//go:build linux

package hostbox

import (
	"path/filepath"
	"strings"

	"github.com/carlosframework/platform/internal/rootstate"
)

func censusVendorUnitLink(root, path string) bool {
	rel, err := filepath.Rel(root, path)
	if err != nil || !filepath.IsLocal(rel) {
		return false
	}
	parts := strings.Split(rel, string(filepath.Separator))
	if len(parts) > 2 || (len(parts) == 2 && !strings.HasSuffix(parts[0], ".wants") && !strings.HasSuffix(parts[0], ".requires")) {
		return false
	}
	for _, part := range parts {
		if strings.HasPrefix(part, "carlos") {
			return false
		}
	}
	target, err := rootstate.ReadTrustedLink(path)
	if err != nil {
		return false
	}
	if !filepath.IsAbs(target) {
		target = filepath.Join(filepath.Dir(path), target)
	}
	target = filepath.Clean(target)
	if filepath.Dir(target) != "/usr/lib/systemd/system" && filepath.Dir(target) != "/lib/systemd/system" {
		return false
	}
	if strings.HasPrefix(filepath.Base(target), "carlos") {
		return false
	}
	resolved, err := filepath.EvalSymlinks(target)
	if err != nil || filepath.Dir(resolved) != "/usr/lib/systemd/system" && filepath.Dir(resolved) != "/lib/systemd/system" {
		return false
	}
	f, err := rootstate.OpenTrustedFile(resolved)
	if err != nil {
		return false
	}
	return f.Close() == nil
}