From 999cbb2ee842a26fba5c0040fb805574fe3cb306 Mon Sep 17 00:00:00 2001
From: Troy Davisson <troy.davisson@gmail.com>
Date: Mon, 23 Oct 2017 13:54:51 -0400
Subject: [PATCH] Automatically re-login if session issue occurs mid-process
 (#175)

* Automatically re-login if session issue occurs mid-process

* Added changelog entries
---
 docs/changelog.md |  2 ++
 src/Session.php   | 87 ++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 76 insertions(+), 13 deletions(-)

diff --git a/docs/changelog.md b/docs/changelog.md
index b40f6e7..6f5a103 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -3,6 +3,8 @@
 _Release TBD_
 
 - Fix RETS 1.8 login response parsing for optional info-token-type
+- Support automatic re-login if session issue occurs mid-process
+- New option `disable_auto_retry` (bool) added to optionally disable automatic re-login behavior
 
 ## 2.4
 
diff --git a/src/Session.php b/src/Session.php
index 63ba0a5..5fcc082 100644
--- a/src/Session.php
+++ b/src/Session.php
@@ -3,6 +3,7 @@
 use GuzzleHttp\Client;
 use GuzzleHttp\Cookie\CookieJar;
 use GuzzleHttp\Cookie\CookieJarInterface;
+use GuzzleHttp\Exception\ClientException;
 use Illuminate\Container\Container;
 use Illuminate\Support\Collection;
 use PHRETS\Exceptions\CapabilityUnavailable;
@@ -300,11 +301,12 @@ public function Disconnect()
     /**
      * @param $capability
      * @param array $options
-     * @throws Exceptions\CapabilityUnavailable
-     * @throws Exceptions\RETSException
+     * @param bool $is_retry
      * @return ResponseInterface
+     * @throws CapabilityUnavailable
+     * @throws RETSException
      */
-    protected function request($capability, $options = [])
+    protected function request($capability, $options = [], $is_retry = false)
     {
         $url = $this->capabilities->get($capability);
 
@@ -328,13 +330,46 @@ protected function request($capability, $options = [])
             $this->last_request_url = $url;
         }
 
-        /** @var ResponseInterface $response */
-        if ($this->configuration->readOption('use_post_method')) {
-            $this->debug('Using POST method per use_post_method option');
-            $query = (array_key_exists('query', $options)) ? $options['query'] : null;
-            $response = $this->client->request('POST', $url, array_merge($options, ['form_params' => $query]));
-        } else {
-            $response = $this->client->request('GET', $url, $options);
+        try {
+            /** @var ResponseInterface $response */
+            if ($this->configuration->readOption('use_post_method')) {
+                $this->debug('Using POST method per use_post_method option');
+                $query = (array_key_exists('query', $options)) ? $options['query'] : null;
+                $response = $this->client->request('POST', $url, array_merge($options, ['form_params' => $query]));
+            } else {
+                $response = $this->client->request('GET', $url, $options);
+            }
+        } catch (ClientException $e) {
+            $this->debug("ClientException: " . $e->getCode() . ": " . $e->getMessage());
+
+            if ($e->getCode() != 401) {
+                // not an Unauthorized error, so bail
+                throw $e;
+            }
+
+            if ($capability == 'Login') {
+                // unauthorized on a Login request, so bail
+                throw $e;
+            }
+
+            if ($is_retry) {
+                // this attempt was already a retry, so let's stop here
+                $this->debug("Request retry failed.  Won't retry again");
+                throw $e;
+            }
+
+            if ($this->getConfiguration()->readOption('disable_auto_retry')) {
+                // this attempt was already a retry, so let's stop here
+                $this->debug("Re-logging in disabled.  Won't retry");
+                throw $e;
+            }
+
+            $this->debug("401 Unauthorized exception returned");
+            $this->debug("Logging in again and retrying request");
+            // see if logging in again and retrying the request works
+            $this->Login();
+
+            return $this->request($capability, $options, true);
         }
 
         $response = new \PHRETS\Http\Response($response);
@@ -349,21 +384,47 @@ protected function request($capability, $options = [])
                 }
             }
         }
-        
+
+        $this->debug('Response: HTTP ' . $response->getStatusCode());
+
         if (preg_match('/text\/xml/', $response->getHeader('Content-Type')) and $capability != 'GetObject') {
             $parser = $this->grab(Strategy::PARSER_XML);
             $xml = $parser->parse($response);
+
             if ($xml and isset($xml['ReplyCode'])) {
                 $rc = (string)$xml['ReplyCode'];
+
+                if ($rc == "20037" and $capability != 'Login') {
+                    // must make Login request again.  let's handle this automatically
+
+                    if ($this->getConfiguration()->readOption('disable_auto_retry')) {
+                        // this attempt was already a retry, so let's stop here
+                        $this->debug("Re-logging in disabled.  Won't retry");
+                        throw new RETSException($xml['ReplyText'], (int)$xml['ReplyCode']);
+                    }
+
+                    if ($is_retry) {
+                        // this attempt was already a retry, so let's stop here
+                        $this->debug("Request retry failed.  Won't retry again");
+                        // let this error fall through to the more generic handling below
+                    } else {
+                        $this->debug("RETS 20037 re-auth requested");
+                        $this->debug("Logging in again and retrying request");
+                        // see if logging in again and retrying the request works
+                        $this->Login();
+
+                        return $this->request($capability, $options, true);
+                    }
+                }
+
                 // 20201 - No records found - not exception worthy in my mind
                 // 20403 - No objects found - not exception worthy in my mind
-                if ($rc != "0" and $rc != "20201" and $rc != "20403") {
+                if (!in_array($rc, [0, 20201, 20403])) {
                     throw new RETSException($xml['ReplyText'], (int)$xml['ReplyCode']);
                 }
             }
         }
 
-        $this->debug('Response: HTTP ' . $response->getStatusCode());
         return $response;
     }