appview/signup: auto-claim pds handle domain at signup

Signed-off-by: Anirudh Oppiliappan <[e-mail]>

appview/oauth/handler.go

···
 	"log/slog"
 	"net/http"
 	"slices"
+	"strings"
 	"time"
 
 	comatproto "github.com/bluesky-social/indigo/api/atproto"
···
 	go o.addToDefaultKnot(sessData.AccountDID.String())
 	go o.addToDefaultSpindle(sessData.AccountDID.String())
 	go o.ensureTangledProfile(sessData)
+	go o.autoClaimTnglShDomain(sessData.AccountDID.String())
 
 	if !o.Config.Core.Dev {
 		err = o.Posthog.Enqueue(posthog.Capture{
···
 	}
 
 	return nil
+}
+
+// autoClaimTnglShDomain checks if the user has a .tngl.sh handle and, if so,
+// ensures their corresponding sites domain is claimed. This is idempotent —
+// ClaimDomain is a no-op if the claim already exists.
+func (o *OAuth) autoClaimTnglShDomain(did string) {
+	l := o.Logger.With("did", did)
+
+	pdsDomain := strings.TrimPrefix(o.Config.Pds.Host, "https://")
+	pdsDomain = strings.TrimPrefix(pdsDomain, "http://")
+
+	resolved, err := o.IdResolver.ResolveIdent(context.Background(), did)
+	if err != nil {
+		l.Error("autoClaimTnglShDomain: failed to resolve ident", "err", err)
+		return
+	}
+
+	handle := resolved.Handle.String()
+	if !strings.HasSuffix(handle, "."+pdsDomain) {
+		return
+	}
+
+	if err := db.ClaimDomain(o.Db, did, handle); err != nil {
+		l.Warn("autoClaimTnglShDomain: failed to claim domain", "domain", handle, "err", err)
+	} else {
+		l.Info("autoClaimTnglShDomain: claimed domain", "domain", handle)
+	}
 }
 
 // getAppPasswordSession returns a cached AppPasswordSession, creating one if needed.

appview/signup/signup.go

···
 	}
 	emailAdded = true
 
+	// step 4: auto-claim <username>.<pds-domain> for this user.
+	// All signups through this flow receive a <username>.tngl.sh handle
+	// (or whatever the configured PDS host is), so we claim the matching
+	// sites subdomain on their behalf. This is the only way to obtain a
+	// *.tngl.sh sites domain; it cannot be claimed manually via settings.
+	pdsDomain := strings.TrimPrefix(s.config.Pds.Host, "https://")
+	pdsDomain = strings.TrimPrefix(pdsDomain, "http://")
+	autoClaimDomain := username + "." + pdsDomain
+	if err := db.ClaimDomain(s.db, did, autoClaimDomain); err != nil {
+		s.l.Warn("failed to auto-claim sites domain at signup",
+			"domain", autoClaimDomain,
+			"did", did,
+			"error", err,
+		)
+	} else {
+		s.l.Info("auto-claimed sites domain at signup", "domain", autoClaimDomain, "did", did)
+	}
+
 	// if we get here, we've successfully created the account and added the email
 	success = true