package main

import (
	"crypto/x509"
	"encoding/pem"
	"errors"
	"flag"
	"fmt"
	"io/ioutil"
	"log"
	"math/rand"
	"net"
	"net/http"
	"net/rpc"
	"os"
	"path/filepath"
	"strconv"
	"time"

	"git.xeserv.us/xena/route/routerpc"
	r "github.com/GoRethink/gorethink"
	"github.com/Xe/uuid"
	"github.com/Yawning/bulb"
	"github.com/facebookgo/flagenv"
	_ "github.com/joho/godotenv/autoload"
	"github.com/koding/tunnel"
	"github.com/sycamoreone/orc/tor"
)

var (
	rethinkDBHost     = flag.String("rethink-host", "", "RethinkDB host")
	rethinkDBDatabase = flag.String("rethink-database", "", "RethinkDB database")
	controlKeyFile    = flag.String("control-key-file", "", "Control host keyfile")
	controlHost       = flag.String("control-host", "", "Control host onion hash")
	torDataDir        = flag.String("tor-data-dir", "./var", "Tor data directory")
	torHashedPassword = flag.String("tor-hashed-password", "", "Tor hashed password")
	torPassword       = flag.String("tor-password", "hunter2", "Tor clear password")
	webPort           = flag.String("web-port", "9234", "HTTP ingress port for backends and users")
)

// RPC constants
const (
	RPCPort uint16 = 39453
)

func main() {
	flag.Parse()
	flagenv.Parse()
	rand.Seed(time.Now().Unix())

	s, err := create(&ServerConfig{
		ControlHost:       *controlHost,
		ControlKeyFile:    *controlKeyFile,
		RethinkDBHost:     *rethinkDBHost,
		RethinkDBDatabase: *rethinkDBDatabase,
		TorDataDir:        *torDataDir,
		TorHashedPassword: *torHashedPassword,
		TorPassword:       *torPassword,
	})
	if err != nil {
		log.Fatal(err)
	}

	l, err := net.Listen("tcp", "127.0.0.1:"+*webPort)
	if err != nil {
		log.Fatal(err)
	}
	defer l.Close()

	hs := &http.Server{
		Handler: s,
		Addr:    "127.0.0.1:" + *webPort,
	}

	hs.Serve(l)
}

// Server is the main server type
type Server struct {
	cfg *ServerConfig

	sess *r.Session

	torCon         *bulb.Conn
	torCmd         *tor.Cmd
	torControlPath string

	rpcS    *rpc.Server
	rpcAddr string

	ts *tunnel.Server
}

// ServerConfig configures Server
type ServerConfig struct {
	ControlHost, ControlKeyFile                string
	RethinkDBHost, RethinkDBDatabase           string
	TorDataDir, TorHashedPassword, TorPassword string
}

func create(cfg *ServerConfig) (*Server, error) {
	session, err := r.Connect(r.ConnectOpts{
		Address:  cfg.RethinkDBHost,
		Database: cfg.RethinkDBDatabase,
	})
	if err != nil {
		return nil, err
	}

	l, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		return nil, err
	}

	torControlPath := filepath.Join(cfg.TorDataDir, fmt.Sprintf("%d.sock", rand.Int63()))

	tc := tor.NewConfig()
	tc.Set("DataDirectory", cfg.TorDataDir)
	tc.Set("HashedControlPassword", cfg.TorHashedPassword)
	tc.Set("SocksPort", "0")
	cp := rand.Intn(64512) // 64k - 1k
	tc.Set("ControlPort", cp)

	tc.Timeout = 30 * time.Second
	log.Println(tc.ToCmdLineFormat())

	tcmd, err := tor.NewCmd(tc)
	if err != nil {
		return nil, err
	}

	err = tcmd.Start()
	if err != nil {
		return nil, err
	}

	time.Sleep(5 * time.Second)

	bc, err := bulb.Dial("tcp", "127.0.0.1:"+strconv.Itoa(cp))
	if err != nil {
		return nil, err
	}

	err = bc.Authenticate(cfg.TorPassword)
	if err != nil {
		return nil, err
	}

	fin, err := os.Open(cfg.ControlKeyFile)
	if err != nil {
		return nil, err
	}
	defer fin.Close()

	data, err := ioutil.ReadAll(fin)
	if err != nil {
		return nil, err
	}

	var block *pem.Block

	block, _ = pem.Decode([]byte(data))
	pKey, err := x509.ParsePKCS1PrivateKey(block.Bytes)
	if err != nil {
		return nil, err
	}

	_, err = bc.AddOnion([]bulb.OnionPortSpec{
		bulb.OnionPortSpec{
			VirtPort: RPCPort,
			Target:   l.Addr().String(),
		},
	}, pKey, false)
	if err != nil {
		return nil, err
	}

	rpcs := rpc.NewServer()

	ts, err := tunnel.NewServer(&tunnel.ServerConfig{})
	if err != nil {
		return nil, err
	}

	s := &Server{
		cfg: cfg,

		sess: session,

		torCon:         bc,
		torCmd:         tcmd,
		torControlPath: torControlPath,

		rpcS:    rpcs,
		rpcAddr: l.Addr().String(),

		ts: ts,
	}

	rpcs.RegisterName("Urls", &RPCServer{Server: s})
	go rpcs.Accept(l)

	return s, nil
}

func (s *Server) onionPath(name string) string {
	return filepath.Join(s.cfg.TorDataDir, name)
}

func (s *Server) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if r.RequestURI == rpc.DefaultRPCPath {
		s.rpcS.ServeHTTP(w, r)
		return
	}
	s.ts.ServeHTTP(w, r)
}

type RPCServer struct {
	*Server
}

func (rs *RPCServer) AddHost(req routerpc.AddHostRequest, resp *routerpc.AddHostResponse) error {
	if req.APIKey != "hunter2" {
		return errors.New("invalid api key")
	}

	token := uuid.New()

	oi, err := rs.torCon.AddOnion([]bulb.OnionPortSpec{
		bulb.OnionPortSpec{
			VirtPort: 80,
			Target:   "127.0.0.1:" + *webPort,
		},
	}, req.PrivKey, false)
	if err != nil {
		return err
	}

	resp.OnionHostname = oi.OnionID + ".onion"
	resp.Token = token

	if req.Hostname != "" {
		rs.Server.ts.AddHost(req.Hostname, token)
		resp.Hostname = req.Hostname
	}
	rs.Server.ts.AddHost(resp.OnionHostname, token)

	if oi.PrivateKey != nil {
		resp.PrivKey = oi.PrivateKey
	} else {
		resp.PrivKey = req.PrivKey
	}

	return nil
}