refactor

[m6w6/seekat] / lib / API / Call / Cache / Control.php

diff --git a/lib/API/Call/Cache/Control.php b/lib/API/Call/Cache/Control.php
new file mode 100644 (file)
index 0000000..99871d6
--- /dev/null
+++ b/lib/API/Call/Cache/Control.php
@@ -0,0 +1,118 @@
+<?php
+
+namespace seekat\API\Call\Cache;
+
+use http\Client\Request;
+use http\Client\Response;
+use http\Header;
+use http\Params;
+use http\QueryString;
+use http\Url;
+
+final class Control
+{
+       /**
+        * @var string
+        */
+       private $key;
+
+       /**
+        * @param Request $request
+        */
+       function __construct(Request $request) {
+               $method = $request->getRequestMethod();
+               switch ($method) {
+                       case "HEAD":
+                       case "GET":
+                               $uid = $this->extractAuth($request);
+                               $url = $request->getRequestUrl();
+                               $this->key = "seekat call $uid $method $url";
+                               break;
+                       default:
+                               $this->key = "";
+                               break;
+               }
+       }
+
+       /**
+        * @return bool
+        */
+       public function isValid() : bool {
+               return strlen($this->key) > 0;
+       }
+
+       /**
+        * @return string
+        */
+       public function getKey() : string {
+               return $this->key;
+       }
+
+       /**
+        * @param Response $response
+        * @return bool
+        */
+       public function isStale(Response $response) : bool {
+               if (false === $response->getHeader("Cache-Control") &&
+                       false === $response->getHeader("Expires")) {
+                       return false;
+               }
+
+               $max_age = $this->extractMaxAge($response);
+               $cur_age = time() - $response->getHeader("X-Cache-Time");
+
+               return $max_age >= 0 && $max_age < $cur_age;
+       }
+
+       /**
+        * @param Response $response
+        * @return int
+        */
+       private function extractMaxAge(Response $response) : int {
+               /* @var Header $date
+                * @var Header $control
+                * @var Header $expires
+                */
+               $control = $response->getHeader("Cache-Control", Header::class);
+               if ($control) {
+                       /* @var Params $params */
+                       $params = $control->getParams();
+                       if (isset($params["max-age"])) {
+                               return (int) $params->params["max-age"]["value"];
+                       }
+               }
+
+               $expires = $response->getHeader("Expires", Header::class);
+               if ($expires) {
+                       if ($expires->match(0, Header::MATCH_FULL)) {
+                               return 0;
+                       }
+
+                       $date = $response->getHeader("Date", Header::class);
+                       if ($date) {
+                               return strtotime($expires->value) - strtotime($date->value);
+                       }
+               }
+
+               return -1;
+       }
+
+       /**
+        * @param Request $request
+        * @return string
+        */
+       private function extractAuth(Request $request) : string {
+               $auth = $request->getHeader("Authorization");
+               if ($auth) {
+                       return substr($auth, strpos($auth, " ") + 1);
+               }
+
+               $opts = $request->getOptions();
+               if (isset($opts["httpauth"])) {
+                       return base64_encode($opts["httpauth"]);
+               }
+
+               $query = new QueryString((new Url($request->getRequestUrl()))->query);
+               return $query->getString("access_token", $query->getString("client_id", ""));
+       }
+}