package identify_test

import (
	"context"
	"testing"
	"time"

	ic "github.com/libp2p/go-libp2p-crypto"
	testutil "github.com/libp2p/go-libp2p-netutil"
	peer "github.com/libp2p/go-libp2p-peer"
	pstore "github.com/libp2p/go-libp2p-peerstore"
	identify "github.com/libp2p/go-libp2p/p2p/protocol/identify"

	blhost "github.com/libp2p/go-libp2p-blankhost"
	host "github.com/libp2p/go-libp2p-host"
	ma "github.com/multiformats/go-multiaddr"
)

func subtestIDService(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	h1 := blhost.NewBlankHost(testutil.GenSwarmNetwork(t, ctx))
	h2 := blhost.NewBlankHost(testutil.GenSwarmNetwork(t, ctx))

	h1p := h1.ID()
	h2p := h2.ID()

	ids1 := identify.NewIDService(h1)
	ids2 := identify.NewIDService(h2)

	testKnowsAddrs(t, h1, h2p, []ma.Multiaddr{}) // nothing
	testKnowsAddrs(t, h2, h1p, []ma.Multiaddr{}) // nothing

	forgetMe, _ := ma.NewMultiaddr("/ip4/1.2.3.4/tcp/1234")

	h2.Peerstore().AddAddr(h1p, forgetMe, pstore.RecentlyConnectedAddrTTL)
	time.Sleep(500 * time.Millisecond)

	h2pi := h2.Peerstore().PeerInfo(h2p)
	if err := h1.Connect(ctx, h2pi); err != nil {
		t.Fatal(err)
	}

	h1t2c := h1.Network().ConnsToPeer(h2p)
	if len(h1t2c) == 0 {
		t.Fatal("should have a conn here")
	}

	ids1.IdentifyConn(h1t2c[0])

	// the IDService should be opened automatically, by the network.
	// what we should see now is that both peers know about each others listen addresses.
	t.Log("test peer1 has peer2 addrs correctly")
	testKnowsAddrs(t, h1, h2p, h2.Peerstore().Addrs(h2p)) // has them
	testHasProtocolVersions(t, h1, h2p)
	testHasPublicKey(t, h1, h2p, h2.Peerstore().PubKey(h2p)) // h1 should have h2's public key

	// now, this wait we do have to do. it's the wait for the Listening side
	// to be done identifying the connection.
	c := h2.Network().ConnsToPeer(h1.ID())
	if len(c) < 1 {
		t.Fatal("should have connection by now at least.")
	}
	ids2.IdentifyConn(c[0])

	addrs := h1.Peerstore().Addrs(h1p)
	addrs = append(addrs, c[0].RemoteMultiaddr(), forgetMe)

	// and the protocol versions.
	t.Log("test peer2 has peer1 addrs correctly")
	testKnowsAddrs(t, h2, h1p, addrs) // has them
	testHasProtocolVersions(t, h2, h1p)
	testHasPublicKey(t, h2, h1p, h1.Peerstore().PubKey(h1p)) // h1 should have h2's public key

	// Need both sides to actually notice that the connection has been closed.
	h1.Network().ClosePeer(h2p)
	h2.Network().ClosePeer(h1p)
	if len(h2.Network().ConnsToPeer(h1.ID())) != 0 || len(h1.Network().ConnsToPeer(h2.ID())) != 0 {
		t.Fatal("should have no connections")
	}

	testKnowsAddrs(t, h2, h1p, addrs)
	testKnowsAddrs(t, h1, h2p, h2.Peerstore().Addrs(h2p))

	time.Sleep(500 * time.Millisecond)

	// Forget the first one.
	testKnowsAddrs(t, h2, h1p, addrs[:len(addrs)-1])

	time.Sleep(500 * time.Millisecond)

	// Forget the rest.
	testKnowsAddrs(t, h1, h2p, []ma.Multiaddr{})
	testKnowsAddrs(t, h2, h1p, []ma.Multiaddr{})
}

func testKnowsAddrs(t *testing.T, h host.Host, p peer.ID, expected []ma.Multiaddr) {
	t.Helper()

	actual := h.Peerstore().Addrs(p)

	if len(actual) != len(expected) {
		t.Errorf("expected: %s", expected)
		t.Errorf("actual: %s", actual)
		t.Fatal("dont have the same addresses")
	}

	have := map[string]struct{}{}
	for _, addr := range actual {
		have[addr.String()] = struct{}{}
	}
	for _, addr := range expected {
		if _, found := have[addr.String()]; !found {
			t.Errorf("%s did not have addr for %s: %s", h.ID(), p, addr)
			// panic("ahhhhhhh")
		}
	}
}

func testHasProtocolVersions(t *testing.T, h host.Host, p peer.ID) {
	v, err := h.Peerstore().Get(p, "ProtocolVersion")
	if v == nil {
		t.Error("no protocol version")
		return
	}
	if v.(string) != identify.LibP2PVersion {
		t.Error("protocol mismatch", err)
	}
	v, err = h.Peerstore().Get(p, "AgentVersion")
	if v.(string) != identify.ClientVersion {
		t.Error("agent version mismatch", err)
	}
}

func testHasPublicKey(t *testing.T, h host.Host, p peer.ID, shouldBe ic.PubKey) {
	k := h.Peerstore().PubKey(p)
	if k == nil {
		t.Error("no public key")
		return
	}
	if !k.Equals(shouldBe) {
		t.Error("key mismatch")
		return
	}

	p2, err := peer.IDFromPublicKey(k)
	if err != nil {
		t.Error("could not make key")
	} else if p != p2 {
		t.Error("key does not match peerid")
	}
}

// TestIDServiceWait gives the ID service 1s to finish after dialing
// this is becasue it used to be concurrent. Now, Dial wait till the
// id service is done.
func TestIDService(t *testing.T) {
	oldTTL := pstore.RecentlyConnectedAddrTTL
	pstore.RecentlyConnectedAddrTTL = time.Second
	defer func() {
		pstore.RecentlyConnectedAddrTTL = oldTTL
	}()

	N := 3
	for i := 0; i < N; i++ {
		subtestIDService(t)
	}
}

func TestProtoMatching(t *testing.T) {
	tcp1, _ := ma.NewMultiaddr("/ip4/1.2.3.4/tcp/1234")
	tcp2, _ := ma.NewMultiaddr("/ip4/1.2.3.4/tcp/2345")
	tcp3, _ := ma.NewMultiaddr("/ip4/1.2.3.4/tcp/4567")
	utp, _ := ma.NewMultiaddr("/ip4/1.2.3.4/udp/1234/utp")

	if !identify.HasConsistentTransport(tcp1, []ma.Multiaddr{tcp2, tcp3, utp}) {
		t.Fatal("expected match")
	}

	if identify.HasConsistentTransport(utp, []ma.Multiaddr{tcp2, tcp3}) {
		t.Fatal("expected mismatch")
	}
}