// Handshake executes the eth protocol handshake, negotiating version number,
// network IDs, difficulties, head and genesis blocks.
func (p *peer) Handshake(network int, td *big.Int, head common.Hash, genesis common.Hash) error {
	// Send out own handshake in a new thread
	errc := make(chan error, 2)
	var status statusData // safe to read after two values have been received from errc

	go func() {
		errc <- p2p.Send(p.rw, StatusMsg, &statusData{
			ProtocolVersion: uint32(p.version),
			NetworkId:       uint32(network),
			TD:              td,
			CurrentBlock:    head,
			GenesisBlock:    genesis,
		})
	}()
	go func() {
		errc <- p.readStatus(network, &status, genesis)
	}()
	timeout := time.NewTimer(handshakeTimeout)
	defer timeout.Stop()
	for i := 0; i < 2; i++ {
		select {
		case err := <-errc:
			if err != nil {
				return err
			}
		case <-timeout.C:
			return p2p.DiscReadTimeout
		}
	}
	p.td, p.head = status.TD, status.CurrentBlock
	return nil
}

// SendBlocks sends a batch of blocks to the remote peer.
func (p *peer) SendBlocks(blocks []*types.Block) error {
	reqBlockOutPacketsMeter.Mark(1)
	for _, block := range blocks {
		reqBlockOutTrafficMeter.Mark(block.Size().Int64())
	}
	return p2p.Send(p.rw, BlocksMsg, blocks)
}

// sendTransactions sends transactions to the peer and includes the hashes
// in it's tx hash set for future reference. The tx hash will allow the
// manager to check whether the peer has already received this particular
// transaction
func (p *peer) sendTransactions(txs types.Transactions) error {
	for _, tx := range txs {
		p.txHashes.Add(tx.Hash())
	}

	return p2p.Send(p.rw, TxMsg, txs)
}

// SendNewBlock propagates an entire block to a remote peer.
func (p *peer) SendNewBlock(block *types.Block, td *big.Int) error {
	propBlockOutPacketsMeter.Mark(1)
	propBlockOutTrafficMeter.Mark(block.Size().Int64())

	p.knownBlocks.Add(block.Hash())
	return p2p.Send(p.rw, NewBlockMsg, []interface{}{block, td})
}

// SendTransactions sends transactions to the peer and includes the hashes
// in its transaction hash set for future reference.
func (p *peer) SendTransactions(txs types.Transactions) error {
	propTxnOutPacketsMeter.Mark(1)
	for _, tx := range txs {
		propTxnOutTrafficMeter.Mark(tx.Size().Int64())
		p.knownTxs.Add(tx.Hash())
	}
	return p2p.Send(p.rw, TxMsg, txs)
}

// SendNewBlockHashes announces the availability of a number of blocks through
// a hash notification.
func (p *peer) SendNewBlockHashes(hashes []common.Hash) error {
	propHashOutPacketsMeter.Mark(1)
	propHashOutTrafficMeter.Mark(int64(32 * len(hashes)))

	for _, hash := range hashes {
		p.knownBlocks.Add(hash)
	}
	return p2p.Send(p.rw, NewBlockHashesMsg, hashes)
}

func testGetReceipt(t *testing.T, protocol int) {
	// Define three accounts to simulate transactions with
	acc1Key, _ := crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
	acc2Key, _ := crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
	acc1Addr := crypto.PubkeyToAddress(acc1Key.PublicKey)
	acc2Addr := crypto.PubkeyToAddress(acc2Key.PublicKey)

	// Create a chain generator with some simple transactions (blatantly stolen from @fjl/chain_makerts_test)
	generator := func(i int, block *core.BlockGen) {
		switch i {
		case 0:
			// In block 1, the test bank sends account #1 some ether.
			tx, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(testBankKey)
			block.AddTx(tx)
		case 1:
			// In block 2, the test bank sends some more ether to account #1.
			// acc1Addr passes it on to account #2.
			tx1, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(testBankKey)
			tx2, _ := types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(acc1Key)
			block.AddTx(tx1)
			block.AddTx(tx2)
		case 2:
			// Block 3 is empty but was mined by account #2.
			block.SetCoinbase(acc2Addr)
			block.SetExtra([]byte("yeehaw"))
		case 3:
			// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
			b2 := block.PrevBlock(1).Header()
			b2.Extra = []byte("foo")
			block.AddUncle(b2)
			b3 := block.PrevBlock(2).Header()
			b3.Extra = []byte("foo")
			block.AddUncle(b3)
		}
	}
	// Assemble the test environment
	pm := newTestProtocolManager(4, generator, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Collect the hashes to request, and the response to expect
	hashes := []common.Hash{}
	for i := uint64(0); i <= pm.chainman.CurrentBlock().NumberU64(); i++ {
		for _, tx := range pm.chainman.GetBlockByNumber(i).Transactions() {
			hashes = append(hashes, tx.Hash())
		}
	}
	receipts := make([]*types.Receipt, len(hashes))
	for i, hash := range hashes {
		receipts[i] = core.GetReceipt(pm.chaindb, hash)
	}
	// Send the hash request and verify the response
	p2p.Send(peer.app, 0x0f, hashes)
	if err := p2p.ExpectMsg(peer.app, 0x10, receipts); err != nil {
		t.Errorf("receipts mismatch: %v", err)
	}
}

func TestPeerDeliver(t *testing.T) {
	// Start a tester and execute the handshake
	tester, err := startTestPeerInited()
	if err != nil {
		t.Fatalf("failed to start initialized peer: %v", err)
	}
	defer tester.stream.Close()

	// Watch for all inbound messages
	arrived := make(chan struct{}, 1)
	tester.client.Watch(Filter{
		Fn: func(message *Message) {
			arrived <- struct{}{}
		},
	})
	// Construct a message and deliver it to the tester peer
	message := NewMessage([]byte("peer broadcast test message"))
	envelope, err := message.Wrap(DefaultPoW, Options{
		TTL: DefaultTTL,
	})
	if err != nil {
		t.Fatalf("failed to wrap message: %v", err)
	}
	if err := p2p.Send(tester.stream, messagesCode, []*Envelope{envelope}); err != nil {
		t.Fatalf("failed to transfer message: %v", err)
	}
	// Check that the message is delivered upstream
	select {
	case <-arrived:
	case <-time.After(time.Second):
		t.Fatalf("message delivery timeout")
	}
	// Check that a resend is not delivered
	if err := p2p.Send(tester.stream, messagesCode, []*Envelope{envelope}); err != nil {
		t.Fatalf("failed to transfer message: %v", err)
	}
	select {
	case <-time.After(2 * transmissionCycle):
	case <-arrived:
		t.Fatalf("repeating message arrived")
	}
}

// SendNewBlockHashes announces the availability of a number of blocks through
// a hash notification.
func (p *peer) SendNewBlockHashes(hashes []common.Hash, numbers []uint64) error {
	for _, hash := range hashes {
		p.knownBlocks.Add(hash)
	}
	request := make(newBlockHashesData, len(hashes))
	for i := 0; i < len(hashes); i++ {
		request[i].Hash = hashes[i]
		request[i].Number = numbers[i]
	}
	return p2p.Send(p.rw, NewBlockHashesMsg, request)
}

// handshake simulates a trivial handshake that expects the same state from the
// remote side as we are simulating locally.
func (p *testPeer) handshake(t *testing.T, td *big.Int, head common.Hash, genesis common.Hash) {
	msg := &statusData{
		ProtocolVersion: uint32(p.version),
		NetworkId:       uint32(NetworkId),
		TD:              td,
		CurrentBlock:    head,
		GenesisBlock:    genesis,
	}
	if err := p2p.ExpectMsg(p.app, StatusMsg, msg); err != nil {
		t.Fatalf("status recv: %v", err)
	}
	if err := p2p.Send(p.app, StatusMsg, msg); err != nil {
		t.Fatalf("status send: %v", err)
	}
}

func (p *testPeer) handshake(t *testing.T) {
	td, currentBlock, genesis := p.pm.chainman.Status()
	msg := &statusMsgData{
		ProtocolVersion: uint32(p.pm.protVer),
		NetworkId:       uint32(p.pm.netId),
		TD:              td,
		CurrentBlock:    currentBlock,
		GenesisBlock:    genesis,
	}
	if err := p2p.ExpectMsg(p, StatusMsg, msg); err != nil {
		t.Fatalf("status recv: %v", err)
	}
	if err := p2p.Send(p, StatusMsg, msg); err != nil {
		t.Fatalf("status send: %v", err)
	}
}

func (p *peer) handleStatus() error {
	errc := make(chan error, 1)
	go func() {
		errc <- p2p.Send(p.rw, StatusMsg, &statusMsgData{
			ProtocolVersion: uint32(p.protv),
			NetworkId:       uint32(p.netid),
			TD:              p.ourTd,
			CurrentBlock:    p.ourHash,
			GenesisBlock:    p.genesis,
		})
	}()

	// read and handle remote status
	msg, err := p.rw.ReadMsg()
	if err != nil {
		return err
	}
	if msg.Code != StatusMsg {
		return errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
	}
	if msg.Size > ProtocolMaxMsgSize {
		return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
	}

	var status statusMsgData
	if err := msg.Decode(&status); err != nil {
		return errResp(ErrDecode, "msg %v: %v", msg, err)
	}

	if status.GenesisBlock != p.genesis {
		return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", status.GenesisBlock, p.genesis)
	}

	if int(status.NetworkId) != p.netid {
		return errResp(ErrNetworkIdMismatch, "%d (!= %d)", status.NetworkId, p.netid)
	}

	if int(status.ProtocolVersion) != p.protv {
		return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, p.protv)
	}
	// Set the total difficulty of the peer
	p.td = status.TD
	// set the best hash of the peer
	p.recentHash = status.CurrentBlock

	return <-errc
}

func TestStatusMsgErrors(t *testing.T) {
	pm := newProtocolManagerForTesting(nil)
	td, currentBlock, genesis := pm.chainman.Status()
	defer pm.Stop()

	tests := []struct {
		code      uint64
		data      interface{}
		wantError error
	}{
		{
			code: TxMsg, data: []interface{}{},
			wantError: errResp(ErrNoStatusMsg, "first msg has code 2 (!= 0)"),
		},
		{
			code: StatusMsg, data: statusMsgData{10, NetworkId, td, currentBlock, genesis},
			wantError: errResp(ErrProtocolVersionMismatch, "10 (!= 0)"),
		},
		{
			code: StatusMsg, data: statusMsgData{ProtocolVersion, 999, td, currentBlock, genesis},
			wantError: errResp(ErrNetworkIdMismatch, "999 (!= 0)"),
		},
		{
			code: StatusMsg, data: statusMsgData{ProtocolVersion, NetworkId, td, currentBlock, common.Hash{3}},
			wantError: errResp(ErrGenesisBlockMismatch, "0300000000000000000000000000000000000000000000000000000000000000 (!= %x)", genesis),
		},
	}

	for i, test := range tests {
		p, errc := newTestPeer(pm)
		// The send call might hang until reset because
		// the protocol might not read the payload.
		go p2p.Send(p, test.code, test.data)

		select {
		case err := <-errc:
			if err == nil {
				t.Errorf("test %d: protocol returned nil error, want %q", test.wantError)
			} else if err.Error() != test.wantError.Error() {
				t.Errorf("test %d: wrong error: got %q, want %q", i, err, test.wantError)
			}
		case <-time.After(2 * time.Second):
			t.Errorf("protocol did not shut down withing 2 seconds")
		}
		p.close()
	}
}

// broadcast iterates over the collection of envelopes and transmits yet unknown
// ones over the network.
func (self *peer) broadcast() error {
	// Fetch the envelopes and collect the unknown ones
	envelopes := self.host.envelopes()
	transmit := make([]*Envelope, 0, len(envelopes))
	for _, envelope := range envelopes {
		if !self.marked(envelope) {
			transmit = append(transmit, envelope)
			self.mark(envelope)
		}
	}
	// Transmit the unknown batch (potentially empty)
	if err := p2p.Send(self.ws, messagesCode, transmit); err != nil {
		return err
	}
	glog.V(logger.Detail).Infoln(self.peer, "broadcasted", len(transmit), "message(s)")
	return nil
}

// Handshake executes the eth protocol handshake, negotiating version number,
// network IDs, difficulties, head and genesis blocks.
func (p *peer) Handshake(td *big.Int, head common.Hash, genesis common.Hash) error {
	// Send out own handshake in a new thread
	errc := make(chan error, 1)
	go func() {
		errc <- p2p.Send(p.rw, StatusMsg, &statusData{
			ProtocolVersion: uint32(p.version),
			NetworkId:       uint32(p.network),
			TD:              td,
			CurrentBlock:    head,
			GenesisBlock:    genesis,
		})
	}()
	// In the mean time retrieve the remote status message
	msg, err := p.rw.ReadMsg()
	if err != nil {
		return err
	}
	if msg.Code != StatusMsg {
		return errResp(ErrNoStatusMsg, "first msg has code %x (!= %x)", msg.Code, StatusMsg)
	}
	if msg.Size > ProtocolMaxMsgSize {
		return errResp(ErrMsgTooLarge, "%v > %v", msg.Size, ProtocolMaxMsgSize)
	}
	// Decode the handshake and make sure everything matches
	var status statusData
	if err := msg.Decode(&status); err != nil {
		return errResp(ErrDecode, "msg %v: %v", msg, err)
	}
	if status.GenesisBlock != genesis {
		return errResp(ErrGenesisBlockMismatch, "%x (!= %x)", status.GenesisBlock, genesis)
	}
	if int(status.NetworkId) != p.network {
		return errResp(ErrNetworkIdMismatch, "%d (!= %d)", status.NetworkId, p.network)
	}
	if int(status.ProtocolVersion) != p.version {
		return errResp(ErrProtocolVersionMismatch, "%d (!= %d)", status.ProtocolVersion, p.version)
	}
	// Configure the remote peer, and sanity check out handshake too
	p.td, p.head = status.TD, status.CurrentBlock
	return <-errc
}

func testRecvTransactions(t *testing.T, protocol int) {
	txAdded := make(chan []*types.Transaction)
	pm := newTestProtocolManagerMust(t, false, 0, nil, txAdded)
	p, _ := newTestPeer("peer", protocol, pm, true)
	defer pm.Stop()
	defer p.close()

	tx := newTestTransaction(testAccount, 0, 0)
	if err := p2p.Send(p.app, TxMsg, []interface{}{tx}); err != nil {
		t.Fatalf("send error: %v", err)
	}
	select {
	case added := <-txAdded:
		if len(added) != 1 {
			t.Errorf("wrong number of added transactions: got %d, want 1", len(added))
		} else if added[0].Hash() != tx.Hash() {
			t.Errorf("added wrong tx hash: got %v, want %v", added[0].Hash(), tx.Hash())
		}
	case <-time.After(2 * time.Second):
		t.Errorf("no TxPreEvent received within 2 seconds")
	}
}

func testGetBlockHashes(t *testing.T, protocol int) {
	pm := newTestProtocolManagerMust(t, false, downloader.MaxHashFetch+15, nil, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Create a batch of tests for various scenarios
	limit := downloader.MaxHashFetch
	tests := []struct {
		origin common.Hash
		number int
		result int
	}{
		{common.Hash{}, 1, 0},                                   // Make sure non existent hashes don't return results
		{pm.blockchain.Genesis().Hash(), 1, 0},                  // There are no hashes to retrieve up from the genesis
		{pm.blockchain.GetBlockByNumber(5).Hash(), 5, 5},        // All the hashes including the genesis requested
		{pm.blockchain.GetBlockByNumber(5).Hash(), 10, 5},       // More hashes than available till the genesis requested
		{pm.blockchain.GetBlockByNumber(100).Hash(), 10, 10},    // All hashes available from the middle of the chain
		{pm.blockchain.CurrentBlock().Hash(), 10, 10},           // All hashes available from the head of the chain
		{pm.blockchain.CurrentBlock().Hash(), limit, limit},     // Request the maximum allowed hash count
		{pm.blockchain.CurrentBlock().Hash(), limit + 1, limit}, // Request more than the maximum allowed hash count
	}
	// Run each of the tests and verify the results against the chain
	for i, tt := range tests {
		// Assemble the hash response we would like to receive
		resp := make([]common.Hash, tt.result)
		if len(resp) > 0 {
			from := pm.blockchain.GetBlock(tt.origin).NumberU64() - 1
			for j := 0; j < len(resp); j++ {
				resp[j] = pm.blockchain.GetBlockByNumber(uint64(int(from) - j)).Hash()
			}
		}
		// Send the hash request and verify the response
		p2p.Send(peer.app, 0x03, getBlockHashesData{tt.origin, uint64(tt.number)})
		if err := p2p.ExpectMsg(peer.app, 0x04, resp); err != nil {
			t.Errorf("test %d: block hashes mismatch: %v", i, err)
		}
	}
}

func testGetBlockHashesFromNumber(t *testing.T, protocol int) {
	pm := newTestProtocolManagerMust(t, false, downloader.MaxHashFetch+15, nil, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Create a batch of tests for various scenarios
	limit := downloader.MaxHashFetch
	tests := []struct {
		origin uint64
		number int
		result int
	}{
		{pm.blockchain.CurrentBlock().NumberU64() + 1, 1, 0},     // Out of bounds requests should return empty
		{pm.blockchain.CurrentBlock().NumberU64(), 1, 1},         // Make sure the head hash can be retrieved
		{pm.blockchain.CurrentBlock().NumberU64() - 4, 5, 5},     // All hashes, including the head hash requested
		{pm.blockchain.CurrentBlock().NumberU64() - 4, 10, 5},    // More hashes requested than available till the head
		{pm.blockchain.CurrentBlock().NumberU64() - 100, 10, 10}, // All hashes available from the middle of the chain
		{0, 10, 10},           // All hashes available from the root of the chain
		{0, limit, limit},     // Request the maximum allowed hash count
		{0, limit + 1, limit}, // Request more than the maximum allowed hash count
		{0, 1, 1},             // Make sure the genesis hash can be retrieved
	}
	// Run each of the tests and verify the results against the chain
	for i, tt := range tests {
		// Assemble the hash response we would like to receive
		resp := make([]common.Hash, tt.result)
		for j := 0; j < len(resp); j++ {
			resp[j] = pm.blockchain.GetBlockByNumber(tt.origin + uint64(j)).Hash()
		}
		// Send the hash request and verify the response
		p2p.Send(peer.app, 0x08, getBlockHashesFromNumberData{tt.origin, uint64(tt.number)})
		if err := p2p.ExpectMsg(peer.app, 0x04, resp); err != nil {
			t.Errorf("test %d: block hashes mismatch: %v", i, err)
		}
	}
}

func (p *peer) requestBlocks(hashes []common.Hash) error {
	glog.V(logger.Debug).Infof("[%s] fetching %v blocks\n", p.id, len(hashes))
	return p2p.Send(p.rw, GetBlocksMsg, hashes)
}

func testGetNodeData(t *testing.T, protocol int) {
	// Define three accounts to simulate transactions with
	acc1Key, _ := crypto.HexToECDSA("8a1f9a8f95be41cd7ccb6168179afb4504aefe388d1e14474d32c45c72ce7b7a")
	acc2Key, _ := crypto.HexToECDSA("49a7b37aa6f6645917e7b807e9d1c00d4fa71f18343b0d4122a4d2df64dd6fee")
	acc1Addr := crypto.PubkeyToAddress(acc1Key.PublicKey)
	acc2Addr := crypto.PubkeyToAddress(acc2Key.PublicKey)

	// Create a chain generator with some simple transactions (blatantly stolen from @fjl/chain_makerts_test)
	generator := func(i int, block *core.BlockGen) {
		switch i {
		case 0:
			// In block 1, the test bank sends account #1 some ether.
			tx, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(10000), params.TxGas, nil, nil).SignECDSA(testBankKey)
			block.AddTx(tx)
		case 1:
			// In block 2, the test bank sends some more ether to account #1.
			// acc1Addr passes it on to account #2.
			tx1, _ := types.NewTransaction(block.TxNonce(testBankAddress), acc1Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(testBankKey)
			tx2, _ := types.NewTransaction(block.TxNonce(acc1Addr), acc2Addr, big.NewInt(1000), params.TxGas, nil, nil).SignECDSA(acc1Key)
			block.AddTx(tx1)
			block.AddTx(tx2)
		case 2:
			// Block 3 is empty but was mined by account #2.
			block.SetCoinbase(acc2Addr)
			block.SetExtra([]byte("yeehaw"))
		case 3:
			// Block 4 includes blocks 2 and 3 as uncle headers (with modified extra data).
			b2 := block.PrevBlock(1).Header()
			b2.Extra = []byte("foo")
			block.AddUncle(b2)
			b3 := block.PrevBlock(2).Header()
			b3.Extra = []byte("foo")
			block.AddUncle(b3)
		}
	}
	// Assemble the test environment
	pm := newTestProtocolManagerMust(t, false, 4, generator, nil)
	peer, _ := newTestPeer("peer", protocol, pm, true)
	defer peer.close()

	// Fetch for now the entire chain db
	hashes := []common.Hash{}
	for _, key := range pm.chaindb.(*ethdb.MemDatabase).Keys() {
		if len(key) == len(common.Hash{}) {
			hashes = append(hashes, common.BytesToHash(key))
		}
	}
	p2p.Send(peer.app, 0x0d, hashes)
	msg, err := peer.app.ReadMsg()
	if err != nil {
		t.Fatalf("failed to read node data response: %v", err)
	}
	if msg.Code != 0x0e {
		t.Fatalf("response packet code mismatch: have %x, want %x", msg.Code, 0x0c)
	}
	var data [][]byte
	if err := msg.Decode(&data); err != nil {
		t.Fatalf("failed to decode response node data: %v", err)
	}
	// Verify that all hashes correspond to the requested data, and reconstruct a state tree
	for i, want := range hashes {
		if hash := crypto.Sha3Hash(data[i]); hash != want {
			fmt.Errorf("data hash mismatch: have %x, want %x", hash, want)
		}
	}
	statedb, _ := ethdb.NewMemDatabase()
	for i := 0; i < len(data); i++ {
		statedb.Put(hashes[i].Bytes(), data[i])
	}
	accounts := []common.Address{testBankAddress, acc1Addr, acc2Addr}
	for i := uint64(0); i <= pm.blockchain.CurrentBlock().NumberU64(); i++ {
		trie, _ := state.New(pm.blockchain.GetBlockByNumber(i).Root(), statedb)

		for j, acc := range accounts {
			state, _ := pm.blockchain.State()
			bw := state.GetBalance(acc)
			bh := trie.GetBalance(acc)

			if (bw != nil && bh == nil) || (bw == nil && bh != nil) {
				t.Errorf("test %d, account %d: balance mismatch: have %v, want %v", i, j, bh, bw)
			}
			if bw != nil && bh != nil && bw.Cmp(bw) != 0 {
				t.Errorf("test %d, account %d: balance mismatch: have %v, want %v", i, j, bh, bw)
			}
		}
	}
}