From 01b8f8caafdcc20df4fa3853c20d4b229597b2f0 Mon Sep 17 00:00:00 2001
From: Wrench56 <dmarkreg@gmail.com>
Date: Tue, 2 Jul 2024 03:48:39 -0400
Subject: [PATCH] Add `expose` API for handling dynamic plugin endpoints

---
 src/backend/api/expose.py  | 50 ++++++++++++++++++++++++++++++++++++++
 src/backend/server/main.py | 28 +++++++++++++++++++--
 src/backend/utils/stack.py | 13 ++++++++++
 3 files changed, 89 insertions(+), 2 deletions(-)
 create mode 100644 src/backend/api/expose.py
 create mode 100644 src/backend/utils/stack.py

diff --git a/src/backend/api/expose.py b/src/backend/api/expose.py
new file mode 100644
index 0000000..7b8fe48
--- /dev/null
+++ b/src/backend/api/expose.py
@@ -0,0 +1,50 @@
+from typing import Any, Callable, Dict, Optional
+
+from fastapi import Request
+
+from utils import stack
+
+_SUBSCRIBERS: Dict[str, Dict[str,
+                             Dict[str, Callable[[str, Request], Any]]]] = {
+    'GET': {},
+    'PUT': {},
+    'POST': {},
+    'DELETE': {}
+}
+
+
+def subscribe_get(endpoint: str, callback: Callable[[str, Request], Any]) -> None:
+    _subscribe(endpoint, _SUBSCRIBERS['GET'], callback)
+
+
+def subscribe_put(endpoint: str, callback: Callable[[str, Request], Any]) -> None:
+    _subscribe(endpoint, _SUBSCRIBERS['PUT'], callback)
+
+
+def subscribe_post(endpoint: str, callback: Callable[[str, Request], Any]) -> None:
+    _subscribe(endpoint, _SUBSCRIBERS['POST'], callback)
+
+
+def subscribe_delete(endpoint: str, callback: Callable[[str, Request], Any]) -> None:
+    _subscribe(endpoint, _SUBSCRIBERS['DELETE'], callback)
+
+
+def _subscribe(endpoint: str, structure: Dict, callback: Callable[[str, Request], Any]) -> None:
+    module_name = stack.get_caller(depth=3)[0]
+    if not module_name.startswith('plugins.plugins.'):
+        return
+
+    plugin_name = module_name.split('.')[2]
+    if plugin_name not in structure:
+        structure[plugin_name] = {}
+
+    structure[plugin_name][endpoint] = callback
+
+
+def fetch_callback(plugin: str, endpoint: str, method: str) -> Optional[Callable[[str, Request], Any]]:
+    endpoints = _SUBSCRIBERS[method.upper()].get(plugin)
+    if endpoints is None:
+        return None
+    if endpoint[-1] == '/':
+        endpoint = endpoint[:-1]
+    return endpoints.get(endpoint)
diff --git a/src/backend/server/main.py b/src/backend/server/main.py
index bca8364..77c024b 100644
--- a/src/backend/server/main.py
+++ b/src/backend/server/main.py
@@ -1,3 +1,5 @@
+from typing import Any
+
 import datetime
 import logging
 
@@ -5,6 +7,7 @@
 from fastapi.responses import FileResponse, ORJSONResponse, PlainTextResponse
 from fastapi.staticfiles import StaticFiles
 
+from api import expose
 from db import users
 from server import build
 from utils import config, const, motd, settings, status
@@ -50,7 +53,8 @@ async def rebuild(request: Request) -> PlainTextResponse:
         return PlainTextResponse('ERROR: BUILD')
     build_size, units = build.get_frontend_size()
     return PlainTextResponse(
-        f'REBUILT: Rebuilt in {build_time}ms\nSize of build folder: {build_size}{units}'
+        f'REBUILT: Rebuilt in {
+            build_time}ms\nSize of build folder: {build_size}{units}'
     )
 
 
@@ -76,7 +80,8 @@ async def login(request: Request) -> PlainTextResponse:
 
     uuid = database.create_uuid(username)
     logging.info(f'Welcome user "{username}"!')
-    expire_time = float(config.get('security').get('auth_cookie_expire_time') or 3600.0)
+    expire_time = float(config.get('security').get(
+        'auth_cookie_expire_time') or 3600.0)
     response.set_cookie(
         key='auth_cookie',
         value=uuid,
@@ -120,3 +125,22 @@ async def update_setting(request: Request, id_: str) -> PlainTextResponse:
     settings.update_setting(id_, data.decode())
 
     return response
+
+
+# Plugins
+@app.get('/plugins/{plugin}/{endpoint:path}')
+@app.put('/plugins/{plugin}/{endpoint:path}')
+@app.post('/plugins/{plugin}/{endpoint:path}')
+@app.delete('/plugins/{plugin}/{endpoint:path}')
+async def plugins(request: Request, plugin: str, endpoint: str) -> Any:
+    response = PlainTextResponse()
+    if not database.uuid_exists(request.cookies.get('auth_cookie')):
+        response.status_code = 401
+        return response
+
+    # Remove sensitive cookie(s)
+    request.cookies['auth_cookie'] = ''
+    callback = expose.fetch_callback(plugin, endpoint, request.method)
+    if callback:
+        return callback(endpoint, request)
+    return response
diff --git a/src/backend/utils/stack.py b/src/backend/utils/stack.py
new file mode 100644
index 0000000..f2a4b92
--- /dev/null
+++ b/src/backend/utils/stack.py
@@ -0,0 +1,13 @@
+# pylint: disable=protected-access
+
+from typing import Tuple
+import sys
+
+
+# Note: The sys wiki states that "It (sys._getframe())
+#       is not guranteed to exist in all
+#       implementations of Python"
+def get_caller(depth: int = 1) -> Tuple[str, str]:
+    frame = sys._getframe(depth)
+    return (frame.f_globals['__name__'],
+            frame.f_code.co_name)