package nscheck

import (
	"net/netip"
	"os"
	"path/filepath"
	"slices"
	"testing"
)

// Without netlink (a sandboxed jarld), the host's addresses come from /proc.
func TestProcAddrs(t *testing.T) {
	dir := t.TempDir()
	os.WriteFile(filepath.Join(dir, "if_inet6"), []byte(
		"00000000000000000000000000000001 01 80 10 80       lo\n"+
			"2a0280137f3d00100000000000000005 02 40 00 80     eth0\n"), 0o644)
	os.WriteFile(filepath.Join(dir, "fib_trie"), []byte(`Main:
  +-- 0.0.0.0/0 3 0 5
     |-- 0.0.0.0
        /0 universe UNICAST
     +-- 10.0.10.0/24 2 0 2
        |-- 10.0.10.0
           /24 link UNICAST
        |-- 10.0.10.5
           /32 host LOCAL
        |-- 10.0.10.255
           /32 link BROADCAST
Local:
  +-- 0.0.0.0/0 3 0 5
        |-- 10.0.10.5
           /32 host LOCAL
`), 0o644)
	got := procAddrs(dir)
	for _, want := range []string{"::1", "2a02:8013:7f3d:10::5", "10.0.10.5"} {
		if !slices.Contains(got, netip.MustParseAddr(want)) {
			t.Errorf("%s missing from %v", want, got)
		}
	}
	if len(got) != 3 {
		t.Errorf("got %v (10.0.10.5 once, no broadcast or network addresses)", got)
	}
	// And the real ones on this machine: at least loopback.
	if len(procAddrs("/proc/net")) == 0 {
		t.Log("no addresses in /proc/net here")
	}
}