package libp2p

import (
	"context"
	"crypto/rand"
	"errors"
	"fmt"
	"regexp"
	"testing"
	"time"

	"github.com/libp2p/go-libp2p/core/connmgr"
	"github.com/libp2p/go-libp2p/core/crypto"
	"github.com/libp2p/go-libp2p/core/event"
	"github.com/libp2p/go-libp2p/core/host"
	"github.com/libp2p/go-libp2p/core/network"
	"github.com/libp2p/go-libp2p/core/peer"
	"github.com/libp2p/go-libp2p/core/peerstore"
	"github.com/libp2p/go-libp2p/core/routing"
	"github.com/libp2p/go-libp2p/core/transport"
	rcmgr "github.com/libp2p/go-libp2p/p2p/host/resource-manager"
	"github.com/libp2p/go-libp2p/p2p/net/swarm"
	"github.com/libp2p/go-libp2p/p2p/protocol/ping"
	"github.com/libp2p/go-libp2p/p2p/security/noise"
	tls "github.com/libp2p/go-libp2p/p2p/security/tls"
	quic "github.com/libp2p/go-libp2p/p2p/transport/quic"
	"github.com/libp2p/go-libp2p/p2p/transport/tcp"
	webtransport "github.com/libp2p/go-libp2p/p2p/transport/webtransport"
	"go.uber.org/goleak"

	ma "github.com/multiformats/go-multiaddr"
	"github.com/stretchr/testify/require"
)

func TestNewHost(t *testing.T) {
	h, err := makeRandomHost(t, 9000)
	if err != nil {
		t.Fatal(err)
	}
	h.Close()
}

func TestTransportConstructor(t *testing.T) {
	ctor := func(
		h host.Host,
		_ connmgr.ConnectionGater,
		upgrader transport.Upgrader,
	) transport.Transport {
		tpt, err := tcp.NewTCPTransport(upgrader, nil)
		require.NoError(t, err)
		return tpt
	}
	h, err := New(Transport(ctor))
	require.NoError(t, err)
	h.Close()
}

func TestNoListenAddrs(t *testing.T) {
	h, err := New(NoListenAddrs)
	require.NoError(t, err)
	defer h.Close()
	if len(h.Addrs()) != 0 {
		t.Fatal("expected no addresses")
	}
}

func TestNoTransports(t *testing.T) {
	ctx := context.Background()
	a, err := New(NoTransports)
	require.NoError(t, err)
	defer a.Close()

	b, err := New(ListenAddrStrings("/ip4/127.0.0.1/tcp/0"))
	require.NoError(t, err)
	defer b.Close()

	err = a.Connect(ctx, peer.AddrInfo{
		ID:    b.ID(),
		Addrs: b.Addrs(),
	})
	if err == nil {
		t.Error("dial should have failed as no transports have been configured")
	}
}

func TestInsecure(t *testing.T) {
	h, err := New(NoSecurity)
	require.NoError(t, err)
	h.Close()
}

func TestDefaultListenAddrs(t *testing.T) {
	reTCP := regexp.MustCompile("/(ip)[4|6]/((0.0.0.0)|(::))/tcp/")
	reQUIC := regexp.MustCompile("/(ip)[4|6]/((0.0.0.0)|(::))/udp/([0-9]*)/quic-v1")
	reCircuit := regexp.MustCompile("/p2p-circuit")

	// Test 1: Setting the correct listen addresses if userDefined.Transport == nil && userDefined.ListenAddrs == nil
	h, err := New()
	require.NoError(t, err)
	for _, addr := range h.Network().ListenAddresses() {
		if reTCP.FindStringSubmatchIndex(addr.String()) == nil &&
			reQUIC.FindStringSubmatchIndex(addr.String()) == nil &&
			reCircuit.FindStringSubmatchIndex(addr.String()) == nil {
			t.Error("expected ip4 or ip6 or relay interface")
		}
	}

	h.Close()

	// Test 2: Listen addr only include relay if user defined transport is passed.
	h, err = New(Transport(tcp.NewTCPTransport))
	require.NoError(t, err)

	if len(h.Network().ListenAddresses()) != 1 {
		t.Error("expected one listen addr with user defined transport")
	}
	if reCircuit.FindStringSubmatchIndex(h.Network().ListenAddresses()[0].String()) == nil {
		t.Error("expected relay address")
	}
	h.Close()
}

func makeRandomHost(t *testing.T, port int) (host.Host, error) {
	priv, _, err := crypto.GenerateKeyPair(crypto.RSA, 2048)
	require.NoError(t, err)

	return New([]Option{
		ListenAddrStrings(fmt.Sprintf("/ip4/127.0.0.1/tcp/%d", port)),
		Identity(priv),
		DefaultTransports,
		DefaultMuxers,
		DefaultSecurity,
		NATPortMap(),
	}...)
}

func TestChainOptions(t *testing.T) {
	var cfg Config
	var optsRun []int
	optcount := 0
	newOpt := func() Option {
		index := optcount
		optcount++
		return func(c *Config) error {
			optsRun = append(optsRun, index)
			return nil
		}
	}

	if err := cfg.Apply(newOpt(), nil, ChainOptions(newOpt(), newOpt(), ChainOptions(), ChainOptions(nil, newOpt()))); err != nil {
		t.Fatal(err)
	}

	// Make sure we ran all options.
	if optcount != 4 {
		t.Errorf("expected to have handled %d options, handled %d", optcount, len(optsRun))
	}

	// Make sure we ran the options in-order.
	for i, x := range optsRun {
		if i != x {
			t.Errorf("expected opt %d, got opt %d", i, x)
		}
	}
}
func tStringCast(s string) ma.Multiaddr {
	st, _ := ma.StringCast(s)
	return st
}

func TestTransportConstructorTCP(t *testing.T) {
	h, err := New(
		Transport(tcp.NewTCPTransport, tcp.DisableReuseport()),
		DisableRelay(),
	)
	require.NoError(t, err)
	defer h.Close()
	require.NoError(t, h.Network().Listen(tStringCast("/ip4/127.0.0.1/tcp/0")))
	err = h.Network().Listen(tStringCast("/ip4/127.0.0.1/udp/0/quic-v1"))
	require.Error(t, err)
	require.Contains(t, err.Error(), swarm.ErrNoTransport.Error())
}

func TestTransportConstructorQUIC(t *testing.T) {
	h, err := New(
		Transport(quic.NewTransport),
		DisableRelay(),
	)
	require.NoError(t, err)
	defer h.Close()
	require.NoError(t, h.Network().Listen(tStringCast("/ip4/127.0.0.1/udp/0/quic-v1")))
	err = h.Network().Listen(tStringCast("/ip4/127.0.0.1/tcp/0"))
	require.Error(t, err)
	require.Contains(t, err.Error(), swarm.ErrNoTransport.Error())
}

type mockTransport struct{}

func (m mockTransport) Dial(context.Context, ma.Multiaddr, peer.ID) (transport.CapableConn, error) {
	panic("implement me")
}

func (m mockTransport) CanDial(ma.Multiaddr) bool                       { panic("implement me") }
func (m mockTransport) Listen(ma.Multiaddr) (transport.Listener, error) { panic("implement me") }
func (m mockTransport) Protocols() []int                                { return []int{1337} }
func (m mockTransport) Proxy() bool                                     { panic("implement me") }

var _ transport.Transport = &mockTransport{}

func TestTransportConstructorWithoutOpts(t *testing.T) {
	t.Run("successful", func(t *testing.T) {
		var called bool
		constructor := func() transport.Transport {
			called = true
			return &mockTransport{}
		}

		h, err := New(
			Transport(constructor),
			DisableRelay(),
		)
		require.NoError(t, err)
		require.True(t, called, "expected constructor to be called")
		defer h.Close()
	})

	t.Run("with options", func(t *testing.T) {
		var called bool
		constructor := func() transport.Transport {
			called = true
			return &mockTransport{}
		}

		_, err := New(
			Transport(constructor, tcp.DisableReuseport()),
			DisableRelay(),
		)
		require.EqualError(t, err, "transport constructor doesn't take any options")
		require.False(t, called, "didn't expected constructor to be called")
	})
}

func TestTransportConstructorWithWrongOpts(t *testing.T) {
	_, err := New(
		Transport(quic.NewTransport, tcp.DisableReuseport()),
		DisableRelay(),
	)
	require.EqualError(t, err, "transport constructor doesn't take any options")
}

func TestSecurityConstructor(t *testing.T) {
	h, err := New(
		Transport(tcp.NewTCPTransport),
		Security("/noisy", noise.New),
		Security("/tls", tls.New),
		DefaultListenAddrs,
		DisableRelay(),
	)
	require.NoError(t, err)
	defer h.Close()

	h1, err := New(
		NoListenAddrs,
		Transport(tcp.NewTCPTransport),
		Security("/noise", noise.New), // different name
		DisableRelay(),
	)
	require.NoError(t, err)
	defer h1.Close()

	h2, err := New(
		NoListenAddrs,
		Transport(tcp.NewTCPTransport),
		Security("/noisy", noise.New),
		DisableRelay(),
	)
	require.NoError(t, err)
	defer h2.Close()

	ai := peer.AddrInfo{
		ID:    h.ID(),
		Addrs: h.Addrs(),
	}
	err = h1.Connect(context.Background(), ai)
	require.Error(t, err)
	require.Contains(t, err.Error(), "failed to negotiate security protocol")
	require.NoError(t, h2.Connect(context.Background(), ai))
}

func TestTransportConstructorWebTransport(t *testing.T) {
	h, err := New(
		Transport(webtransport.New),
		DisableRelay(),
	)
	require.NoError(t, err)
	defer h.Close()
	require.NoError(t, h.Network().Listen(tStringCast("/ip4/127.0.0.1/udp/0/quic-v1/webtransport")))
	err = h.Network().Listen(tStringCast("/ip4/127.0.0.1/udp/0/quic-v1/"))
	require.Error(t, err)
	require.Contains(t, err.Error(), swarm.ErrNoTransport.Error())
}

func TestTransportCustomAddressWebTransport(t *testing.T) {
	customAddr, err := ma.NewMultiaddr("/ip4/127.0.0.1/udp/0/quic-v1/webtransport")
	if err != nil {
		t.Fatal(err)
	}
	h, err := New(
		Transport(webtransport.New),
		ListenAddrs(customAddr),
		DisableRelay(),
		AddrsFactory(func(multiaddrs []ma.Multiaddr) []ma.Multiaddr {
			return []ma.Multiaddr{customAddr}
		}),
	)
	require.NoError(t, err)
	defer h.Close()
	require.NoError(t, h.Network().Listen(tStringCast("/ip4/127.0.0.1/udp/0/quic-v1/webtransport")))
	addrs := h.Addrs()
	require.Len(t, addrs, 1)
	require.NotEqual(t, addrs[0], customAddr)
	restOfAddr, lastComp, _ := ma.SplitLast(addrs[0])
	restOfAddr, secondToLastComp, _ := ma.SplitLast(restOfAddr)
	require.Equal(t, ma.P_CERTHASH, lastComp.Protocol().Code)
	require.Equal(t, ma.P_CERTHASH, secondToLastComp.Protocol().Code)
	require.True(t, restOfAddr.Equal(customAddr))
}

// TestTransportCustomAddressWebTransportDoesNotStall tests that if the user
// manually returns a webtransport address from AddrsFactory, but we aren't
// listening on a webtranport address, we don't stall.
func TestTransportCustomAddressWebTransportDoesNotStall(t *testing.T) {
	customAddr, err := ma.NewMultiaddr("/ip4/127.0.0.1/udp/0/quic-v1/webtransport")
	if err != nil {
		t.Fatal(err)
	}
	h, err := New(
		Transport(webtransport.New),
		// Purposely not listening on the custom address so that we make sure the node doesn't stall if it fails to add a certhash to the multiaddr
		// ListenAddrs(customAddr),
		DisableRelay(),
		AddrsFactory(func(multiaddrs []ma.Multiaddr) []ma.Multiaddr {
			return []ma.Multiaddr{customAddr}
		}),
	)
	require.NoError(t, err)
	defer h.Close()
	addrs := h.Addrs()
	require.Len(t, addrs, 1)
	_, lastComp, _ := ma.SplitLast(addrs[0])
	require.NotEqual(t, ma.P_CERTHASH, lastComp.Protocol().Code)
	// We did not add the certhash to the multiaddr
	require.Equal(t, addrs[0], customAddr)
}

type mockPeerRouting struct {
	queried []peer.ID
}

func (r *mockPeerRouting) FindPeer(_ context.Context, id peer.ID) (peer.AddrInfo, error) {
	r.queried = append(r.queried, id)
	return peer.AddrInfo{}, errors.New("mock peer routing error")
}

func TestRoutedHost(t *testing.T) {
	mockRouter := &mockPeerRouting{}
	h, err := New(
		NoListenAddrs,
		Routing(func(host.Host) (routing.PeerRouting, error) { return mockRouter, nil }),
		DisableRelay(),
	)
	require.NoError(t, err)
	defer h.Close()

	priv, _, err := crypto.GenerateEd25519Key(rand.Reader)
	require.NoError(t, err)
	id, err := peer.IDFromPrivateKey(priv)
	require.NoError(t, err)
	require.EqualError(t, h.Connect(context.Background(), peer.AddrInfo{ID: id}), "mock peer routing error")
	require.Equal(t, []peer.ID{id}, mockRouter.queried)
}

func TestAutoNATService(t *testing.T) {
	h, err := New(EnableNATService())
	require.NoError(t, err)
	h.Close()
}

func TestInsecureConstructor(t *testing.T) {
	h, err := New(
		EnableNATService(),
		NoSecurity,
	)
	require.NoError(t, err)
	h.Close()

	h, err = New(
		NoSecurity,
	)
	require.NoError(t, err)
	h.Close()
}

func TestDisableIdentifyAddressDiscovery(t *testing.T) {
	h, err := New(DisableIdentifyAddressDiscovery())
	require.NoError(t, err)
	h.Close()
}

func TestMain(m *testing.M) {
	goleak.VerifyTestMain(
		m,
		// This will return eventually (5s timeout) but doesn't take a context.
		goleak.IgnoreAnyFunction("github.com/koron/go-ssdp.Search"),
		// Logging & Stats
		goleak.IgnoreTopFunction("github.com/ipfs/go-log/v2/writer.(*MirrorWriter).logRoutine"),
		goleak.IgnoreTopFunction("go.opencensus.io/stats/view.(*worker).start"),
		goleak.IgnoreAnyFunction("github.com/jackpal/go-nat-pmp.(*Client).GetExternalAddress"),
	)
}

func TestDialCircuitAddrWithWrappedResourceManager(t *testing.T) {
	relay, err := New(EnableRelayService())
	require.NoError(t, err)
	defer relay.Close()

	// Fake that the relay is publicly reachable
	emitterForRelay, err := relay.EventBus().Emitter(&event.EvtLocalReachabilityChanged{})
	require.NoError(t, err)
	defer emitterForRelay.Close()
	emitterForRelay.Emit(event.EvtLocalReachabilityChanged{Reachability: network.ReachabilityPublic})

	peerBehindRelay, err := New(EnableAutoRelayWithStaticRelays([]peer.AddrInfo{{ID: relay.ID(), Addrs: relay.Addrs()}}))
	require.NoError(t, err)
	defer peerBehindRelay.Close()
	// Emit an event to tell this peer it is private
	emitterForPeerBehindRelay, err := peerBehindRelay.EventBus().Emitter(&event.EvtLocalReachabilityChanged{})
	require.NoError(t, err)
	defer emitterForPeerBehindRelay.Close()
	emitterForPeerBehindRelay.Emit(event.EvtLocalReachabilityChanged{Reachability: network.ReachabilityPrivate})

	// Use a wrapped resource manager to test that the circuit dialing works
	// with it. Look at the PR introducing this test for context
	type wrappedRcmgr struct{ network.ResourceManager }
	mgr, err := rcmgr.NewResourceManager(rcmgr.NewFixedLimiter(rcmgr.DefaultLimits.AutoScale()))
	require.NoError(t, err)
	wmgr := wrappedRcmgr{mgr}
	h, err := New(ResourceManager(wmgr))
	require.NoError(t, err)
	defer h.Close()

	h.Peerstore().AddAddrs(relay.ID(), relay.Addrs(), 10*time.Minute)
	h.Peerstore().AddAddr(peerBehindRelay.ID(),
		tStringCast(
			fmt.Sprintf("/p2p/%s/p2p-circuit", relay.ID()),
		),
		peerstore.TempAddrTTL,
	)
	require.NoError(t, err)

	ctx, cancel := context.WithCancel(context.Background())
	res := <-ping.Ping(ctx, h, peerBehindRelay.ID())
	require.NoError(t, res.Error)
	defer cancel()
}