X-Git-Url: https://git.m6w6.name/?p=m6w6%2Fseekat;a=blobdiff_plain;f=lib%2FAPI%2FCall%2FCache%2FControl.php;fp=lib%2FAPI%2FCall%2FCache%2FControl.php;h=99871d669b1b6f713e43a40e7caf7ec496685a2a;hp=0000000000000000000000000000000000000000;hb=2451d97f1cb7b97e445b4dd839835b8673a4d0fc;hpb=3958595e9ff27162ae918db1453ddecd4840d481

diff --git a/lib/API/Call/Cache/Control.php b/lib/API/Call/Cache/Control.php
new file mode 100644
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", ""));
+	}
+}