refactor: single class

catalyst_voices/lib/common/bip39/seed_phrase.dart

@@ -1,4 +1,4 @@
-import 'dart:convert';
+import 'dart:typed_data';
 import 'package:bip39/bip39.dart' as bip39;
 
 /// Represents a seed phrase consisting of a mnemonic and its associated seed.
@@ -9,53 +9,65 @@ import 'package:bip39/bip39.dart' as bip39;
 /// cryptocurrency wallets or secure key management.
 class SeedPhrase {
   final String mnemonic;
-  final String seed;
 
   /// Generates a new seed phrase with a random mnemonic
   /// and its corresponding seed.
   SeedPhrase() : this.fromMnemonic(bip39.generateMnemonic());
 
+  SeedPhrase.fromUint8ListEntropy(Uint8List encodedData)
+      : this.fromHexEntropy(_uint8ListToHex(encodedData));
+
+  SeedPhrase.fromHexEntropy(String encodedData)
+      : this.fromMnemonic(bip39.entropyToMnemonic(encodedData));
+
   /// Creates a SeedPhrase from an existing [mnemonic].
+  ///
+  /// Throws an [ArgumentError] if the mnemonic is invalid.
+  ///
+  /// [mnemonic]: The mnemonic to derive the seed from.
   SeedPhrase.fromMnemonic(this.mnemonic)
-      : seed = bip39.mnemonicToSeedHex(mnemonic);
+      : assert(bip39.validateMnemonic(mnemonic), 'Invalid mnemonic phrase');
 
   /// Returns the seed hex string associated with the mnemonic.
-  String getSeed() {
-    return seed;
+  Uint8List getUint8ListSeed() {
+    return bip39.mnemonicToSeed(mnemonic);
+  }
+
+  String getHexSeed() {
+    return bip39.mnemonicToSeedHex(mnemonic);
   }
 
   /// Returns the mnemonic phrase.
   String getMnemonic() {
     return mnemonic;
   }
-}
 
-class SeedPhraseSerialisation {
-  // Encode the seed phrase into a JSON string
-  static String encode(SeedPhrase seedPhrase) {
-    final data = {
-      'mnemonic': seedPhrase.getMnemonic(),
-      'seed': seedPhrase.getSeed(),
-    };
-    return jsonEncode(data);
+  Uint8List toUint8ListEntropy() {
+    return _hexStringToUint8List(toHexEntropy());
   }
 
-  // Decode the JSON string back into a SeedPhrase object
-  static SeedPhrase decode(String encodedData) {
-    final Map<String, dynamic> data = jsonDecode(encodedData);
-    final String mnemonic = data['mnemonic'];
-    return SeedPhrase.fromMnemonic(mnemonic);
+  String toHexEntropy() {
+    return bip39.mnemonicToEntropy(mnemonic);
   }
 }
 
-class SeedPhraseFactory {
-  // Generate a new SeedPhrase
-  static SeedPhrase generateNew() {
-    return SeedPhrase();
+String _uint8ListToHex(Uint8List encodedData) {
+  final hexString = StringBuffer();
+  for (final byte in encodedData) {
+    hexString.write(byte.toRadixString(16).padLeft(2, '0'));
   }
+  return hexString.toString();
+}
 
-  // Create a SeedPhrase from an existing mnemonic
-  static SeedPhrase fromMnemonic(String mnemonic) {
-    return SeedPhrase.fromMnemonic(mnemonic);
+Uint8List _hexStringToUint8List(String hex) {
+  if (hex.length % 2 != 0) {
+    throw ArgumentError('Hex string must have an even length.');
   }
+
+  return Uint8List.fromList(
+    List.generate(
+      hex.length ~/ 2,
+      (i) => int.parse(hex.substring(i * 2, i * 2 + 2), radix: 16),
+    ),
+  );
 }