From 4ed8512db54076cd54e0cfce844690e4799f0007 Mon Sep 17 00:00:00 2001
From: abefernan <44572727+abefernan@users.noreply.github.com>
Date: Wed, 19 Jun 2024 17:00:43 +0200
Subject: [PATCH] Add keplr helpers

---
 lib/keplr.ts | 106 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 106 insertions(+)
 create mode 100644 lib/keplr.ts

diff --git a/lib/keplr.ts b/lib/keplr.ts
new file mode 100644
index 0000000..89ee177
--- /dev/null
+++ b/lib/keplr.ts
@@ -0,0 +1,106 @@
+import { ChainInfo } from "@/context/ChainsContext/types";
+import { StdSignature, decodeSignature, pubkeyToAddress } from "@cosmjs/amino";
+import { toBase64 } from "@cosmjs/encoding";
+import { verifyADR36Amino } from "@keplr-wallet/cosmos";
+import { StdSignDoc } from "@keplr-wallet/types";
+import { useLayoutEffect } from "react";
+
+const getKeplr = async (chainId: string) => {
+  const keplr = window.keplr;
+  if (!keplr) {
+    throw new Error("Keplr not found");
+  }
+
+  await keplr.enable(chainId);
+
+  keplr.defaultOptions = {
+    sign: { preferNoSetFee: true, preferNoSetMemo: true, disableBalanceCheck: true },
+  };
+
+  return keplr;
+};
+
+export const getKeplrKey = async (chainId: string) => {
+  const keplr = await getKeplr(chainId);
+  const keplrKey = await keplr.getKey(chainId);
+
+  return keplrKey;
+};
+
+export const getKeplrAminoSigner = async (chainId: string) => {
+  const keplr = await getKeplr(chainId);
+  const aminoSigner = keplr.getOfflineSignerOnlyAmino(chainId);
+
+  return aminoSigner;
+};
+
+export const getKeplrVerifySignature = async (signer: string, chain: ChainInfo, nonce: number) => {
+  const keplr = await getKeplr(chain.chainId);
+
+  const { signature } = await keplr.signAmino(
+    chain.chainId,
+    signer,
+    getKeplrVerifyMsg(signer, chain.chainDisplayName, nonce),
+  );
+
+  return signature;
+};
+
+const getKeplrVerifyMsg = (
+  signer: string,
+  chainDisplayName: string,
+  nonce: number,
+): StdSignDoc => ({
+  chain_id: "",
+  account_number: "0",
+  sequence: "0",
+  fee: { gas: "0", amount: [] },
+  memo: "",
+  msgs: [
+    {
+      type: "sign/MsgSignData",
+      value: {
+        signer,
+        data: toBase64(new Uint8Array(Buffer.from(getKeplrVerifyData(chainDisplayName, nonce)))),
+      },
+    },
+  ],
+});
+
+const getKeplrVerifyData = (chainDisplayName: string, nonce: number) =>
+  JSON.stringify({
+    title: `Keplr Login to ${chainDisplayName}`,
+    description: "Sign this no fee transaction to login with your Keplr wallet",
+    nonce,
+  });
+
+export const verifyKeplrSignature = (signature: StdSignature, chain: ChainInfo, nonce: number) => {
+  const signer = pubkeyToAddress(signature.pub_key, chain.addressPrefix);
+  const data = getKeplrVerifyData(chain.chainDisplayName, nonce);
+  const { pubkey: decodedPubKey, signature: decodedSignature } = decodeSignature(signature);
+
+  const verified = verifyADR36Amino(
+    chain.addressPrefix,
+    signer,
+    data,
+    decodedPubKey,
+    decodedSignature,
+  );
+
+  return verified;
+};
+
+const accountChangeKey = "keplr_keystorechange";
+export const useKeplrReconnect = (condition: boolean, connectWallet: () => Promise<void>) => {
+  useLayoutEffect(() => {
+    if (!condition) {
+      return;
+    }
+
+    window.addEventListener(accountChangeKey, connectWallet);
+
+    return () => {
+      window.removeEventListener(accountChangeKey, connectWallet);
+    };
+  }, [condition, connectWallet]);
+};