feat: add user centric features

2026-05-30 23:43:27 +05:30
parent 97422c1ef5
commit aecdd1030a
21 changed files with 2037 additions and 69 deletions
@@ -0,0 +1,257 @@
+package repository
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"github.com/jackc/pgx/v5"
+	"github.com/prabhupadasays/spsays-bff/internal/model"
+)
+
+// ErrPostNotFound is returned by lookup methods when no row matches.
+var ErrPostNotFound = errors.New("post not found")
+
+// PostRepo wraps Postgres access for posts + post_images.
+type PostRepo struct{ pg *Postgres }
+
+func NewPostRepo(pg *Postgres) *PostRepo { return &PostRepo{pg: pg} }
+
+// Create inserts a post + its images in a single transaction so we never
+// end up with orphan images.
+func (r *PostRepo) Create(ctx context.Context, userID, caption, sourceURL, sourceTitle string, imageURLs []string) (*model.Post, error) {
+	tx, err := r.pg.Pool.Begin(ctx)
+	if err != nil {
+		return nil, fmt.Errorf("begin tx: %w", err)
+	}
+	defer func() { _ = tx.Rollback(ctx) }()
+
+	p := &model.Post{}
+	err = tx.QueryRow(ctx, `
+		INSERT INTO posts (user_id, caption, source_url, source_title)
+		VALUES ($1, $2, $3, $4)
+		RETURNING id, user_id, caption, source_url, COALESCE(source_title, ''), created_at, updated_at`,
+		userID, caption, sourceURL, sourceTitle,
+	).Scan(&p.ID, &p.UserID, &p.Caption, &p.SourceURL, &p.SourceTitle, &p.CreatedAt, &p.UpdatedAt)
+	if err != nil {
+		return nil, fmt.Errorf("insert post: %w", err)
+	}
+
+	for i, url := range imageURLs {
+		var img model.PostImage
+		err = tx.QueryRow(ctx, `
+			INSERT INTO post_images (post_id, url, position)
+			VALUES ($1, $2, $3)
+			RETURNING id, url, position`,
+			p.ID, url, i,
+		).Scan(&img.ID, &img.URL, &img.Position)
+		if err != nil {
+			return nil, fmt.Errorf("insert post image %d: %w", i, err)
+		}
+		p.Images = append(p.Images, img)
+	}
+
+	if err := tx.Commit(ctx); err != nil {
+		return nil, fmt.Errorf("commit: %w", err)
+	}
+	return p, nil
+}
+
+// ReplaceImages atomically swaps a post's image set. Ownership is
+// enforced inside the tx by locking the post row and checking user_id —
+// non-owners get ErrPostNotFound (we don't distinguish "not yours" from
+// "doesn't exist" to non-owners). Existing rows are wiped, the new URLs
+// are inserted with sequential positions, and the post's `updated_at`
+// is touched so list views can sort by recency if needed later.
+func (r *PostRepo) ReplaceImages(ctx context.Context, postID, userID string, imageURLs []string) error {
+	tx, err := r.pg.Pool.Begin(ctx)
+	if err != nil {
+		return fmt.Errorf("begin tx: %w", err)
+	}
+	defer func() { _ = tx.Rollback(ctx) }()
+
+	var owner string
+	if err := tx.QueryRow(ctx, `SELECT user_id FROM posts WHERE id = $1 FOR UPDATE`, postID).Scan(&owner); err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return ErrPostNotFound
+		}
+		return fmt.Errorf("lock post: %w", err)
+	}
+	if owner != userID {
+		return ErrPostNotFound
+	}
+
+	if _, err := tx.Exec(ctx, `DELETE FROM post_images WHERE post_id = $1`, postID); err != nil {
+		return fmt.Errorf("delete images: %w", err)
+	}
+	for i, url := range imageURLs {
+		if _, err := tx.Exec(ctx, `
+			INSERT INTO post_images (post_id, url, position)
+			VALUES ($1, $2, $3)`, postID, url, i,
+		); err != nil {
+			return fmt.Errorf("insert image %d: %w", i, err)
+		}
+	}
+	if _, err := tx.Exec(ctx, `UPDATE posts SET updated_at = now() WHERE id = $1`, postID); err != nil {
+		return fmt.Errorf("touch post: %w", err)
+	}
+	return tx.Commit(ctx)
+}
+
+// FindByID returns one post with its images and author info.
+func (r *PostRepo) FindByID(ctx context.Context, id string) (*model.Post, error) {
+	const q = `
+		SELECT p.id, p.user_id, p.caption, p.source_url, COALESCE(p.source_title, ''),
+		       p.created_at, p.updated_at, u.name, u.handle, u.avatar_url
+		FROM posts p
+		JOIN users u ON u.id = p.user_id
+		WHERE p.id = $1`
+	p := &model.Post{}
+	err := r.pg.Pool.QueryRow(ctx, q, id).Scan(
+		&p.ID, &p.UserID, &p.Caption, &p.SourceURL, &p.SourceTitle,
+		&p.CreatedAt, &p.UpdatedAt,
+		&p.AuthorName, &p.AuthorHandle, &p.AuthorAvatarURL,
+	)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return nil, ErrPostNotFound
+		}
+		return nil, fmt.Errorf("find post: %w", err)
+	}
+	imgs, err := r.imagesFor(ctx, []string{p.ID})
+	if err != nil {
+		return nil, err
+	}
+	p.Images = imgs[p.ID]
+	return p, nil
+}
+
+// ListByHandle returns the public feed for a user, newest-first, paginated.
+func (r *PostRepo) ListByHandle(ctx context.Context, handle string, limit, offset int) ([]model.Post, int, error) {
+	var total int
+	if err := r.pg.Pool.QueryRow(ctx, `
+		SELECT COUNT(*) FROM posts p
+		JOIN users u ON u.id = p.user_id
+		WHERE u.handle = $1`, handle,
+	).Scan(&total); err != nil {
+		return nil, 0, fmt.Errorf("count posts: %w", err)
+	}
+
+	const q = `
+		SELECT p.id, p.user_id, p.caption, p.source_url, COALESCE(p.source_title, ''),
+		       p.created_at, p.updated_at, u.name, u.handle, u.avatar_url
+		FROM posts p
+		JOIN users u ON u.id = p.user_id
+		WHERE u.handle = $1
+		ORDER BY p.created_at DESC
+		LIMIT $2 OFFSET $3`
+	return r.collectPosts(ctx, total, q, handle, limit, offset)
+}
+
+// ListByUser returns the user's own posts (private listing — same shape).
+func (r *PostRepo) ListByUser(ctx context.Context, userID string, limit, offset int) ([]model.Post, int, error) {
+	var total int
+	if err := r.pg.Pool.QueryRow(ctx, `SELECT COUNT(*) FROM posts WHERE user_id = $1`, userID).Scan(&total); err != nil {
+		return nil, 0, fmt.Errorf("count posts: %w", err)
+	}
+	const q = `
+		SELECT p.id, p.user_id, p.caption, p.source_url, COALESCE(p.source_title, ''),
+		       p.created_at, p.updated_at, u.name, u.handle, u.avatar_url
+		FROM posts p
+		JOIN users u ON u.id = p.user_id
+		WHERE p.user_id = $1
+		ORDER BY p.created_at DESC
+		LIMIT $2 OFFSET $3`
+	return r.collectPosts(ctx, total, q, userID, limit, offset)
+}
+
+// Delete removes a post only if it belongs to the caller.
+func (r *PostRepo) Delete(ctx context.Context, postID, userID string) error {
+	tag, err := r.pg.Pool.Exec(ctx,
+		`DELETE FROM posts WHERE id = $1 AND user_id = $2`, postID, userID)
+	if err != nil {
+		return fmt.Errorf("delete post: %w", err)
+	}
+	if tag.RowsAffected() == 0 {
+		return ErrPostNotFound
+	}
+	return nil
+}
+
+// CountByUser is used by services that need to know how many posts a user
+// has — currently the public-profile endpoint only.
+func (r *PostRepo) CountByUser(ctx context.Context, userID string) (int, error) {
+	var n int
+	err := r.pg.Pool.QueryRow(ctx, `SELECT COUNT(*) FROM posts WHERE user_id = $1`, userID).Scan(&n)
+	if err != nil {
+		return 0, fmt.Errorf("count user posts: %w", err)
+	}
+	return n, nil
+}
+
+// --- internal helpers ---
+
+func (r *PostRepo) collectPosts(ctx context.Context, total int, query string, args ...any) ([]model.Post, int, error) {
+	rows, err := r.pg.Pool.Query(ctx, query, args...)
+	if err != nil {
+		return nil, 0, fmt.Errorf("query posts: %w", err)
+	}
+	defer rows.Close()
+
+	posts := []model.Post{}
+	ids := []string{}
+	for rows.Next() {
+		var p model.Post
+		if err := rows.Scan(
+			&p.ID, &p.UserID, &p.Caption, &p.SourceURL, &p.SourceTitle,
+			&p.CreatedAt, &p.UpdatedAt,
+			&p.AuthorName, &p.AuthorHandle, &p.AuthorAvatarURL,
+		); err != nil {
+			return nil, 0, fmt.Errorf("scan post: %w", err)
+		}
+		posts = append(posts, p)
+		ids = append(ids, p.ID)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, 0, fmt.Errorf("iterate posts: %w", err)
+	}
+
+	if len(ids) > 0 {
+		imgs, err := r.imagesFor(ctx, ids)
+		if err != nil {
+			return nil, 0, err
+		}
+		for i := range posts {
+			posts[i].Images = imgs[posts[i].ID]
+		}
+	}
+	return posts, total, nil
+}
+
+// imagesFor returns a map post_id → [images...] for a batch of post IDs in
+// a single query so we don't N+1 the feed endpoint.
+func (r *PostRepo) imagesFor(ctx context.Context, postIDs []string) (map[string][]model.PostImage, error) {
+	out := make(map[string][]model.PostImage, len(postIDs))
+	if len(postIDs) == 0 {
+		return out, nil
+	}
+	rows, err := r.pg.Pool.Query(ctx, `
+		SELECT post_id, id, url, position
+		FROM post_images
+		WHERE post_id = ANY($1)
+		ORDER BY post_id, position`, postIDs,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("query post images: %w", err)
+	}
+	defer rows.Close()
+	for rows.Next() {
+		var postID string
+		var img model.PostImage
+		if err := rows.Scan(&postID, &img.ID, &img.URL, &img.Position); err != nil {
+			return nil, fmt.Errorf("scan post image: %w", err)
+		}
+		out[postID] = append(out[postID], img)
+	}
+	return out, rows.Err()
+}