package main

import (
	"flag"
	"fmt"
	"os"
	"strconv"
	"strings"
	"time"

	log "github.com/Sirupsen/logrus"

	"github.com/weaveworks/scope/app"
	"github.com/weaveworks/scope/common/xfer"
	"github.com/weaveworks/weave/common"
)

var version = "dev" // set at build time

type prefixFormatter struct {
	prefix []byte
	next   log.Formatter
}

func (f *prefixFormatter) Format(entry *log.Entry) ([]byte, error) {
	formatted, err := f.next.Format(entry)
	if err != nil {
		return formatted, err
	}
	return append(f.prefix, formatted...), nil
}

func setLogFormatter(prefix string) {
	if !strings.HasSuffix(prefix, " ") {
		prefix += " "
	}
	f := prefixFormatter{
		prefix: []byte(prefix),
		// reuse weave's log format
		next: common.Log.Formatter,
	}
	log.SetFormatter(&f)
}

func setLogLevel(levelname string) {
	level, err := log.ParseLevel(levelname)
	if err != nil {
		log.Fatal(err)
	}
	log.SetLevel(level)
}

type flags struct {
	probe probeFlags
	app   appFlags
}

type probeFlags struct {
	token           string
	httpListen      string
	publishInterval time.Duration
	spyInterval     time.Duration
	pluginsRoot     string
	insecure        bool
	logPrefix       string
	logLevel        string
	resolver        string
	noApp           bool

	useConntrack bool // Use conntrack for endpoint topo
	spyProcs     bool // Associate endpoints with processes (must be root)
	procEnabled  bool // Produce process topology & process nodes in endpoint
	procRoot     string

	dockerEnabled  bool
	dockerInterval time.Duration
	dockerBridge   string

	kubernetesEnabled  bool
	kubernetesAPI      string
	kubernetesInterval time.Duration

	weaveAddr     string
	weaveHostname string
}

type appFlags struct {
	window    time.Duration
	listen    string
	logLevel  string
	logPrefix string
	logHTTP   bool

	weaveAddr      string
	weaveHostname  string
	containerName  string
	dockerEndpoint string

	collectorURL     string
	controlRouterURL string
	pipeRouterURL    string
	userIDHeader     string

	awsCreateTables bool
	consulInf       string
}

func main() {
	var (
		flags         = flags{}
		mode          string
		debug         bool
		weaveHostname string
	)

	// Flags that apply to both probe and app
	flag.StringVar(&mode, "mode", "help", "For internal use.")
	flag.BoolVar(&debug, "debug", false, "Force debug logging.")
	flag.StringVar(&weaveHostname, "weave.hostname", "", "Hostname to advertise/lookup in WeaveDNS")

	// We need to know how to parse them, but they are mainly interpreted by the entrypoint script.
	// They are also here so they are included in usage, and the probe uses them to decide if to
	// publish to localhost.
	noApp := flag.Bool("no-app", false, "Don't run the app.")
	probeOnly := flag.Bool("app-only", false, "Only run the app")
	flag.Bool("probe-only", false, "Only run the probe.")
	flag.Bool("no-probe", false, "Don't run the probe.")

	// Probe flags
	flag.StringVar(&flags.probe.token, "service-token", "", "Token to use to authenticate with scope.weave.works")
	flag.StringVar(&flags.probe.token, "probe.token", "", "Token to use to authenticate with scope.weave.works")
	flag.StringVar(&flags.probe.httpListen, "probe.http.listen", "", "listen address for HTTP profiling and instrumentation server")
	flag.DurationVar(&flags.probe.publishInterval, "probe.publish.interval", 3*time.Second, "publish (output) interval")
	flag.DurationVar(&flags.probe.spyInterval, "probe.spy.interval", time.Second, "spy (scan) interval")
	flag.StringVar(&flags.probe.pluginsRoot, "probe.plugins.root", "/var/run/scope/plugins", "Root directory to search for plugins")

	flag.BoolVar(&flags.probe.insecure, "probe.insecure", false, "(SSL) explicitly allow \"insecure\" SSL connections and transfers")
	flag.StringVar(&flags.probe.resolver, "probe.resolver", "", "IP address & port of resolver to use.  Default is to use system resolver.")
	flag.StringVar(&flags.probe.logPrefix, "probe.log.prefix", "<probe>", "prefix for each log line")
	flag.StringVar(&flags.probe.logLevel, "probe.log.level", "info", "logging threshold level: debug|info|warn|error|fatal|panic")

	// Proc & endpoint
	flag.BoolVar(&flags.probe.useConntrack, "probe.conntrack", true, "also use conntrack to track connections")
	flag.BoolVar(&flags.probe.spyProcs, "probe.proc.spy", true, "associate endpoints with processes (needs root)")
	flag.StringVar(&flags.probe.procRoot, "probe.proc.root", "/proc", "location of the proc filesystem")
	flag.BoolVar(&flags.probe.procEnabled, "probe.processes", true, "produce process topology & include procspied connections")

	// Docker
	flag.BoolVar(&flags.probe.dockerEnabled, "probe.docker", false, "collect Docker-related attributes for processes")
	flag.DurationVar(&flags.probe.dockerInterval, "probe.docker.interval", 10*time.Second, "how often to update Docker attributes")
	flag.StringVar(&flags.probe.dockerBridge, "probe.docker.bridge", "docker0", "the docker bridge name")

	// K8s
	flag.BoolVar(&flags.probe.kubernetesEnabled, "probe.kubernetes", false, "collect kubernetes-related attributes for containers, should only be enabled on the master node")
	flag.StringVar(&flags.probe.kubernetesAPI, "probe.kubernetes.api", "", "Address of kubernetes master api")
	flag.DurationVar(&flags.probe.kubernetesInterval, "probe.kubernetes.interval", 10*time.Second, "how often to do a full resync of the kubernetes data")

	// Weave
	flag.StringVar(&flags.probe.weaveAddr, "probe.weave.addr", "127.0.0.1:6784", "IP address & port of the Weave router")
	flag.StringVar(&flags.probe.weaveHostname, "probe.weave.hostname", app.DefaultHostname, "Hostname to lookup in WeaveDNS")

	// App flags
	flag.DurationVar(&flags.app.window, "app.window", 15*time.Second, "window")
	flag.StringVar(&flags.app.listen, "app.http.address", ":"+strconv.Itoa(xfer.AppPort), "webserver listen address")
	flag.StringVar(&flags.app.logLevel, "app.log.level", "info", "logging threshold level: debug|info|warn|error|fatal|panic")
	flag.StringVar(&flags.app.logPrefix, "app.log.prefix", "<app>", "prefix for each log line")
	flag.BoolVar(&flags.app.logHTTP, "app.log.http", false, "Log individual HTTP requests")

	flag.StringVar(&flags.app.weaveAddr, "app.weave.addr", app.DefaultWeaveURL, "Address on which to contact WeaveDNS")
	flag.StringVar(&flags.app.weaveHostname, "app.weave.hostname", app.DefaultHostname, "Hostname to advertise in WeaveDNS")
	flag.StringVar(&flags.app.containerName, "app.container.name", app.DefaultContainerName, "Name of this container (to lookup container ID)")
	flag.StringVar(&flags.app.dockerEndpoint, "app.docker", app.DefaultDockerEndpoint, "Location of docker endpoint (to lookup container ID)")

	flag.StringVar(&flags.app.collectorURL, "app.collector", "local", "Collector to use (local of dynamodb)")
	flag.StringVar(&flags.app.controlRouterURL, "app.control.router", "local", "Control router to use (local or sqs)")
	flag.StringVar(&flags.app.pipeRouterURL, "app.pipe.router", "local", "Pipe router to use (local)")
	flag.StringVar(&flags.app.userIDHeader, "app.userid.header", "", "HTTP header to use as userid")

	flag.BoolVar(&flags.app.awsCreateTables, "app.aws.create.tables", false, "Create the tables in DynamoDB")
	flag.StringVar(&flags.app.consulInf, "app.consul.inf", "", "The interface who's address I should advertise myself under in consul")

	flag.Parse()

	// Deal with common args
	if debug {
		flags.probe.logLevel = "debug"
		flags.app.logLevel = "debug"
	}
	if weaveHostname != "" {
		flags.probe.weaveHostname = weaveHostname
		flags.app.weaveHostname = weaveHostname
	}
	flags.probe.noApp = *noApp || *probeOnly

	switch mode {
	case "app":
		appMain(flags.app)
	case "probe":
		probeMain(flags.probe)
	case "version":
		fmt.Println("Weave Scope version", version)
	case "help":
		flag.PrintDefaults()
	default:
		fmt.Printf("command '%s' not recognices", mode)
		os.Exit(1)
	}
}