Add bare bones user API (#1127)

* Add bare bones user API

with tests!

* linting

userapi/userapi.go

@@ -0,0 +1,41 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package userapi
+
+import (
+	"github.com/gorilla/mux"
+	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
+	"github.com/matrix-org/dendrite/clientapi/auth/storage/devices"
+	"github.com/matrix-org/dendrite/userapi/api"
+	"github.com/matrix-org/dendrite/userapi/internal"
+	"github.com/matrix-org/dendrite/userapi/inthttp"
+	"github.com/matrix-org/gomatrixserverlib"
+)
+
+// AddInternalRoutes registers HTTP handlers for the internal API. Invokes functions
+// on the given input API.
+func AddInternalRoutes(router *mux.Router, intAPI api.UserInternalAPI) {
+	inthttp.AddRoutes(router, intAPI)
+}
+
+// NewInternalAPI returns a concerete implementation of the internal API. Callers
+// can call functions directly on the returned API or via an HTTP interface using AddInternalRoutes.
+func NewInternalAPI(accountDB accounts.Database, deviceDB devices.Database, serverName gomatrixserverlib.ServerName) api.UserInternalAPI {
+	return &internal.UserInternalAPI{
+		AccountDB:  accountDB,
+		DeviceDB:   deviceDB,
+		ServerName: serverName,
+	}
+}