refactor: modularize the sdk codebase (#47)

* refactor: modularize the sdk codebase

Signed-off-by: Árpád Csepi <csepi.arpad@outlook.com>

* fix: do not fallback to any verifier on empty provider

Signed-off-by: Árpád Csepi <csepi.arpad@outlook.com>

* fix: close file after read

Signed-off-by: Árpád Csepi <csepi.arpad@outlook.com>

---------

Signed-off-by: Árpád Csepi <csepi.arpad@outlook.com>

Author: arpad-csepi

README.md

@@ -154,7 +154,8 @@ client = Client(config)
 # Client construction does not start browser login automatically.
 # Opens the system browser and completes PKCE on loopback:
 try:
-    client.authenticate_oauth_pkce()
+    if not client.has_cached_oauth_token():
+        client.authenticate_oauth_pkce()
 except OAuthPkceError as e:
     print(f"Login failed: {e}")
 ```

dir-sdk-python/agntcy/dir_sdk/__init__.py

@@ -0,0 +1,2 @@
+# Copyright AGNTCY Contributors (https://github.com/agntcy)
+# SPDX-License-Identifier: Apache-2.0

dir-sdk-python/agntcy/dir_sdk/client/__init__.py

@@ -3,4 +3,4 @@
 
 from agntcy.dir_sdk.client.client import Client
 from agntcy.dir_sdk.client.config import Config
-from agntcy.dir_sdk.client.oauth_pkce import OAuthPkceError as OAuthPkceError
+from agntcy.dir_sdk.client.auth.oauth_pkce import OAuthPkceError as OAuthPkceError

dir-sdk-python/agntcy/dir_sdk/client/auth/__init__.py

@@ -0,0 +1,10 @@
+# Copyright AGNTCY Contributors (https://github.com/agntcy)
+# SPDX-License-Identifier: Apache-2.0
+
+"""Authentication/session helpers for the Directory client."""
+
+from agntcy.dir_sdk.client.auth.oauth_pkce import OAuthTokenHolder
+from agntcy.dir_sdk.client.auth.session import OAuthSessionManager, cached_token_from_response
+from agntcy.dir_sdk.client.auth.token_cache import CachedToken, TokenCache
+
+__all__ = ["CachedToken", "OAuthSessionManager", "OAuthTokenHolder", "TokenCache", "cached_token_from_response"]

…thon/agntcy/dir_sdk/client/oauth_pkce.py …agntcy/dir_sdk/client/auth/oauth_pkce.pydir-sdk-python/agntcy/dir_sdk/client/oauth_pkce.py renamed to dir-sdk-python/agntcy/dir_sdk/client/auth/oauth_pkce.py dir-sdk-python/agntcy/dir_sdk/client/oauth_pkce.py renamed to dir-sdk-python/agntcy/dir_sdk/client/auth/oauth_pkce.py

@@ -0,0 +1,93 @@
+# Copyright AGNTCY Contributors (https://github.com/agntcy)
+# SPDX-License-Identifier: Apache-2.0
+
+"""OAuth session management and token cache integration."""
+
+from __future__ import annotations
+
+from datetime import UTC, datetime, timedelta
+
+from agntcy.dir_sdk.client.config import Config
+from agntcy.dir_sdk.client.auth.oauth_pkce import (
+    OAuthTokenHolder,
+    fetch_openid_configuration,
+    run_loopback_pkce_login,
+)
+from agntcy.dir_sdk.client.auth.token_cache import CachedToken, TokenCache
+
+
+def cached_token_from_response(config: Config, payload: dict[str, object]) -> CachedToken:
+    expires_at = None
+    expires_in = payload.get("expires_in")
+    if expires_in is not None:
+        expires_at = datetime.now(UTC) + timedelta(seconds=int(expires_in))
+
+    refresh_token = payload.get("refresh_token")
+    token_type = payload.get("token_type")
+    return CachedToken(
+        access_token=str(payload["access_token"]),
+        token_type=str(token_type) if isinstance(token_type, str) else "",
+        provider="oidc",
+        issuer=config.oidc_issuer,
+        refresh_token=str(refresh_token) if isinstance(refresh_token, str) else "",
+        expires_at=expires_at,
+        created_at=datetime.now(UTC),
+    )
+
+
+class OAuthSessionManager:
+    """Coordinates OIDC token state with interactive PKCE flow and cache."""
+
+    def __init__(
+        self,
+        config: Config,
+        token_cache: TokenCache | None = None,
+    ) -> None:
+        self.config = config
+        self._token_cache = token_cache or TokenCache()
+        self._oauth_holder: OAuthTokenHolder | None = None
+
+        if self.config.auth_mode == "oidc":
+            self._oauth_holder = OAuthTokenHolder()
+            if self.config.auth_token:
+                self._oauth_holder.set_tokens(self.config.auth_token)
+            else:
+                cached_token = self._token_cache.get_valid_token()
+                if cached_token is not None:
+                    self._oauth_holder.set_tokens(cached_token.access_token)
+
+    @property
+    def oauth_holder(self) -> OAuthTokenHolder | None:
+        return self._oauth_holder
+
+    def has_access_token(self) -> bool:
+        if self._oauth_holder is None:
+            return False
+        try:
+            self._oauth_holder.get_access_token()
+            return True
+        except RuntimeError:
+            return False
+
+    def authenticate(self) -> None:
+        if self.config.auth_mode != "oidc":
+            msg = "authenticate_oauth_pkce() requires auth_mode='oidc'"
+            raise ValueError(msg)
+        if not self.config.oidc_issuer:
+            msg = "oidc_issuer is required for authenticate_oauth_pkce()"
+            raise ValueError(msg)
+        if not self.config.oidc_client_id:
+            msg = "oidc_client_id is required for authenticate_oauth_pkce()"
+            raise ValueError(msg)
+        if self._oauth_holder is None:
+            msg = "OAuth token holder not initialized"
+            raise RuntimeError(msg)
+
+        meta = fetch_openid_configuration(
+            self.config.oidc_issuer,
+            verify=not self.config.tls_skip_verify,
+            timeout=min(30.0, self.config.oidc_auth_timeout),
+        )
+        payload = run_loopback_pkce_login(self.config, metadata=meta)
+        self._oauth_holder.update_from_token_response(payload)
+        self._token_cache.save(cached_token_from_response(self.config, payload))