// SPDX-License-Identifier: EUPL-1.2

package api

import "strings"

// normaliseServers trims whitespace, removes empty entries, and preserves
// the first occurrence of each server URL.
func normaliseServers(servers []string) []string {
	if len(servers) == 0 {
		return nil
	}

	cleaned := make([]string, 0, len(servers))
	seen := make(map[string]struct{}, len(servers))

	for _, server := range servers {
		server = strings.TrimSpace(server)
		if server == "" {
			continue
		}
		if _, ok := seen[server]; ok {
			continue
		}
		seen[server] = struct{}{}
		cleaned = append(cleaned, server)
	}

	if len(cleaned) == 0 {
		return nil
	}

	return cleaned
}