feat:增加睡眠记录

lib/service/health_service.dart

@@ -20,15 +20,25 @@ class HealthService {
   }
 
   HealthRecord getAllRecordByDate(String date) {
-    return box.values.toList().firstWhere(
+    final record = box.values.toList().firstWhere(
       (item) => item.date == date,
-      orElse: () => HealthRecord.getEmpty(),
+      orElse: () => HealthRecord.getEmpty(date),
     );
+
+    return record.copyWith();
   }
 
   Future<bool> updateRecord(HealthRecord record) async {
     try {
-      await record.save();
+      List<HealthRecord> records =
+          box.values.where((item) => item.date == record.date).toList();
+
+      if (records.isEmpty) {
+        await addRecord(record);
+      } else {
+        await record.save();
+      }
+
       return true;
     } catch (e) {
       return false;