From 673fcc610df2d1e120ca6ced3ee2562ae0d66ade Mon Sep 17 00:00:00 2001
From: John Oshalusi <john.oshalusi@iohk.io>
Date: Wed, 26 Jun 2024 14:51:22 +0100
Subject: [PATCH] feat: create Cip1854PublicKey core type

---
 .../types/Cip1854ExtendedAccountPublicKey.ts  | 31 +++++++++++++++
 packages/core/src/Cardano/types/index.ts      |  1 +
 .../Cip1854ExtendedAccountPublicKey.test.ts   | 39 +++++++++++++++++++
 3 files changed, 71 insertions(+)
 create mode 100644 packages/core/src/Cardano/types/Cip1854ExtendedAccountPublicKey.ts
 create mode 100644 packages/core/test/Cardano/types/Cip1854ExtendedAccountPublicKey.test.ts

diff --git a/packages/core/src/Cardano/types/Cip1854ExtendedAccountPublicKey.ts b/packages/core/src/Cardano/types/Cip1854ExtendedAccountPublicKey.ts
new file mode 100644
index 00000000000..24c7df58a84
--- /dev/null
+++ b/packages/core/src/Cardano/types/Cip1854ExtendedAccountPublicKey.ts
@@ -0,0 +1,31 @@
+import * as BaseEncoding from '@scure/base';
+import { Bip32PublicKeyHex } from '@cardano-sdk/crypto';
+import { InvalidStringError, OpaqueString, assertIsBech32WithPrefix } from '@cardano-sdk/util';
+
+const MAX_BECH32_LENGTH_LIMIT = 1023;
+const bip32PublicKeyPrefix = 'acct_shared_xvk';
+
+/** This key is a bech32 encoded string with the prefix `acct_shared_xvk`. */
+export type Cip1854ExtendedAccountPublicKey = OpaqueString<'Cip1854PublicKey'>;
+
+export const Cip1854ExtendedAccountPublicKey = (value: string): Cip1854ExtendedAccountPublicKey => {
+  try {
+    assertIsBech32WithPrefix(value, [bip32PublicKeyPrefix]);
+  } catch {
+    throw new InvalidStringError(value, 'Expected key to be a bech32 encoded string');
+  }
+
+  return value as Cip1854ExtendedAccountPublicKey;
+};
+
+Cip1854ExtendedAccountPublicKey.fromBip32PublicKeyHex = (value: Bip32PublicKeyHex): Cip1854ExtendedAccountPublicKey => {
+  const words = BaseEncoding.bech32.toWords(Buffer.from(value, 'hex'));
+  return Cip1854ExtendedAccountPublicKey(
+    BaseEncoding.bech32.encode(bip32PublicKeyPrefix, words, MAX_BECH32_LENGTH_LIMIT)
+  );
+};
+
+Cip1854ExtendedAccountPublicKey.toBip32PublicKeyHex = (value: Cip1854ExtendedAccountPublicKey): Bip32PublicKeyHex => {
+  const { words } = BaseEncoding.bech32.decode(value, MAX_BECH32_LENGTH_LIMIT);
+  return Bip32PublicKeyHex(Buffer.from(BaseEncoding.bech32.fromWords(words)).toString('hex'));
+};
diff --git a/packages/core/src/Cardano/types/index.ts b/packages/core/src/Cardano/types/index.ts
index d63255c1e6f..0515d4d3cae 100644
--- a/packages/core/src/Cardano/types/index.ts
+++ b/packages/core/src/Cardano/types/index.ts
@@ -13,3 +13,4 @@ export * from './ProtocolParameters';
 export * from './PlutusData';
 export * from './UtilityTypes';
 export * from './Governance';
+export * from './Cip1854ExtendedAccountPublicKey';
diff --git a/packages/core/test/Cardano/types/Cip1854ExtendedAccountPublicKey.test.ts b/packages/core/test/Cardano/types/Cip1854ExtendedAccountPublicKey.test.ts
new file mode 100644
index 00000000000..1d82f1fa3ba
--- /dev/null
+++ b/packages/core/test/Cardano/types/Cip1854ExtendedAccountPublicKey.test.ts
@@ -0,0 +1,39 @@
+import { Bip32PublicKeyHex } from '@cardano-sdk/crypto';
+import { Cip1854ExtendedAccountPublicKey } from '../../../src/Cardano';
+
+const bip32PublicKeyPrefix = 'acct_shared_xvk';
+
+describe('Cardano/types/Cip1854ExtendedAccountPublicKey', () => {
+  const publicKeyHex = Bip32PublicKeyHex(
+    '979693650bb44f26010e9f7b3b550b0602c748d1d00981747bac5c34cf5b945fe01a39317b9b701e58ee16b5ed16aa4444704b98cc997bdd6c5a9502a8b7d70d'
+  );
+
+  describe('Cip1854ExtendedAccountPublicKey', () => {
+    it('Accepts a valid bech32-encoded CIP1854 public key', () => {
+      const bip32PublicKey =
+        'acct_shared_xvk1q395kywke7mufrysg33nsm6ggjxswu4g8q8ag7ks9kdyaczchtemd5d2armrfstfa32lamhxfl3sskgcmxm4zdhtvut362796ez4ecqx6vnht';
+      expect(Cip1854ExtendedAccountPublicKey(bip32PublicKey)).toEqual(bip32PublicKey);
+    });
+
+    it('Throws an error when an invalid bech32-encoded CIP1854 public key is passed', () => {
+      expect(() => Cip1854ExtendedAccountPublicKey(publicKeyHex)).toThrow();
+      expect(() =>
+        Cip1854ExtendedAccountPublicKey(
+          'addr_test1qpfhhfy2qgls50r9u4yh0l7z67xpg0a5rrhkmvzcuqrd0znuzcjqw982pcftgx53fu5527z2cj2tkx2h8ux2vxsg475q9gw0lz'
+        )
+      ).toThrow();
+      expect(() => Cip1854ExtendedAccountPublicKey('invalid')).toThrow();
+    });
+  });
+
+  it('fromBip32PublicKeyHex encodes a valid CIP1854 bip32 public key according to CIP5 specification', () => {
+    const cip1854PublicKey = Cip1854ExtendedAccountPublicKey.fromBip32PublicKeyHex(publicKeyHex);
+    expect(cip1854PublicKey.startsWith(bip32PublicKeyPrefix)).toBe(true);
+  });
+
+  it('toBip32PublicKeyHex decodes a bech32-encoded CIP1854 bip32 public key to a hex string', () => {
+    const cip1854PublicKey = Cip1854ExtendedAccountPublicKey.fromBip32PublicKeyHex(publicKeyHex);
+    const originalHex = Cip1854ExtendedAccountPublicKey.toBip32PublicKeyHex(cip1854PublicKey);
+    expect(originalHex).toEqual(publicKeyHex);
+  });
+});