Feature: strategies

composer.json

@@ -10,8 +10,8 @@
   "require": {
     "php": "^7.0",
     "api-clients/middleware": "^1.0",
-    "guzzlehttp/psr7": "^1.3",
-    "react/cache": "^0.4.1"
+    "react/cache": "^0.4.1",
+    "ringcentral/psr7": "^1.2"
   },
   "require-dev": {
     "api-clients/test-utilities": "^2.0"

src/CacheKey.php

@@ -0,0 +1,51 @@
+<?php declare(strict_types=1);
+
+namespace ApiClients\Middleware\Cache;
+
+use Psr\Http\Message\UriInterface;
+
+final class CacheKey
+{
+    /**
+     * Create a cache key based on the URI and glue
+     *
+     * @param UriInterface $uri
+     * @param string $glue
+     * @return string
+     */
+    public static function create(UriInterface $uri, string $glue): string
+    {
+        return self::stripExtraSlashes(
+            implode(
+                $glue,
+                [
+                    (string)$uri->getScheme(),
+                    (string)$uri->getHost(),
+                    (string)$uri->getPort(),
+                    self::chunkUp(md5((string)$uri->getPath()), $glue),
+                    self::chunkUp(md5((string)$uri->getQuery()), $glue),
+                ]
+            ),
+            $glue
+        );
+    }
+
+    /**
+     * @param string $string
+     * @param string $glue
+     * @return string
+     */
+    private static function chunkUp(string $string, string $glue): string
+    {
+        return implode($glue, str_split($string, 2));
+    }
+
+    /**
+     * @param string $string
+     * @return string
+     */
+    private static function stripExtraSlashes(string $string, string $glue): string
+    {
+        return preg_replace('#' . $glue . '+#', $glue, $string);
+    }
+}