refac: API 캐시 컨트롤에서 max-age, public 지정 가능하도록

src/sammo/APICacheResult.php

@@ -5,6 +5,8 @@ class APICacheResult{
     function __construct(
         public ?\DateTimeInterface $lastModified = null,
         public ?string $etag = null,
+        public int $validSeconds = 60,
+        public bool $isPublic = false,
     )
     {
     }

src/sammo/TimeUtil.php

@@ -181,6 +181,16 @@ class TimeUtil
         return $seconds;
     }
 
+    public static function nowDateTime(): \DateTime{
+        $now = time();
+        return static::secondsToDateTime($now, false, true);
+    }
+
+    public static function nowDateTimeImmutable(): \DateTimeImmutable{
+        $now = time();
+        return static::secondsToDateTime($now, true, true);
+    }
+
     public static function format(\DateTimeInterface $dateTime, bool $withFraction): string{
         if (!$withFraction) {
             return $dateTime->format('Y-m-d H:i:s');

src/sammo/WebUtil.php

@@ -36,9 +36,10 @@ class WebUtil
         return strtolower($_SERVER['HTTP_X_REQUESTED_WITH'] ?? null) === 'xmlhttprequest';
     }
 
-    public static function setCacheHeader(?APICacheResult $cache, int $maxAge=60){
+    public static function setCacheHeader(?APICacheResult $cache){
+        $control = $cache->isPublic?'public':'private';
         header_remove('expires');
-        header("Cache-Control: private, max-age={$maxAge}");
+        header("Cache-Control: {$control}, max-age={$cache->validSeconds}");
         header("Pragma: cache");
         if($cache->etag !== null){
             header("ETag: \"{$cache->etag}\"");