init

lib/services/merge_service.dart

@@ -0,0 +1,85 @@
+import 'package:lbjconsole/models/train_record.dart';
+import 'package:lbjconsole/models/merged_record.dart';
+
+class MergeService {
+  static String? _generateGroupKey(TrainRecord record, GroupBy groupBy) {
+    final train = record.train.trim();
+    final loco = record.loco.trim();
+    final hasTrain = train.isNotEmpty && train != "<NUL>";
+    final hasLoco = loco.isNotEmpty && loco != "<NUL>";
+
+    switch (groupBy) {
+      case GroupBy.trainOnly:
+        return hasTrain ? train : null;
+      case GroupBy.locoOnly:
+        return hasLoco ? loco : null;
+      case GroupBy.trainOrLoco:
+        if (hasTrain) return train;
+        if (hasLoco) return loco;
+        return null;
+      case GroupBy.trainAndLoco:
+        return (hasTrain && hasLoco) ? "${train}_$loco" : null;
+    }
+  }
+
+  static List<Object> getMixedList(
+      List<TrainRecord> allRecords, MergeSettings settings) {
+    if (!settings.enabled) {
+      allRecords
+          .sort((a, b) => b.receivedTimestamp.compareTo(a.receivedTimestamp));
+      return allRecords;
+    }
+
+    final now = DateTime.now();
+    final validRecords = settings.timeWindow.duration == null
+        ? allRecords
+        : allRecords
+            .where((r) =>
+                now.difference(r.receivedTimestamp) <=
+                settings.timeWindow.duration!)
+            .toList();
+
+    final groupedRecords = <String, List<TrainRecord>>{};
+    for (final record in validRecords) {
+      final key = _generateGroupKey(record, settings.groupBy);
+      if (key != null) {
+        groupedRecords.putIfAbsent(key, () => []).add(record);
+      }
+    }
+
+    final List<MergedTrainRecord> mergedRecords = [];
+    final Set<String> mergedRecordIds = {};
+
+    groupedRecords.forEach((key, group) {
+      if (group.length >= 2) {
+        group
+            .sort((a, b) => b.receivedTimestamp.compareTo(a.receivedTimestamp));
+        final latestRecord = group.first;
+        mergedRecords.add(MergedTrainRecord(
+          groupKey: key,
+          records: group,
+          latestRecord: latestRecord,
+        ));
+        for (final record in group) {
+          mergedRecordIds.add(record.uniqueId);
+        }
+      }
+    });
+
+    final singleRecords =
+        allRecords.where((r) => !mergedRecordIds.contains(r.uniqueId)).toList();
+
+    final List<Object> mixedList = [...mergedRecords, ...singleRecords];
+    mixedList.sort((a, b) {
+      final aTime = a is MergedTrainRecord
+          ? a.latestRecord.receivedTimestamp
+          : (a as TrainRecord).receivedTimestamp;
+      final bTime = b is MergedTrainRecord
+          ? b.latestRecord.receivedTimestamp
+          : (b as TrainRecord).receivedTimestamp;
+      return bTime.compareTo(aTime);
+    });
+
+    return mixedList;
+  }
+}