1 files changed, 184 insertions, 0 deletions
diff --git a/fetchers/app.bsky.actor.go b/fetchers/app.bsky.actor.go
new file mode 100644
index 0000000..ebac250
--- /dev/null
+++ b/fetchers/app.bsky.actor.go
@@ -0,0 +1,184 @@
+package fetchers
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"llostre/auth"
+	"llostre/general"
+	"llostre/notes"
+	"net"
+	"net/http"
+	"strings"
+	"time"
+)
+
+type DIDDocument struct {
+	AlsoKnownAs []string `json:"alsoKnownAs"`
+	Service     []struct {
+		ID              string `json:"id"`
+		Type            string `json:"type"`
+		ServiceEndpoint string `json:"serviceEndpoint"`
+	} `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)
+
+	resp, err := http.Get(didDocURL)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		return nil, fmt.Errorf("DID resolution failed: %d", resp.StatusCode)
+	}
+
+	var didDoc DIDDocument
+	if err := json.NewDecoder(resp.Body).Decode(&didDoc); err != nil {
+		return nil, err
+	}
+
+	return &didDoc, nil
+}
+
+func FetchHandle(did string) (string, error) {
+	var didDoc, err = FetchDidDoc(did)
+	if err != nil {
+		return "", err
+	}
+
+	if len(didDoc.AlsoKnownAs) == 0 {
+		return "", fmt.Errorf("no handle found")
+	}
+
+	handle := strings.TrimPrefix(didDoc.AlsoKnownAs[0], "at://")
+	return handle, nil
+}
+
+func FetchPDS(did string) (string, error) {
+	var didDoc, err = FetchDidDoc(did)
+	if err != nil {
+		return "", err
+	}
+
+	for _, svc := range didDoc.Service {
+		if svc.Type == "AtprotoPersonalDataServer" {
+			return svc.ServiceEndpoint, nil
+		}
+	}
+
+	return "", fmt.Errorf("no PDS found for DID %s", did)
+}
+
+func FetchHandleAndPDS(did string) (string, string, error) {
+	var didDoc, err = FetchDidDoc(did)
+	if err != nil {
+		return "", "", err
+	}
+
+	if len(didDoc.AlsoKnownAs) == 0 {
+		return "", "", fmt.Errorf("no handle found")
+	}
+
+	var pds string
+	for _, svc := range didDoc.Service {
+		if svc.Type == "AtprotoPersonalDataServer" {
+			pds = svc.ServiceEndpoint
+			break
+		}
+	}
+
+	handle := strings.TrimPrefix(didDoc.AlsoKnownAs[0], "at://")
+
+	return handle, pds, nil
+}
+
+func FetchAppBskyActorProfile(conf *Config, did, pdsURL string, session *auth.OAuthState) (*notes.Author, error) {
+	// construct profile record URI
+	uri := fmt.Sprintf("at://%s/app.bsky.actor.profile/self", did)
+
+	// try slingshot first
+	if conf.SlingshotURL != "" && general.SlingshotAvailable() {
+		rawRecord, err := general.FetchRawRecordByURI(conf.Logger, uri, conf.SlingshotURL, session)
+		if err != nil {
+			conf.Logger.Warn("slingshot profile fetch failed", "did", did, "error", err)
+			general.SetSlingshotBackoff(5 * time.Minute)
+		} else {
+			return parseAppBskyActorProfile(did, pdsURL, rawRecord, conf.Cache)
+		}
+	}
+
+	// fallback to PDS
+	rawRecord, err := general.FetchRawRecordByURI(conf.Logger, uri, pdsURL, session)
+	if err != nil {
+		return nil, err
+	}
+
+	return parseAppBskyActorProfile(did, pdsURL, rawRecord, conf.Cache)
+}
+
+func FetchAppBskyActorProfiles(conf *Config, dids []string, pdsURL string, session *auth.OAuthState) map[string]notes.Author {
+	authors := make(map[string]notes.Author)
+	for _, did := range dids {
+		author, err := FetchAppBskyActorProfile(conf, did, pdsURL, session)
+		if err == nil {
+			authors[did] = *author
+		}
+	}
+	return authors
+}
+
+func parseAppBskyActorProfile(did, pds string, rawRecord *general.RawRecord, cache *Cache) (*notes.Author, error) {
+	var profile notes.AppBskyActorProfileRecord
+	if err := json.Unmarshal(rawRecord.Value, &profile); err != nil {
+		return nil, err
+	}
+
+	handle, err := FetchHandle(did)
+	if err != nil {
+		handle = "handle.invalid"
+	}
+
+	author, err := notes.AuthorFromAppBskyActorProfileRecord(profile, did, handle, pds)
+
+	cache.SetAuthor(did, author)
+	return author, nil
+}