package privval

import (
	"fmt"
	"net"
	"testing"
	"time"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	"github.com/tendermint/tendermint/crypto/ed25519"
	cmn "github.com/tendermint/tendermint/libs/common"
	"github.com/tendermint/tendermint/libs/log"

	p2pconn "github.com/tendermint/tendermint/p2p/conn"
	"github.com/tendermint/tendermint/types"
)

var (
	testAcceptDeadline = defaultAcceptDeadlineSeconds * time.Second

	testConnDeadline    = 100 * time.Millisecond
	testConnDeadline2o3 = 66 * time.Millisecond // 2/3 of the other one

	testHeartbeatTimeout    = 10 * time.Millisecond
	testHeartbeatTimeout3o2 = 6 * time.Millisecond // 3/2 of the other one
)

func TestSocketPVAddress(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewMockPV())
	)
	defer sc.Stop()
	defer rs.Stop()

	serverAddr := rs.privVal.GetPubKey().Address()
	clientAddr := sc.GetPubKey().Address()

	assert.Equal(t, serverAddr, clientAddr)
}

func TestSocketPVPubKey(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewMockPV())
	)
	defer sc.Stop()
	defer rs.Stop()

	clientKey := sc.GetPubKey()

	privvalPubKey := rs.privVal.GetPubKey()

	assert.Equal(t, privvalPubKey, clientKey)
}

func TestSocketPVProposal(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewMockPV())

		ts             = time.Now()
		privProposal   = &types.Proposal{Timestamp: ts}
		clientProposal = &types.Proposal{Timestamp: ts}
	)
	defer sc.Stop()
	defer rs.Stop()

	require.NoError(t, rs.privVal.SignProposal(chainID, privProposal))
	require.NoError(t, sc.SignProposal(chainID, clientProposal))
	assert.Equal(t, privProposal.Signature, clientProposal.Signature)
}

func TestSocketPVVote(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewMockPV())

		ts    = time.Now()
		vType = types.PrecommitType
		want  = &types.Vote{Timestamp: ts, Type: vType}
		have  = &types.Vote{Timestamp: ts, Type: vType}
	)
	defer sc.Stop()
	defer rs.Stop()

	require.NoError(t, rs.privVal.SignVote(chainID, want))
	require.NoError(t, sc.SignVote(chainID, have))
	assert.Equal(t, want.Signature, have.Signature)
}

func TestSocketPVVoteResetDeadline(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewMockPV())

		ts    = time.Now()
		vType = types.PrecommitType
		want  = &types.Vote{Timestamp: ts, Type: vType}
		have  = &types.Vote{Timestamp: ts, Type: vType}
	)
	defer sc.Stop()
	defer rs.Stop()

	time.Sleep(testConnDeadline2o3)

	require.NoError(t, rs.privVal.SignVote(chainID, want))
	require.NoError(t, sc.SignVote(chainID, have))
	assert.Equal(t, want.Signature, have.Signature)

	// This would exceed the deadline if it was not extended by the previous message
	time.Sleep(testConnDeadline2o3)

	require.NoError(t, rs.privVal.SignVote(chainID, want))
	require.NoError(t, sc.SignVote(chainID, have))
	assert.Equal(t, want.Signature, have.Signature)
}

func TestSocketPVVoteKeepalive(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewMockPV())

		ts    = time.Now()
		vType = types.PrecommitType
		want  = &types.Vote{Timestamp: ts, Type: vType}
		have  = &types.Vote{Timestamp: ts, Type: vType}
	)
	defer sc.Stop()
	defer rs.Stop()

	time.Sleep(testConnDeadline * 2)

	require.NoError(t, rs.privVal.SignVote(chainID, want))
	require.NoError(t, sc.SignVote(chainID, have))
	assert.Equal(t, want.Signature, have.Signature)
}

func TestSocketPVDeadline(t *testing.T) {
	var (
		addr            = testFreeAddr(t)
		listenc         = make(chan struct{})
		thisConnTimeout = 100 * time.Millisecond
		sc              = newSocketVal(log.TestingLogger(), addr, thisConnTimeout)
	)

	go func(sc *SocketVal) {
		defer close(listenc)

		assert.Equal(t, sc.Start().(cmn.Error).Data(), ErrConnTimeout)

		assert.False(t, sc.IsRunning())
	}(sc)

	for {
		conn, err := cmn.Connect(addr)
		if err != nil {
			continue
		}

		_, err = p2pconn.MakeSecretConnection(
			conn,
			ed25519.GenPrivKey(),
		)
		if err == nil {
			break
		}
	}

	<-listenc
}

func TestRemoteSignerRetry(t *testing.T) {
	var (
		attemptc = make(chan int)
		retries  = 2
	)

	ln, err := net.Listen("tcp", "127.0.0.1:0")
	require.NoError(t, err)

	go func(ln net.Listener, attemptc chan<- int) {
		attempts := 0

		for {
			conn, err := ln.Accept()
			require.NoError(t, err)

			err = conn.Close()
			require.NoError(t, err)

			attempts++

			if attempts == retries {
				attemptc <- attempts
				break
			}
		}
	}(ln, attemptc)

	rs := NewRemoteSigner(
		log.TestingLogger(),
		cmn.RandStr(12),
		types.NewMockPV(),
		DialTCPFn(ln.Addr().String(), testConnDeadline, ed25519.GenPrivKey()),
	)
	defer rs.Stop()

	RemoteSignerConnDeadline(time.Millisecond)(rs)
	RemoteSignerConnRetries(retries)(rs)

	assert.Equal(t, rs.Start(), ErrDialRetryMax)

	select {
	case attempts := <-attemptc:
		assert.Equal(t, retries, attempts)
	case <-time.After(100 * time.Millisecond):
		t.Error("expected remote to observe connection attempts")
	}
}

func TestRemoteSignVoteErrors(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewErroringMockPV())

		ts    = time.Now()
		vType = types.PrecommitType
		vote  = &types.Vote{Timestamp: ts, Type: vType}
	)
	defer sc.Stop()
	defer rs.Stop()

	err := sc.SignVote("", vote)
	require.Equal(t, err.(*RemoteSignerError).Description, types.ErroringMockPVErr.Error())

	err = rs.privVal.SignVote(chainID, vote)
	require.Error(t, err)
	err = sc.SignVote(chainID, vote)
	require.Error(t, err)
}

func TestRemoteSignProposalErrors(t *testing.T) {
	var (
		chainID = cmn.RandStr(12)
		sc, rs  = testSetupSocketPair(t, chainID, types.NewErroringMockPV())

		ts       = time.Now()
		proposal = &types.Proposal{Timestamp: ts}
	)
	defer sc.Stop()
	defer rs.Stop()

	err := sc.SignProposal("", proposal)
	require.Equal(t, err.(*RemoteSignerError).Description, types.ErroringMockPVErr.Error())

	err = rs.privVal.SignProposal(chainID, proposal)
	require.Error(t, err)

	err = sc.SignProposal(chainID, proposal)
	require.Error(t, err)
}

func TestErrUnexpectedResponse(t *testing.T) {
	var (
		addr    = testFreeAddr(t)
		logger  = log.TestingLogger()
		chainID = cmn.RandStr(12)
		readyc  = make(chan struct{})
		errc    = make(chan error, 1)

		rs = NewRemoteSigner(
			logger,
			chainID,
			types.NewMockPV(),
			DialTCPFn(addr, testConnDeadline, ed25519.GenPrivKey()),
		)
		sc = newSocketVal(logger, addr, testConnDeadline)
	)

	testStartSocketPV(t, readyc, sc)
	defer sc.Stop()
	RemoteSignerConnDeadline(time.Millisecond)(rs)
	RemoteSignerConnRetries(100)(rs)
	// we do not want to Start() the remote signer here and instead use the connection to
	// reply with intentionally wrong replies below:
	rsConn, err := rs.connect()
	defer rsConn.Close()
	require.NoError(t, err)
	require.NotNil(t, rsConn)
	// send over public key to get the remote signer running:
	go testReadWriteResponse(t, &PubKeyResponse{}, rsConn)
	<-readyc

	// Proposal:
	go func(errc chan error) {
		errc <- sc.SignProposal(chainID, &types.Proposal{})
	}(errc)
	// read request and write wrong response:
	go testReadWriteResponse(t, &SignedVoteResponse{}, rsConn)
	err = <-errc
	require.Error(t, err)
	require.Equal(t, err, ErrUnexpectedResponse)

	// Vote:
	go func(errc chan error) {
		errc <- sc.SignVote(chainID, &types.Vote{})
	}(errc)
	// read request and write wrong response:
	go testReadWriteResponse(t, &SignedProposalResponse{}, rsConn)
	err = <-errc
	require.Error(t, err)
	require.Equal(t, err, ErrUnexpectedResponse)
}

func TestRetryTCPConnToRemoteSigner(t *testing.T) {
	var (
		addr    = testFreeAddr(t)
		logger  = log.TestingLogger()
		chainID = cmn.RandStr(12)
		readyc  = make(chan struct{})

		rs = NewRemoteSigner(
			logger,
			chainID,
			types.NewMockPV(),
			DialTCPFn(addr, testConnDeadline, ed25519.GenPrivKey()),
		)
		thisConnTimeout = testConnDeadline
		sc              = newSocketVal(logger, addr, thisConnTimeout)
	)
	// Ping every:
	SocketValHeartbeat(testHeartbeatTimeout)(sc)

	RemoteSignerConnDeadline(testConnDeadline)(rs)
	RemoteSignerConnRetries(10)(rs)

	testStartSocketPV(t, readyc, sc)
	defer sc.Stop()
	require.NoError(t, rs.Start())
	assert.True(t, rs.IsRunning())

	<-readyc
	time.Sleep(testHeartbeatTimeout * 2)

	rs.Stop()
	rs2 := NewRemoteSigner(
		logger,
		chainID,
		types.NewMockPV(),
		DialTCPFn(addr, testConnDeadline, ed25519.GenPrivKey()),
	)
	// let some pings pass
	time.Sleep(testHeartbeatTimeout3o2)
	require.NoError(t, rs2.Start())
	assert.True(t, rs2.IsRunning())
	defer rs2.Stop()

	// give the client some time to re-establish the conn to the remote signer
	// should see sth like this in the logs:
	//
	// E[10016-01-10|17:12:46.128] Ping                                         err="remote signer timed out"
	// I[10016-01-10|17:16:42.447] Re-created connection to remote signer       impl=SocketVal
	time.Sleep(testConnDeadline * 2)
}

func newSocketVal(logger log.Logger, addr string, connDeadline time.Duration) *SocketVal {
	ln, err := net.Listen(cmn.ProtocolAndAddress(addr))
	if err != nil {
		panic(err)
	}
	tcpLn := NewTCPListener(ln, ed25519.GenPrivKey())
	TCPListenerAcceptDeadline(testAcceptDeadline)(tcpLn)
	TCPListenerConnDeadline(testConnDeadline)(tcpLn)
	return NewSocketVal(logger, tcpLn)
}

func testSetupSocketPair(
	t *testing.T,
	chainID string,
	privValidator types.PrivValidator,
) (*SocketVal, *RemoteSigner) {
	var (
		addr    = testFreeAddr(t)
		logger  = log.TestingLogger()
		privVal = privValidator
		readyc  = make(chan struct{})
		rs      = NewRemoteSigner(
			logger,
			chainID,
			privVal,
			DialTCPFn(addr, testConnDeadline, ed25519.GenPrivKey()),
		)

		thisConnTimeout = testConnDeadline
		sc              = newSocketVal(logger, addr, thisConnTimeout)
	)

	SocketValHeartbeat(testHeartbeatTimeout)(sc)
	RemoteSignerConnDeadline(testConnDeadline)(rs)
	RemoteSignerConnRetries(1e6)(rs)

	testStartSocketPV(t, readyc, sc)

	require.NoError(t, rs.Start())
	assert.True(t, rs.IsRunning())

	<-readyc

	return sc, rs
}

func testReadWriteResponse(t *testing.T, resp RemoteSignerMsg, rsConn net.Conn) {
	_, err := readMsg(rsConn)
	require.NoError(t, err)

	err = writeMsg(rsConn, resp)
	require.NoError(t, err)
}

func testStartSocketPV(t *testing.T, readyc chan struct{}, sc *SocketVal) {
	go func(sc *SocketVal) {
		require.NoError(t, sc.Start())
		assert.True(t, sc.IsRunning())

		readyc <- struct{}{}
	}(sc)
}

// testFreeAddr claims a free port so we don't block on listener being ready.
func testFreeAddr(t *testing.T) string {
	ln, err := net.Listen("tcp", "127.0.0.1:0")
	require.NoError(t, err)
	defer ln.Close()

	return fmt.Sprintf("127.0.0.1:%d", ln.Addr().(*net.TCPAddr).Port)
}