Validating the token on the back end

internal/models/tokens.go

@@ -71,3 +71,27 @@ func (m *DBModel) InsertToken(t *Token, u User) error {
 	}
 	return nil
 }
+
+func (m *DBModel) GetUserForToken(token string) (*User, error) {
+	ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
+	defer cancel()
+
+	tokenHash := sha256.Sum256([]byte(token))
+	var user User
+
+	query := `SELECT u.id, u.first_name, u.last_name, u.email
+              FROM users u
+              INNER JOIN tokens t on (u.id = t.user_id)
+              WHERE t.token_hash = ?`
+
+	err := m.DB.QueryRowContext(ctx, query, tokenHash[:]).Scan(
+		&user.ID,
+		&user.FirstName,
+		&user.LastName,
+		&user.Email,
+	)
+	if err != nil {
+		return nil, err
+	}
+	return &user, nil
+}