package stacks

import (
	"errors"
	"io"
	"log"
	"testing"
)

// v0.151.0 (S-2): the `ip -4 -o addr show eth0` parse. Isolated because it is the one part of the
// connect-address path that can silently produce a PLAUSIBLE WRONG string — and a wrong address on
// that page is worse than no address, which is the whole reason the card exists.
func TestParseIPv4FromIPAddrOutput(t *testing.T) {
	// Verbatim from the live demo guest (felhom-samba, host netns), backslash-continuation and all.
	const live = `2: eth0    inet 192.168.0.104/24 brd 192.168.0.255 scope global dynamic eth0\       valid_lft 1486sec preferred_lft 1486sec`

	ok := []struct{ name, in, want string }{
		{"live demo output", live, "192.168.0.104"},
		{"no lifetime suffix", "2: eth0    inet 10.0.0.5/8 brd 10.255.255.255 scope global eth0", "10.0.0.5"},
		{"secondary address after loopback line", "1: lo    inet 127.0.0.1/8 scope host lo\n2: eth0    inet 172.16.4.2/16 scope global eth0", "172.16.4.2"},
	}
	for _, tc := range ok {
		got, err := parseIPv4FromIPAddrOutput(tc.in)
		if err != nil {
			t.Errorf("%s: unexpected error %v", tc.name, err)
			continue
		}
		if got != tc.want {
			t.Errorf("%s: got %q, want %q", tc.name, got, tc.want)
		}
	}

	// Every one of these would put a USELESS or MISLEADING address in front of a customer, so each
	// must be an error the caller turns into an omitted line — never a best-effort string.
	bad := []struct{ name, in string }{
		{"empty", ""},
		{"interface exists but has no address", "2: eth0    <NO-CARRIER>"},
		{"loopback only", "1: lo    inet 127.0.0.1/8 scope host lo"},
		{"unspecified", "2: eth0    inet 0.0.0.0/0 scope global eth0"},
		{"link-local (DHCP never answered)", "2: eth0    inet 169.254.11.9/16 scope link eth0"},
		{"IPv6 only", "2: eth0    inet6 fe80::be24:11ff:fede:1be7/64 scope link"},
		{"garbage", "docker: Error response from daemon: No such container: felhom-samba"},
		{"inet with no value", "2: eth0    inet"},
	}
	for _, tc := range bad {
		if got, err := parseIPv4FromIPAddrOutput(tc.in); err == nil {
			t.Errorf("%s: must be an error, got %q", tc.name, got)
		}
	}
}

// SambaLANAddress swallows the error into "" — the page omits a line rather than failing — and
// passes a good address straight through.
func TestSambaLANAddressFailsQuiet(t *testing.T) {
	m := &Manager{logger: log.New(io.Discard, "", 0)}

	m.sambaAddrFn = func() (string, error) { return "", errors.New("no such container") }
	if got := m.SambaLANAddress(); got != "" {
		t.Errorf("error path: got %q, want empty", got)
	}
	m.sambaAddrFn = func() (string, error) { return "192.0.2.10", nil }
	if got := m.SambaLANAddress(); got != "192.0.2.10" {
		t.Errorf("happy path: got %q, want 192.0.2.10", got)
	}
}