package main

import (
	"context"
	"errors"
	"flag"
	"fmt"
	stdlog "log"
	"os"
	"os/signal"
	"runtime"
	"strings"
	"time"

	"github.com/status-im/status-go/logutils"

	"github.com/ethereum/go-ethereum/log"
	gethmetrics "github.com/ethereum/go-ethereum/metrics"
	"github.com/ethereum/go-ethereum/p2p/discv5"
	"github.com/status-im/status-go/api"
	"github.com/status-im/status-go/cmd/statusd/debug"
	"github.com/status-im/status-go/cmd/statusd/topics"
	nodemetrics "github.com/status-im/status-go/metrics/node"
	"github.com/status-im/status-go/node"
	"github.com/status-im/status-go/params"
	"github.com/status-im/status-go/profiling"
	"golang.org/x/crypto/ssh/terminal"
)

const (
	serverClientName = "Statusd"
)

var (
	buildStamp = "N/A" // rely on linker: -ldflags -X main.buildStamp"
)

var (
	clusterConfigFile = flag.String("clusterconfig", "", "Cluster configuration file")
	nodeKeyFile       = flag.String("nodekey", "", "P2P node key file (private key)")
	dataDir           = flag.String("datadir", params.DataDir, "Data directory for the databases and keystore")
	networkID         = flag.Int("networkid", params.RopstenNetworkID, "Network identifier (integer, 1=Homestead, 3=Ropsten, 4=Rinkeby, 777=StatusChain)")
	lesEnabled        = flag.Bool("les", false, "Enable LES protocol")
	whisperEnabled    = flag.Bool("shh", false, "Enable Whisper protocol")
	statusService     = flag.String("status", "", `Enable StatusService, possible values: "ipc", "http"`)
	debugAPI          = flag.Bool("debug", false, `Enable debug API endpoints under "debug_" namespace`)
	swarmEnabled      = flag.Bool("swarm", false, "Enable Swarm protocol")
	maxPeers          = flag.Int("maxpeers", 25, "maximum number of p2p peers (including all protocols)")
	httpEnabled       = flag.Bool("http", false, "Enable HTTP RPC endpoint")
	httpHost          = flag.String("httphost", "127.0.0.1", "HTTP RPC host of the listening socket")
	httpPort          = flag.Int("httpport", params.HTTPPort, "HTTP RPC server's listening port")
	httpModules       = flag.String("httpmodules", params.APIModules, "Comma separated list of HTTP RPC APIs")
	ipcEnabled        = flag.Bool("ipc", false, "Enable IPC RPC endpoint")
	ipcFile           = flag.String("ipcfile", "", "Set IPC file path")
	cliEnabled        = flag.Bool("cli", false, "Enable debugging CLI server")
	cliPort           = flag.String("cliport", debug.CLIPort, "CLI server's listening port")
	pprofEnabled      = flag.Bool("pprof", false, "Enable runtime profiling via pprof")
	pprofPort         = flag.Int("pprofport", 52525, "Port for runtime profiling via pprof")
	logLevel          = flag.String("log", "INFO", `Log level, one of: "ERROR", "WARN", "INFO", "DEBUG", and "TRACE"`)
	logFile           = flag.String("logfile", "", "Path to the log file")
	logWithoutColors  = flag.Bool("log-without-color", false, "Disables log colors")
	version           = flag.Bool("version", false, "Print version")

	listenAddr      = flag.String("listenaddr", ":30303", "IP address and port of this node (e.g. 127.0.0.1:30303)")
	fleet           = flag.String("fleet", params.FleetBeta, "Name of the fleet like 'eth.staging' (default to 'eth.beta')")
	standalone      = flag.Bool("standalone", true, "Don't actively connect to peers, wait for incoming connections")
	bootnodes       = flag.String("bootnodes", "", "A list of bootnodes separated by comma")
	discoveryFlag   = flag.Bool("discovery", false, "Enable discovery protocol")
	rendezvous      = flag.Bool("rendezvous", false, "Enable rendezvous protocol")
	rendezvousNodes = StringSlice{}

	// don't change the name of this flag, https://github.com/ethereum/go-ethereum/blob/master/metrics/metrics.go#L41
	metrics = flag.Bool("metrics", false, "Expose ethereum metrics with debug_metrics jsonrpc call.")
	// shh stuff
	passwordFile = flag.String("shh.passwordfile", "", "Password file (password is used for symmetric encryption)")
	minPow       = flag.Float64("shh.pow", params.WhisperMinimumPoW, "PoW for messages to be added to queue, in float format")
	ttl          = flag.Int("shh.ttl", params.WhisperTTL, "Time to live for messages, in seconds")
	lightClient  = flag.Bool("shh.lightclient", false, "Start with empty bloom filter, and don't forward messages")

	// MailServer
	enableMailServer = flag.Bool("shh.mailserver", false, "Delivers expired messages on demand")

	// Push Notification
	firebaseAuth = flag.String("shh.firebaseauth", "", "FCM Authorization Key used for sending Push Notifications")

	syncAndExit = flag.Int("sync-and-exit", -1, "Timeout in minutes for blockchain sync and exit, zero means no timeout unless sync is finished")

	ntpSyncEnabled = flag.Bool("ntp", true, "Enable/disable whisper NTP synchronization")

	// Topics that will be search and registered by discovery v5.
	searchTopics   = topics.TopicLimitsFlag{}
	registerTopics = topics.TopicFlag{}
)

// All general log messages in this package should be routed through this logger.
var logger = log.New("package", "status-go/cmd/statusd")

func init() {
	flag.Var(&searchTopics, "topic.search", "Topic that will be searched in discovery v5, e.g (mailserver=1,1)")
	flag.Var(&registerTopics, "topic.register", "Topic that will be registered using discovery v5.")
	flag.Var(&rendezvousNodes, "rendezvous-node", "Rendezvous server.")

	flag.Usage = printUsage
	flag.Parse()
	if flag.NArg() > 0 {
		stdlog.Printf("Extra args in command line: %v", flag.Args())
		printUsage()
		os.Exit(1)
	}
}

func main() {
	colors := !(*logWithoutColors) && terminal.IsTerminal(int(os.Stdin.Fd()))
	if err := logutils.OverrideRootLog(logEnabled(), *logLevel, *logFile, colors); err != nil {
		stdlog.Fatalf("Error initializing logger: %s", err)
	}

	config, err := makeNodeConfig()
	if err != nil {
		stdlog.Fatalf("Making config failed, %s", err)
	}
	// We want statusd to be distinct from StatusIM client.
	config.Name = serverClientName

	if *version {
		printVersion(config, buildStamp)
		return
	}

	backend := api.NewStatusBackend()
	err = backend.StartNode(config)
	if err != nil {
		logger.Error("Node start failed", "error", err)
		return
	}

	// handle interrupt signals
	interruptCh := haltOnInterruptSignal(backend.StatusNode())

	// Check if debugging CLI connection shall be enabled.
	if *cliEnabled {
		err := startDebug(backend)
		if err != nil {
			logger.Error("Starting debugging CLI server failed", "error", err)
			return
		}
	}

	// Check if profiling shall be enabled.
	if *pprofEnabled {
		profiling.NewProfiler(*pprofPort).Go()
	}

	// Run stats server.
	if *metrics {
		go startCollectingNodeMetrics(interruptCh, backend.StatusNode())
		go gethmetrics.CollectProcessMetrics(3 * time.Second)
	}

	// Sync blockchain and stop.
	if *syncAndExit >= 0 {
		exitCode := syncAndStopNode(interruptCh, backend.StatusNode(), *syncAndExit)
		// Call was interrupted. Wait for graceful shutdown.
		if exitCode == -1 {
			if gethNode := backend.StatusNode().GethNode(); gethNode != nil {
				gethNode.Wait()
			}
			return
		}
		// Otherwise, exit immediately with a returned exit code.
		os.Exit(exitCode)
	}

	gethNode := backend.StatusNode().GethNode()
	if gethNode != nil {
		// wait till node has been stopped
		gethNode.Wait()
	}
}

// startDebug starts the debugging API server.
func startDebug(backend *api.StatusBackend) error {
	_, err := debug.New(backend, *cliPort)
	return err
}

// startCollectingStats collects various stats about the node and other protocols like Whisper.
func startCollectingNodeMetrics(interruptCh <-chan struct{}, statusNode *node.StatusNode) {
	logger.Info("Starting collecting node metrics")

	gethNode := statusNode.GethNode()
	if gethNode == nil {
		logger.Error("Failed to run metrics because it could not get the node")
		return
	}

	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()
	go func() {
		if err := nodemetrics.SubscribeServerEvents(ctx, gethNode); err != nil {
			logger.Error("Failed to subscribe server events", "error", err)
		}
	}()

	<-interruptCh
}

func logEnabled() bool {
	return *logLevel != "" || *logFile != ""
}

// makeNodeConfig parses incoming CLI options and returns node configuration object
func makeNodeConfig() (*params.NodeConfig, error) {
	nodeConfig, err := params.NewNodeConfig(*dataDir, *clusterConfigFile, *fleet, uint64(*networkID))
	if err != nil {
		return nil, err
	}

	nodeConfig.ListenAddr = *listenAddr

	// TODO(divan): move this logic into params package
	if *nodeKeyFile != "" {
		nodeConfig.NodeKeyFile = *nodeKeyFile
	}

	if *logLevel != "" {
		nodeConfig.LogLevel = *logLevel
	}

	if *logFile != "" {
		nodeConfig.LogFile = *logFile
	}

	nodeConfig.LogEnabled = logEnabled()

	nodeConfig.RPCEnabled = *httpEnabled
	nodeConfig.WhisperConfig.Enabled = *whisperEnabled
	nodeConfig.MaxPeers = *maxPeers

	nodeConfig.HTTPHost = *httpHost
	nodeConfig.HTTPPort = *httpPort
	nodeConfig.APIModules = *httpModules
	nodeConfig.IPCEnabled = *ipcEnabled

	if *ipcFile != "" {
		nodeConfig.IPCEnabled = true
		nodeConfig.IPCFile = *ipcFile
	}

	nodeConfig.LightEthConfig.Enabled = *lesEnabled
	nodeConfig.SwarmConfig.Enabled = *swarmEnabled

	if *standalone {
		nodeConfig.ClusterConfig.Enabled = false
		nodeConfig.ClusterConfig.BootNodes = nil
	}

	nodeConfig.ClusterConfig.RendezvousNodes = []string(rendezvousNodes)
	nodeConfig.NoDiscovery = !(*discoveryFlag)
	nodeConfig.Rendezvous = *rendezvous
	nodeConfig.RequireTopics = map[discv5.Topic]params.Limits(searchTopics)
	nodeConfig.RegisterTopics = []discv5.Topic(registerTopics)

	// Even if standalone is true and discovery is disabled,
	// it's possible to use bootnodes.
	if *bootnodes != "" {
		nodeConfig.ClusterConfig.BootNodes = strings.Split(*bootnodes, ",")
	}

	if nodeConfig, err = configureStatusService(*statusService, nodeConfig); err != nil {
		return nil, err
	}

	nodeConfig.DebugAPIEnabled = *debugAPI
	if nodeConfig.DebugAPIEnabled {
		nodeConfig.AddAPIModule("debug")
	}

	if *whisperEnabled {
		return whisperConfig(nodeConfig)
	}

	// RPC configuration
	if !*httpEnabled {
		nodeConfig.HTTPHost = "" // HTTP RPC is disabled
	}

	return nodeConfig, nil
}

var errStatusServiceRequiresIPC = errors.New("to enable the StatusService on IPC, -ipc flag must be set")
var errStatusServiceRequiresHTTP = errors.New("to enable the StatusService on HTTP, -http flag must be set")
var errStatusServiceInvalidFlag = errors.New("-status flag valid values are: ipc, http")

func configureStatusService(flagValue string, nodeConfig *params.NodeConfig) (*params.NodeConfig, error) {
	switch flagValue {
	case "ipc":
		if !nodeConfig.IPCEnabled {
			return nil, errStatusServiceRequiresIPC
		}
		nodeConfig.StatusServiceEnabled = true
	case "http":
		if !nodeConfig.RPCEnabled {
			return nil, errStatusServiceRequiresHTTP
		}
		nodeConfig.StatusServiceEnabled = true
		nodeConfig.AddAPIModule("status")
	case "":
		nodeConfig.StatusServiceEnabled = false
	default:
		return nil, errStatusServiceInvalidFlag
	}

	return nodeConfig, nil
}

// printVersion prints verbose output about version and config.
func printVersion(config *params.NodeConfig, buildStamp string) {
	fmt.Println(strings.Title(config.Name))
	fmt.Println("Version:", config.Version)

	if buildStamp != "" {
		fmt.Println("Build Stamp:", buildStamp)
	}

	fmt.Println("Network Id:", config.NetworkID)
	fmt.Println("Go Version:", runtime.Version())
	fmt.Println("OS:", runtime.GOOS)
	fmt.Printf("GOPATH=%s\n", os.Getenv("GOPATH"))
	fmt.Printf("GOROOT=%s\n", runtime.GOROOT())

	config.LightEthConfig.Genesis = "SKIP"
	fmt.Println("Loaded Config: ", config)
}

func printUsage() {
	usage := `
Usage: statusd [options]
Examples:
  statusd               # run status node with defaults
  statusd -networkid 4  # run node on Rinkeby network
  statusd -datadir /dir # specify different dir for data
  statusd -ipc          # enable IPC for usage with "geth attach"
  statusd -cli          # enable connection by statusd-cli on default port

Options:
`
	fmt.Fprintf(os.Stderr, usage)
	flag.PrintDefaults()
}

// haltOnInterruptSignal catches interrupt signal (SIGINT) and
// stops the node. It times out after 5 seconds
// if the node can not be stopped.
func haltOnInterruptSignal(statusNode *node.StatusNode) <-chan struct{} {
	interruptCh := make(chan struct{})
	go func() {
		signalCh := make(chan os.Signal, 1)
		signal.Notify(signalCh, os.Interrupt)
		defer signal.Stop(signalCh)
		<-signalCh
		close(interruptCh)
		logger.Info("Got interrupt, shutting down...")
		if err := statusNode.Stop(); err != nil {
			logger.Error("Failed to stop node", "error", err)
			os.Exit(1)
		}
	}()
	return interruptCh
}