package store

import (
	"context"
	"time"
)

// ClaimNotice claims the sending of a notification: true when nobody has
// sent the same one within the window, and from now on, nobody else may
// until it has passed. One statement, so two control planes asking at once
// cannot both be told yes.
func (s *DB) ClaimNotice(ctx context.Context, key string, at time.Time, window time.Duration) (bool, error) {
	now := at.UnixMilli()
	res, err := s.db.ExecContext(ctx,
		`INSERT INTO notify_sent (key, sent_at) VALUES (?, ?)
		 ON CONFLICT (key) DO UPDATE SET sent_at = excluded.sent_at WHERE notify_sent.sent_at < ?`,
		key, now, now-window.Milliseconds())
	if err != nil {
		return false, err
	}
	n, err := res.RowsAffected()
	return n == 1, err
}