From aff5de85f9e81ccf989bd14f9e83f8950f10efa3 Mon Sep 17 00:00:00 2001
From: Benjamin Neff <benjamin@coding4coffee.ch>
Date: Tue, 16 Jun 2015 02:49:37 +0200
Subject: [PATCH] add validation for configuration

---
 lib/diaspora_federation.rb | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/lib/diaspora_federation.rb b/lib/diaspora_federation.rb
index 80dd47f..572189e 100644
--- a/lib/diaspora_federation.rb
+++ b/lib/diaspora_federation.rb
@@ -34,7 +34,39 @@ module DiasporaFederation
     #   end
     def configure
       yield self
+      validate_config
       logger.info "successfully configured the federation engine"
     end
+
+    private
+
+    def validate_config
+      raise ConfigurationError, "missing server_uri" unless @server_uri.respond_to? :host
+      validate_class(@person_class, "person_class", %i(
+        find_local_by_diaspora_handle
+        guid
+        url
+        diaspora_handle
+        serialized_public_key
+        salmon_url
+        atom_url
+        profile_url
+        hcard_url
+      ))
+    end
+
+    def validate_class(klass, name, methods)
+      raise ConfigurationError, "missing #{name}" unless klass
+      const = const_get(klass)
+      methods.each {|method|
+        valid = const.respond_to?(method) || const.column_names.include?(method.to_s) || const.method_defined?(method)
+        raise ConfigurationError, "the configured class #{const} for #{name} does not respond to #{method}" unless valid
+      }
+    end
+  end
+
+  ##
+  # raised, if the engine is not configured correctly
+  class ConfigurationError < RuntimeError
   end
 end