Add Web Push sender (similar to email sender)

internal/webpush/realsender.go

@@ -0,0 +1,249 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package webpush
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"time"
+
+	webpushgo "github.com/SherClockHolmes/webpush-go"
+	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
+	"github.com/superseriousbusiness/gotosocial/internal/filter/usermute"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/httpclient"
+	"github.com/superseriousbusiness/gotosocial/internal/log"
+	"github.com/superseriousbusiness/gotosocial/internal/state"
+	"github.com/superseriousbusiness/gotosocial/internal/text"
+	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
+)
+
+// realSender is the production Web Push sender, backed by an HTTP client, DB, and worker pool.
+type realSender struct {
+	httpClient *http.Client
+	state      *state.State
+	tc         *typeutils.Converter
+}
+
+// NewRealSender creates a Sender from an http.Client instead of an httpclient.Client.
+// This should only be used by NewSender and in tests.
+func NewRealSender(httpClient *http.Client, state *state.State) Sender {
+	return &realSender{
+		httpClient: httpClient,
+		state:      state,
+		tc:         typeutils.NewConverter(state),
+	}
+}
+
+// TTL is an arbitrary time to ask the Web Push server to store notifications
+// while waiting for the client to retrieve them.
+const TTL = 48 * time.Hour
+
+func (r *realSender) Send(
+	ctx context.Context,
+	notification *gtsmodel.Notification,
+	filters []*gtsmodel.Filter,
+	mutes *usermute.CompiledUserMuteList,
+) error {
+	// Load subscriptions.
+	subscriptions, err := r.state.DB.GetWebPushSubscriptionsByAccountID(ctx, notification.TargetAccountID)
+	if err != nil {
+		return gtserror.Newf(
+			"error getting Web Push subscriptions for account %s: %w",
+			notification.TargetAccountID,
+			err,
+		)
+	}
+	if len(subscriptions) == 0 {
+		return nil
+	}
+
+	// Subscriptions we're actually going to send to.
+	relevantSubscriptions := make([]*gtsmodel.WebPushSubscription, 0, len(subscriptions))
+	for _, subscription := range subscriptions {
+		// Check whether this subscription wants this type of notification.
+		notify := false
+		switch notification.NotificationType {
+		case gtsmodel.NotificationFollow:
+			notify = *subscription.NotifyFollow
+		case gtsmodel.NotificationFollowRequest:
+			notify = *subscription.NotifyFollowRequest
+		case gtsmodel.NotificationMention:
+			notify = *subscription.NotifyMention
+		case gtsmodel.NotificationReblog:
+			notify = *subscription.NotifyReblog
+		case gtsmodel.NotificationFavourite:
+			notify = *subscription.NotifyFavourite
+		case gtsmodel.NotificationPoll:
+			notify = *subscription.NotifyPoll
+		case gtsmodel.NotificationStatus:
+			notify = *subscription.NotifyStatus
+		case gtsmodel.NotificationAdminSignup:
+			notify = *subscription.NotifyAdminSignup
+		case gtsmodel.NotificationAdminReport:
+			notify = *subscription.NotifyAdminReport
+		case gtsmodel.NotificationPendingFave:
+			notify = *subscription.NotifyPendingFave
+		case gtsmodel.NotificationPendingReply:
+			notify = *subscription.NotifyPendingReply
+		case gtsmodel.NotificationPendingReblog:
+			notify = *subscription.NotifyPendingReblog
+		default:
+			log.Errorf(
+				ctx,
+				"notification type not supported by Web Push subscriptions: %v",
+				notification.NotificationType,
+			)
+			continue
+		}
+		if !notify {
+			continue
+		}
+		relevantSubscriptions = append(relevantSubscriptions, subscription)
+	}
+	if len(relevantSubscriptions) == 0 {
+		return nil
+	}
+
+	// Load VAPID keys into webpush-go options struct.
+	vapidKeyPair, err := r.state.DB.GetVAPIDKeyPair(ctx)
+	if err != nil {
+		return gtserror.Newf("error getting VAPID key pair: %w", err)
+	}
+
+	// Get API representations of notification and accounts involved.
+	// This also loads the target account's settings.
+	apiNotification, err := r.tc.NotificationToAPINotification(ctx, notification, filters, mutes)
+	if err != nil {
+		return gtserror.Newf("error converting notification %s to API representation: %w", notification.ID, err)
+	}
+
+	// Queue up a .Send() call for each relevant subscription.
+	for _, subscription := range relevantSubscriptions {
+		r.state.Workers.WebPush.Queue.Push(func(ctx context.Context) {
+			if err := r.sendToSubscription(
+				ctx,
+				vapidKeyPair,
+				subscription,
+				notification.TargetAccount,
+				apiNotification,
+			); err != nil {
+				log.Errorf(
+					ctx,
+					"error sending Web Push notification for subscription with token ID %s: %v",
+					subscription.TokenID,
+					err,
+				)
+			}
+		})
+	}
+
+	return nil
+}
+
+// sendToSubscription sends a notification to a single Web Push subscription.
+func (r *realSender) sendToSubscription(
+	ctx context.Context,
+	vapidKeyPair *gtsmodel.VAPIDKeyPair,
+	subscription *gtsmodel.WebPushSubscription,
+	targetAccount *gtsmodel.Account,
+	apiNotification *apimodel.Notification,
+) error {
+	// Get the associated access token.
+	token, err := r.state.DB.GetTokenByID(ctx, subscription.TokenID)
+	if err != nil {
+		return gtserror.Newf("error getting token %s: %w", subscription.TokenID, err)
+	}
+
+	// Create push notification payload struct.
+	pushNotification := &apimodel.PushNotification{
+		NotificationID:   apiNotification.ID,
+		NotificationType: apiNotification.Type,
+		Icon:             apiNotification.Account.Avatar,
+		PreferredLocale:  targetAccount.Settings.Language,
+		AccessToken:      token.Access,
+	}
+
+	// Set the notification title.
+	displayNameOrAcct := apiNotification.Account.DisplayName
+	if displayNameOrAcct == "" {
+		displayNameOrAcct = apiNotification.Account.Acct
+	}
+	// TODO: (Vyr) improve copy
+	pushNotification.Title = fmt.Sprintf("%s from %s", apiNotification.Type, displayNameOrAcct)
+
+	// Set the notification body.
+	if apiNotification.Status != nil {
+		if apiNotification.Status.SpoilerText != "" {
+			pushNotification.Body = apiNotification.Status.SpoilerText
+		} else {
+			pushNotification.Body = text.SanitizeToPlaintext(apiNotification.Status.Content)
+		}
+	} else {
+		pushNotification.Body = text.SanitizeToPlaintext(apiNotification.Account.Note)
+	}
+	// TODO: (Vyr) trim this
+
+	// Encode the push notification as JSON.
+	pushNotificationBytes, err := json.Marshal(pushNotification)
+	if err != nil {
+		return gtserror.Newf("error encoding Web Push notification: %w", err)
+	}
+
+	// Send push notification.
+	resp, err := webpushgo.SendNotificationWithContext(
+		ctx,
+		pushNotificationBytes,
+		&webpushgo.Subscription{
+			Endpoint: subscription.Endpoint,
+			Keys: webpushgo.Keys{
+				Auth:   subscription.Auth,
+				P256dh: subscription.P256dh,
+			},
+		},
+		&webpushgo.Options{
+			HTTPClient:      r.httpClient,
+			VAPIDPublicKey:  vapidKeyPair.Public,
+			VAPIDPrivateKey: vapidKeyPair.Private,
+			TTL:             int(TTL.Seconds()),
+		},
+	)
+	if err != nil {
+		return gtserror.Newf("error sending Web Push notification: %w", err)
+	}
+	// We're not going to use the response body, but we need to close it so we don't leak the connection.
+	_ = resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return gtserror.Newf("unexpected HTTP status received when sending Web Push notification: %s", resp.Status)
+	}
+
+	return nil
+}
+
+// gtsHttpClientRoundTripper helps wrap a GtS HTTP client back into a regular HTTP client,
+// so that webpush-go can use our IP filters, bad hosts list, and retries.
+type gtsHttpClientRoundTripper struct {
+	httpClient *httpclient.Client
+}
+
+func (r *gtsHttpClientRoundTripper) RoundTrip(request *http.Request) (*http.Response, error) {
+	return r.httpClient.Do(request)
+}