Add post video upload.

post_images.kind is image or video. A post can keep one video alongside up to four images.

Reviewed-on: #21
Co-authored-by: codegirl-007 <s.raide@gmail.com>

db/queries/posts.sql

@@ -63,7 +63,7 @@ WHERE id = sqlc.arg(id);
 
 -- name: CreatePostImage :exec
 INSERT INTO post_images (
-  id, post_id, object_key, public_url, description, position, width, height, created_at
+  id, post_id, object_key, public_url, description, kind, position, width, height, created_at
 )
 VALUES (
   sqlc.arg(id),
@@ -71,6 +71,7 @@ VALUES (
   sqlc.arg(object_key),
   sqlc.arg(public_url),
   sqlc.arg(description),
+  sqlc.arg(kind),
   sqlc.arg(position),
   sqlc.arg(width),
   sqlc.arg(height),
@@ -83,7 +84,7 @@ WHERE post_id = sqlc.arg(post_id);
 
 -- name: ListPostImages :many
 SELECT
-  id, post_id, object_key, public_url, description, position, width, height, created_at
+  id, post_id, object_key, public_url, description, kind, position, width, height, created_at
 FROM post_images
 WHERE post_id = sqlc.arg(post_id)
 ORDER BY position;
@@ -102,7 +103,7 @@ WITH RECURSIVE thread AS (
 )
 SELECT
   images.id, images.post_id, images.object_key, images.public_url,
-  images.description, images.position, images.width, images.height, images.created_at
+  images.description, images.kind, images.position, images.width, images.height, images.created_at
 FROM post_images images
 JOIN thread ON thread.id = images.post_id
 ORDER BY images.post_id, images.position;

internal/store/migrate.go

@@ -158,6 +158,32 @@ CREATE UNIQUE INDEX IF NOT EXISTS discord_post_links_thread_uidx
 	return nil
 }
 
+func migratePostImageVideo(ctx context.Context, exec execContext) error {
+	steps := []struct {
+		name string
+		sql  string
+	}{
+		{"add kind", `ALTER TABLE post_images ADD COLUMN IF NOT EXISTS kind TEXT NOT NULL DEFAULT 'image'`},
+		{"drop kind check", `ALTER TABLE post_images DROP CONSTRAINT IF EXISTS post_images_kind_check`},
+		{"add kind check", `ALTER TABLE post_images ADD CONSTRAINT post_images_kind_check CHECK (kind IN ('image', 'video'))`},
+		{"drop width check", `ALTER TABLE post_images DROP CONSTRAINT IF EXISTS post_images_width_check`},
+		{"drop height check", `ALTER TABLE post_images DROP CONSTRAINT IF EXISTS post_images_height_check`},
+		{"add width check", `ALTER TABLE post_images ADD CONSTRAINT post_images_width_check CHECK (width >= 0)`},
+		{"add height check", `ALTER TABLE post_images ADD CONSTRAINT post_images_height_check CHECK (height >= 0)`},
+		{"drop image dims check", `ALTER TABLE post_images DROP CONSTRAINT IF EXISTS post_images_image_dims_check`},
+		{"add image dims check", `ALTER TABLE post_images ADD CONSTRAINT post_images_image_dims_check CHECK (kind <> 'image' OR (width > 0 AND height > 0))`},
+		{"drop position check", `ALTER TABLE post_images DROP CONSTRAINT IF EXISTS post_images_position_check`},
+		{"add position check", `ALTER TABLE post_images ADD CONSTRAINT post_images_position_check CHECK (position BETWEEN 0 AND 4)`},
+		{"one video index", `CREATE UNIQUE INDEX IF NOT EXISTS post_images_one_video_uidx ON post_images (post_id) WHERE kind = 'video'`},
+	}
+	for _, step := range steps {
+		if _, err := exec.ExecContext(ctx, step.sql); err != nil {
+			return fmt.Errorf("%s: %w", step.name, err)
+		}
+	}
+	return nil
+}
+
 func migratePostDate(ctx context.Context, exec execContext) error {
 	steps := []struct {
 		name string
@@ -351,6 +377,7 @@ CREATE TABLE IF NOT EXISTS schema_migrations (
 		{"009_drop_legacy_post_tables", migrateDropLegacyPostTables},
 		{"010_post_images", migratePostImages},
 		{"011_discord_post_links", migrateDiscordPostLinks},
+		{"012_post_image_video", migratePostImageVideo},
 	}
 	for _, m := range migrations {
 		if applied[m.version] {

internal/store/migrate_posts_test.go

@@ -87,6 +87,12 @@ CREATE TABLE users (
 	if err := migrateDiscordPostLinks(ctx, conn); err != nil {
 		t.Fatalf("discord post links migration is not idempotent: %v", err)
 	}
+	if err := migratePostImageVideo(ctx, conn); err != nil {
+		t.Fatal(err)
+	}
+	if err := migratePostImageVideo(ctx, conn); err != nil {
+		t.Fatalf("post image video migration is not idempotent: %v", err)
+	}
 	if _, err := conn.ExecContext(ctx, `
 INSERT INTO users (id, name, role)
 VALUES ('homeowner', 'Home Owner', 'user'), ('plumber', 'The Plumber', 'admin');
@@ -118,9 +124,9 @@ VALUES ('homeowner', 'root-1', 1);`); err != nil {
 	}
 	imageQueries := sqlc.New(conn)
 	for _, image := range []sqlc.CreatePostImageParams{
-		{ID: "root-image-1", PostID: "root-1", ObjectKey: "posts/root-1/1.jpg", PublicUrl: "https://cdn.example/root-1.jpg", Description: "Valve", Position: 0, Width: 1200, Height: 900, CreatedAt: "2026-08-26T08:00:00Z"},
+		{ID: "root-image-1", PostID: "root-1", ObjectKey: "posts/root-1/1.jpg", PublicUrl: "https://cdn.example/root-1.jpg", Description: "Valve", Kind: "image", Position: 0, Width: 1200, Height: 900, CreatedAt: "2026-08-26T08:00:00Z"},
-		{ID: "root-image-2", PostID: "root-1", ObjectKey: "posts/root-1/2.png", PublicUrl: "https://cdn.example/root-2.png", Position: 1, Width: 900, Height: 1200, CreatedAt: "2026-08-26T08:00:00Z"},
+		{ID: "root-image-2", PostID: "root-1", ObjectKey: "posts/root-1/2.png", PublicUrl: "https://cdn.example/root-2.png", Kind: "image", Position: 1, Width: 900, Height: 1200, CreatedAt: "2026-08-26T08:00:00Z"},
-		{ID: "reply-image-1", PostID: "reply-1", ObjectKey: "posts/reply-1/1.jpg", PublicUrl: "https://cdn.example/reply-1.jpg", Description: "Cartridge", Position: 0, Width: 1000, Height: 1000, CreatedAt: "2026-08-26T09:00:00Z"},
+		{ID: "reply-image-1", PostID: "reply-1", ObjectKey: "posts/reply-1/1.jpg", PublicUrl: "https://cdn.example/reply-1.jpg", Description: "Cartridge", Kind: "image", Position: 0, Width: 1000, Height: 1000, CreatedAt: "2026-08-26T09:00:00Z"},
 	} {
 		if err := imageQueries.CreatePostImage(ctx, image); err != nil {
 			t.Fatal(err)
@@ -144,10 +150,24 @@ VALUES ('homeowner', 'root-1', 1);`); err != nil {
 	}
 	if err := imageQueries.CreatePostImage(ctx, sqlc.CreatePostImageParams{
 		ID: "too-many", PostID: "root-1", ObjectKey: "posts/root-1/5.jpg",
-		PublicUrl: "https://cdn.example/root-5.jpg", Position: 4,
+		PublicUrl: "https://cdn.example/root-5.jpg", Kind: "image", Position: 5,
 		Width: 100, Height: 100, CreatedAt: "2026-08-26T08:00:00Z",
 	}); err == nil {
-		t.Fatal("fifth image position unexpectedly succeeded")
+		t.Fatal("position 5 unexpectedly succeeded")
+	}
+	if err := imageQueries.CreatePostImage(ctx, sqlc.CreatePostImageParams{
+		ID: "root-video-1", PostID: "root-1", ObjectKey: "posts/root-1/clip.mp4",
+		PublicUrl: "https://cdn.example/clip.mp4", Kind: "video", Position: 2,
+		Width: 0, Height: 0, CreatedAt: "2026-08-26T08:00:00Z",
+	}); err != nil {
+		t.Fatal(err)
+	}
+	if err := imageQueries.CreatePostImage(ctx, sqlc.CreatePostImageParams{
+		ID: "root-video-2", PostID: "root-1", ObjectKey: "posts/root-1/clip-2.mp4",
+		PublicUrl: "https://cdn.example/clip-2.mp4", Kind: "video", Position: 3,
+		Width: 0, Height: 0, CreatedAt: "2026-08-26T08:00:00Z",
+	}); err == nil {
+		t.Fatal("second video unexpectedly succeeded")
 	}
 	if err := imageQueries.UpsertDiscordPostLink(ctx, sqlc.UpsertDiscordPostLinkParams{
 		PostID:           "root-1",

internal/store/post.go

@@ -29,16 +29,20 @@ const (
 	PostStateHidden          PostState = "hidden"
 	PostStateLocked          PostState = "locked"
 	MaxPostImages                      = 4
+	MaxPostVideos                      = 1
 	MaxImageDescriptionRunes           = 500
+	MediaKindImage                     = "image"
+	MediaKindVideo                     = "video"
 )
 
-// PostImage is one ordered public image attached to a post.
+// PostImage is one ordered public image or video attached to a post.
 type PostImage struct {
 	ID          string
 	PostID      string
 	ObjectKey   string
 	PublicURL   string
 	Description string
+	Kind        string
 	Position    int
 	Width       int
 	Height      int
@@ -200,12 +204,13 @@ func preparePost(p *Post) error {
 }
 
 func preparePostImages(p *Post) error {
-	if len(p.Images) > MaxPostImages {
+	if len(p.Images) > MaxPostImages+MaxPostVideos {
-		return fmt.Errorf("%w: at most %d images are allowed", ErrInvalidPost, MaxPostImages)
+		return fmt.Errorf("%w: at most %d images and %d video are allowed", ErrInvalidPost, MaxPostImages, MaxPostVideos)
 	}
 	ids := make(map[string]bool, len(p.Images))
 	keys := make(map[string]bool, len(p.Images))
 	now := time.Now().UTC().Format(time.RFC3339Nano)
+	images, videos := 0, 0
 	for i := range p.Images {
 		image := &p.Images[i]
 		image.ID = strings.TrimSpace(image.ID)
@@ -213,6 +218,13 @@ func preparePostImages(p *Post) error {
 		image.ObjectKey = strings.TrimSpace(image.ObjectKey)
 		image.PublicURL = strings.TrimSpace(image.PublicURL)
 		image.Description = strings.TrimSpace(image.Description)
+		image.Kind = strings.TrimSpace(image.Kind)
+		if image.Kind == "" {
+			image.Kind = MediaKindImage
+		}
+		if image.Kind != MediaKindImage && image.Kind != MediaKindVideo {
+			return fmt.Errorf("%w: invalid media kind", ErrInvalidPost)
+		}
 		if image.ID == "" {
 			image.ID = uuid.NewString()
 		}
@@ -228,9 +240,18 @@ func preparePostImages(p *Post) error {
 		if len([]rune(image.Description)) > MaxImageDescriptionRunes {
 			return fmt.Errorf("%w: image description is too long", ErrInvalidPost)
 		}
-		if image.Width <= 0 || image.Height <= 0 ||
+		if image.Kind == MediaKindImage {
-			image.Width > math.MaxInt32 || image.Height > math.MaxInt32 {
+			images++
-			return fmt.Errorf("%w: invalid image dimensions", ErrInvalidPost)
+			if image.Width <= 0 || image.Height <= 0 ||
+				image.Width > math.MaxInt32 || image.Height > math.MaxInt32 {
+				return fmt.Errorf("%w: invalid image dimensions", ErrInvalidPost)
+			}
+		} else {
+			videos++
+			if image.Width < 0 || image.Height < 0 ||
+				image.Width > math.MaxInt32 || image.Height > math.MaxInt32 {
+				return fmt.Errorf("%w: invalid video dimensions", ErrInvalidPost)
+			}
 		}
 		if ids[image.ID] || keys[image.ObjectKey] {
 			return fmt.Errorf("%w: duplicate image", ErrInvalidPost)
@@ -242,6 +263,12 @@ func preparePostImages(p *Post) error {
 			image.CreatedAt = now
 		}
 	}
+	if images > MaxPostImages {
+		return fmt.Errorf("%w: at most %d images are allowed", ErrInvalidPost, MaxPostImages)
+	}
+	if videos > MaxPostVideos {
+		return fmt.Errorf("%w: at most %d video is allowed", ErrInvalidPost, MaxPostVideos)
+	}
 	return nil
 }
 
@@ -253,6 +280,7 @@ func createPostImages(ctx context.Context, q *sqlc.Queries, images []PostImage)
 			ObjectKey:   image.ObjectKey,
 			PublicUrl:   image.PublicURL,
 			Description: image.Description,
+			Kind:        image.Kind,
 			Position:    int16(image.Position),
 			Width:       int32(image.Width),
 			Height:      int32(image.Height),
@@ -271,6 +299,7 @@ func postImageFromSQL(image sqlc.PostImage) PostImage {
 		ObjectKey:   image.ObjectKey,
 		PublicURL:   image.PublicUrl,
 		Description: image.Description,
+		Kind:        image.Kind,
 		Position:    int(image.Position),
 		Width:       int(image.Width),
 		Height:      int(image.Height),

internal/store/post_test.go

@@ -338,6 +338,36 @@ func TestMemoryPostImages(t *testing.T) {
 	if err := mem.CreatePost(ctx, tooMany); !errors.Is(err, ErrInvalidPost) {
 		t.Fatalf("five-image create error = %v, want ErrInvalidPost", err)
 	}
+
+	withVideo := &Post{
+		AuthorID: homeowner.ID,
+		Title:    "With video",
+		Body:     "Four photos and a clip.",
+		Images: append(validPostImages(4), PostImage{
+			ID:        "clip-1",
+			ObjectKey: "posts/clip-1.mp4",
+			PublicURL: "https://cdn.example/clip-1.mp4",
+			Kind:      MediaKindVideo,
+		}),
+	}
+	if err := mem.CreatePost(ctx, withVideo); err != nil {
+		t.Fatalf("four images and one video: %v", err)
+	}
+	if withVideo.Images[4].Kind != MediaKindVideo || withVideo.Images[4].Position != 4 {
+		t.Fatalf("video not stored: %+v", withVideo.Images[4])
+	}
+	twoVideos := &Post{
+		AuthorID: homeowner.ID,
+		Title:    "Two clips",
+		Body:     "Not allowed.",
+		Images: []PostImage{
+			{ObjectKey: "posts/a.mp4", PublicURL: "https://cdn.example/a.mp4", Kind: MediaKindVideo},
+			{ObjectKey: "posts/b.mp4", PublicURL: "https://cdn.example/b.mp4", Kind: MediaKindVideo},
+		},
+	}
+	if err := mem.CreatePost(ctx, twoVideos); !errors.Is(err, ErrInvalidPost) {
+		t.Fatalf("two-video create error = %v, want ErrInvalidPost", err)
+	}
 }
 
 func validPostImages(count int) []PostImage {

internal/store/sqlc/models.go

@@ -35,6 +35,7 @@ type PostImage struct {
 	ObjectKey   string
 	PublicUrl   string
 	Description string
+	Kind        string
 	Position    int16
 	Width       int32
 	Height      int32

internal/store/sqlc/posts.sql.go

@@ -59,7 +59,7 @@ func (q *Queries) CreatePost(ctx context.Context, arg CreatePostParams) error {
 
 const createPostImage = `-- name: CreatePostImage :exec
 INSERT INTO post_images (
-  id, post_id, object_key, public_url, description, position, width, height, created_at
+  id, post_id, object_key, public_url, description, kind, position, width, height, created_at
 )
 VALUES (
   $1,
@@ -70,7 +70,8 @@ VALUES (
   $6,
   $7,
   $8,
-  $9
+  $9,
+  $10
 )
 `
 
@@ -80,6 +81,7 @@ type CreatePostImageParams struct {
 	ObjectKey   string
 	PublicUrl   string
 	Description string
+	Kind        string
 	Position    int16
 	Width       int32
 	Height      int32
@@ -93,6 +95,7 @@ func (q *Queries) CreatePostImage(ctx context.Context, arg CreatePostImageParams
 		arg.ObjectKey,
 		arg.PublicUrl,
 		arg.Description,
+		arg.Kind,
 		arg.Position,
 		arg.Width,
 		arg.Height,
@@ -201,7 +204,7 @@ func (q *Queries) GetRootPostVoteSummary(ctx context.Context, arg GetRootPostVot
 
 const listPostImages = `-- name: ListPostImages :many
 SELECT
-  id, post_id, object_key, public_url, description, position, width, height, created_at
+  id, post_id, object_key, public_url, description, kind, position, width, height, created_at
 FROM post_images
 WHERE post_id = $1
 ORDER BY position
@@ -222,6 +225,7 @@ func (q *Queries) ListPostImages(ctx context.Context, postID string) ([]PostImag
 			&i.ObjectKey,
 			&i.PublicUrl,
 			&i.Description,
+			&i.Kind,
 			&i.Position,
 			&i.Width,
 			&i.Height,
@@ -327,7 +331,7 @@ WITH RECURSIVE thread AS (
 )
 SELECT
   images.id, images.post_id, images.object_key, images.public_url,
-  images.description, images.position, images.width, images.height, images.created_at
+  images.description, images.kind, images.position, images.width, images.height, images.created_at
 FROM post_images images
 JOIN thread ON thread.id = images.post_id
 ORDER BY images.post_id, images.position
@@ -348,6 +352,7 @@ func (q *Queries) ListPostThreadImages(ctx context.Context, rootID string) ([]Po
 			&i.ObjectKey,
 			&i.PublicUrl,
 			&i.Description,
+			&i.Kind,
 			&i.Position,
 			&i.Width,
 			&i.Height,

internal/web/events.go

@@ -55,6 +55,9 @@ func (s *Server) postEvent(post, root *store.Post, author *store.User) events.Po
 	if n := len(post.Images); n > 0 {
 		ev.Images = make([]events.Image, 0, n)
 		for _, img := range post.Images {
+			if img.Kind == store.MediaKindVideo {
+				continue
+			}
 			ev.Images = append(ev.Images, events.Image{
 				URL:         img.PublicURL,
 				Description: img.Description,

internal/web/events_test.go

@@ -236,3 +236,21 @@ func assertPostEvent(t *testing.T, got, want events.PostEvent) {
 		t.Fatalf("event = %+v, want %+v", got, want)
 	}
 }
+
+func TestPostEventOmitsVideos(t *testing.T) {
+	t.Parallel()
+
+	srv, _ := newTestServer(t, Config{})
+	got := srv.postEvent(&store.Post{
+		ID:     "root-1",
+		Title:  "Clip",
+		Body:   "Photo and video.",
+		Images: []store.PostImage{
+			{PublicURL: "https://cdn.example/a.jpg", Description: "Still", Kind: store.MediaKindImage},
+			{PublicURL: "https://cdn.example/a.mp4", Description: "Walkthrough", Kind: store.MediaKindVideo},
+		},
+	}, nil, nil)
+	if len(got.Images) != 1 || got.Images[0].URL != "https://cdn.example/a.jpg" {
+		t.Fatalf("event images = %+v", got.Images)
+	}
+}

internal/web/post_images.go

@@ -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()
+		newKeys = append(newKeys, objectKey)
-		objectKey := path.Join("post-images", postID, imageID+prepared.extension)
+		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 store.PostImage{}, "", &postImageRequestError{
-			return nil, nil, &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)
+		return store.PostImage{
-		images = append(images, store.PostImage{
+			ID:          mediaID,
-			ID:          imageID,
 			PostID:      postID,
 			ObjectKey:   objectKey,
 			PublicURL:   publicURL,
 			Description: description,
-			Width:       prepared.width,
+			Kind:        store.MediaKindVideo,
-			Height:      prepared.height,
+		}, 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 {

internal/web/post_images_test.go

@@ -12,6 +12,7 @@ import (
 	"mime/multipart"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"sync"
 	"testing"
 
@@ -56,6 +57,33 @@ func TestPreparePostImage(t *testing.T) {
 	}
 }
 
+func TestPreparePostVideo(t *testing.T) {
+	t.Parallel()
+
+	prepared, err := preparePostVideoHeader(t, "clip.mp4", tinyMP4())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if prepared.extension != ".mp4" || prepared.contentType != "video/mp4" || len(prepared.body) == 0 {
+		t.Fatalf("prepared MP4 = %+v", prepared)
+	}
+	prepared, err = preparePostVideoHeader(t, "clip.webm", tinyWebM())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if prepared.extension != ".webm" || prepared.contentType != "video/webm" {
+		t.Fatalf("prepared WebM = %+v", prepared)
+	}
+	if _, err := preparePostVideoHeader(t, "notes.txt", []byte("not a video")); err == nil {
+		t.Fatal("text video upload unexpectedly succeeded")
+	}
+	_, err = preparePostVideoHeader(t, "too-large.mp4", make([]byte, postVideoMaxFileBytes+1))
+	var requestErr *postImageRequestError
+	if !errors.As(err, &requestErr) || requestErr.status != http.StatusRequestEntityTooLarge {
+		t.Fatalf("oversized video error = %v, want 413 request error", err)
+	}
+}
+
 func TestOrientPostImage(t *testing.T) {
 	t.Parallel()
 
@@ -203,6 +231,76 @@ func TestPostImageMultipartLifecycle(t *testing.T) {
 	}
 }
 
+func TestPostVideoMultipartLifecycle(t *testing.T) {
+	t.Parallel()
+
+	blobs := &recordingImageBlob{}
+	srv, mem := newTestServer(t, Config{Blob: blobs})
+	handler := srv.Handler()
+	homeowner := seedUser(t, mem, uniq("video"), "hunter22", store.RoleUser)
+	cookies := loginUser(t, handler, homeowner.Username, "hunter22")
+	csrf := csrfForCookies(t, handler, cookies)
+
+	rec := multipartPost(t, handler, "/submit", map[string][]string{
+		"_csrf":             {csrf},
+		"title":             {"Valve clip"},
+		"body":              {"A photo and a video."},
+		"city":              {"Oakland"},
+		"image_description": {"Still", "Walkthrough"},
+	}, []multipartTestFile{
+		{name: "still.png", body: solidPNG(t, 40, 20)},
+		{name: "walk.mp4", body: tinyMP4()},
+	}, cookies)
+	if rec.Code != http.StatusSeeOther {
+		t.Fatalf("root video upload status = %d: %s", rec.Code, rec.Body.String())
+	}
+	roots, err := mem.ListRootPosts(context.Background(), pacific.Today(), homeowner.ID)
+	if err != nil || len(roots) != 1 {
+		t.Fatalf("roots = %+v, %v", roots, err)
+	}
+	root, err := mem.GetPost(context.Background(), roots[0].ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(root.Images) != 2 ||
+		root.Images[0].Kind != store.MediaKindImage ||
+		root.Images[1].Kind != store.MediaKindVideo ||
+		root.Images[1].Description != "Walkthrough" ||
+		!strings.HasPrefix(root.Images[1].ObjectKey, "post-videos/") {
+		t.Fatalf("root media = %+v", root.Images)
+	}
+
+	rec = multipartPost(t, handler, "/posts/"+root.ID+"/edit", map[string][]string{
+		"_csrf":                      {csrf},
+		"body":                       {"Keep the clip."},
+		"existing_image_id":          {root.Images[1].ID},
+		"existing_image_description": {"Kept clip"},
+	}, nil, cookies)
+	if rec.Code != http.StatusSeeOther {
+		t.Fatalf("retain video status = %d: %s", rec.Code, rec.Body.String())
+	}
+	edited, err := mem.GetPost(context.Background(), root.ID)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(edited.Images) != 1 || edited.Images[0].Kind != store.MediaKindVideo ||
+		edited.Images[0].Description != "Kept clip" {
+		t.Fatalf("retained video = %+v", edited.Images)
+	}
+
+	rec = multipartPost(t, handler, "/posts", map[string][]string{
+		"_csrf":     {csrf},
+		"parent_id": {root.ID},
+		"body":      {"Two clips."},
+	}, []multipartTestFile{
+		{name: "a.mp4", body: tinyMP4()},
+		{name: "b.mp4", body: tinyMP4()},
+	}, cookies)
+	if rec.Code != http.StatusBadRequest {
+		t.Fatalf("two-video status = %d, want 400", rec.Code)
+	}
+}
+
 func TestPostImageUploadCompensation(t *testing.T) {
 	t.Parallel()
 
@@ -318,6 +416,12 @@ func multipartPost(
 	return rec
 }
 
+func preparePostVideoHeader(t *testing.T, name string, body []byte) (preparedPostVideo, error) {
+	t.Helper()
+	header := multipartFileHeader(t, name, body)
+	return preparePostVideo(header)
+}
+
 func preparePostImageHeader(t *testing.T, name string, body []byte) (preparedPostImage, error) {
 	t.Helper()
 	var requestBody bytes.Buffer
@@ -341,6 +445,41 @@ func preparePostImageHeader(t *testing.T, name string, body []byte) (preparedPos
 	return preparePostImage(req.MultipartForm.File["images"][0])
 }
 
+func multipartFileHeader(t *testing.T, name string, body []byte) *multipart.FileHeader {
+	t.Helper()
+	var requestBody bytes.Buffer
+	writer := multipart.NewWriter(&requestBody)
+	part, err := writer.CreateFormFile("images", name)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := part.Write(body); err != nil {
+		t.Fatal(err)
+	}
+	if err := writer.Close(); err != nil {
+		t.Fatal(err)
+	}
+	req := httptest.NewRequest(http.MethodPost, "/posts", &requestBody)
+	req.Header.Set("Content-Type", writer.FormDataContentType())
+	if err := req.ParseMultipartForm(postImageMultipartMemory); err != nil {
+		t.Fatal(err)
+	}
+	t.Cleanup(func() { _ = req.MultipartForm.RemoveAll() })
+	return req.MultipartForm.File["images"][0]
+}
+
+func tinyMP4() []byte {
+	body := make([]byte, 16)
+	body[3] = 16
+	copy(body[4:], "ftypisom")
+	copy(body[12:], "isom")
+	return body
+}
+
+func tinyWebM() []byte {
+	return []byte{0x1a, 0x45, 0xdf, 0xa3, 0x01, 0x00, 0x00, 0x00}
+}
+
 func solidPNG(t *testing.T, width, height int) []byte {
 	t.Helper()
 	img := image.NewNRGBA(image.Rect(0, 0, width, height))

schema.sql

@@ -48,13 +48,23 @@ CREATE TABLE IF NOT EXISTS post_images (
   object_key TEXT NOT NULL UNIQUE,
   public_url TEXT NOT NULL,
   description TEXT NOT NULL DEFAULT '' CHECK (char_length(description) <= 500),
-  position SMALLINT NOT NULL CHECK (position BETWEEN 0 AND 3),
+  kind TEXT NOT NULL DEFAULT 'image',
-  width INTEGER NOT NULL CHECK (width > 0),
+  position SMALLINT NOT NULL,
-  height INTEGER NOT NULL CHECK (height > 0),
+  width INTEGER NOT NULL,
+  height INTEGER NOT NULL,
   created_at TEXT NOT NULL,
+  CONSTRAINT post_images_kind_check CHECK (kind IN ('image', 'video')),
+  CONSTRAINT post_images_width_check CHECK (width >= 0),
+  CONSTRAINT post_images_height_check CHECK (height >= 0),
+  CONSTRAINT post_images_image_dims_check CHECK (kind <> 'image' OR (width > 0 AND height > 0)),
+  CONSTRAINT post_images_position_check CHECK (position BETWEEN 0 AND 4),
   UNIQUE (post_id, position)
 );
 
+CREATE UNIQUE INDEX IF NOT EXISTS post_images_one_video_uidx
+  ON post_images (post_id)
+  WHERE kind = 'video';
+
 CREATE TABLE IF NOT EXISTS post_votes (
   user_id TEXT NOT NULL REFERENCES users(id),
   post_id TEXT NOT NULL REFERENCES posts(id) ON DELETE CASCADE,