funny graph

src/main/java/app/controllers/StatsController.java

@@ -14,6 +14,8 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import java.time.Instant;
+import java.util.HashMap;
 import java.util.List;
 
 @RestController
@@ -22,6 +24,7 @@ public class StatsController {
     private Stats stats;
     private ExternalServices externalServices;
     private OnlineUpdater onlineUpdater;
+    private HashMap<Integer, HashMap<List<OnlineUpdater.StatsOfPeakOfDay>, Long>> cache = new HashMap<>();
 
     @Autowired
     public StatsController(Stats stats, ExternalServices externalServices, OnlineUpdater onlineUpdater){
@@ -47,8 +50,15 @@ public class StatsController {
         return new ResponseEntity(externalServices.getServices(), HttpStatus.OK);
     }
 
-    @GetMapping("/graph")
-    public ResponseEntity GetPeakOfDays() {
-        return new ResponseEntity(onlineUpdater.getPeakOfDays(7), HttpStatus.OK);
+    @GetMapping("/graph/peak/of/days")
+    public ResponseEntity<List<OnlineUpdater.StatsOfPeakOfDay>> GetPeakOfDays(@RequestParam(required = false, defaultValue = "7") Integer limit) {
+        if (!cache.containsKey(limit)) {
+            cache.put(limit, new HashMap<>(){{put(onlineUpdater.getPeakOfDays(limit), Instant.now().getEpochSecond());}});
+        }
+        if (Instant.now().getEpochSecond() - cache.get(limit).values().stream().findFirst().orElse(0L) < 60L) {
+            cache.put(limit, new HashMap<>(){{put(onlineUpdater.getPeakOfDays(limit), Instant.now().getEpochSecond());}});
+        }
+
+        return new ResponseEntity<>(cache.get(limit).keySet().stream().findFirst().orElse(null), HttpStatus.OK);
     }
 }