cli: implement NEP5 token import

To work with NEP5 tokens, one need to save some info
e.g. token Name. This way we will not make additional
RPC just to get Decimals.

cli/wallet/nep5.go

@@ -0,0 +1,77 @@
+package wallet
+
+import (
+	"fmt"
+
+	"github.com/nspcc-dev/neo-go/pkg/rpc/client"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/nspcc-dev/neo-go/pkg/wallet"
+	"github.com/urfave/cli"
+)
+
+func newNEP5Commands() []cli.Command {
+	return []cli.Command{
+		{
+			Name:      "import",
+			Usage:     "import NEP5 token to a wallet",
+			UsageText: "import --path <path> --rpc <node> --token <hash>",
+			Action:    importNEP5Token,
+			Flags: []cli.Flag{
+				walletPathFlag,
+				rpcFlag,
+				cli.StringFlag{
+					Name:  "token",
+					Usage: "Token contract hash in LE",
+				},
+			},
+		},
+	}
+}
+
+func importNEP5Token(ctx *cli.Context) error {
+	wall, err := openWallet(ctx.String("path"))
+	if err != nil {
+		return cli.NewExitError(err, 1)
+	}
+	defer wall.Close()
+
+	tokenHash, err := util.Uint160DecodeStringLE(ctx.String("token"))
+	if err != nil {
+		return cli.NewExitError(fmt.Errorf("invalid token contract hash: %v", err), 1)
+	}
+
+	for _, t := range wall.Extra.Tokens {
+		if t.Hash.Equals(tokenHash) {
+			printTokenInfo(t)
+			return cli.NewExitError("token already exists", 1)
+		}
+	}
+
+	gctx, cancel := getGoContext(ctx)
+	defer cancel()
+
+	c, err := client.New(gctx, ctx.String("rpc"), client.Options{})
+	if err != nil {
+		return cli.NewExitError(err, 1)
+	}
+
+	tok, err := c.NEP5TokenInfo(tokenHash)
+	if err != nil {
+		return cli.NewExitError(fmt.Errorf("can't receive token info: %v", err), 1)
+	}
+
+	wall.AddToken(tok)
+	if err := wall.Save(); err != nil {
+		return cli.NewExitError(err, 1)
+	}
+	printTokenInfo(tok)
+	return nil
+}
+
+func printTokenInfo(tok *wallet.Token) {
+	fmt.Printf("Name:\t%s\n", tok.Name)
+	fmt.Printf("Symbol:\t%s\n", tok.Symbol)
+	fmt.Printf("Hash:\t%s\n", tok.Hash.StringLE())
+	fmt.Printf("Decimals: %d\n", tok.Decimals)
+	fmt.Printf("Address: %s\n", tok.Address)
+}

cli/wallet/wallet.go

@@ -186,6 +186,11 @@ func NewCommands() []cli.Command {
 				Usage:       "work with multisig address",
 				Subcommands: newMultisigCommands(),
 			},
+			{
+				Name:        "nep5",
+				Usage:       "work with NEP5 contracts",
+				Subcommands: newNEP5Commands(),
+			},
 		},
 	}}
 }