neutrinorpc: add getblockhash command

cmd/lncli/neutrino_active.go

@@ -6,6 +6,8 @@ package main
 import (
 	"github.com/lightningnetwork/lnd/lnrpc/neutrinorpc"
 	"github.com/urfave/cli"
+
+	"strconv"
 )
 
 func getNeutrinoKitClient(ctx *cli.Context) (neutrinorpc.NeutrinoKitClient, func()) {
@@ -261,6 +263,47 @@ func getCFilter(ctx *cli.Context) error {
 	return nil
 }
 
+var getBlockHashCommand = cli.Command{
+	Name:        "getblockhash",
+	Usage:       "Get a block hash.",
+	Category:    "Neutrino",
+	Description: "Returns the header hash of a block at a given height.",
+	ArgsUsage:   "height",
+	Action:      actionDecorator(getBlockHash),
+}
+
+func getBlockHash(ctx *cli.Context) error {
+	ctxc := getContext()
+	args := ctx.Args()
+
+	// Display the command's help message if we do not have the expected
+	// number of arguments/flags.
+	if !args.Present() {
+		return cli.ShowCommandHelp(ctx, "getblockhash")
+	}
+
+	client, cleanUp := getNeutrinoKitClient(ctx)
+	defer cleanUp()
+
+	height, err := strconv.ParseInt(args.First(), 10, 32)
+	if err != nil {
+		return err
+	}
+
+	req := &neutrinorpc.GetBlockHashRequest{
+		Height: int32(height),
+	}
+
+	resp, err := client.GetBlockHash(ctxc, req)
+	if err != nil {
+		return err
+	}
+
+	printRespJSON(resp)
+
+	return nil
+}
+
 // neutrinoCommands will return the set of commands to enable for neutrinorpc
 // builds.
 func neutrinoCommands() []cli.Command {
@@ -278,6 +321,7 @@ func neutrinoCommands() []cli.Command {
 				getBlockCommand,
 				getBlockHeaderCommand,
 				getCFilterCommand,
+				getBlockHashCommand,
 			},
 		},
 	}