1 files changed, 38 insertions, 0 deletions
diff --git a/backend/fetchers/profiles.go b/backend/fetchers/profiles.go
index 038a07f..01a27c0 100644
--- a/backend/fetchers/profiles.go
+++ b/backend/fetchers/profiles.go
@@ -3,7 +3,9 @@ package fetchers
 import (
 	"encoding/json"
 	"fmt"
+	"io"
 	"llostre/backend/general"
+	"net"
 	"net/http"
 	"strings"
 )
@@ -17,6 +19,42 @@ type DIDDocument struct {
 	} `json:"service"`
 }
 
+func FetchDID(handle string) (string, error) {
+	// return if it's a DID already
+	if strings.HasPrefix(handle, "did:") {
+		return handle, nil
+	}
+
+	// resolve DNS record first
+	txtRecords, err := net.LookupTXT("_atproto." + handle)
+	if err == nil {
+		for _, txt := range txtRecords {
+			if after, ok := strings.CutPrefix(txt, "did="); ok {
+				return after, nil
+			}
+		}
+	}
+
+	// fallback to HTTPS well-known
+	resp, err := http.Get(fmt.Sprintf("https://%s/.well-known/atproto-did", handle))
+	if err != nil {
+		return "", err
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", err
+	}
+
+	did := strings.TrimSpace(string(body))
+	if !strings.HasPrefix(did, "did:") {
+		return "", fmt.Errorf("invalid DID returned: %s", did)
+	}
+
+	return did, nil
+}
+
 func FetchDidDoc(did string) (*DIDDocument, error) {
 	didDocURL := fmt.Sprintf("https://plc.directory/%s", did)