[wip] Keep old pre-hash string around

Signed-off-by: Olivier Mehani <olivier.mehani@learnosity.com>

src/Request/Init.php

@@ -155,7 +155,8 @@ public function __construct(
         $this->preHashStringGenerator = $this->preHashStringFactory->getPreHashStringGenerator($service);
 
         // First validate the arguments passed
-        list ($requestPacket, $securityPacket) = $this->validate($service, $secret, $securityPacket, $requestPacket);
+        /* list ($requestPacket, $securityPacket) = $this->validate($service, $secret, $securityPacket, $requestPacket); */
+        list ($requestPacket, $securityPacket) = $this->legacyValidate($service, $secret, $securityPacket, $requestPacket);
 
         if (self::$telemetryEnabled) {
             $requestPacket = $this->addMeta($requestPacket);
@@ -292,6 +293,81 @@ public function generate(bool $encode = true)
         return $encode ? Json::encode($output) : $output;
     }
 
+    public function legacyValidate(string $service, string $secret, $securityPacket, $requestPacket): array
+    {
+        if (is_string($requestPacket)) {
+            $requestPacket = json_decode($requestPacket, true);
+            $this->requestPassedAsString = true;
+        }
+
+        if (is_null($requestPacket)) {
+            $requestPacket = [];
+        }
+
+        // In case the user gave us a JSON securityPacket, convert to an array
+        if (!is_array($securityPacket) && is_string($securityPacket)) {
+            $securityPacket = json_decode($securityPacket, true);
+        }
+
+        if (empty($service)) {
+            throw new ValidationException('The `service` argument wasn\'t found or was empty');
+        } elseif (!in_array(strtolower($service), $this->validServices)) {
+            throw new ValidationException("The service provided ($service) is not valid");
+        }
+
+        if (empty($securityPacket) || !is_array($securityPacket)) {
+            throw new ValidationException('The security packet must be an array or a valid JSON string');
+        }
+
+        foreach (array_keys($securityPacket) as $key) {
+            if (!in_array($key, LegacyPreHashString::$validSecurityKeys)) {
+                throw new ValidationException('Invalid key found in the security packet: ' . $key);
+            }
+        }
+        if ($service === "questions" && !array_key_exists('user_id', $securityPacket)) {
+            throw new ValidationException('Questions API requires a `user_id` in the security packet');
+        }
+        if (!array_key_exists('timestamp', $securityPacket)) {
+            $securityPacket['timestamp'] = gmdate('Ymd-Hi');
+        }
+
+        if (empty($secret)) {
+            throw new ValidationException('The `secret` argument must be a valid string');
+        }
+
+        if (!empty($requestPacket) && !is_array($requestPacket)) {
+            throw new ValidationException('The request packet must be an array or a valid JSON string');
+        }
+
+        return [$requestPacket, $securityPacket];
+    }
+
+    public function generatePreHashString()
+    {
+          $signatureArray = [];
+
+        // Create a pre-hash string based on the security credentials
+        // The order is important
+        foreach (LegacyPreHashString::$validSecurityKeys as $key) {
+            if (array_key_exists($key, $this->securityPacket)) {
+                $signatureArray[] = $this->securityPacket[$key];
+            }
+        }
+
+        // Add the requestPacket if necessary
+        if ($this->signRequestData && !empty($this->requestPacket)) {
+            $signatureArray[] = Json::encode($this->requestPacket);
+        }
+
+        // Add the action if necessary
+        if (!empty($this->action)) {
+            $signatureArray[] = $this->action;
+        }
+
+        $preHashString = implode('_', $signatureArray);
+        return $preHashString;
+    }
+
     /**
      * Generate a signature hash for the request, this includes:
      *  - the security credentials
@@ -304,7 +380,8 @@ public function generateSignature(): string
     {
         $preHashStringGenerator = $this->preHashStringFactory->getPreHashStringGenerator($this->service);
 
-        $preHashString = $preHashStringGenerator->getPreHashString($this->securityPacket, $this->requestPacket);
+        /* $preHashString = $preHashStringGenerator->getPreHashString($this->securityPacket, $this->requestPacket); */
+        $preHashString  = $this->generatePreHashString();
 
         // As we only support v2 from this point onwards
         // we do not need to check the version at this point,