programmesPROGRAMMES-6052 findOnNowByService cache issues (#217)

- Set max cache time to 300s
- Add function flushOnNowByService so we can flush it when an stale object still in memory and is not longer valid

src/Cache/Cache.php

@@ -99,6 +99,16 @@ public function getOrSet(string $key, $ttl, callable $function, array $arguments
         return $result;
     }
 
+    /**
+     * @param string $key
+     * @return bool True if the item was successfully removed. False if there was an error.
+     */
+    public function deleteItem(string $key): bool
+    {
+        $key = $this->standardiseKey($key);
+        return $this->cachePool->deleteItem($key);
+    }
+
     /**
      * Helps you to construct good cache keys by prodding you in the correct direction.
      * Entirely optional but you are encouraged to use it.

src/Cache/CacheInterface.php

@@ -19,6 +19,8 @@ public function setItem(CacheItemInterface $item, $value, $ttl): bool;
 
     public function getOrSet(string $key, $ttl, callable $function, array $arguments = [], $nullTtl = CacheInterface::NONE);
 
+    public function deleteItem(string $key): bool;
+
     public function setFlushCacheItems(bool $flushCacheItems): void;
 
     public function keyHelper(string $className, string $functionName, ...$uniqueValues): string;

src/Service/BroadcastsService.php

@@ -113,8 +113,30 @@ public function findOnNowByService(
         $entity = $this->mapSingleEntity($dbEntity);
 
         if ($entity) {
-            $this->cache->setItem($cacheItem, $entity, $entity->getEndAt());
+            // cache $entity with dynamic TTL
+            $now = ApplicationTime::getTime();
+            $diffInSeconds = $entity->getEndAt()->getTimestamp() - $now->getTimestamp();
+            if ($diffInSeconds > 300) {
+                // limit TTL to 5 minutes max
+                $ttl = 300;
+            } else {
+                $ttl = $diffInSeconds;
+            }
+            $this->cache->setItem($cacheItem, $entity, $ttl);
         }
         return $entity;
     }
+
+    public function flushOnNowByService(
+        Service $service,
+        $ttl = CacheInterface::NORMAL
+    ): bool {
+        $key = $this->cache->keyHelper(
+            __CLASS__,
+            'findOnNowByService',
+            $service->getDbId(),
+            $ttl
+        );
+        return $this->cache->deleteItem($key);
+    }
 }

tests/Service/BroadcastsService/FindOnNowByServiceTest.php

@@ -35,4 +35,11 @@ public function testFindOnNowByServiceEmptyResults()
 
         $this->assertSame(null, $broadcast);
     }
+
+    public function testFlushOnNowByService()
+    {
+        $service = $this->createConfiguredMock(Service::class, ['getDbId' => 1]);
+        $result = $this->service()->flushOnNowByService($service);
+        $this->assertTrue($result);
+    }
 }