feat: update handlers in posts

backend/internal/repositories/interface.go

@@ -9,6 +9,8 @@ import (
 type PostRepository interface {
 	GetAll(ctx context.Context) ([]storage.PostReq, error)
 	GetByID(ctx context.Context, id int) (storage.PostReq, error)
+	GetLastID(ctx context.Context) (int, error)
+	IsExist(ctx context.Context, id int) bool
 	Create(ctx context.Context, post storage.Post) error
 	Update(ctx context.Context, id int, post storage.Post) error
 	Delete(ctx context.Context, id int) error

backend/internal/repositories/post_repository.go

@@ -92,6 +92,33 @@ func (p *postRepository) Update(ctx context.Context, id int, post storage.Post)
 }
 
 func (p *postRepository) Delete(ctx context.Context, id int) error {
-
+	_, err := p.db.Exec("DELETE FROM posts WHERE id = ?", id)
+	if err != nil {
+		return err
+	}
+	p.logger.Info("Post deleted:", "id", id)
 	return nil
 }
+
+func (p *postRepository) GetLastID(ctx context.Context) (int, error) {
+	var id int
+	row := p.db.QueryRow("SELECT id FROM posts ORDER BY id DESC LIMIT 1")
+	err := row.Scan(&id)
+	if err != nil {
+		p.logger.Error("error scan: " + err.Error())
+	}
+	return id, nil
+}
+
+func (p *postRepository) IsExist(ctx context.Context, id int) bool {
+	var exists int
+	err := p.db.QueryRowContext(ctx, "SELECT 1 FROM posts WHERE id = ? LIMIT 1", id).Scan(&exists)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return false
+		}
+		p.logger.Error("error checking post existence: " + err.Error())
+		return false
+	}
+	return true
+}