From 92a2ba163e3399a171488182804abf013aeab110 Mon Sep 17 00:00:00 2001
From: Conner Fromknecht <conner@mit.edu>
Date: Mon, 26 Mar 2018 14:15:04 -0700
Subject: [PATCH] cmd/lncli/commands: ask for recovery window after restore
 seed

---
 cmd/lncli/commands.go | 64 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 63 insertions(+), 1 deletion(-)

diff --git a/cmd/lncli/commands.go b/cmd/lncli/commands.go
index 4a1f3297..53abbc7c 100644
--- a/cmd/lncli/commands.go
+++ b/cmd/lncli/commands.go
@@ -35,6 +35,8 @@ import (
 
 // TODO(roasbeef): expose all fee conf targets
 
+const defaultRecoveryWindow int32 = 250
+
 func printJSON(resp interface{}) {
 	b, err := json.Marshal(resp)
 	if err != nil {
@@ -1132,6 +1134,7 @@ mnemonicCheck:
 	var (
 		cipherSeedMnemonic []string
 		aezeedPass         []byte
+		recoveryWindow     int32
 	)
 	if hasMnemonic {
 		// We'll now prompt the user to enter in their 24-word
@@ -1170,7 +1173,37 @@ mnemonicCheck:
 
 		aezeedPass = []byte(passphrase)
 
-		fmt.Println()
+		for {
+			fmt.Println()
+			fmt.Printf("Input an optional address look-ahead "+
+				"used to scan for used keys (default %d): ",
+				defaultRecoveryWindow)
+
+			reader := bufio.NewReader(os.Stdin)
+			answer, err := reader.ReadString('\n')
+			if err != nil {
+				return err
+			}
+
+			fmt.Println()
+
+			answer = strings.TrimSpace(answer)
+
+			if len(answer) == 0 {
+				recoveryWindow = defaultRecoveryWindow
+				break
+			}
+
+			lookAhead, err := strconv.Atoi(answer)
+			if err != nil {
+				fmt.Println("Unable to parse recovery "+
+					"window: %v", err)
+				continue
+			}
+
+			recoveryWindow = int32(lookAhead)
+			break
+		}
 	} else {
 		// Otherwise, if the user doesn't have a mnemonic that they
 		// want to use, we'll generate a fresh one with the GenSeed
@@ -1247,6 +1280,7 @@ mnemonicCheck:
 		WalletPassword:     pw1,
 		CipherSeedMnemonic: cipherSeedMnemonic,
 		AezeedPassphrase:   aezeedPass,
+		RecoveryWindow:     recoveryWindow,
 	}
 	if _, err := client.InitWallet(ctxb, req); err != nil {
 		return err
@@ -1265,6 +1299,16 @@ var unlockCommand = cli.Command{
 	able to carry out its duties. An exception is if a user is running with
 	--noencryptwallet, then a default passphrase will be used.
 	`,
+	Flags: []cli.Flag{
+		cli.IntFlag{
+			Name: "recovery_window",
+			Usage: "address lookahead to resume recovery rescan, " +
+				"value should be non-zero --  To recover all " +
+				"funds, this should be greater than the " +
+				"maximum number of consecutive, unused " +
+				"addresses ever generated by the wallet.",
+		},
+	},
 	Action: actionDecorator(unlock),
 }
 
@@ -1280,8 +1324,26 @@ func unlock(ctx *cli.Context) error {
 	}
 	fmt.Println()
 
+	args := ctx.Args()
+
+	// Parse the optional recovery window if it is specified. By default,
+	// the recovery window will be 0, indicating no lookahead should be
+	// used.
+	var recoveryWindow int32
+	switch {
+	case ctx.IsSet("recovery_window"):
+		recoveryWindow = int32(ctx.Int64("recovery_window"))
+	case args.Present():
+		window, err := strconv.ParseInt(args.First(), 10, 64)
+		if err != nil {
+			return err
+		}
+		recoveryWindow = int32(window)
+	}
+
 	req := &lnrpc.UnlockWalletRequest{
 		WalletPassword: pw,
+		RecoveryWindow: recoveryWindow,
 	}
 	_, err = client.UnlockWallet(ctxb, req)
 	if err != nil {