update logic for stock history

src/main/java/com/danielbohry/stocks/domain/StockHistory.java

@@ -18,5 +18,4 @@ public class StockHistory {
     private String currency;
     private BigDecimal price;
     private Instant createdAt;
-
 }

src/main/java/com/danielbohry/stocks/repository/stock/StockHistoryRepository.java

@@ -10,8 +10,8 @@ import java.util.List;
 @Repository
 public interface StockHistoryRepository extends MongoRepository<StockHistory, String> {
 
-    List<StockHistory> findAllByCode(String code);
-
     List<StockHistory> findByCodeAndCreatedAtBetween(String code, Instant start, Instant end);
 
+    boolean existsByCodeAndCreatedAtBetween(String code, Instant startOfDay, Instant endOfDay);
+
 }

src/main/java/com/danielbohry/stocks/service/stock/StockHistoryService.java

@@ -10,9 +10,12 @@ import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Service;
 
 import java.time.Instant;
+import java.time.LocalDate;
+import java.time.ZoneOffset;
 import java.util.List;
 
 import static java.time.Instant.now;
+import static java.time.ZoneOffset.UTC;
 import static java.time.temporal.ChronoUnit.DAYS;
 
 @Service
@@ -22,21 +25,31 @@ public class StockHistoryService {
     private final StockService service;
     private final StockHistoryRepository repository;
 
-    public static final String ONCE_PER_DAY_AT_11PM = "0 0 23 * * *";
+    public static final String ONCE_PER_DAY_AT_2AM = "0 0 2 * * *";
 
-    @Scheduled(cron = ONCE_PER_DAY_AT_11PM)
+    @Scheduled(cron = ONCE_PER_DAY_AT_2AM)
     @SchedulerLock(name = "StockQuoteService_saveQuotes", lockAtLeastFor = "PT5M", lockAtMostFor = "PT15M")
     public void saveQuotes() {
-        List<StockHistory> stocks = service.getAll().stream()
-            .map(stock -> new StockHistory(stock.getCode(), stock.getCurrency(), stock.getPrice(), now()))
+        LocalDate today = LocalDate.now(UTC);
+        Instant startOfDay = today.atStartOfDay(UTC).toInstant();
+        Instant endOfDay = today.plusDays(1).atStartOfDay(UTC).toInstant();
+
+        List<StockHistory> stocksToSave = service.getAll().stream()
+            .filter(stock -> !repository.existsByCodeAndCreatedAtBetween(stock.getCode(), startOfDay, endOfDay))
+            .map(stock -> new StockHistory(
+                stock.getCode(),
+                stock.getCurrency(),
+                stock.getPrice(),
+                now()
+            ))
             .toList();
 
-        repository.saveAll(stocks);
+        repository.saveAll(stocksToSave);
     }
 
     @Cacheable(value = "stockHistory", key = "#code + '-' + #range")
     public List<StockHistory> get(String code, String range) {
-        Instant end = Instant.now();
+        Instant end = now();
         Instant start = switch (range) {
             case "5d" -> end.minus(5, DAYS);
             case "30d" -> end.minus(30, DAYS);