Add post video storage (#21)

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>

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 {
-		return fmt.Errorf("%w: at most %d images are allowed", ErrInvalidPost, MaxPostImages)
+	if len(p.Images) > MaxPostImages+MaxPostVideos {
+		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 ||
-			image.Width > math.MaxInt32 || image.Height > math.MaxInt32 {
-			return fmt.Errorf("%w: invalid image dimensions", ErrInvalidPost)
+		if image.Kind == MediaKindImage {
+			images++
+			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),