Add post image storage

2026-08-27 23:46:06 -07:00
parent c6f80e243d
commit 1840a662d9
9 changed files with 534 additions and 11 deletions
@@ -5,6 +5,7 @@ import (
 	"database/sql"
 	"errors"
 	"fmt"
+	"math"
 	"sort"
 	"strings"
 	"time"
@@ -24,11 +25,26 @@ var (
 type PostState string

 const (
-	PostStateVisible PostState = "visible"
-	PostStateHidden  PostState = "hidden"
-	PostStateLocked  PostState = "locked"
+	PostStateVisible         PostState = "visible"
+	PostStateHidden          PostState = "hidden"
+	PostStateLocked          PostState = "locked"
+	MaxPostImages                      = 4
+	MaxImageDescriptionRunes           = 500
 )

+// PostImage is one ordered public image attached to a post.
+type PostImage struct {
+	ID          string
+	PostID      string
+	ObjectKey   string
+	PublicURL   string
+	Description string
+	Position    int
+	Width       int
+	Height      int
+	CreatedAt   string
+}
+
 // Post is either a root question (ParentID nil) or a reply to another post.
 type Post struct {
 	ID         string
@@ -46,6 +62,7 @@ type Post struct {
 	Score      int
 	Answered   bool
 	UserVote   int
+	Images     []PostImage
 	Replies    []*Post
 	db         *sql.DB
 }
@@ -63,7 +80,16 @@ func (p *Post) Create(ctx context.Context) error {
 	if err := preparePost(p); err != nil {
 		return err
 	}
-	err := sqlc.New(p.db).CreatePost(ctx, sqlc.CreatePostParams{
+	if err := preparePostImages(p); err != nil {
+		return err
+	}
+	tx, err := p.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	q := sqlc.New(tx)
+	if err := q.CreatePost(ctx, sqlc.CreatePostParams{
 		ID:        p.ID,
 		ParentID:  nullableParentID(p.ParentID),
 		AuthorID:  p.AuthorID,
@@ -74,11 +100,16 @@ func (p *Post) Create(ctx context.Context) error {
 		PostState: string(p.PostState),
 		CreatedAt: p.CreatedAt,
 		UpdatedAt: p.UpdatedAt,
-	})
-	return mapPostCreateError(err)
+	}); err != nil {
+		return mapPostCreateError(err)
+	}
+	if err := createPostImages(ctx, q, p.Images); err != nil {
+		return mapPostCreateError(err)
+	}
+	return tx.Commit()
 }

-// Update changes only the post body and update timestamp.
+// Update changes the post body, update timestamp, and complete image set.
 func (p *Post) Update(ctx context.Context) error {
 	if p == nil || p.db == nil {
 		return fmt.Errorf("post: no database")
@@ -88,7 +119,16 @@ func (p *Post) Update(ctx context.Context) error {
 		return fmt.Errorf("%w: body is required", ErrInvalidPost)
 	}
 	p.UpdatedAt = time.Now().UTC().Format(time.RFC3339Nano)
-	n, err := sqlc.New(p.db).UpdatePost(ctx, sqlc.UpdatePostParams{
+	if err := preparePostImages(p); err != nil {
+		return err
+	}
+	tx, err := p.db.BeginTx(ctx, nil)
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	q := sqlc.New(tx)
+	n, err := q.UpdatePost(ctx, sqlc.UpdatePostParams{
 		ID:        p.ID,
 		Body:      p.Body,
 		UpdatedAt: p.UpdatedAt,
@@ -99,7 +139,13 @@ func (p *Post) Update(ctx context.Context) error {
 	if n == 0 {
 		return sql.ErrNoRows
 	}
-	return nil
+	if err := q.DeletePostImages(ctx, p.ID); err != nil {
+		return err
+	}
+	if err := createPostImages(ctx, q, p.Images); err != nil {
+		return mapPostCreateError(err)
+	}
+	return tx.Commit()
 }

 func preparePost(p *Post) error {
@@ -153,6 +199,85 @@ func preparePost(p *Post) error {
 	return nil
 }

+func preparePostImages(p *Post) error {
+	if len(p.Images) > MaxPostImages {
+		return fmt.Errorf("%w: at most %d images are allowed", ErrInvalidPost, MaxPostImages)
+	}
+	ids := make(map[string]bool, len(p.Images))
+	keys := make(map[string]bool, len(p.Images))
+	now := time.Now().UTC().Format(time.RFC3339Nano)
+	for i := range p.Images {
+		image := &p.Images[i]
+		image.ID = strings.TrimSpace(image.ID)
+		image.PostID = strings.TrimSpace(image.PostID)
+		image.ObjectKey = strings.TrimSpace(image.ObjectKey)
+		image.PublicURL = strings.TrimSpace(image.PublicURL)
+		image.Description = strings.TrimSpace(image.Description)
+		if image.ID == "" {
+			image.ID = uuid.NewString()
+		}
+		if image.PostID == "" {
+			image.PostID = p.ID
+		}
+		if image.PostID != p.ID {
+			return fmt.Errorf("%w: image belongs to another post", ErrInvalidPost)
+		}
+		if image.ObjectKey == "" || image.PublicURL == "" {
+			return fmt.Errorf("%w: image storage metadata is required", ErrInvalidPost)
+		}
+		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 ids[image.ID] || keys[image.ObjectKey] {
+			return fmt.Errorf("%w: duplicate image", ErrInvalidPost)
+		}
+		ids[image.ID] = true
+		keys[image.ObjectKey] = true
+		image.Position = i
+		if image.CreatedAt == "" {
+			image.CreatedAt = now
+		}
+	}
+	return nil
+}
+
+func createPostImages(ctx context.Context, q *sqlc.Queries, images []PostImage) error {
+	for _, image := range images {
+		if err := q.CreatePostImage(ctx, sqlc.CreatePostImageParams{
+			ID:          image.ID,
+			PostID:      image.PostID,
+			ObjectKey:   image.ObjectKey,
+			PublicUrl:   image.PublicURL,
+			Description: image.Description,
+			Position:    int16(image.Position),
+			Width:       int32(image.Width),
+			Height:      int32(image.Height),
+			CreatedAt:   image.CreatedAt,
+		}); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func postImageFromSQL(image sqlc.PostImage) PostImage {
+	return PostImage{
+		ID:          image.ID,
+		PostID:      image.PostID,
+		ObjectKey:   image.ObjectKey,
+		PublicURL:   image.PublicUrl,
+		Description: image.Description,
+		Position:    int(image.Position),
+		Width:       int(image.Width),
+		Height:      int(image.Height),
+		CreatedAt:   image.CreatedAt,
+	}
+}
+
 func nullableParentID(parentID *string) sql.NullString {
 	if parentID == nil {
 		return sql.NullString{}
@@ -209,7 +334,8 @@ func postFromValues(

 // GetPost returns one post without loading its replies.
 func GetPost(ctx context.Context, db *sql.DB, id string) (*Post, error) {
-	r, err := sqlc.New(db).GetPost(ctx, id)
+	q := sqlc.New(db)
+	r, err := q.GetPost(ctx, id)
 	if err != nil {
 		return nil, err
 	}
@@ -228,12 +354,20 @@ func GetPost(ctx context.Context, db *sql.DB, id string) (*Post, error) {
 		r.CreatedAt,
 		r.UpdatedAt,
 	)
+	imageRows, err := q.ListPostImages(ctx, id)
+	if err != nil {
+		return nil, err
+	}
+	for _, image := range imageRows {
+		p.Images = append(p.Images, postImageFromSQL(image))
+	}
 	return &p, nil
 }

 // GetPostThread returns a root post with all descendants nested under Replies.
 func GetPostThread(ctx context.Context, db *sql.DB, rootID string) (*Post, error) {
-	rows, err := sqlc.New(db).ListPostThread(ctx, rootID)
+	q := sqlc.New(db)
+	rows, err := q.ListPostThread(ctx, rootID)
 	if err != nil {
 		return nil, err
 	}
@@ -255,6 +389,21 @@ func GetPostThread(ctx context.Context, db *sql.DB, rootID string) (*Post, error
 			r.UpdatedAt,
 		))
 	}
+	imageRows, err := q.ListPostThreadImages(ctx, rootID)
+	if err != nil {
+		return nil, err
+	}
+	postsByID := make(map[string]*Post, len(posts))
+	for i := range posts {
+		postsByID[posts[i].ID] = &posts[i]
+	}
+	for _, image := range imageRows {
+		post, ok := postsByID[image.PostID]
+		if !ok {
+			return nil, fmt.Errorf("image %s belongs to missing post %s", image.ID, image.PostID)
+		}
+		post.Images = append(post.Images, postImageFromSQL(image))
+	}
 	return buildPostTree(posts, rootID)
 }