package awg

import (
	"encoding/base64"
	"net"
	"testing"
)

func TestParseINI_AWG20(t *testing.T) {
	raw := `[Interface]
PrivateKey = AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
Address = 10.8.0.2/32
DNS = 1.1.1.1
Jc = 4
Jmin = 40
Jmax = 70
H1 = 1
H2 = 2
H3 = 3
H4 = 4
I1 = <r 128>

[Peer]
PublicKey = AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEE=
Endpoint = 203.0.113.10:51820
AllowedIPs = 0.0.0.0/0
PersistentKeepalive = 25
`
	c, err := Parse(raw)
	if err != nil {
		t.Fatal(err)
	}
	if c.Jc != 4 || c.I1 != "<r 128>" || c.Endpoint != "203.0.113.10:51820" {
		t.Fatalf("unexpected conf: %+v", c)
	}
	if !c.IsAWG20() {
		t.Fatal("expected AWG2 markers")
	}
	ipc, err := c.ToIPC()
	if err != nil {
		t.Fatal(err)
	}
	if !containsAll(ipc, "jc=4", "i1=<r 128>", "endpoint=203.0.113.10:51820") {
		t.Fatalf("bad ipc: %s", ipc)
	}
}

func TestParseURI_UserInfoPrivateKey(t *testing.T) {
	priv := "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
	pub := "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEE="
	raw := "awg://" + priv + "@203.0.113.10:51820/?public_key=" + pub + "&address=10.8.0.2/32&jc=4"
	c, err := Parse(raw)
	if err != nil {
		t.Fatal(err)
	}
	if c.PrivateKey != priv {
		t.Fatalf("private key: %q", c.PrivateKey)
	}
	if c.PublicKey != pub {
		t.Fatalf("public key: %q", c.PublicKey)
	}
	if c.Endpoint != "203.0.113.10:51820" {
		t.Fatalf("endpoint: %q", c.Endpoint)
	}
}

func TestParseINI_SpacedKeysAndQuotes(t *testing.T) {
	raw := `Private Key = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA="
Address = 10.8.0.2/32
[Peer]
Public Key = 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEE='
Endpoint = 1.2.3.4:51820
`
	c, err := Parse(raw)
	if err != nil {
		t.Fatal(err)
	}
	if c.PrivateKey == "" || c.PublicKey == "" {
		t.Fatalf("keys missing: %+v", c)
	}
}

func TestParseAmneziaJSON(t *testing.T) {
	raw := `{
  "client_priv_key": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
  "server_pub_key": "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEE=",
  "client_ip": "10.8.0.2/32",
  "hostName": "203.0.113.10",
  "port": "51820",
  "Jc": 4,
  "Jmin": 10,
  "Jmax": 50,
  "H1": "1",
  "H2": "2",
  "H3": "3",
  "H4": "4"
}`
	c, err := Parse(raw)
	if err != nil {
		t.Fatal(err)
	}
	if c.Endpoint != "203.0.113.10:51820" {
		t.Fatalf("endpoint %q", c.Endpoint)
	}
	if c.Jc != 4 {
		t.Fatalf("jc %d", c.Jc)
	}
}

func TestParseVPNScheme(t *testing.T) {
	inner := `{"client_priv_key":"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=","server_pub_key":"AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEE=","client_ip":"10.8.0.2/32","hostName":"9.9.9.9","port":"51820"}`
	raw := "vpn://" + base64.StdEncoding.EncodeToString([]byte(inner))
	c, err := Parse(raw)
	if err != nil {
		t.Fatal(err)
	}
	if c.Endpoint != "9.9.9.9:51820" {
		t.Fatalf("endpoint %q", c.Endpoint)
	}
}

func TestDetect(t *testing.T) {
	if !Detect("[Interface]\nPrivateKey = x") {
		t.Fatal("expected detect")
	}
	if !Detect("awg://1.2.3.4:51820/?private_key=a&public_key=b&address=10.0.0.2/32") {
		t.Fatal("expected awg uri detect")
	}
	if !Detect(`{"client_priv_key":"x","server_pub_key":"y"}`) {
		t.Fatal("expected json detect")
	}
}

func TestDecodeKeyURLSafe(t *testing.T) {
	// 32 zero bytes, URL-safe without padding
	raw := base64.RawURLEncoding.EncodeToString(make([]byte, 32))
	b, err := decodeKey(raw)
	if err != nil || len(b) != 32 {
		t.Fatalf("url-safe: %v %d", err, len(b))
	}
}

func TestResolveEndpointPrefersIPv4(t *testing.T) {
	got, err := resolveEndpointWith("peer.example:41421", func(host string) ([]net.IP, error) {
		if host != "peer.example" {
			t.Fatalf("host %q", host)
		}
		return []net.IP{
			net.ParseIP("2001:db8::1"),
			net.ParseIP("203.0.113.44"),
		}, nil
	})
	if err != nil {
		t.Fatal(err)
	}
	if got != "203.0.113.44:41421" {
		t.Fatalf("got %q", got)
	}
}

func TestResolveEndpointAlreadyIP(t *testing.T) {
	got, err := resolveEndpointWith("203.0.113.10:51820", func(string) ([]net.IP, error) {
		t.Fatal("lookup should not run for IP")
		return nil, nil
	})
	if err != nil || got != "203.0.113.10:51820" {
		t.Fatalf("%q %v", got, err)
	}
}

func TestResolveEndpointDNSError(t *testing.T) {
	_, err := resolveEndpointWith("missing.invalid:41421", func(string) ([]net.IP, error) {
		return nil, &net.DNSError{Err: "no such host", Name: "missing.invalid", IsNotFound: true}
	})
	if err == nil || !stringsContains(err.Error(), "не удалось разрешить DNS") {
		t.Fatalf("expected Russian DNS error, got %v", err)
	}
}

func TestToIPCResolvesEndpoint(t *testing.T) {
	old := lookupIP
	lookupIP = func(host string) ([]net.IP, error) {
		return []net.IP{net.ParseIP("198.51.100.9")}, nil
	}
	defer func() { lookupIP = old }()

	c := Conf{
		PrivateKey: "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=",
		PublicKey:  "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEE=",
		Address:    []string{"10.8.0.2/32"},
		Endpoint:   "peer.example:41421",
	}
	ipc, err := c.ToIPC()
	if err != nil {
		t.Fatal(err)
	}
	if !stringsContains(ipc, "endpoint=198.51.100.9:41421") {
		t.Fatalf("ipc missing resolved endpoint: %s", ipc)
	}
}

func TestConfResolveEndpointMutates(t *testing.T) {
	old := lookupIP
	lookupIP = func(string) ([]net.IP, error) {
		return []net.IP{net.ParseIP("198.51.100.1")}, nil
	}
	defer func() { lookupIP = old }()

	c := Conf{Endpoint: "host.example:41421"}
	if err := c.ResolveEndpoint(); err != nil {
		t.Fatal(err)
	}
	if c.Endpoint != "198.51.100.1:41421" {
		t.Fatalf("endpoint %q", c.Endpoint)
	}
}

func containsAll(s string, parts ...string) bool {
	for _, p := range parts {
		if !stringsContains(s, p) {
			return false
		}
	}
	return true
}

func stringsContains(s, sub string) bool {
	return len(sub) == 0 || (len(s) >= len(sub) && indexOf(s, sub) >= 0)
}

func indexOf(s, sub string) int {
	for i := 0; i+len(sub) <= len(s); i++ {
		if s[i:i+len(sub)] == sub {
			return i
		}
	}
	return -1
}

func TestHostPortLightINI(t *testing.T) {
	raw := `[Interface]
PrivateKey = AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
Address = 10.8.0.2/32

[Peer]
PublicKey = AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEE=
Endpoint = 203.0.113.10:51820
AllowedIPs = 0.0.0.0/0
`
	h, p, err := HostPort(raw)
	if err != nil {
		t.Fatal(err)
	}
	if h != "203.0.113.10" || p != "51820" {
		t.Fatalf("got %s:%s", h, p)
	}
	h2, p2, err := HostPort("awg://AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=@9.9.9.9:41421")
	if err != nil {
		t.Fatal(err)
	}
	if h2 != "9.9.9.9" || p2 != "41421" {
		t.Fatalf("uri got %s:%s", h2, p2)
	}
}