Initial discord remote auth support.

It works, but nothing is persisted yet as the user object needs some tweaking
especially the database side.

bridge/commands.go

@@ -1,6 +1,7 @@
 package bridge
 
 import (
+	"context"
 	"fmt"
 
 	"github.com/alecthomas/kong"
@@ -11,6 +12,7 @@ import (
 	"maunium.net/go/mautrix/id"
 
 	"gitlab.com/beeper/discord/consts"
+	"gitlab.com/beeper/discord/remoteauth"
 	"gitlab.com/beeper/discord/version"
 )
 
@@ -45,6 +47,7 @@ type commands struct {
 	globals
 
 	Help    helpCmd    `kong:"cmd,help='Displays this message.'"`
+	Login   loginCmd   `kong:"cmd,help='Log in to Discord.'"`
 	Version versionCmd `kong:"cmd,help='Displays the version of the bridge.'"`
 }
 
@@ -79,3 +82,53 @@ func (c *versionCmd) Run(g *globals) error {
 
 	return nil
 }
+
+type loginCmd struct{}
+
+func (l *loginCmd) Run(g *globals) error {
+	client, err := remoteauth.New()
+	if err != nil {
+		return err
+	}
+
+	qrChan := make(chan string)
+	doneChan := make(chan struct{})
+
+	go func() {
+		code := <-qrChan
+
+		_, err := g.user.sendQRCode(g.bot, g.roomID, code)
+		if err != nil {
+			fmt.Fprintln(g.context.Stdout, "failed to generate the qrcode")
+
+			return
+		}
+	}()
+
+	ctx := context.Background()
+
+	if err := client.Dial(ctx, qrChan, doneChan); err != nil {
+		close(qrChan)
+		close(doneChan)
+
+		return err
+	}
+
+	<-doneChan
+
+	user, err := client.Result()
+	if err != nil {
+		fmt.Printfln(g.context.Stdout, "failed to log in")
+
+		return err
+	}
+
+	g.user.User.ID = user.UserID
+	g.user.User.Discriminator = user.Discriminator
+	g.user.User.Username = user.Username
+
+	g.handler.log.Warnln("users:", user)
+	g.handler.log.Warnln("err:", err)
+
+	return nil
+}

bridge/user.go

@@ -1,7 +1,11 @@
 package bridge
 
 import (
+	"github.com/skip2/go-qrcode"
+
 	log "maunium.net/go/maulogger/v2"
+	"maunium.net/go/mautrix/appservice"
+	"maunium.net/go/mautrix/event"
 	"maunium.net/go/mautrix/id"
 
 	"gitlab.com/beeper/discord/database"
@@ -91,3 +95,43 @@ func (u *User) SetManagementRoom(roomID id.RoomID) {
 func (u *User) HasSession() bool {
 	return u.User.Session != nil
 }
+
+func (u *User) sendQRCode(bot *appservice.IntentAPI, roomID id.RoomID, code string) (id.EventID, error) {
+	url, err := u.uploadQRCode(code)
+	if err != nil {
+		return "", err
+	}
+
+	content := event.MessageEventContent{
+		MsgType: event.MsgImage,
+		Body:    code,
+		URL:     url.CUString(),
+	}
+
+	resp, err := bot.SendMessageEvent(roomID, event.EventMessage, &content)
+	if err != nil {
+		return "", err
+	}
+
+	return resp.EventID, nil
+}
+
+func (u *User) uploadQRCode(code string) (id.ContentURI, error) {
+	qrCode, err := qrcode.Encode(code, qrcode.Low, 256)
+	if err != nil {
+		u.log.Errorln("Failed to encode QR code:", err)
+
+		return id.ContentURI{}, err
+	}
+
+	bot := u.bridge.as.BotClient()
+
+	resp, err := bot.UploadBytes(qrCode, "image/png")
+	if err != nil {
+		u.log.Errorln("Failed to upload QR code:", err)
+
+		return id.ContentURI{}, err
+	}
+
+	return resp.ContentURI, nil
+}