// Copyright 2018 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package protocols

// import (
// 	"context"
// 	"flag"
// 	"fmt"
// 	"io/ioutil"
// 	"math/rand"
// 	"os"
// 	"path/filepath"
// 	"reflect"
// 	"sync"
// 	"testing"
// 	"time"

// 	"github.com/mattn/go-colorable"

// 	"github.com/ethereum/go-ethereum/log"
// 	"github.com/ethereum/go-ethereum/rpc"

// 	"github.com/ethereum/go-ethereum/node"
// 	"github.com/ethereum/go-ethereum/p2p"
// 	"github.com/ethereum/go-ethereum/p2p/enode"
// 	"github.com/ethereum/go-ethereum/p2p/simulations"
// 	"github.com/ethereum/go-ethereum/p2p/simulations/adapters"
// )

// const (
// 	content = "123456789"
// )

// var (
// 	nodes    = flag.Int("nodes", 30, "number of nodes to create (default 30)")
// 	msgs     = flag.Int("msgs", 100, "number of messages sent by node (default 100)")
// 	loglevel = flag.Int("loglevel", 0, "verbosity of logs")
// 	rawlog   = flag.Bool("rawlog", false, "remove terminal formatting from logs")
// )

// func init() {
// 	flag.Parse()
// 	log.PrintOrigins(true)
// 	log.Root().SetHandler(log.LvlFilterHandler(log.Lvl(*loglevel), log.StreamHandler(colorable.NewColorableStderr(), log.TerminalFormat(!*rawlog))))
// }

// //TestAccountingSimulation runs a p2p/simulations simulation
// //It creates a *nodes number of nodes, connects each one with each other,
// //then sends out a random selection of messages up to *msgs amount of messages
// //from the test protocol spec.
// //The spec has some accounted messages defined through the Prices interface.
// //The test does accounting for all the message exchanged, and then checks
// //that every node has the same balance with a peer, but with opposite signs.
// //Balance(AwithB) = 0 - Balance(BwithA) or Abs|Balance(AwithB)| == Abs|Balance(BwithA)|
// func TestAccountingSimulation(t *testing.T) {
// 	//setup the balances objects for every node
// 	bal := newBalances(*nodes)
// 	//setup the metrics system or tests will fail trying to write metrics
// 	dir, err := ioutil.TempDir("", "account-sim")
// 	if err != nil {
// 		t.Fatal(err)
// 	}
// 	defer os.RemoveAll(dir)
// 	SetupAccountingMetrics(1*time.Second, filepath.Join(dir, "metrics.db"))
// 	//define the node.Service for this test
// 	services := adapters.Services{
// 		"accounting": func(ctx *adapters.ServiceContext) (node.Service, error) {
// 			return bal.newNode(), nil
// 		},
// 	}
// 	//setup the simulation
// 	adapter := adapters.NewSimAdapter(services)
// 	net := simulations.NewNetwork(adapter, &simulations.NetworkConfig{DefaultService: "accounting"})
// 	defer net.Shutdown()

// 	// we send msgs messages per node, wait for all messages to arrive
// 	bal.wg.Add(*nodes * *msgs)
// 	trigger := make(chan enode.ID)
// 	go func() {
// 		// wait for all of them to arrive
// 		bal.wg.Wait()
// 		// then trigger a check
// 		// the selected node for the trigger is irrelevant,
// 		// we just want to trigger the end of the simulation
// 		trigger <- net.Nodes[0].ID()
// 	}()

// 	// create nodes and start them
// 	for i := 0; i < *nodes; i++ {
// 		conf := adapters.RandomNodeConfig()
// 		bal.id2n[conf.ID] = i
// 		if _, err := net.NewNodeWithConfig(conf); err != nil {
// 			t.Fatal(err)
// 		}
// 		if err := net.Start(conf.ID); err != nil {
// 			t.Fatal(err)
// 		}
// 	}
// 	// fully connect nodes
// 	for i, n := range net.Nodes {
// 		for _, m := range net.Nodes[i+1:] {
// 			if err := net.Connect(n.ID(), m.ID()); err != nil {
// 				t.Fatal(err)
// 			}
// 		}
// 	}

// 	// empty action
// 	action := func(ctx context.Context) error {
// 		return nil
// 	}
// 	// 	check always checks out
// 	check := func(ctx context.Context, id enode.ID) (bool, error) {
// 		return true, nil
// 	}

// 	// run simulation
// 	timeout := 30 * time.Second
// 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
// 	defer cancel()
// 	result := simulations.NewSimulation(net).Run(ctx, &simulations.Step{
// 		Action:  action,
// 		Trigger: trigger,
// 		Expect: &simulations.Expectation{
// 			Nodes: []enode.ID{net.Nodes[0].ID()},
// 			Check: check,
// 		},
// 	})

// 	if result.Error != nil {
// 		t.Fatal(result.Error)
// 	}

// 	// check if balance matrix is symmetric
// 	if err := bal.symmetric(); err != nil {
// 		t.Fatal(err)
// 	}
// }

// // matrix is a matrix of nodes and its balances
// // matrix is in fact a linear array of size n*n,
// // so the balance for any node A with B is at index
// // A*n + B, while the balance of node B with A is at
// // B*n + A
// // (n entries in the array will not be filled -
// //  the balance of a node with itself)
// type matrix struct {
// 	n int     //number of nodes
// 	m []int64 //array of balances
// }

// // create a new matrix
// func newMatrix(n int) *matrix {
// 	return &matrix{
// 		n: n,
// 		m: make([]int64, n*n),
// 	}
// }

// // called from the testBalance's Add accounting function: register balance change
// func (m *matrix) add(i, j int, v int64) error {
// 	// index for the balance of local node i with remote nodde j is
// 	// i * number of nodes + remote node
// 	mi := i*m.n + j
// 	// register that balance
// 	m.m[mi] += v
// 	return nil
// }

// // check that the balances are symmetric:
// // balance of node i with node j is the same as j with i but with inverted signs
// func (m *matrix) symmetric() error {
// 	//iterate all nodes
// 	for i := 0; i < m.n; i++ {
// 		//iterate starting +1
// 		for j := i + 1; j < m.n; j++ {
// 			log.Debug("bal", "1", i, "2", j, "i,j", m.m[i*m.n+j], "j,i", m.m[j*m.n+i])
// 			if m.m[i*m.n+j] != -m.m[j*m.n+i] {
// 				return fmt.Errorf("value mismatch. m[%v, %v] = %v; m[%v, %v] = %v", i, j, m.m[i*m.n+j], j, i, m.m[j*m.n+i])
// 			}
// 		}
// 	}
// 	return nil
// }

// // all the balances
// type balances struct {
// 	i int
// 	*matrix
// 	id2n map[enode.ID]int
// 	wg   *sync.WaitGroup
// }

// func newBalances(n int) *balances {
// 	return &balances{
// 		matrix: newMatrix(n),
// 		id2n:   make(map[enode.ID]int),
// 		wg:     &sync.WaitGroup{},
// 	}
// }

// // create a new testNode for every node created as part of the service
// func (b *balances) newNode() *testNode {
// 	defer func() { b.i++ }()
// 	return &testNode{
// 		bal:   b,
// 		i:     b.i,
// 		peers: make([]*testPeer, b.n), //a node will be connected to n-1 peers
// 	}
// }

// type testNode struct {
// 	bal       *balances
// 	i         int
// 	lock      sync.Mutex
// 	peers     []*testPeer
// 	peerCount int
// }

// // do the accounting for the peer's test protocol
// // testNode implements protocols.Balance
// func (t *testNode) Add(a int64, p *Peer) error {
// 	//get the index for the remote peer
// 	remote := t.bal.id2n[p.ID()]
// 	log.Debug("add", "local", t.i, "remote", remote, "amount", a)
// 	return t.bal.add(t.i, remote, a)
// }

// //run the p2p protocol
// //for every node, represented by testNode, create a remote testPeer
// func (t *testNode) run(p *p2p.Peer, rw p2p.MsgReadWriter) error {
// 	spec := createTestSpec()
// 	//create accounting hook
// 	spec.Hook = NewAccounting(t, &dummyPrices{})

// 	//create a peer for this node
// 	tp := &testPeer{NewPeer(p, rw, spec), t.i, t.bal.id2n[p.ID()], t.bal.wg}
// 	t.lock.Lock()
// 	t.peers[t.bal.id2n[p.ID()]] = tp
// 	t.peerCount++
// 	if t.peerCount == t.bal.n-1 {
// 		//when all peer connections are established, start sending messages from this peer
// 		go t.send()
// 	}
// 	t.lock.Unlock()
// 	return tp.Run(tp.handle)
// }

// // p2p message receive handler function
// func (tp *testPeer) handle(ctx context.Context, msg interface{}) error {
// 	tp.wg.Done()
// 	log.Debug("receive", "from", tp.remote, "to", tp.local, "type", reflect.TypeOf(msg), "msg", msg)
// 	return nil
// }

// type testPeer struct {
// 	*Peer
// 	local, remote int
// 	wg            *sync.WaitGroup
// }

// func (t *testNode) send() {
// 	log.Debug("start sending")
// 	for i := 0; i < *msgs; i++ {
// 		//determine randomly to which peer to send
// 		whom := rand.Intn(t.bal.n - 1)
// 		if whom >= t.i {
// 			whom++
// 		}
// 		t.lock.Lock()
// 		p := t.peers[whom]
// 		t.lock.Unlock()

// 		//determine a random message from the spec's messages to be sent
// 		which := rand.Intn(len(p.spec.Messages))
// 		msg := p.spec.Messages[which]
// 		switch msg.(type) {
// 		case *perBytesMsgReceiverPays:
// 			msg = &perBytesMsgReceiverPays{Content: content[:rand.Intn(len(content))]}
// 		case *perBytesMsgSenderPays:
// 			msg = &perBytesMsgSenderPays{Content: content[:rand.Intn(len(content))]}
// 		}
// 		log.Debug("send", "from", t.i, "to", whom, "type", reflect.TypeOf(msg), "msg", msg)
// 		p.Send(context.TODO(), msg)
// 	}
// }

// // define the protocol
// func (t *testNode) Protocols() []p2p.Protocol {
// 	return []p2p.Protocol{{
// 		Length: 100,
// 		Run:    t.run,
// 	}}
// }

// func (t *testNode) APIs() []rpc.API {
// 	return nil
// }

// func (t *testNode) Start(server *p2p.Server) error {
// 	return nil
// }

// func (t *testNode) Stop() error {
// 	return nil
// }