package vpn

import (
	"strings"
	"testing"
)

func tunnel(addrs []string, peers ...string) Tunnel {
	t := Tunnel{Name: "wg0", PublicKey: "SERVERKEY=", Addrs: addrs}
	for _, p := range peers {
		t.Peers = append(t.Peers, Peer{PublicKey: p + "KEY=", AllowedIPs: []string{p}})
	}
	return t
}

func TestNextAddress(t *testing.T) {
	// .1 is the interface itself and .2 and .3 are taken, so the next free one is .4
	got, err := NextAddress(tunnel([]string{"172.21.46.1/24"}, "172.21.46.3/32", "172.21.46.2/32"))
	if err != nil || got != "172.21.46.4" {
		t.Errorf("NextAddress = %q, %v; want 172.21.46.4", got, err)
	}
	// a gap is filled before the end is reached
	got, _ = NextAddress(tunnel([]string{"172.21.46.1/24"}, "172.21.46.2/32", "172.21.46.4/32"))
	if got != "172.21.46.3" {
		t.Errorf("NextAddress = %q, want the gap at .3", got)
	}
	// an empty tunnel starts after the server
	got, _ = NextAddress(tunnel([]string{"10.9.0.1/24"}))
	if got != "10.9.0.2" {
		t.Errorf("NextAddress = %q, want 10.9.0.2", got)
	}
	// a full one says so rather than handing out a duplicate
	full := tunnel([]string{"10.9.0.1/30"}, "10.9.0.2/32")
	if _, err := NextAddress(full); err != ErrNoRoom {
		t.Errorf("err = %v, want ErrNoRoom on a full range", err)
	}
	// IPv6-only, or nothing at all, is refused rather than guessed
	if _, err := NextAddress(tunnel([]string{"fc00::1/64"})); err == nil {
		t.Error("want an error when there is no IPv4 range")
	}
}

func TestSlug(t *testing.T) {
	for in, want := range map[string]string{
		"ip12":                  "ip12",
		"Mitchell's iPad":       "mitchells_ipad",
		"my-phone":              "my_phone",
		"  spaced  out  ":       "spaced__out",
		"!!!":                   "peer",
		strings.Repeat("a", 40): strings.Repeat("a", 24),
	} {
		if got := slug(in); got != want {
			t.Errorf("slug(%q) = %q, want %q", in, got, want)
		}
	}
}

func TestProfile(t *testing.T) {
	tun := tunnel([]string{"172.21.46.1/24"})
	got := profile("PRIV=", "PSK=", tun, "172.21.46.4", "home.example.com:51820", "1.1.1.1, 1.0.0.1", false)
	for _, want := range []string{
		"PrivateKey = PRIV=",
		"Address = 172.21.46.4/24", // the interface's own prefix, not a bare /32
		"DNS = 1.1.1.1, 1.0.0.1",
		"PublicKey = SERVERKEY=",
		"PresharedKey = PSK=",
		"Endpoint = home.example.com:51820",
		"AllowedIPs = 0.0.0.0/0",
	} {
		if !strings.Contains(got, want) {
			t.Errorf("profile is missing %q:\n%s", want, got)
		}
	}
	// no DNS line at all when none was asked for, rather than an empty one
	if strings.Contains(profile("P=", "", tun, "172.21.46.4", "h:1", "", false), "DNS") {
		t.Error("an empty DNS should leave the line out")
	}
	// split routes the private ranges instead of everything
	split := profile("P=", "", tun, "172.21.46.4", "h:1", "", true)
	if strings.Contains(split, "0.0.0.0/0") {
		t.Errorf("a split tunnel must not route everything:\n%s", split)
	}
	if !strings.Contains(split, "172.21.46.0/24") {
		t.Errorf("a split tunnel should include the tunnel's own range:\n%s", split)
	}
}

func TestCheckEndpoint(t *testing.T) {
	for _, ok := range []string{"bigham.dev:51820", "1.2.3.4:51820", "[2001:db8::1]:51820"} {
		if _, err := checkEndpoint(ok); err != nil {
			t.Errorf("checkEndpoint(%q) = %v, want it accepted", ok, err)
		}
	}
	for _, bad := range []string{"", "bigham.dev", ":51820", "bigham.dev:0", "bigham.dev:notaport", "bigham.dev:99999"} {
		if _, err := checkEndpoint(bad); err == nil {
			t.Errorf("checkEndpoint(%q) was accepted, want refused", bad)
		}
	}
}

func TestHostOf(t *testing.T) {
	for in, want := range map[string]string{"172.21.46.4": "172.21.46.4", "172.21.46.4/32": "172.21.46.4", " 10.0.0.9/24 ": "10.0.0.9"} {
		got, err := hostOf(in)
		if err != nil || got != want {
			t.Errorf("hostOf(%q) = %q, %v; want %q", in, got, err, want)
		}
	}
	if _, err := hostOf("not-an-address"); err == nil {
		t.Error("hostOf accepted nonsense")
	}
}

// The name is what becomes a configuration section, so it is the input worth being strict
// about; everything refused here is refused before anything is written.
func TestNameRe(t *testing.T) {
	for _, ok := range []string{"ip12", "My Phone", "a", "work-laptop.2"} {
		if !NameRe.MatchString(ok) {
			t.Errorf("%q should be a valid name", ok)
		}
	}
	for _, bad := range []string{"", " leading", "semi;colon", "quote'd", "back`tick", "new\nline", "$(whoami)", strings.Repeat("a", 32)} {
		if NameRe.MatchString(bad) {
			t.Errorf("%q should be refused as a name", bad)
		}
	}
}