package node

import (
	"bytes"
	"io/ioutil"
	"net"
	"net/http"
	"strings"
	"sync"
	"time"

	. "github.com/tendermint/go-common"
	cfg "github.com/tendermint/go-config"
	"github.com/tendermint/go-crypto"
	dbm "github.com/tendermint/go-db"
	"github.com/tendermint/go-events"
	"github.com/tendermint/go-p2p"
	"github.com/tendermint/go-rpc"
	"github.com/tendermint/go-rpc/server"
	"github.com/tendermint/go-wire"
	bc "github.com/tendermint/tendermint/blockchain"
	"github.com/tendermint/tendermint/consensus"
	mempl "github.com/tendermint/tendermint/mempool"
	"github.com/tendermint/tendermint/proxy"
	rpccore "github.com/tendermint/tendermint/rpc/core"
	sm "github.com/tendermint/tendermint/state"
	"github.com/tendermint/tendermint/types"
	"github.com/tendermint/tendermint/version"
	tmspcli "github.com/tendermint/tmsp/client"
	"github.com/tendermint/tmsp/example/dummy"
	"github.com/tendermint/tmsp/example/nil"
)

import _ "net/http/pprof"

type Node struct {
	config           cfg.Config
	sw               *p2p.Switch
	evsw             *events.EventSwitch
	blockStore       *bc.BlockStore
	bcReactor        *bc.BlockchainReactor
	mempoolReactor   *mempl.MempoolReactor
	consensusState   *consensus.ConsensusState
	consensusReactor *consensus.ConsensusReactor
	privValidator    *types.PrivValidator
	genesisDoc       *types.GenesisDoc
	privKey          crypto.PrivKeyEd25519
}

func NewNode(config cfg.Config, privValidator *types.PrivValidator, getProxyApp func(proxyAddr, transport string, appHash []byte) proxy.AppConn) *Node {

	EnsureDir(config.GetString("db_dir"), 0700) // incase we use memdb, cswal still gets written here

	// Get BlockStore
	blockStoreDB := dbm.NewDB("blockstore", config.GetString("db_backend"), config.GetString("db_dir"))
	blockStore := bc.NewBlockStore(blockStoreDB)

	// Get State db
	stateDB := dbm.NewDB("state", config.GetString("db_backend"), config.GetString("db_dir"))

	// Get State
	state := getState(config, stateDB)

	// Create two proxyAppConn connections,
	// one for the consensus and one for the mempool.
	proxyAddr := config.GetString("proxy_app")
	transport := config.GetString("tmsp")
	proxyAppConnMempool := getProxyApp(proxyAddr, transport, state.AppHash)
	proxyAppConnConsensus := getProxyApp(proxyAddr, transport, state.AppHash)

	// add the chainid and number of validators to the global config
	config.Set("chain_id", state.ChainID)
	config.Set("num_vals", state.Validators.Size())

	// Generate node PrivKey
	privKey := crypto.GenPrivKeyEd25519()

	// Make event switch
	eventSwitch := events.NewEventSwitch()
	_, err := eventSwitch.Start()
	if err != nil {
		Exit(Fmt("Failed to start switch: %v", err))
	}

	// Decide whether to fast-sync or not
	// We don't fast-sync when the only validator is us.
	fastSync := config.GetBool("fast_sync")
	if state.Validators.Size() == 1 {
		addr, _ := state.Validators.GetByIndex(0)
		if bytes.Equal(privValidator.Address, addr) {
			fastSync = false
		}
	}

	// Make BlockchainReactor
	bcReactor := bc.NewBlockchainReactor(state.Copy(), proxyAppConnConsensus, blockStore, fastSync)

	// Make MempoolReactor
	mempool := mempl.NewMempool(config, proxyAppConnMempool)
	mempoolReactor := mempl.NewMempoolReactor(config, mempool)

	// Make ConsensusReactor
	consensusState := consensus.NewConsensusState(config, state.Copy(), proxyAppConnConsensus, blockStore, mempool)
	consensusReactor := consensus.NewConsensusReactor(consensusState, blockStore, fastSync)
	if privValidator != nil {
		consensusReactor.SetPrivValidator(privValidator)
	}

	// deterministic accountability
	err = consensusState.OpenWAL(config.GetString("cswal"))
	if err != nil {
		log.Error("Failed to open cswal", "error", err.Error())
	}

	// Make p2p network switch
	sw := p2p.NewSwitch(config.GetConfig("p2p"))
	sw.AddReactor("MEMPOOL", mempoolReactor)
	sw.AddReactor("BLOCKCHAIN", bcReactor)
	sw.AddReactor("CONSENSUS", consensusReactor)

	// add the event switch to all services
	// they should all satisfy events.Eventable
	SetEventSwitch(eventSwitch, bcReactor, mempoolReactor, consensusReactor)

	// run the profile server
	profileHost := config.GetString("prof_laddr")
	if profileHost != "" {
		go func() {
			log.Warn("Profile server", "error", http.ListenAndServe(profileHost, nil))
		}()
	}

	return &Node{
		config:           config,
		sw:               sw,
		evsw:             eventSwitch,
		blockStore:       blockStore,
		bcReactor:        bcReactor,
		mempoolReactor:   mempoolReactor,
		consensusState:   consensusState,
		consensusReactor: consensusReactor,
		privValidator:    privValidator,
		genesisDoc:       state.GenesisDoc,
		privKey:          privKey,
	}
}

// Call Start() after adding the listeners.
func (n *Node) Start() error {
	n.sw.SetNodeInfo(makeNodeInfo(n.config, n.sw, n.privKey))
	n.sw.SetNodePrivKey(n.privKey)
	_, err := n.sw.Start()
	return err
}

func (n *Node) Stop() {
	log.Notice("Stopping Node")
	// TODO: gracefully disconnect from peers.
	n.sw.Stop()
}

// Add the event switch to reactors, mempool, etc.
func SetEventSwitch(evsw *events.EventSwitch, eventables ...events.Eventable) {
	for _, e := range eventables {
		e.SetEventSwitch(evsw)
	}
}

// Add a Listener to accept inbound peer connections.
// Add listeners before starting the Node.
// The first listener is the primary listener (in NodeInfo)
func (n *Node) AddListener(l p2p.Listener) {
	log.Notice(Fmt("Added %v", l))
	n.sw.AddListener(l)
}

func (n *Node) StartRPC() ([]net.Listener, error) {
	rpccore.SetConfig(n.config)

	rpccore.SetEventSwitch(n.evsw)
	rpccore.SetBlockStore(n.blockStore)
	rpccore.SetConsensusState(n.consensusState)
	rpccore.SetConsensusReactor(n.consensusReactor)
	rpccore.SetMempoolReactor(n.mempoolReactor)
	rpccore.SetSwitch(n.sw)
	rpccore.SetPrivValidator(n.privValidator)
	rpccore.SetGenesisDoc(n.genesisDoc)

	listenAddrs := strings.Split(n.config.GetString("rpc_laddr"), ",")

	// we may expose the rpc over both a unix and tcp socket
	listeners := make([]net.Listener, len(listenAddrs))
	for i, listenAddr := range listenAddrs {
		mux := http.NewServeMux()
		wm := rpcserver.NewWebsocketManager(rpccore.Routes, n.evsw)
		mux.HandleFunc("/websocket", wm.WebsocketHandler)
		rpcserver.RegisterRPCFuncs(mux, rpccore.Routes)
		listener, err := rpcserver.StartHTTPServer(listenAddr, mux)
		if err != nil {
			return nil, err
		}
		listeners[i] = listener
	}
	return listeners, nil
}

func (n *Node) Switch() *p2p.Switch {
	return n.sw
}

func (n *Node) BlockStore() *bc.BlockStore {
	return n.blockStore
}

func (n *Node) ConsensusState() *consensus.ConsensusState {
	return n.consensusState
}

func (n *Node) ConsensusReactor() *consensus.ConsensusReactor {
	return n.consensusReactor
}

func (n *Node) MempoolReactor() *mempl.MempoolReactor {
	return n.mempoolReactor
}

func (n *Node) EventSwitch() *events.EventSwitch {
	return n.evsw
}

// XXX: for convenience
func (n *Node) PrivValidator() *types.PrivValidator {
	return n.privValidator
}

func makeNodeInfo(config cfg.Config, sw *p2p.Switch, privKey crypto.PrivKeyEd25519) *p2p.NodeInfo {

	nodeInfo := &p2p.NodeInfo{
		PubKey:  privKey.PubKey().(crypto.PubKeyEd25519),
		Moniker: config.GetString("moniker"),
		Network: config.GetString("chain_id"),
		Version: version.Version,
		Other: []string{
			Fmt("wire_version=%v", wire.Version),
			Fmt("p2p_version=%v", p2p.Version),
			Fmt("consensus_version=%v", consensus.Version),
			Fmt("rpc_version=%v/%v", rpc.Version, rpccore.Version),
		},
	}

	// include git hash in the nodeInfo if available
	if rev, err := ReadFile(config.GetString("revision_file")); err == nil {
		nodeInfo.Other = append(nodeInfo.Other, Fmt("revision=%v", string(rev)))
	}

	if !sw.IsListening() {
		return nodeInfo
	}

	p2pListener := sw.Listeners()[0]
	p2pHost := p2pListener.ExternalAddress().IP.String()
	p2pPort := p2pListener.ExternalAddress().Port
	rpcListenAddr := config.GetString("rpc_laddr")

	// We assume that the rpcListener has the same ExternalAddress.
	// This is probably true because both P2P and RPC listeners use UPnP,
	// except of course if the rpc is only bound to localhost
	nodeInfo.ListenAddr = Fmt("%v:%v", p2pHost, p2pPort)
	nodeInfo.Other = append(nodeInfo.Other, Fmt("rpc_addr=%v", rpcListenAddr))
	return nodeInfo
}

// Get a connection to the proxyAppConn addr.
// Check the current hash, and panic if it doesn't match.
func GetProxyApp(addr, transport string, hash []byte) (proxyAppConn proxy.AppConn) {
	// use local app (for testing)
	switch addr {
	case "nilapp":
		app := nilapp.NewNilApplication()
		mtx := new(sync.Mutex)
		proxyAppConn = tmspcli.NewLocalClient(mtx, app)
	case "dummy":
		app := dummy.NewDummyApplication()
		mtx := new(sync.Mutex)
		proxyAppConn = tmspcli.NewLocalClient(mtx, app)
	default:
		// Run forever in a loop
		remoteApp, err := proxy.NewRemoteAppConn(addr, transport)
		if err != nil {
			Exit(Fmt("Failed to connect to proxy for mempool: %v", err))
		}
		proxyAppConn = remoteApp
	}

	// Check the hash
	res := proxyAppConn.CommitSync()
	if res.IsErr() {
		PanicCrisis(Fmt("Error in getting proxyAppConn hash: %v", res))
	}
	if !bytes.Equal(hash, res.Data) {
		log.Warn(Fmt("ProxyApp hash does not match.  Expected %X, got %X", hash, res.Data))
	}

	return proxyAppConn
}

// Load the most recent state from "state" db,
// or create a new one (and save) from genesis.
func getState(config cfg.Config, stateDB dbm.DB) *sm.State {
	state := sm.LoadState(stateDB)
	if state == nil {
		state = sm.MakeGenesisStateFromFile(stateDB, config.GetString("genesis_file"))
		state.Save()
	}
	return state
}

//------------------------------------------------------------------------------

// Users wishing to use an external signer for their validators
// should fork tendermint/tendermint and implement RunNode to
// load their custom priv validator and call NewNode(privVal, getProxyFunc)
func RunNode(config cfg.Config) {
	// Wait until the genesis doc becomes available
	genDocFile := config.GetString("genesis_file")
	if !FileExists(genDocFile) {
		log.Notice(Fmt("Waiting for genesis file %v...", genDocFile))
		for {
			time.Sleep(time.Second)
			if !FileExists(genDocFile) {
				continue
			}
			jsonBlob, err := ioutil.ReadFile(genDocFile)
			if err != nil {
				Exit(Fmt("Couldn't read GenesisDoc file: %v", err))
			}
			genDoc := types.GenesisDocFromJSON(jsonBlob)
			if genDoc.ChainID == "" {
				PanicSanity(Fmt("Genesis doc %v must include non-empty chain_id", genDocFile))
			}
			config.Set("chain_id", genDoc.ChainID)
		}
	}

	// Get PrivValidator
	privValidatorFile := config.GetString("priv_validator_file")
	privValidator := types.LoadOrGenPrivValidator(privValidatorFile)

	// Create & start node
	n := NewNode(config, privValidator, GetProxyApp)

	protocol, address := ProtocolAndAddress(config.GetString("node_laddr"))
	l := p2p.NewDefaultListener(protocol, address, config.GetBool("skip_upnp"))
	n.AddListener(l)
	err := n.Start()
	if err != nil {
		Exit(Fmt("Failed to start node: %v", err))
	}

	log.Notice("Started node", "nodeInfo", n.sw.NodeInfo())

	// If seedNode is provided by config, dial out.
	if config.GetString("seeds") != "" {
		seeds := strings.Split(config.GetString("seeds"), ",")
		n.sw.DialSeeds(seeds)
	}

	// Run the RPC server.
	if config.GetString("rpc_laddr") != "" {
		_, err := n.StartRPC()
		if err != nil {
			PanicCrisis(err)
		}
	}

	// Sleep forever and then...
	TrapSignal(func() {
		n.Stop()
	})
}

func (n *Node) NodeInfo() *p2p.NodeInfo {
	return n.sw.NodeInfo()
}

func (n *Node) DialSeeds(seeds []string) {
	n.sw.DialSeeds(seeds)
}

//------------------------------------------------------------------------------
// replay

// convenience for replay mode
func newConsensusState(config cfg.Config) *consensus.ConsensusState {
	// Get BlockStore
	blockStoreDB := dbm.NewDB("blockstore", config.GetString("db_backend"), config.GetString("db_dir"))
	blockStore := bc.NewBlockStore(blockStoreDB)

	// Get State
	stateDB := dbm.NewDB("state", config.GetString("db_backend"), config.GetString("db_dir"))
	state := sm.MakeGenesisStateFromFile(stateDB, config.GetString("genesis_file"))

	// Create two proxyAppConn connections,
	// one for the consensus and one for the mempool.
	proxyAddr := config.GetString("proxy_app")
	transport := config.GetString("tmsp")
	proxyAppConnMempool := GetProxyApp(proxyAddr, transport, state.AppHash)
	proxyAppConnConsensus := GetProxyApp(proxyAddr, transport, state.AppHash)

	// add the chainid to the global config
	config.Set("chain_id", state.ChainID)

	// Make event switch
	eventSwitch := events.NewEventSwitch()
	_, err := eventSwitch.Start()
	if err != nil {
		Exit(Fmt("Failed to start event switch: %v", err))
	}

	mempool := mempl.NewMempool(config, proxyAppConnMempool)

	consensusState := consensus.NewConsensusState(config, state.Copy(), proxyAppConnConsensus, blockStore, mempool)
	consensusState.SetEventSwitch(eventSwitch)
	return consensusState
}

func RunReplayConsole(config cfg.Config) {
	walFile := config.GetString("cswal")
	if walFile == "" {
		Exit("cswal file name not set in tendermint config")
	}

	consensusState := newConsensusState(config)

	if err := consensusState.ReplayConsole(walFile); err != nil {
		Exit(Fmt("Error during consensus replay: %v", err))
	}
}

func RunReplay(config cfg.Config) {
	walFile := config.GetString("cswal")
	if walFile == "" {
		Exit("cswal file name not set in tendermint config")
	}

	consensusState := newConsensusState(config)

	if err := consensusState.ReplayMessages(walFile); err != nil {
		Exit(Fmt("Error during consensus replay: %v", err))
	}
	log.Notice("Replay run successfully")
}

// Defaults to tcp
func ProtocolAndAddress(listenAddr string) (string, string) {
	protocol, address := "tcp", listenAddr
	parts := strings.SplitN(address, "://", 2)
	if len(parts) == 2 {
		protocol, address = parts[0], parts[1]
	}
	return protocol, address
}