// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package migrations

import (
	"context"

	"github.com/uptrace/bun"
	"github.com/uptrace/bun/dialect"
)

// doesColumnExist safely checks whether given column exists on table, handling both SQLite and PostgreSQL appropriately.
func doesColumnExist(ctx context.Context, tx bun.Tx, table, col string) (bool, error) {
	var n int
	var err error
	switch tx.Dialect().Name() {
	case dialect.SQLite:
		err = tx.NewRaw("SELECT COUNT(*) FROM pragma_table_info(?) WHERE name=?", table, col).Scan(ctx, &n)
	case dialect.PG:
		err = tx.NewRaw("SELECT COUNT(*) FROM information_schema.columns WHERE table_name=? and column_name=?", table, col).Scan(ctx, &n)
	default:
		panic("unexpected dialect")
	}
	return (n > 0), err
}