modules/federation: Add query endpoint; add profile handler.

modules/Makefile.am

@@ -241,6 +241,7 @@ federation_federation_get_missing_events_la_SOURCES = federation/get_missing_eve
 federation_federation_get_groups_publicised_la_SOURCES = federation/get_groups_publicised.cc
 federation_federation_version_la_SOURCES = federation/version.cc
 federation_federation_sender_la_SOURCES = federation/sender.cc
+federation_federation_query_la_SOURCES = federation/query.cc
 
 federation_module_LTLIBRARIES = \
 	federation/federation_send.la \
@@ -249,6 +250,7 @@ federation_module_LTLIBRARIES = \
 	federation/federation_get_groups_publicised.la \
 	federation/federation_version.la \
 	federation/federation_sender.la \
+	federation/federation_query.la \
 	###
 
 ###############################################################################

modules/federation/query.cc

@@ -0,0 +1,103 @@
+// Matrix Construct
+//
+// Copyright (C) Matrix Construct Developers, Authors & Contributors
+// Copyright (C) 2016-2018 Jason Volk <jason@zemos.net>
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice is present in all copies. The
+// full license for this software is available in the LICENSE file.
+
+using namespace ircd;
+
+mapi::header
+IRCD_MODULE
+{
+	"Federation :Query"
+};
+
+const string_view
+query_description
+{R"(
+Performs a single query request on the receiving homeserver. 
+The Query Type part of the path specifies the kind of query 
+being made, and its query arguments have a meaning specific to 
+that kind of query. The response is a JSON-encoded object whose 
+meaning also depends on the kind of query.
+)"};
+
+resource
+query_resource
+{
+	"/_matrix/federation/v1/query/",
+	{
+		query_description,
+		resource::DIRECTORY
+	}
+};
+
+static resource::response
+get__query_profile(client &client,
+                   const resource::request &request);
+
+resource::response
+get__query(client &client,
+           const resource::request &request)
+{
+	const auto type
+	{
+		request.parv[0]
+	};
+
+	if(type == "profile")
+		return get__query_profile(client, request);
+
+	throw m::NOT_FOUND
+	{
+		"Query type not found."
+	};
+}
+
+resource::method
+method_get
+{
+	query_resource, "GET", get__query,
+	{
+		method_get.VERIFY_ORIGIN
+	}
+};
+
+resource::response
+get__query_profile(client &client,
+                   const resource::request &request)
+{
+	m::user::id::buf user_id
+	{
+		url::decode(request.query.at("user_id"), user_id)
+	};
+
+	const string_view field
+	{
+		//TODO: XXX full profile aggregation w/ user:: linkage
+		request.query.at("field")
+	};
+
+	const m::user user
+	{
+		user_id
+	};
+
+	user.profile(field, [&client, &field]
+	(const string_view &value)
+	{
+		resource::response
+		{
+			client, json::members
+			{
+				{ field, value }
+			}
+		};
+	});
+
+	return {}; // responded from closure
+}