//go:build linux

package host

import (
	"errors"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"testing"

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

// journal-migrate holds the registry through a child it runs as the service
// user. The quiesce scan must not count that child (or any other direct
// child of the migration) as a running service process, or the migration
// refuses itself every time; any other service-user process still refuses.
func TestQuiesceScanSkipsOwnChildren(t *testing.T) {
	uid := os.Getuid()
	self := 4242
	proc := t.TempDir()
	mk := func(pid, ppid int) {
		dir := filepath.Join(proc, strconv.Itoa(pid))
		if err := os.Mkdir(dir, 0o755); err != nil {
			t.Fatal(err)
		}
		// /proc/<pid>/stat: "pid (comm) state ppid ..."
		stat := strconv.Itoa(pid) + " (carlos x) S " + strconv.Itoa(ppid) + " 1 1 0\n"
		if err := os.WriteFile(filepath.Join(dir, "stat"), []byte(stat), 0o644); err != nil {
			t.Fatal(err)
		}
	}
	mk(5000, self) // the registry child
	if err := scanQuiesceProcs(proc, uid, self); err != nil {
		t.Fatalf("own child refused: %v", err)
	}
	mk(5001, 1) // any other service-user process
	err := scanQuiesceProcs(proc, uid, self)
	if !errors.Is(err, hostbox.ErrTypedJournal) || !strings.Contains(err.Error(), "5001") {
		t.Fatalf("foreign process not refused by pid: %v", err)
	}
}