Add post video upload (#22)

Questions and replies can attach one MP4 or WebM (25 MB) alongside up to four images. Videos are stored as-is and omitted from Discord embeds. Reviewed-on: #22 Co-authored-by: codegirl-007 <s.raide@gmail.com>
2026-08-31 06:28:53 +00:00
parent 728ae68811
commit a6e414853d
4 changed files with 334 additions and 18 deletions
@@ -28,7 +28,8 @@ import (
 const (
 	defaultRequestBodyBytes  = 3 << 20
 	postImageMaxFileBytes    = 5 << 20
-	postImageMaxRequestBytes = 22 << 20
+	postVideoMaxFileBytes    = 25 << 20
+	postImageMaxRequestBytes = 50 << 20 // 4 images + 1 video + form fields
 	postImageMultipartMemory = 2 << 20
 	postImageMaxSourceDim    = 6000
 	postImageMaxSourcePixels = 16_000_000
@@ -67,7 +68,7 @@ func parsePostMutationForm(w http.ResponseWriter, r *http.Request) (func(), bool
 	contentType := r.Header.Get("Content-Type")
 	mediaType, _, err := mime.ParseMediaType(contentType)
 	if err != nil && strings.HasPrefix(strings.ToLower(contentType), "multipart/") {
-		http.Error(w, "Could not read image upload.", http.StatusBadRequest)
+		http.Error(w, "Could not read upload.", http.StatusBadRequest)
 		return func() {}, false
 	}
 	if mediaType != "multipart/form-data" {
@@ -97,10 +98,10 @@ func writePostImageRequestError(w http.ResponseWriter, err error) {
 	}
 	var maxErr *http.MaxBytesError
 	if errors.As(err, &maxErr) {
-		http.Error(w, "Image upload is too large.", http.StatusRequestEntityTooLarge)
+		http.Error(w, "Upload is too large.", http.StatusRequestEntityTooLarge)
 		return
 	}
-	http.Error(w, "Could not read image upload.", http.StatusBadRequest)
+	http.Error(w, "Could not read upload.", http.StatusBadRequest)
 }

 func (s *Server) postImagesFromForm(
@@ -121,9 +122,23 @@ func (s *Server) postImagesFromForm(
 	if len(descriptions) > len(files) {
 		return nil, nil, invalidPostImage("Image descriptions do not match selected images.", nil)
 	}
-	if len(retained)+len(files) > store.MaxPostImages {
+	kinds := make([]string, len(files))
+	newImages, newVideos := 0, 0
+	for i, header := range files {
+		kinds[i] = sniffPostMedia(header)
+		if kinds[i] == store.MediaKindVideo {
+			newVideos++
+		} else {
+			newImages++
+		}
+	}
+	retainedImages, retainedVideos := countPostMedia(retained)
+	if retainedImages+newImages > store.MaxPostImages {
 		return nil, nil, invalidPostImage("You can attach up to 4 images.", nil)
 	}
+	if retainedVideos+newVideos > store.MaxPostVideos {
+		return nil, nil, invalidPostImage("You can attach one video.", nil)
+	}
 	if len(files) > 0 && !s.cfg.Blob.Enabled() {
 		return nil, nil, &postImageRequestError{
 			status:  http.StatusServiceUnavailable,
@@ -142,13 +157,41 @@ func (s *Server) postImagesFromForm(
 			s.deletePostImageObjects(newKeys)
 			return nil, nil, invalidPostImage("Image descriptions must be 500 characters or fewer.", nil)
 		}
-		prepared, err := preparePostImage(header)
+		item, objectKey, err := s.uploadPostMedia(ctx, postID, header, kinds[i], description)
 		if err != nil {
 			s.deletePostImageObjects(newKeys)
 			return nil, nil, err
 		}
-		imageID := uuid.NewString()
-		objectKey := path.Join("post-images", postID, imageID+prepared.extension)
+		newKeys = append(newKeys, objectKey)
+		images = append(images, item)
+	}
+	return images, newKeys, nil
+}
+
+func countPostMedia(items []store.PostImage) (images, videos int) {
+	for _, item := range items {
+		if item.Kind == store.MediaKindVideo {
+			videos++
+		} else {
+			images++
+		}
+	}
+	return images, videos
+}
+
+func (s *Server) uploadPostMedia(
+	ctx context.Context,
+	postID string,
+	header *multipart.FileHeader,
+	kind, description string,
+) (store.PostImage, string, error) {
+	if kind == store.MediaKindVideo {
+		prepared, err := preparePostVideo(header)
+		if err != nil {
+			return store.PostImage{}, "", err
+		}
+		mediaID := uuid.NewString()
+		objectKey := path.Join("post-videos", postID, mediaID+prepared.extension)
 		publicURL, err := s.cfg.Blob.Upload(ctx, blob.FileUpload{
 			Key:         objectKey,
 			Body:        bytes.NewReader(prepared.body),
@@ -156,25 +199,50 @@ func (s *Server) postImagesFromForm(
 			Size:        int64(len(prepared.body)),
 		})
 		if err != nil {
-			s.deletePostImageObjects(newKeys)
-			return nil, nil, &postImageRequestError{
+			return store.PostImage{}, "", &postImageRequestError{
 				status:  http.StatusServiceUnavailable,
-				message: "Could not upload image. Try again later.",
+				message: "Could not upload video. Try again later.",
 				cause:   err,
 			}
 		}
-		newKeys = append(newKeys, objectKey)
-		images = append(images, store.PostImage{
-			ID:          imageID,
+		return store.PostImage{
+			ID:          mediaID,
 			PostID:      postID,
 			ObjectKey:   objectKey,
 			PublicURL:   publicURL,
 			Description: description,
-			Width:       prepared.width,
-			Height:      prepared.height,
-		})
+			Kind:        store.MediaKindVideo,
+		}, objectKey, nil
 	}
-	return images, newKeys, nil
+	prepared, err := preparePostImage(header)
+	if err != nil {
+		return store.PostImage{}, "", err
+	}
+	imageID := uuid.NewString()
+	objectKey := path.Join("post-images", postID, imageID+prepared.extension)
+	publicURL, err := s.cfg.Blob.Upload(ctx, blob.FileUpload{
+		Key:         objectKey,
+		Body:        bytes.NewReader(prepared.body),
+		ContentType: prepared.contentType,
+		Size:        int64(len(prepared.body)),
+	})
+	if err != nil {
+		return store.PostImage{}, "", &postImageRequestError{
+			status:  http.StatusServiceUnavailable,
+			message: "Could not upload image. Try again later.",
+			cause:   err,
+		}
+	}
+	return store.PostImage{
+		ID:          imageID,
+		PostID:      postID,
+		ObjectKey:   objectKey,
+		PublicURL:   publicURL,
+		Description: description,
+		Kind:        store.MediaKindImage,
+		Width:       prepared.width,
+		Height:      prepared.height,
+	}, objectKey, nil
 }

 func retainedPostImages(form *multipart.Form, existing []store.PostImage) ([]store.PostImage, error) {
@@ -298,6 +366,94 @@ func preparePostImage(header *multipart.FileHeader) (preparedPostImage, error) {
 	return result, nil
 }

+func sniffPostMedia(header *multipart.FileHeader) string {
+	if header == nil {
+		return store.MediaKindImage
+	}
+	file, err := header.Open()
+	if err != nil {
+		return store.MediaKindImage
+	}
+	defer file.Close()
+	peek := make([]byte, 512)
+	n, err := io.ReadFull(file, peek)
+	if err != nil && !errors.Is(err, io.ErrUnexpectedEOF) && !errors.Is(err, io.EOF) {
+		return store.MediaKindImage
+	}
+	return mediaKindFromBytes(peek[:n])
+}
+
+func mediaKindFromBytes(raw []byte) string {
+	switch http.DetectContentType(raw) {
+	case "video/mp4", "video/webm":
+		return store.MediaKindVideo
+	case "image/jpeg", "image/png", "image/webp":
+		return store.MediaKindImage
+	}
+	if isMP4(raw) || isWebM(raw) {
+		return store.MediaKindVideo
+	}
+	return store.MediaKindImage
+}
+
+func isMP4(raw []byte) bool {
+	return len(raw) >= 8 && string(raw[4:8]) == "ftyp"
+}
+
+func isWebM(raw []byte) bool {
+	return len(raw) >= 4 && raw[0] == 0x1a && raw[1] == 0x45 && raw[2] == 0xdf && raw[3] == 0xa3
+}
+
+type preparedPostVideo struct {
+	body        []byte
+	extension   string
+	contentType string
+}
+
+func preparePostVideo(header *multipart.FileHeader) (preparedPostVideo, error) {
+	if header == nil {
+		return preparedPostVideo{}, invalidPostImage("Select a valid video.", nil)
+	}
+	if header.Size > postVideoMaxFileBytes {
+		return preparedPostVideo{}, &postImageRequestError{
+			status:  http.StatusRequestEntityTooLarge,
+			message: "Each video must be 25 MB or smaller.",
+		}
+	}
+	file, err := header.Open()
+	if err != nil {
+		return preparedPostVideo{}, invalidPostImage("Could not read video.", err)
+	}
+	defer file.Close()
+	raw, err := io.ReadAll(io.LimitReader(file, postVideoMaxFileBytes+1))
+	if err != nil {
+		return preparedPostVideo{}, invalidPostImage("Could not read video.", err)
+	}
+	if len(raw) == 0 {
+		return preparedPostVideo{}, invalidPostImage("Videos cannot be empty.", nil)
+	}
+	if int64(len(raw)) > postVideoMaxFileBytes {
+		return preparedPostVideo{}, &postImageRequestError{
+			status:  http.StatusRequestEntityTooLarge,
+			message: "Each video must be 25 MB or smaller.",
+		}
+	}
+	switch mediaKindFromBytes(raw) {
+	case store.MediaKindVideo:
+	default:
+		return preparedPostVideo{}, invalidPostImage("Videos must be MP4 or WebM.", nil)
+	}
+	result := preparedPostVideo{body: raw}
+	if isWebM(raw) {
+		result.extension = ".webm"
+		result.contentType = "video/webm"
+		return result, nil
+	}
+	result.extension = ".mp4"
+	result.contentType = "video/mp4"
+	return result, nil
+}
+
 func jpegOrientation(raw []byte) int {
 	metadata, err := exif.Decode(bytes.NewReader(raw))
 	if err != nil {