package server

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

	"git.xeserv.us/xena/route/database"
	"git.xeserv.us/xena/route/lib/elfs"
	"git.xeserv.us/xena/route/routerpc"
	"github.com/Xe/uuid"
	"github.com/Yawning/bulb"
	"github.com/koding/tunnel"
	"github.com/sycamoreone/orc/tor"
)

// RPC constants
const (
	RPCPort uint16 = 39453
)

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

	db *database.DB

	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
	WebPort, DomainSuffix                      string
}

// New creates a new Server
func New(cfg *ServerConfig) (*Server, error) {
	db, err := database.New(cfg.RethinkDBHost, 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,

		db: db,

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

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

		ts: ts,
	}

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

	err = s.restore()
	if err != nil {
		return nil, err
	}

	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)
}

func (s *Server) restore() error {
	rts, err := s.db.GetAllRoutes()
	if err != nil {
		return err
	}

	for _, rt := range rts {
		var block *pem.Block

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

		ports := []bulb.OnionPortSpec{
			genPortSpec(80, "127.0.0.1:"+s.cfg.WebPort),
		}

		_, err = s.torCon.AddOnion(ports, pKey, false)
		if err != nil {
			return err
		}

		s.ts.AddHost(rt.Hostname, rt.Token)
		s.ts.AddHost(rt.OnionHostname, rt.Token)

		log.Printf("added: %s (%s)", rt.Hostname, rt.OnionHostname)
	}

	return nil
}

func genPortSpec(incoming uint16, outgoing string) bulb.OnionPortSpec {
	return bulb.OnionPortSpec{
		VirtPort: incoming,
		Target:   outgoing,
	}
}

// RPCServer is a Server wrapped to work inside the context of net/rpc
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:" + rs.cfg.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
	} else {
		resp.Hostname = elfs.MakeName() + rs.cfg.DomainSuffix
		rs.ts.AddHost(resp.Hostname, token)
	}
	rs.Server.ts.AddHost(resp.OnionHostname, token)

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

	err = rs.db.SaveRoute(resp)
	if err != nil {
		return err
	}

	return nil
}