// 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 admin

import (
	"context"
	"errors"

	"code.superseriousbusiness.org/gotosocial/internal/db"
	"code.superseriousbusiness.org/gotosocial/internal/gtserror"
	"code.superseriousbusiness.org/gotosocial/internal/gtsmodel"
)

// rangeDomainAccounts iterates through all accounts
// originating from the given domain, and calls the
// provided range function on each account.
//
// If an error is returned while selecting accounts,
// the loop will stop and return the error.
func (a *Actions) rangeDomainAccounts(
	ctx context.Context,
	domain string,
	rangeF func(*gtsmodel.Account),
) error {
	var (
		limit = 50   // Limit selection to avoid spiking mem/cpu.
		maxID string // Start with empty string to select from top.
	)

	for {
		// Get (next) page of accounts.
		accounts, err := a.db.GetInstanceAccounts(ctx, domain, maxID, limit)
		if err != nil && !errors.Is(err, db.ErrNoEntries) {
			// Real db error.
			return gtserror.Newf("db error getting instance accounts: %w", err)
		}

		if len(accounts) == 0 {
			// No accounts left, we're done.
			return nil
		}

		// Set next max ID for paging down.
		maxID = accounts[len(accounts)-1].ID

		// Call provided range function.
		for _, account := range accounts {
			rangeF(account)
		}
	}
}
