package p2p

import (
	"crypto/ecdsa"
	"fmt"
	"math/rand"
	"net"
	"os"
	"path"
	"strconv"
	"testing"
	"time"

	"github.com/ethereum/go-ethereum/p2p/discover"
	"github.com/ethereum/go-ethereum/p2p/enode"
	"github.com/libp2p/go-libp2p-core/host"
	mock "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
	"github.com/prysmaticlabs/prysm/beacon-chain/core/feed"
	statefeed "github.com/prysmaticlabs/prysm/beacon-chain/core/feed/state"
	"github.com/prysmaticlabs/prysm/shared/iputils"
	"github.com/prysmaticlabs/prysm/shared/testutil"
	"github.com/prysmaticlabs/prysm/shared/testutil/assert"
	"github.com/prysmaticlabs/prysm/shared/testutil/require"
	logTest "github.com/sirupsen/logrus/hooks/test"
)

var discoveryWaitTime = 1 * time.Second

func init() {
	rand.Seed(time.Now().Unix())
}

func createAddrAndPrivKey(t *testing.T) (net.IP, *ecdsa.PrivateKey) {
	ip, err := iputils.ExternalIPv4()
	if err != nil {
		t.Fatalf("Could not get ip: %v", err)
	}
	ipAddr := net.ParseIP(ip)
	temp := testutil.TempDir()
	randNum := rand.Int()
	tempPath := path.Join(temp, strconv.Itoa(randNum))
	require.NoError(t, os.Mkdir(tempPath, 0700))
	pkey, err := privKey(&Config{DataDir: tempPath})
	require.NoError(t, err, "Could not get private key")
	return ipAddr, pkey
}

func TestCreateListener(t *testing.T) {
	port := 1024
	ipAddr, pkey := createAddrAndPrivKey(t)
	s := &Service{
		genesisTime:           time.Now(),
		genesisValidatorsRoot: []byte{'A'},
		cfg:                   &Config{UDPPort: uint(port)},
	}
	listener, err := s.createListener(ipAddr, pkey)
	require.NoError(t, err)
	defer listener.Close()

	assert.Equal(t, true, listener.Self().IP().Equal(ipAddr), "IP address is not the expected type")
	assert.Equal(t, port, listener.Self().UDP(), "Incorrect port number")

	pubkey := listener.Self().Pubkey()
	XisSame := pkey.PublicKey.X.Cmp(pubkey.X) == 0
	YisSame := pkey.PublicKey.Y.Cmp(pubkey.Y) == 0

	if !(XisSame && YisSame) {
		t.Error("Pubkey is different from what was used to create the listener")
	}
}

func TestStartDiscV5_DiscoverAllPeers(t *testing.T) {
	port := 2000
	ipAddr, pkey := createAddrAndPrivKey(t)
	genesisTime := time.Now()
	genesisValidatorsRoot := make([]byte, 32)
	s := &Service{
		cfg:                   &Config{UDPPort: uint(port)},
		genesisTime:           genesisTime,
		genesisValidatorsRoot: genesisValidatorsRoot,
	}
	bootListener, err := s.createListener(ipAddr, pkey)
	require.NoError(t, err)
	defer bootListener.Close()

	bootNode := bootListener.Self()

	var listeners []*discover.UDPv5
	for i := 1; i <= 5; i++ {
		port = 3000 + i
		cfg := &Config{
			Discv5BootStrapAddr: []string{bootNode.String()},
			UDPPort:             uint(port),
		}
		ipAddr, pkey := createAddrAndPrivKey(t)
		s = &Service{
			cfg:                   cfg,
			genesisTime:           genesisTime,
			genesisValidatorsRoot: genesisValidatorsRoot,
		}
		listener, err := s.startDiscoveryV5(ipAddr, pkey)
		assert.NoError(t, err, "Could not start discovery for node")
		listeners = append(listeners, listener)
	}
	defer func() {
		// Close down all peers.
		for _, listener := range listeners {
			listener.Close()
		}
	}()

	// Wait for the nodes to have their local routing tables to be populated with the other nodes
	time.Sleep(discoveryWaitTime)

	lastListener := listeners[len(listeners)-1]
	nodes := lastListener.Lookup(bootNode.ID())
	if len(nodes) < 4 {
		t.Errorf("The node's local table doesn't have the expected number of nodes. "+
			"Expected more than or equal to %d but got %d", 4, len(nodes))
	}
}

func TestMultiAddrsConversion_InvalidIPAddr(t *testing.T) {
	addr := net.ParseIP("invalidIP")
	_, pkey := createAddrAndPrivKey(t)
	s := &Service{
		genesisTime:           time.Now(),
		genesisValidatorsRoot: []byte{'A'},
	}
	node, err := s.createLocalNode(pkey, addr, 0, 0)
	require.NoError(t, err)
	multiAddr := convertToMultiAddr([]*enode.Node{node.Node()})
	assert.Equal(t, 0, len(multiAddr), "Invalid ip address converted successfully")
}

func TestMultiAddrConversion_OK(t *testing.T) {
	hook := logTest.NewGlobal()
	ipAddr, pkey := createAddrAndPrivKey(t)
	s := &Service{
		cfg: &Config{
			TCPPort: 0,
			UDPPort: 0,
		},
		genesisTime:           time.Now(),
		genesisValidatorsRoot: []byte{'A'},
	}
	listener, err := s.createListener(ipAddr, pkey)
	require.NoError(t, err)
	defer listener.Close()

	_ = convertToMultiAddr([]*enode.Node{listener.Self()})
	testutil.AssertLogsDoNotContain(t, hook, "Node doesn't have an ip4 address")
	testutil.AssertLogsDoNotContain(t, hook, "Invalid port, the tcp port of the node is a reserved port")
	testutil.AssertLogsDoNotContain(t, hook, "Could not get multiaddr")
}

func TestStaticPeering_PeersAreAdded(t *testing.T) {
	cfg := &Config{
		MaxPeers: 30,
	}
	port := 6000
	var staticPeers []string
	var hosts []host.Host
	// setup other nodes
	for i := 1; i <= 5; i++ {
		h, _, ipaddr := createHost(t, port+i)
		staticPeers = append(staticPeers, fmt.Sprintf("/ip4/%s/tcp/%d/p2p/%s", ipaddr, port+i, h.ID()))
		hosts = append(hosts, h)
	}

	defer func() {
		for _, h := range hosts {
			if err := h.Close(); err != nil {
				t.Log(err)
			}
		}
	}()

	cfg.TCPPort = 14500
	cfg.UDPPort = 14501
	cfg.StaticPeers = staticPeers
	cfg.StateNotifier = &mock.MockStateNotifier{}
	cfg.NoDiscovery = true
	s, err := NewService(cfg)
	require.NoError(t, err)

	exitRoutine := make(chan bool)
	go func() {
		s.Start()
		<-exitRoutine
	}()
	// Send in a loop to ensure it is delivered (busy wait for the service to subscribe to the state feed).
	for sent := 0; sent == 0; {
		sent = s.stateNotifier.StateFeed().Send(&feed.Event{
			Type: statefeed.Initialized,
			Data: &statefeed.InitializedData{
				StartTime:             time.Now(),
				GenesisValidatorsRoot: make([]byte, 32),
			},
		})
	}
	time.Sleep(4 * time.Second)
	peers := s.host.Network().Peers()
	assert.Equal(t, 5, len(peers), "Not all peers added to peerstore")
	require.NoError(t, s.Stop())
	exitRoutine <- true
}
