package nebula

import (
	"fmt"
	"net"
	"testing"

	"github.com/golang/protobuf/proto"
	"github.com/stretchr/testify/assert"
)

//TODO: Add a test to ensure udpAddr is copied and not reused

func TestOldIPv4Only(t *testing.T) {
	// This test ensures our new ipv6 enabled LH protobuf IpAndPorts works with the old style to enable backwards compatibility
	b := []byte{8, 129, 130, 132, 80, 16, 10}
	var m Ip4AndPort
	err := proto.Unmarshal(b, &m)
	assert.NoError(t, err)
	assert.Equal(t, "10.1.1.1", int2ip(m.GetIp()).String())
}

func TestNewLhQuery(t *testing.T) {
	myIp := net.ParseIP("192.1.1.1")
	myIpint := ip2int(myIp)

	// Generating a new lh query should work
	a := NewLhQueryByInt(myIpint)

	// The result should be a nebulameta protobuf
	assert.IsType(t, &NebulaMeta{}, a)

	// It should also Marshal fine
	b, err := proto.Marshal(a)
	assert.Nil(t, err)

	// and then Unmarshal fine
	n := &NebulaMeta{}
	err = proto.Unmarshal(b, n)
	assert.Nil(t, err)

}

func Test_lhStaticMapping(t *testing.T) {
	l := NewTestLogger()
	lh1 := "10.128.0.2"
	lh1IP := net.ParseIP(lh1)

	udpServer, _ := NewListener(l, "0.0.0.0", 0, true)

	meh := NewLightHouse(l, true, 1, []uint32{ip2int(lh1IP)}, 10, 10003, udpServer, false, 1, false)
	meh.AddRemote(ip2int(lh1IP), NewUDPAddr(lh1IP, uint16(4242)), true)
	err := meh.ValidateLHStaticEntries()
	assert.Nil(t, err)

	lh2 := "10.128.0.3"
	lh2IP := net.ParseIP(lh2)

	meh = NewLightHouse(l, true, 1, []uint32{ip2int(lh1IP), ip2int(lh2IP)}, 10, 10003, udpServer, false, 1, false)
	meh.AddRemote(ip2int(lh1IP), NewUDPAddr(lh1IP, uint16(4242)), true)
	err = meh.ValidateLHStaticEntries()
	assert.EqualError(t, err, "Lighthouse 10.128.0.3 does not have a static_host_map entry")
}

func BenchmarkLighthouseHandleRequest(b *testing.B) {
	l := NewTestLogger()
	lh1 := "10.128.0.2"
	lh1IP := net.ParseIP(lh1)

	udpServer, _ := NewListener(l, "0.0.0.0", 0, true)

	lh := NewLightHouse(l, true, 1, []uint32{ip2int(lh1IP)}, 10, 10003, udpServer, false, 1, false)

	hAddr := NewUDPAddrFromString("4.5.6.7:12345")
	hAddr2 := NewUDPAddrFromString("4.5.6.7:12346")
	lh.addrMap[3] = &ip4And6{v4: []*Ip4AndPort{
		NewIp4AndPort(hAddr.IP, uint32(hAddr.Port)),
		NewIp4AndPort(hAddr2.IP, uint32(hAddr2.Port))},
	}

	rAddr := NewUDPAddrFromString("1.2.2.3:12345")
	rAddr2 := NewUDPAddrFromString("1.2.2.3:12346")
	lh.addrMap[2] = &ip4And6{v4: []*Ip4AndPort{
		NewIp4AndPort(rAddr.IP, uint32(rAddr.Port)),
		NewIp4AndPort(rAddr2.IP, uint32(rAddr2.Port))},
	}

	mw := &mockEncWriter{}

	b.Run("notfound", func(b *testing.B) {
		lhh := lh.NewRequestHandler()
		req := &NebulaMeta{
			Type: NebulaMeta_HostQuery,
			Details: &NebulaMetaDetails{
				VpnIp:       4,
				Ip4AndPorts: nil,
			},
		}
		p, err := proto.Marshal(req)
		assert.NoError(b, err)
		for n := 0; n < b.N; n++ {
			lhh.HandleRequest(rAddr, 2, p, mw)
		}
	})
	b.Run("found", func(b *testing.B) {
		lhh := lh.NewRequestHandler()
		req := &NebulaMeta{
			Type: NebulaMeta_HostQuery,
			Details: &NebulaMetaDetails{
				VpnIp:       3,
				Ip4AndPorts: nil,
			},
		}
		p, err := proto.Marshal(req)
		assert.NoError(b, err)

		for n := 0; n < b.N; n++ {
			lhh.HandleRequest(rAddr, 2, p, mw)
		}
	})
}

func TestLighthouse_Memory(t *testing.T) {
	l := NewTestLogger()

	myUdpAddr0 := &udpAddr{IP: net.ParseIP("10.0.0.2"), Port: 4242}
	myUdpAddr1 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4242}
	myUdpAddr2 := &udpAddr{IP: net.ParseIP("172.16.0.2"), Port: 4242}
	myUdpAddr3 := &udpAddr{IP: net.ParseIP("100.152.0.2"), Port: 4242}
	myUdpAddr4 := &udpAddr{IP: net.ParseIP("24.15.0.2"), Port: 4242}
	myUdpAddr5 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4243}
	myUdpAddr6 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4244}
	myUdpAddr7 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4245}
	myUdpAddr8 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4246}
	myUdpAddr9 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4247}
	myUdpAddr10 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4248}
	myUdpAddr11 := &udpAddr{IP: net.ParseIP("192.168.0.2"), Port: 4249}
	myVpnIp := ip2int(net.ParseIP("10.128.0.2"))

	theirUdpAddr0 := &udpAddr{IP: net.ParseIP("10.0.0.3"), Port: 4242}
	theirUdpAddr1 := &udpAddr{IP: net.ParseIP("192.168.0.3"), Port: 4242}
	theirUdpAddr2 := &udpAddr{IP: net.ParseIP("172.16.0.3"), Port: 4242}
	theirUdpAddr3 := &udpAddr{IP: net.ParseIP("100.152.0.3"), Port: 4242}
	theirUdpAddr4 := &udpAddr{IP: net.ParseIP("24.15.0.3"), Port: 4242}
	theirVpnIp := ip2int(net.ParseIP("10.128.0.3"))

	lhIP := net.ParseIP("10.128.0.1")
	udpServer, _ := NewListener(l, "0.0.0.0", 0, true)
	lh := NewLightHouse(l, true, 1, []uint32{ip2int(lhIP)}, 10, 10003, udpServer, false, 1, false)
	lhh := lh.NewRequestHandler()

	// Test that my first update responds with just that
	newLHHostUpdate(myUdpAddr0, myVpnIp, []*udpAddr{myUdpAddr1, myUdpAddr2}, lhh)
	r := newLHHostRequest(myUdpAddr0, myVpnIp, myVpnIp, lhh)
	assertIp4InArray(t, r.msg.Details.Ip4AndPorts, myUdpAddr1, myUdpAddr2)

	// Ensure we don't accumulate addresses
	newLHHostUpdate(myUdpAddr0, myVpnIp, []*udpAddr{myUdpAddr3}, lhh)
	r = newLHHostRequest(myUdpAddr0, myVpnIp, myVpnIp, lhh)
	assertIp4InArray(t, r.msg.Details.Ip4AndPorts, myUdpAddr3)

	// Grow it back to 2
	newLHHostUpdate(myUdpAddr0, myVpnIp, []*udpAddr{myUdpAddr1, myUdpAddr4}, lhh)
	r = newLHHostRequest(myUdpAddr0, myVpnIp, myVpnIp, lhh)
	assertIp4InArray(t, r.msg.Details.Ip4AndPorts, myUdpAddr1, myUdpAddr4)

	// Update a different host
	newLHHostUpdate(theirUdpAddr0, theirVpnIp, []*udpAddr{theirUdpAddr1, theirUdpAddr2, theirUdpAddr3, theirUdpAddr4}, lhh)
	r = newLHHostRequest(theirUdpAddr0, theirVpnIp, myVpnIp, lhh)
	assertIp4InArray(t, r.msg.Details.Ip4AndPorts, theirUdpAddr1, theirUdpAddr2, theirUdpAddr3, theirUdpAddr4)

	// Make sure we didn't get changed
	r = newLHHostRequest(myUdpAddr0, myVpnIp, myVpnIp, lhh)
	assertIp4InArray(t, r.msg.Details.Ip4AndPorts, myUdpAddr1, myUdpAddr4)

	// Finally ensure proper ordering and limiting
	// Send 12 addrs, get 10 back, one removed on a dupe check the other by limiting
	newLHHostUpdate(
		myUdpAddr0,
		myVpnIp,
		[]*udpAddr{
			myUdpAddr1,
			myUdpAddr2,
			myUdpAddr3,
			myUdpAddr4,
			myUdpAddr5,
			myUdpAddr5, //Duplicated on purpose
			myUdpAddr6,
			myUdpAddr7,
			myUdpAddr8,
			myUdpAddr9,
			myUdpAddr10,
			myUdpAddr11, // This should get cut
		}, lhh)
	r = newLHHostRequest(myUdpAddr0, myVpnIp, myVpnIp, lhh)
	assertIp4InArray(
		t,
		r.msg.Details.Ip4AndPorts,
		myUdpAddr1, myUdpAddr2, myUdpAddr3, myUdpAddr4, myUdpAddr5, myUdpAddr6, myUdpAddr7, myUdpAddr8, myUdpAddr9, myUdpAddr10,
	)
}

func newLHHostRequest(fromAddr *udpAddr, myVpnIp, queryVpnIp uint32, lhh *LightHouseHandler) testLhReply {
	req := &NebulaMeta{
		Type: NebulaMeta_HostQuery,
		Details: &NebulaMetaDetails{
			VpnIp: queryVpnIp,
		},
	}

	b, err := req.Marshal()
	if err != nil {
		panic(err)
	}

	w := &testEncWriter{}
	lhh.HandleRequest(fromAddr, myVpnIp, b, w)
	return w.lastReply
}

func newLHHostUpdate(fromAddr *udpAddr, vpnIp uint32, addrs []*udpAddr, lhh *LightHouseHandler) {
	req := &NebulaMeta{
		Type: NebulaMeta_HostUpdateNotification,
		Details: &NebulaMetaDetails{
			VpnIp:       vpnIp,
			Ip4AndPorts: make([]*Ip4AndPort, len(addrs)),
		},
	}

	for k, v := range addrs {
		req.Details.Ip4AndPorts[k] = &Ip4AndPort{Ip: ip2int(v.IP), Port: uint32(v.Port)}
	}

	b, err := req.Marshal()
	if err != nil {
		panic(err)
	}

	w := &testEncWriter{}
	lhh.HandleRequest(fromAddr, vpnIp, b, w)
}

func Test_lhRemoteAllowList(t *testing.T) {
	l := NewTestLogger()
	c := NewConfig(l)
	c.Settings["remoteallowlist"] = map[interface{}]interface{}{
		"10.20.0.0/12": false,
	}
	allowList, err := c.GetAllowList("remoteallowlist", false)
	assert.Nil(t, err)

	lh1 := "10.128.0.2"
	lh1IP := net.ParseIP(lh1)

	udpServer, _ := NewListener(l, "0.0.0.0", 0, true)

	lh := NewLightHouse(l, true, 1, []uint32{ip2int(lh1IP)}, 10, 10003, udpServer, false, 1, false)
	lh.SetRemoteAllowList(allowList)

	// A disallowed ip should not enter the cache but we should end up with an empty entry in the addrMap
	remote1IP := net.ParseIP("10.20.0.3")
	lh.AddRemote(ip2int(remote1IP), NewUDPAddr(remote1IP, uint16(4242)), true)
	assert.NotNil(t, lh.addrMap[ip2int(remote1IP)])
	assert.Empty(t, lh.addrMap[ip2int(remote1IP)].v4)
	assert.Empty(t, lh.addrMap[ip2int(remote1IP)].v6)

	// Make sure a good ip enters the cache and addrMap
	remote2IP := net.ParseIP("10.128.0.3")
	remote2UDPAddr := NewUDPAddr(remote2IP, uint16(4242))
	lh.AddRemote(ip2int(remote2IP), remote2UDPAddr, true)
	assertIp4InArray(t, lh.addrMap[ip2int(remote2IP)].learnedV4, remote2UDPAddr)

	// Another good ip gets into the cache, ordering is inverted
	remote3IP := net.ParseIP("10.128.0.4")
	remote3UDPAddr := NewUDPAddr(remote3IP, uint16(4243))
	lh.AddRemote(ip2int(remote2IP), remote3UDPAddr, true)
	assertIp4InArray(t, lh.addrMap[ip2int(remote2IP)].learnedV4, remote3UDPAddr, remote2UDPAddr)

	// If we exceed the length limit we should only have the most recent addresses
	addedAddrs := []*udpAddr{}
	for i := 0; i < 11; i++ {
		remoteUDPAddr := NewUDPAddr(net.IP{10, 128, 0, 4}, uint16(4243+i))
		lh.AddRemote(ip2int(remote2IP), remoteUDPAddr, true)
		// The first entry here is a duplicate, don't add it to the assert list
		if i != 0 {
			addedAddrs = append(addedAddrs, remoteUDPAddr)
		}
	}

	// We should only have the last 10 of what we tried to add
	assert.True(t, len(addedAddrs) >= 10, "We should have tried to add at least 10 addresses")
	ln := len(addedAddrs)
	assertIp4InArray(
		t,
		lh.addrMap[ip2int(remote2IP)].learnedV4,
		addedAddrs[ln-1],
		addedAddrs[ln-2],
		addedAddrs[ln-3],
		addedAddrs[ln-4],
		addedAddrs[ln-5],
		addedAddrs[ln-6],
		addedAddrs[ln-7],
		addedAddrs[ln-8],
		addedAddrs[ln-9],
		addedAddrs[ln-10],
	)
}

type testLhReply struct {
	nebType    NebulaMessageType
	nebSubType NebulaMessageSubType
	vpnIp      uint32
	msg        *NebulaMeta
}

type testEncWriter struct {
	lastReply testLhReply
}

func (tw *testEncWriter) SendMessageToVpnIp(t NebulaMessageType, st NebulaMessageSubType, vpnIp uint32, p, _, _ []byte) {
	tw.lastReply = testLhReply{
		nebType:    t,
		nebSubType: st,
		vpnIp:      vpnIp,
		msg:        &NebulaMeta{},
	}

	err := proto.Unmarshal(p, tw.lastReply.msg)
	if err != nil {
		panic(err)
	}
}

// assertIp4InArray asserts every address in want is at the same position in have and that the lengths match
func assertIp4InArray(t *testing.T, have []*Ip4AndPort, want ...*udpAddr) {
	assert.Len(t, have, len(want))
	for k, w := range want {
		if !(have[k].Ip == ip2int(w.IP) && have[k].Port == uint32(w.Port)) {
			assert.Fail(t, fmt.Sprintf("Response did not contain: %v:%v at %v; %v", w.IP, w.Port, k, translateV4toUdpAddr(have)))
		}
	}
}

func translateV4toUdpAddr(ips []*Ip4AndPort) []*udpAddr {
	addrs := make([]*udpAddr, len(ips))
	for k, v := range ips {
		addrs[k] = NewUDPAddrFromLH4(v)
	}
	return addrs
}