Introduce vault layer

src/password_manager/vault.py

@@ -0,0 +1,49 @@
+"""Vault utilities for reading and writing encrypted files."""
+
+from pathlib import Path
+from typing import Optional
+
+from .encryption import EncryptionManager
+
+
+class Vault:
+    """Simple wrapper around :class:`EncryptionManager` for vault storage."""
+
+    INDEX_FILENAME = "seedpass_passwords_db.json.enc"
+    CONFIG_FILENAME = "seedpass_config.json.enc"
+
+    def __init__(self, encryption_manager: EncryptionManager, fingerprint_dir: Path):
+        self.encryption_manager = encryption_manager
+        self.fingerprint_dir = fingerprint_dir
+        self.index_file = self.fingerprint_dir / self.INDEX_FILENAME
+        self.config_file = self.fingerprint_dir / self.CONFIG_FILENAME
+
+    def set_encryption_manager(self, manager: EncryptionManager) -> None:
+        """Replace the internal encryption manager."""
+        self.encryption_manager = manager
+
+    # ----- Password index helpers -----
+    def load_index(self) -> dict:
+        """Return decrypted password index data as a dict."""
+        return self.encryption_manager.load_json_data(self.index_file)
+
+    def save_index(self, data: dict) -> None:
+        """Encrypt and write password index."""
+        self.encryption_manager.save_json_data(data, self.index_file)
+
+    def get_encrypted_index(self) -> Optional[bytes]:
+        """Return the encrypted index bytes if present."""
+        return self.encryption_manager.get_encrypted_index()
+
+    def decrypt_and_save_index_from_nostr(self, encrypted_data: bytes) -> None:
+        """Decrypt Nostr payload and overwrite the local index."""
+        self.encryption_manager.decrypt_and_save_index_from_nostr(encrypted_data)
+
+    # ----- Config helpers -----
+    def load_config(self) -> dict:
+        """Load decrypted configuration."""
+        return self.encryption_manager.load_json_data(self.config_file)
+
+    def save_config(self, config: dict) -> None:
+        """Encrypt and persist configuration."""
+        self.encryption_manager.save_json_data(config, self.config_file)