Show meaningful error when xmlrpc broken

Podfile.lock

@@ -27,7 +27,7 @@ PODS:
   - OHHTTPStubs/Swift (6.1.0):
     - OHHTTPStubs/Default
   - UIDeviceIdentifier (0.5.0)
-  - WordPressKit (1.4.3-beta.1):
+  - WordPressKit (1.4.3-beta.2):
     - Alamofire (~> 4.7.3)
     - CocoaLumberjack (= 3.4.2)
     - NSObject-SafeExpectations (= 0.0.3)
@@ -70,7 +70,7 @@ SPEC CHECKSUMS:
   OCMock: ebe9ee1dca7fbed0ff9193ac0b3e2d8862ea56f6
   OHHTTPStubs: 1e21c7d2c084b8153fc53d48400d8919d2d432d0
   UIDeviceIdentifier: a959a6d4f51036b4180dd31fb26483a820f1cc46
-  WordPressKit: 07501ceb3e9cbebbbe64ad02dcaff44807406450
+  WordPressKit: 7b6fec9b382c0a9f553b82a4eb133ad685b9f879
   WordPressShared: 7ef0253d54989b195e020a74100a8500be0a4315
   wpxmlrpc: bfc572f62ce7ee897f6f38b098d2ba08732ecef4
 

WordPressKit.podspec

@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name          = "WordPressKit"
-  s.version       = "1.4.3-beta.1"
+  s.version       = "1.4.3-beta.2"
 
   s.summary       = "WordPressKit offers a clean and simple WordPress.com and WordPress.org API."
 

WordPressKit/WordPressOrgXMLRPCValidator.swift

@@ -11,6 +11,7 @@ import CocoaLumberjack
     case forbidden = 403 // Server returned a 403 error while reading xmlrpc file
     case blocked = 405 // Server returned a 405 error while reading xmlrpc file
     case invalid // Doesn't look to be valid XMLRPC Endpoint.
+    case xmlrpc_missing // site contains RSD link but XML-RPC information is missing
 
     public var localizedDescription: String {
         switch (self) {
@@ -25,11 +26,13 @@ import CocoaLumberjack
         case .mobilePluginRedirectedError:
             return NSLocalizedString("You seem to have installed a mobile plugin from DudaMobile which is preventing the app to connect to your blog", comment: "")
         case .invalid:
-            return NSLocalizedString("We're sure this is a great site - but it's not a WordPress site, so you can't connect to it with this app.", comment: "Error message shown a URL points to a valid site but not a WordPress site.")
+            return NSLocalizedString("Couldn't connect to the WordPress site. There is no valid WordPress site at this address. Check the site address (URL) you entered.", comment: "Error message shown a URL points to a valid site but not a WordPress site.")
         case .blocked:
             return NSLocalizedString("Couldn't connect. Your host is blocking POST requests, and the app needs that in order to communicate with your site. Contact your host to solve this problem.", comment: "Message to show to user when he tries to add a self-hosted site but the host returned a 405 error, meaning that the host is blocking POST requests on /xmlrpc.php file.")
         case .forbidden:
             return NSLocalizedString("Couldn't connect. We received a 403 error when trying to access your site XMLRPC endpoint. The app needs that in order to communicate with your site. Contact your host to solve this problem.", comment: "Message to show to user when he tries to add a self-hosted site but the host returned a 403 error, meaning that the access to the /xmlrpc.php file is forbidden.")
+        case .xmlrpc_missing:
+            return NSLocalizedString("Couldn't connect. Required XML-RPC methods are missing on the server.", comment: "Message to show to user when he tries to add a self-hosted site with RSD link present, but xmlrpc is missing.")
         }
     }
 }
@@ -192,6 +195,7 @@ open class WordPressOrgXMLRPCValidator: NSObject {
                                        redirectCount: Int = 0,
                                    success: @escaping (_ xmlrpcURL: URL) -> (),
                                    failure: @escaping (_ error: NSError) -> ()) {
+
         guard redirectCount < redirectLimit else {
             let error = NSError(domain: URLError.errorDomain,
                                 code: URLError.httpTooManyRedirects.rawValue,
@@ -247,6 +251,8 @@ open class WordPressOrgXMLRPCValidator: NSObject {
                                            success: @escaping (_ xmlrpcURL: URL) -> (),
                                            failure: @escaping (_ error: NSError) -> ()) {
         DDLogInfo("Fetch the original url and look for the RSD link by using RegExp")
+
+        var isWpSite = false
         let session = URLSession(configuration: URLSessionConfiguration.ephemeral)
         let dataTask = session.dataTask(with: htmlURL, completionHandler: { (data, response, error) in
             if let error = error {
@@ -261,6 +267,9 @@ open class WordPressOrgXMLRPCValidator: NSObject {
                 return
             }
 
+            // If the site contains RSD link, it is WP.org site
+            isWpSite = true
+
             // Try removing "?rsd" from the url, it should point to the XML-RPC endpoint
             let xmlrpc = rsdURL.replacingOccurrences(of: "?rsd", with: "")
             if xmlrpc != rsdURL {
@@ -273,7 +282,9 @@ open class WordPressOrgXMLRPCValidator: NSObject {
                     if error.code == 403 || error.code == 405, let xmlrpcValidatorError = error as? WordPressOrgXMLRPCValidatorError {
                         failure(xmlrpcValidatorError as NSError)
                     } else {
-                        failure(WordPressOrgXMLRPCValidatorError.invalid as NSError)
+                        let validatorError = isWpSite ? WordPressOrgXMLRPCValidatorError.xmlrpc_missing :
+                                                        WordPressOrgXMLRPCValidatorError.invalid
+                            failure(validatorError as NSError)
                     }
                 })
             } else {