bsky-app/bskyweb/cmd/embedr/handlers.go

208 lines
6.0 KiB
Go

package main
import (
"context"
"errors"
"fmt"
"net/http"
"net/url"
"strconv"
"strings"
appbsky "github.com/bluesky-social/indigo/api/bsky"
"github.com/bluesky-social/indigo/atproto/syntax"
"github.com/labstack/echo/v4"
)
var ErrPostNotFound = errors.New("post not found")
var ErrPostNotPublic = errors.New("post is not publicly accessible")
func (srv *Server) getBlueskyPost(ctx context.Context, did syntax.DID, rkey syntax.RecordKey) (*appbsky.FeedDefs_PostView, error) {
// fetch the post post (with extra context)
uri := fmt.Sprintf("at://%s/app.bsky.feed.post/%s", did, rkey)
tpv, err := appbsky.FeedGetPostThread(ctx, srv.xrpcc, 1, 0, uri)
if err != nil {
log.Warnf("failed to fetch post: %s\t%v", uri, err)
// TODO: detect 404, specifically?
return nil, ErrPostNotFound
}
if tpv.Thread.FeedDefs_BlockedPost != nil {
return nil, ErrPostNotPublic
} else if tpv.Thread.FeedDefs_ThreadViewPost.Post == nil {
return nil, ErrPostNotFound
}
postView := tpv.Thread.FeedDefs_ThreadViewPost.Post
for _, label := range postView.Author.Labels {
if label.Src == postView.Author.Did && label.Val == "!no-unauthenticated" {
return nil, ErrPostNotPublic
}
}
return postView, nil
}
func (srv *Server) WebHome(c echo.Context) error {
return c.Render(http.StatusOK, "home.html", nil)
}
type OEmbedResponse struct {
Type string `json:"type"`
Version string `json:"version"`
AuthorName string `json:"author_name,omitempty"`
AuthorURL string `json:"author_url,omitempty"`
ProviderName string `json:"provider_url,omitempty"`
CacheAge int `json:"cache_age,omitempty"`
Width *int `json:"width"`
Height *int `json:"height"`
HTML string `json:"html,omitempty"`
}
func (srv *Server) parseBlueskyURL(ctx context.Context, raw string) (*syntax.ATURI, error) {
if raw == "" {
return nil, fmt.Errorf("empty url")
}
// first try simple AT-URI
uri, err := syntax.ParseATURI(raw)
if nil == err {
return &uri, nil
}
// then try bsky.app post URL
u, err := url.Parse(raw)
if err != nil {
return nil, err
}
if u.Hostname() != "bsky.app" {
return nil, fmt.Errorf("only bsky.app URLs currently supported")
}
pathParts := strings.Split(u.Path, "/") // NOTE: pathParts[0] will be empty string
if len(pathParts) != 5 || pathParts[1] != "profile" || pathParts[3] != "post" {
return nil, fmt.Errorf("only bsky.app post URLs currently supported")
}
atid, err := syntax.ParseAtIdentifier(pathParts[2])
if err != nil {
return nil, err
}
rkey, err := syntax.ParseRecordKey(pathParts[4])
if err != nil {
return nil, err
}
var did syntax.DID
if atid.IsHandle() {
ident, err := srv.dir.Lookup(ctx, *atid)
if err != nil {
return nil, err
}
did = ident.DID
} else {
did, err = atid.AsDID()
if err != nil {
return nil, err
}
}
// TODO: don't really need to re-parse here, if we had test coverage
aturi, err := syntax.ParseATURI(fmt.Sprintf("at://%s/app.bsky.feed.post/%s", did, rkey))
if err != nil {
return nil, err
} else {
return &aturi, nil
}
}
func (srv *Server) WebOEmbed(c echo.Context) error {
formatParam := c.QueryParam("format")
if formatParam != "" && formatParam != "json" {
return c.String(http.StatusNotImplemented, "Unsupported oEmbed format: "+formatParam)
}
// TODO: do we actually do something with width?
width := 550
maxWidthParam := c.QueryParam("maxwidth")
if maxWidthParam != "" {
maxWidthInt, err := strconv.Atoi(maxWidthParam)
if err != nil || maxWidthInt < 220 || maxWidthInt > 550 {
return c.String(http.StatusBadRequest, "Invalid maxwidth (expected integer between 220 and 550)")
}
width = maxWidthInt
}
// NOTE: maxheight ignored
aturi, err := srv.parseBlueskyURL(c.Request().Context(), c.QueryParam("url"))
if err != nil {
return c.String(http.StatusBadRequest, fmt.Sprintf("Expected 'url' to be bsky.app URL or AT-URI: %v", err))
}
if aturi.Collection() != syntax.NSID("app.bsky.feed.post") {
return c.String(http.StatusNotImplemented, "Only posts (app.bsky.feed.post records) can be embedded currently")
}
did, err := aturi.Authority().AsDID()
if err != nil {
return err
}
post, err := srv.getBlueskyPost(c.Request().Context(), did, aturi.RecordKey())
if err == ErrPostNotFound {
return c.String(http.StatusNotFound, fmt.Sprintf("%v", err))
} else if err == ErrPostNotPublic {
return c.String(http.StatusForbidden, fmt.Sprintf("%v", err))
} else if err != nil {
return c.String(http.StatusInternalServerError, fmt.Sprintf("%v", err))
}
html, err := srv.postEmbedHTML(post)
if err != nil {
return c.String(http.StatusInternalServerError, fmt.Sprintf("%v", err))
}
data := OEmbedResponse{
Type: "rich",
Version: "1.0",
AuthorName: "@" + post.Author.Handle,
AuthorURL: fmt.Sprintf("https://bsky.app/profile/%s", post.Author.Handle),
ProviderName: "Bluesky Social",
CacheAge: 86400,
Width: &width,
Height: nil,
HTML: html,
}
if post.Author.DisplayName != nil {
data.AuthorName = fmt.Sprintf("%s (@%s)", *post.Author.DisplayName, post.Author.Handle)
}
return c.JSON(http.StatusOK, data)
}
func (srv *Server) WebPostEmbed(c echo.Context) error {
// sanity check arguments. don't 4xx, just let app handle if not expected format
rkeyParam := c.Param("rkey")
rkey, err := syntax.ParseRecordKey(rkeyParam)
if err != nil {
return c.String(http.StatusBadRequest, fmt.Sprintf("Invalid RecordKey: %v", err))
}
didParam := c.Param("did")
did, err := syntax.ParseDID(didParam)
if err != nil {
return c.String(http.StatusBadRequest, fmt.Sprintf("Invalid DID: %v", err))
}
_ = rkey
_ = did
// NOTE: this request was't really necessary; the JS will do the same fetch
/*
postView, err := srv.getBlueskyPost(ctx, did, rkey)
if err == ErrPostNotFound {
return c.String(http.StatusNotFound, fmt.Sprintf("%v", err))
} else if err == ErrPostNotPublic {
return c.String(http.StatusForbidden, fmt.Sprintf("%v", err))
} else if err != nil {
return c.String(http.StatusInternalServerError, fmt.Sprintf("%v", err))
}
*/
return c.Render(http.StatusOK, "postEmbed.html", nil)
}