// NodeKey retrieves the currently configured private key of the node, checking
// first any manually set key, falling back to the one found in the configured
// data folder. If no key can be found, a new one is generated.
func (c *Config) NodeKey() *ecdsa.PrivateKey {
	// Use any specifically configured key
	if c.PrivateKey != nil {
		return c.PrivateKey
	}
	// Generate ephemeral key if no datadir is being used
	if c.DataDir == "" {
		key, err := crypto.GenerateKey()
		if err != nil {
			glog.Fatalf("Failed to generate ephemeral node key: %v", err)
		}
		return key
	}
	// Fall back to persistent key from the data directory
	keyfile := filepath.Join(c.DataDir, datadirPrivateKey)
	if key, err := crypto.LoadECDSA(keyfile); err == nil {
		return key
	}
	// No persistent key found, generate and store a new one
	key, err := crypto.GenerateKey()
	if err != nil {
		glog.Fatalf("Failed to generate node key: %v", err)
	}
	if err := crypto.SaveECDSA(keyfile, key); err != nil {
		glog.V(logger.Error).Infof("Failed to persist node key: %v", err)
	}
	return key
}

// Tests that node keys can be correctly created, persisted, loaded and/or made
// ephemeral.
func TestNodeKeyPersistency(t *testing.T) {
	// Create a temporary folder and make sure no key is present
	dir, err := ioutil.TempDir("", "")
	if err != nil {
		t.Fatalf("failed to create temporary data directory: %v", err)
	}
	defer os.RemoveAll(dir)

	if _, err := os.Stat(filepath.Join(dir, datadirPrivateKey)); err == nil {
		t.Fatalf("non-created node key already exists")
	}
	// Configure a node with a preset key and ensure it's not persisted
	key, err := crypto.GenerateKey()
	if err != nil {
		t.Fatalf("failed to generate one-shot node key: %v", err)
	}
	if _, err := New(&Config{DataDir: dir, PrivateKey: key}); err != nil {
		t.Fatalf("failed to create empty stack: %v", err)
	}
	if _, err := os.Stat(filepath.Join(dir, datadirPrivateKey)); err == nil {
		t.Fatalf("one-shot node key persisted to data directory")
	}
	// Configure a node with no preset key and ensure it is persisted this time
	if _, err := New(&Config{DataDir: dir}); err != nil {
		t.Fatalf("failed to create newly keyed stack: %v", err)
	}
	if _, err := os.Stat(filepath.Join(dir, datadirPrivateKey)); err != nil {
		t.Fatalf("node key not persisted to data directory: %v", err)
	}
	key, err = crypto.LoadECDSA(filepath.Join(dir, datadirPrivateKey))
	if err != nil {
		t.Fatalf("failed to load freshly persisted node key: %v", err)
	}
	blob1, err := ioutil.ReadFile(filepath.Join(dir, datadirPrivateKey))
	if err != nil {
		t.Fatalf("failed to read freshly persisted node key: %v", err)
	}
	// Configure a new node and ensure the previously persisted key is loaded
	if _, err := New(&Config{DataDir: dir}); err != nil {
		t.Fatalf("failed to create previously keyed stack: %v", err)
	}
	blob2, err := ioutil.ReadFile(filepath.Join(dir, datadirPrivateKey))
	if err != nil {
		t.Fatalf("failed to read previously persisted node key: %v", err)
	}
	if bytes.Compare(blob1, blob2) != 0 {
		t.Fatalf("persisted node key mismatch: have %x, want %x", blob2, blob1)
	}
	// Configure ephemeral node and ensure no key is dumped locally
	if _, err := New(&Config{DataDir: ""}); err != nil {
		t.Fatalf("failed to create ephemeral stack: %v", err)
	}
	if _, err := os.Stat(filepath.Join(".", datadirPrivateKey)); err == nil {
		t.Fatalf("ephemeral node key persisted to disk")
	}
}

func (am *Manager) Import(path string, keyAuth string) (Account, error) {
	privateKeyECDSA, err := crypto.LoadECDSA(path)
	if err != nil {
		return Account{}, err
	}
	key := crypto.NewKeyFromECDSA(privateKeyECDSA)
	if err = am.keyStore.StoreKey(key, keyAuth); err != nil {
		return Account{}, err
	}
	return Account{Address: key.Address}, nil
}

func main() {
	var (
		listenAddr  = flag.String("addr", ":30301", "listen address")
		genKey      = flag.String("genkey", "", "generate a node key and quit")
		nodeKeyFile = flag.String("nodekey", "", "private key filename")
		nodeKeyHex  = flag.String("nodekeyhex", "", "private key as hex (for testing)")
		natdesc     = flag.String("nat", "none", "port mapping mechanism (any|none|upnp|pmp|extip:<IP>)")

		nodeKey *ecdsa.PrivateKey
		err     error
	)
	flag.Var(glog.GetVerbosity(), "verbosity", "log verbosity (0-9)")
	flag.Var(glog.GetVModule(), "vmodule", "log verbosity pattern")
	glog.SetToStderr(true)
	flag.Parse()

	if *genKey != "" {
		key, err := crypto.GenerateKey()
		if err != nil {
			utils.Fatalf("could not generate key: %v", err)
		}
		if err := crypto.SaveECDSA(*genKey, key); err != nil {
			utils.Fatalf("%v", err)
		}
		os.Exit(0)
	}

	natm, err := nat.Parse(*natdesc)
	if err != nil {
		utils.Fatalf("-nat: %v", err)
	}
	switch {
	case *nodeKeyFile == "" && *nodeKeyHex == "":
		utils.Fatalf("Use -nodekey or -nodekeyhex to specify a private key")
	case *nodeKeyFile != "" && *nodeKeyHex != "":
		utils.Fatalf("Options -nodekey and -nodekeyhex are mutually exclusive")
	case *nodeKeyFile != "":
		if nodeKey, err = crypto.LoadECDSA(*nodeKeyFile); err != nil {
			utils.Fatalf("-nodekey: %v", err)
		}
	case *nodeKeyHex != "":
		if nodeKey, err = crypto.HexToECDSA(*nodeKeyHex); err != nil {
			utils.Fatalf("-nodekeyhex: %v", err)
		}
	}

	if _, err := discover.ListenUDP(nodeKey, *listenAddr, natm, ""); err != nil {
		utils.Fatalf("%v", err)
	}
	select {}
}

func GetNodeKey(ctx *cli.Context) (key *ecdsa.PrivateKey) {
	hex, file := ctx.GlobalString(NodeKeyHexFlag.Name), ctx.GlobalString(NodeKeyFileFlag.Name)
	var err error
	switch {
	case file != "" && hex != "":
		Fatalf("Options %q and %q are mutually exclusive", NodeKeyFileFlag.Name, NodeKeyHexFlag.Name)
	case file != "":
		if key, err = crypto.LoadECDSA(file); err != nil {
			Fatalf("Option %q: %v", NodeKeyFileFlag.Name, err)
		}
	case hex != "":
		if key, err = crypto.HexToECDSA(hex); err != nil {
			Fatalf("Option %q: %v", NodeKeyHexFlag.Name, err)
		}
	}
	return key
}

func accountImport(ctx *cli.Context) {
	keyfile := ctx.Args().First()
	if len(keyfile) == 0 {
		utils.Fatalf("keyfile must be given as argument")
	}
	key, err := crypto.LoadECDSA(keyfile)
	if err != nil {
		utils.Fatalf("keyfile must be given as argument")
	}
	accman := utils.MakeAccountManager(ctx)
	passphrase := getPassPhrase("Your new account is locked with a password. Please give a password. Do not forget this password.", true, 0, utils.MakePasswordList(ctx))
	acct, err := accman.ImportECDSA(key, passphrase)
	if err != nil {
		utils.Fatalf("Could not create the account: %v", err)
	}
	fmt.Printf("Address: {%x}\n", acct.Address)
}

func main() {
	var (
		listenAddr  = flag.String("addr", ":30301", "listen address")
		genKey      = flag.String("genkey", "", "generate a node key and quit")
		nodeKeyFile = flag.String("nodekey", "", "private key filename")
		nodeKeyHex  = flag.String("nodekeyhex", "", "private key as hex (for testing)")
		natdesc     = flag.String("nat", "none", "port mapping mechanism (any|none|upnp|pmp|extip:<IP>)")

		nodeKey *ecdsa.PrivateKey
		err     error
	)
	flag.Parse()
	logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.DebugLevel))

	if *genKey != "" {
		writeKey(*genKey)
		os.Exit(0)
	}

	natm, err := nat.Parse(*natdesc)
	if err != nil {
		log.Fatalf("-nat: %v", err)
	}
	switch {
	case *nodeKeyFile == "" && *nodeKeyHex == "":
		log.Fatal("Use -nodekey or -nodekeyhex to specify a private key")
	case *nodeKeyFile != "" && *nodeKeyHex != "":
		log.Fatal("Options -nodekey and -nodekeyhex are mutually exclusive")
	case *nodeKeyFile != "":
		if nodeKey, err = crypto.LoadECDSA(*nodeKeyFile); err != nil {
			log.Fatalf("-nodekey: %v", err)
		}
	case *nodeKeyHex != "":
		if nodeKey, err = crypto.HexToECDSA(*nodeKeyHex); err != nil {
			log.Fatalf("-nodekeyhex: %v", err)
		}
	}

	if _, err := discover.ListenUDP(nodeKey, *listenAddr, natm, ""); err != nil {
		log.Fatal(err)
	}
	select {}
}

func (cfg *Config) nodeKey() (*ecdsa.PrivateKey, error) {
	// use explicit key from command line args if set
	if cfg.NodeKey != nil {
		return cfg.NodeKey, nil
	}
	// use persistent key if present
	keyfile := filepath.Join(cfg.DataDir, "nodekey")
	key, err := crypto.LoadECDSA(keyfile)
	if err == nil {
		return key, nil
	}
	// no persistent key, generate and store a new one
	if key, err = crypto.GenerateKey(); err != nil {
		return nil, fmt.Errorf("could not generate server key: %v", err)
	}
	if err := crypto.SaveECDSA(keyfile, key); err != nil {
		glog.V(logger.Error).Infoln("could not persist nodekey: ", err)
	}
	return key, nil
}