package repositories

import (
	"agent-desk/internal/models"
	"agent-desk/internal/pkg/enums"
	"gorm.io/gorm"
)

// UpdatesConfigIfUnchanged prevents a stale read/modify/write from replacing a
// concurrently tightened authentication policy or rotated channel secret. HEX is
// available in SQLite and MySQL and compares exact bytes even when MySQL's text
// column uses a case-insensitive or trailing-space-insensitive collation.
func (r *channelRepository) UpdatesConfigIfUnchanged(db *gorm.DB, expected *models.Channel, columns map[string]any) (bool, error) {
	if expected == nil || expected.ID <= 0 {
		return false, nil
	}
	result := db.Model(&models.Channel{}).
		Where("id = ? AND status <> ? AND updated_at = ?", expected.ID, enums.StatusDeleted, expected.UpdatedAt).
		Where("HEX(COALESCE(config_json, '')) = HEX(?)", expected.ConfigJSON).
		Updates(columns)
	return result.RowsAffected == 1, result.Error
}