feat: support offline mode (#29)

deps/tasks.py

@@ -6,7 +6,7 @@
 
 from conf import settings
 from deps.logs import logger
-from deps.utils import repeat_every
+from deps.utils import repeat_every, check_for_internet
 
 
 @asynccontextmanager
@@ -20,6 +20,8 @@ async def startup(_app: FastAPI) -> None:
 @repeat_every(seconds=settings.library_index_refresh_interval, logger=logger)
 async def refresh_library_index():
     """Update the Arduino library index"""
+    if not check_for_internet():
+        return
     logger.info("Updating library index...")
     installer = await asyncio.create_subprocess_exec(
         settings.arduino_cli_path,

deps/utils.py

@@ -6,6 +6,7 @@
 from traceback import format_exception
 from typing import Any, Callable, Coroutine, Optional, Union
 
+import httpx
 from starlette.concurrency import run_in_threadpool
 
 NoArgsNoReturnFuncT = Callable[[], None]
@@ -85,3 +86,16 @@ async def loop() -> None:
         return wrapped
 
     return decorator
+
+
+async def check_for_internet() -> bool:
+    """Check if internet connection is available"""
+    client = httpx.AsyncClient()
+    try:
+        response = await client.get(
+            "https://downloads.arduino.cc", headers={"User-Agent": ""}
+        )
+        response.raise_for_status()
+    except (httpx.RequestError, httpx.HTTPError):
+        return False
+    return True

main.py

@@ -14,6 +14,7 @@
 from deps.logs import logger
 from deps.session import Session, sessions
 from deps.tasks import startup
+from deps.utils import check_for_internet
 from models import Sketch, Library, PythonProgram
 
 app = FastAPI(lifespan=startup)
@@ -32,6 +33,9 @@
 
 async def _install_libraries(libraries: list[Library]) -> None:
     # Install required libraries
+    if not check_for_internet():
+        logger.warning("No internet connection, skipping library install")
+        return
     for library in libraries:
         if library_cache.get(library):
             continue

requirements.txt

@@ -6,3 +6,4 @@ pydantic-settings==2.2.1
 cachetools==5.3.3
 python-minifier==2.9.0
 pyserial==3.5
+httpx==0.27.0