';
 import 'package:flutter/material.dart';
 
 import '../../constants/color_constants.dart';
@@ -61,7 +62,7 @@ class QuickInfoBanner extends StatelessWidget {
           color: const Color(0xFF00F260),
           icon: Icons.timelapse,
           title: "Average Build Time",
-          subtitle: stats.avg_build_time.toString()),
+          subtitle: stats.avg_build_time.readableDuration()),
     ];
   }
 

frontend/lib/models/build.dart

@@ -4,7 +4,8 @@ class Build {
   final int pkg_id;
   final String version;
   final int status;
-  final int? start_time, end_time;
+  final DateTime? end_time;
+  final DateTime start_time;
 
   Build(
       {required this.id,
@@ -16,12 +17,18 @@ class Build {
       required this.status});
 
   factory Build.fromJson(Map<String, dynamic> json) {
+    final startTime =
+        DateTime.fromMillisecondsSinceEpoch(json["start_time"] * 1000);
+    final endTime = json["end_time"] != null
+        ? DateTime.fromMillisecondsSinceEpoch((json["end_time"] as int) * 1000)
+        : null;
+
     return Build(
       id: json["id"] as int,
       pkg_id: json["pkg_id"] as int,
       status: json["status"] as int,
-      start_time: json["start_time"] as int?,
-      end_time: json["end_time"] as int?,
+      start_time: startTime,
+      end_time: endTime,
       pkg_name: json["pkg_name"] as String,
       version: json["version"] as String,
     );

frontend/lib/models/stats.dart

@@ -2,17 +2,17 @@ class Stats {
   final int total_builds,
       failed_builds,
       avg_queue_wait_time,
-      avg_build_time,
       repo_storage_size,
       active_builds,
       total_packages;
+  final Duration avg_build_time;
 
   factory Stats.fromJson(Map<String, dynamic> json) {
     return Stats(
       total_builds: json["total_builds"] as int,
       failed_builds: json["failed_builds"] as int,
       avg_queue_wait_time: json["avg_queue_wait_time"] as int,
-      avg_build_time: json["avg_build_time"] as int,
+      avg_build_time: Duration(seconds: json["avg_build_time"]),
       repo_storage_size: json["repo_storage_size"] as int,
       active_builds: json["active_builds"] as int,
       total_packages: json["total_packages"] as int,

frontend/lib/screens/build_screen.dart

@@ -70,9 +70,6 @@ class _BuildScreenState extends State<BuildScreen> {
   }
 
   Widget _buildTopBar(Build buildData, BuildContext context) {
-    final start_time =
-        DateTime.fromMillisecondsSinceEpoch((buildData.start_time ?? 0) * 1000);
-
     return Container(
       color: secondaryColor,
       child: Padding(
@@ -117,7 +114,7 @@ class _BuildScreenState extends State<BuildScreen> {
                 const SizedBox(
                   width: 10,
                 ),
-                Text("triggered ${start_time.readableDuration()}")
+                Text("triggered ${buildData.start_time.readableDuration()}")
               ],
             ),
             Row(
@@ -246,18 +243,12 @@ class _BuildScreenState extends State<BuildScreen> {
               title: "Finished",
               textRight: buildData.end_time == null
                   ? "Not yet"
-                  : DateTime.fromMillisecondsSinceEpoch(
-                          buildData.end_time! * 1000)
-                      .readableDuration(),
+                  : buildData.end_time!.readableDuration(),
             ),
             SideCard(
               title: "Duration",
-              textRight: (buildData.end_time != null
-                      ? DateTime.fromMillisecondsSinceEpoch(
-                          buildData.end_time! * 1000)
-                      : DateTime.now())
-                  .difference(DateTime.fromMillisecondsSinceEpoch(
-                      buildData.start_time! * 1000))
+              textRight: (buildData.end_time ?? DateTime.now())
+                  .difference(buildData.start_time)
                   .readableDuration(),
             ),
           ],