use go module for dependencies (#594)

appservice/api/query.go

@@ -0,0 +1,178 @@
+// Copyright 2018 New Vector Ltd
+//
+// 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 api contains methods used by dendrite components in multi-process
+// mode to send requests to the appservice component, typically in order to ask
+// an application service for some information.
+package api
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"net/http"
+
+	"github.com/matrix-org/dendrite/clientapi/auth/authtypes"
+	"github.com/matrix-org/dendrite/clientapi/auth/storage/accounts"
+	"github.com/matrix-org/gomatrixserverlib"
+
+	commonHTTP "github.com/matrix-org/dendrite/common/http"
+	opentracing "github.com/opentracing/opentracing-go"
+)
+
+// RoomAliasExistsRequest is a request to an application service
+// about whether a room alias exists
+type RoomAliasExistsRequest struct {
+	// Alias we want to lookup
+	Alias string `json:"alias"`
+}
+
+// RoomAliasExistsResponse is a response from an application service
+// about whether a room alias exists
+type RoomAliasExistsResponse struct {
+	AliasExists bool `json:"exists"`
+}
+
+// UserIDExistsRequest is a request to an application service about whether a
+// user ID exists
+type UserIDExistsRequest struct {
+	// UserID we want to lookup
+	UserID string `json:"user_id"`
+}
+
+// UserIDExistsRequestAccessToken is a request to an application service
+// about whether a user ID exists. Includes an access token
+type UserIDExistsRequestAccessToken struct {
+	// UserID we want to lookup
+	UserID      string `json:"user_id"`
+	AccessToken string `json:"access_token"`
+}
+
+// UserIDExistsResponse is a response from an application service about
+// whether a user ID exists
+type UserIDExistsResponse struct {
+	UserIDExists bool `json:"exists"`
+}
+
+// AppServiceQueryAPI is used to query user and room alias data from application
+// services
+type AppServiceQueryAPI interface {
+	// Check whether a room alias exists within any application service namespaces
+	RoomAliasExists(
+		ctx context.Context,
+		req *RoomAliasExistsRequest,
+		resp *RoomAliasExistsResponse,
+	) error
+	// Check whether a user ID exists within any application service namespaces
+	UserIDExists(
+		ctx context.Context,
+		req *UserIDExistsRequest,
+		resp *UserIDExistsResponse,
+	) error
+}
+
+// AppServiceRoomAliasExistsPath is the HTTP path for the RoomAliasExists API
+const AppServiceRoomAliasExistsPath = "/api/appservice/RoomAliasExists"
+
+// AppServiceUserIDExistsPath is the HTTP path for the UserIDExists API
+const AppServiceUserIDExistsPath = "/api/appservice/UserIDExists"
+
+// httpAppServiceQueryAPI contains the URL to an appservice query API and a
+// reference to a httpClient used to reach it
+type httpAppServiceQueryAPI struct {
+	appserviceURL string
+	httpClient    *http.Client
+}
+
+// NewAppServiceQueryAPIHTTP creates a AppServiceQueryAPI implemented by talking
+// to a HTTP POST API.
+// If httpClient is nil then it uses http.DefaultClient
+func NewAppServiceQueryAPIHTTP(
+	appserviceURL string,
+	httpClient *http.Client,
+) AppServiceQueryAPI {
+	if httpClient == nil {
+		httpClient = http.DefaultClient
+	}
+	return &httpAppServiceQueryAPI{appserviceURL, httpClient}
+}
+
+// RoomAliasExists implements AppServiceQueryAPI
+func (h *httpAppServiceQueryAPI) RoomAliasExists(
+	ctx context.Context,
+	request *RoomAliasExistsRequest,
+	response *RoomAliasExistsResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "appserviceRoomAliasExists")
+	defer span.Finish()
+
+	apiURL := h.appserviceURL + AppServiceRoomAliasExistsPath
+	return commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}
+
+// UserIDExists implements AppServiceQueryAPI
+func (h *httpAppServiceQueryAPI) UserIDExists(
+	ctx context.Context,
+	request *UserIDExistsRequest,
+	response *UserIDExistsResponse,
+) error {
+	span, ctx := opentracing.StartSpanFromContext(ctx, "appserviceUserIDExists")
+	defer span.Finish()
+
+	apiURL := h.appserviceURL + AppServiceUserIDExistsPath
+	return commonHTTP.PostJSON(ctx, span, h.httpClient, apiURL, request, response)
+}
+
+// RetreiveUserProfile is a wrapper that queries both the local database and
+// application services for a given user's profile
+func RetreiveUserProfile(
+	ctx context.Context,
+	userID string,
+	asAPI AppServiceQueryAPI,
+	accountDB *accounts.Database,
+) (*authtypes.Profile, error) {
+	localpart, _, err := gomatrixserverlib.SplitID('@', userID)
+	if err != nil {
+		return nil, err
+	}
+
+	// Try to query the user from the local database
+	profile, err := accountDB.GetProfileByLocalpart(ctx, localpart)
+	if err != nil && err != sql.ErrNoRows {
+		return nil, err
+	} else if profile != nil {
+		return profile, nil
+	}
+
+	// Query the appservice component for the existence of an AS user
+	userReq := UserIDExistsRequest{UserID: userID}
+	var userResp UserIDExistsResponse
+	if err = asAPI.UserIDExists(ctx, &userReq, &userResp); err != nil {
+		return nil, err
+	}
+
+	// If no user exists, return
+	if !userResp.UserIDExists {
+		return nil, errors.New("no known profile for given user ID")
+	}
+
+	// Try to query the user from the local database again
+	profile, err = accountDB.GetProfileByLocalpart(ctx, localpart)
+	if err != nil {
+		return nil, err
+	}
+
+	// profile should not be nil at this point
+	return profile, nil
+}