backend barebone done, big chunk of work done

server/internal/store/sessions.go

@@ -0,0 +1,67 @@
+package store
+
+import (
+	"context"
+	"errors"
+	"time"
+
+	"github.com/jackc/pgconn"
+	"github.com/jackc/pgerrcode"
+	"github.com/jackc/pgx/v5"
+)
+
+// CreateSession adds a new session record.
+func (s *Store) CreateSession(ctx context.Context, userID int64, refreshHash, userAgent, ip string, expiresAt time.Time) (*Session, error) {
+	var sess Session
+	err := s.pool.QueryRow(ctx, `
+       INSERT INTO sessions(user_id, refresh_hash, user_agent, ip, expires_at)
+       VALUES($1, $2, $3, $4, $5)
+       RETURNING id, user_id, refresh_hash, expires_at, revoked_at, created_at, user_agent, ip
+   `, userID, refreshHash, userAgent, ip, expiresAt).Scan(
+		&sess.ID, &sess.UserID, &sess.RefreshHash, &sess.ExpiresAt,
+		&sess.RevokedAt, &sess.CreatedAt, &sess.UserAgent, &sess.IP,
+	)
+	if err != nil {
+		var pgErr *pgconn.PgError
+		if errors.As(err, &pgErr) && pgErr.Code == pgerrcode.UniqueViolation {
+			return nil, ErrDuplicate
+		}
+		return nil, err
+	}
+	return &sess, nil
+}
+
+// GetSessionByRefreshHash returns a session by its refresh hash or ErrNotFound.
+func (s *Store) GetSessionByRefreshHash(ctx context.Context, hash string) (*Session, error) {
+	var sess Session
+	err := s.pool.QueryRow(ctx, `
+       SELECT id, user_id, refresh_hash, expires_at, revoked_at, created_at, user_agent, ip
+       FROM sessions WHERE refresh_hash=$1
+   `, hash).Scan(
+		&sess.ID, &sess.UserID, &sess.RefreshHash, &sess.ExpiresAt,
+		&sess.RevokedAt, &sess.CreatedAt, &sess.UserAgent, &sess.IP,
+	)
+	if err != nil {
+		if errors.Is(err, pgx.ErrNoRows) {
+			return nil, ErrNotFound
+		}
+		return nil, err
+	}
+	return &sess, nil
+}
+
+// RevokeSession sets revoked_at to now() for the given session ID.
+func (s *Store) RevokeSession(ctx context.Context, id int64) error {
+	_, err := s.pool.Exec(ctx, `
+       UPDATE sessions SET revoked_at = now() WHERE id = $1
+   `, id)
+	return err
+}
+
+// RevokeAllSessions revokes all sessions for a given user.
+func (s *Store) RevokeAllSessions(ctx context.Context, userID int64) error {
+	_, err := s.pool.Exec(ctx, `
+       UPDATE sessions SET revoked_at = now() WHERE user_id = $1
+   `, userID)
+	return err
+}