Add video picker and Discord video attachments.

The picker accepts one MP4 or WebM, the thread lightbox zooms photos, and Discord gets the video as a file on a follow-up message so photo embeds still render.

internal/web/server.go

@@ -37,6 +37,8 @@ type Config struct {
 	Blob           blob.Uploader
 	Events         events.Publisher
 	BaseURL        string
+	// HoldUploadUntilDiscord keeps create-post temp files until PostedToDiscord.
+	HoldUploadUntilDiscord bool
 }
 
 type Server struct {
@@ -107,7 +109,27 @@ type threadPostCtx struct {
 
 type imagePickerCtx struct {
 	ID     string
-	Images []store.PostImage
+	Video  *store.PostImage
+	Photos []store.PostImage
+}
+
+func splitPickerMedia(images []store.PostImage) (*store.PostImage, []store.PostImage) {
+	photos := make([]store.PostImage, 0, len(images))
+	var video *store.PostImage
+	for i := range images {
+		if images[i].Kind == store.MediaKindVideo {
+			img := images[i]
+			video = &img
+			continue
+		}
+		photos = append(photos, images[i])
+	}
+	return video, photos
+}
+
+func postPhotos(images []store.PostImage) []store.PostImage {
+	_, photos := splitPickerMedia(images)
+	return photos
 }
 
 func New(st store.Store, sessionStore scs.Store, templateFS fs.FS, staticFS fs.FS, cfg Config) (*Server, error) {
@@ -125,11 +147,13 @@ func New(st store.Store, sessionStore scs.Store, templateFS fs.FS, staticFS fs.F
 			return threadPostCtx{User: user, CSRF: csrf, Root: root, Post: post, Depth: depth}
 		},
 		"imagePicker": func(id string, images []store.PostImage) imagePickerCtx {
-			return imagePickerCtx{ID: id, Images: images}
+			video, photos := splitPickerMedia(images)
+			return imagePickerCtx{ID: id, Video: video, Photos: photos}
 		},
 		"newImagePicker": func(id string) imagePickerCtx {
 			return imagePickerCtx{ID: id}
 		},
+		"postPhotos":  postPhotos,
 		"add":         func(a, b int) int { return a + b },
 		"rank":        func(i int) int { return i + 1 },
 		"isAdmin":     func(u *store.User) bool { return u.Admin() },
@@ -348,7 +372,14 @@ func (s *Server) handleSubmit(w http.ResponseWriter, r *http.Request) {
 	if !ok {
 		return
 	}
-	defer cleanup()
+	var media []events.Media
+	held := false
+	defer func() {
+		if !held {
+			closeHeldMedia(media)
+			cleanup()
+		}
+	}()
 	if !s.requireCSRF(w, r) {
 		return
 	}
@@ -386,7 +417,7 @@ func (s *Server) handleSubmit(w http.ResponseWriter, r *http.Request) {
 		Body:     body,
 		City:     city,
 	}
-	images, newKeys, err := s.postImagesFromForm(r.Context(), r, post.ID, nil)
+	images, newKeys, media, err := s.postImagesFromForm(r.Context(), r, post.ID, nil)
 	if err != nil {
 		writePostImageRequestError(w, err)
 		return
@@ -397,7 +428,8 @@ func (s *Server) handleSubmit(w http.ResponseWriter, r *http.Request) {
 		http.Error(w, "could not save question", http.StatusInternalServerError)
 		return
 	}
-	s.publishPostCreated(post, post, u)
+	s.publishPostCreated(post, post, u, media, cleanup)
+	held = true
 	http.Redirect(w, r, "/questions/"+url.PathEscape(post.ID), http.StatusSeeOther)
 }