1 files changed, 143 insertions, 0 deletions
diff --git a/backend/fetchers/app.bsky.feed.go b/backend/fetchers/app.bsky.feed.go
new file mode 100644
index 0000000..92303fc
--- /dev/null
+++ b/backend/fetchers/app.bsky.feed.go
@@ -0,0 +1,143 @@
+package fetchers
+
+import (
+	"encoding/json"
+	"fmt"
+	"io"
+	"llostre/backend/auth"
+	"llostre/backend/general"
+	"llostre/backend/notes"
+	"log/slog"
+	"net/http"
+)
+
+type ListRecordsResponse struct {
+	Records []notes.AppBskyFeedPostRecord `json:"records"`
+}
+
+func FetchAppBskyFeedPosts(logger *slog.Logger, did, pdsURL, accessToken string, keypair *auth.DPoPKeyPair, notesCache *Cache) ([]notes.Note, error) {
+	url := fmt.Sprintf("%s/xrpc/com.atproto.repo.listRecords?repo=%s&collection=app.bsky.feed.post", pdsURL, did)
+
+	logger.Debug("generating DPoP proof", "url", url)
+	dpopProof, err := keypair.GenerateDPoPProof("GET", url, "")
+	if err != nil {
+		logger.Error("DPoP generation failed", "error", err)
+		return nil, err
+	}
+
+	logger.Debug("making request to PDS")
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Authorization", "Bearer "+accessToken)
+	req.Header.Set("DPoP", dpopProof)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	var response ListRecordsResponse
+	if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
+		return nil, err
+	}
+
+	profile, err := FetchProfile(did, pdsURL, notesCache)
+	if err != nil {
+		logger.Error("profile fetch failed", "did", did, "error", err)
+	} else {
+		logger.Debug("fetched profile")
+	}
+
+	posts := make([]notes.Note, 0, len(response.Records))
+	for _, record := range response.Records {
+		bp, err := notes.NoteFromAppBskyFeedPostRecord(record, profile)
+		if err != nil {
+			logger.Error("failed to convert record", "error", err, "uri", record.URI)
+			continue
+		}
+		notesCache.Set(bp.URI, bp)
+		posts = append(posts, *bp)
+	}
+
+	return posts, nil
+}
+
+func FetchPostByURI(uri, accessToken string, keypair *auth.DPoPKeyPair, cache *Cache) (*notes.Note, error) {
+	// check cache
+	if cached, found := cache.Get(uri); found {
+		return cached, nil
+	}
+
+	repo, collection, rkey, err := general.ParseURI(uri)
+
+	// need to resolve DID to PDS
+	pds, err := FetchPDS(repo)
+	if err != nil {
+		return nil, err
+	}
+
+	url := fmt.Sprintf("%s/xrpc/com.atproto.repo.getRecord?repo=%s&collection=%s&rkey=%s",
+		pds, repo, collection, rkey)
+
+	// fetch with DPoP
+	dpopProof, err := keypair.GenerateDPoPProof("GET", url, "")
+	if err != nil {
+		return nil, err
+	}
+
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Authorization", "Bearer "+accessToken)
+	req.Header.Set("DPoP", dpopProof)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		body, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("PDS returned status %d: %s", resp.StatusCode, string(body))
+	}
+
+	var result struct {
+		URI   string          `json:"uri"`
+		Value json.RawMessage `json:"value"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return nil, err
+	}
+
+	// convert to AppBskyFeedPostRecord
+	record := notes.AppBskyFeedPostRecord{
+		URI: result.URI,
+	}
+	if err := json.Unmarshal(result.Value, &record.Value); err != nil {
+		return nil, err
+	}
+
+	// get author of the note
+	profile, found := cache.GetProfile(repo)
+	if !found {
+		profile, err = FetchProfile(repo, pds, cache)
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	note, err := notes.NoteFromAppBskyFeedPostRecord(record, profile)
+	if err != nil {
+		return nil, err
+	}
+
+	// cache it
+	cache.Set(note.URI, note)
+
+	return note, nil
+}