refactor: add English docstrings to all functions

main.py

@@ -1,3 +1,14 @@
+"""
+This module defines the main FastAPI application, including route handlers,
+middleware, static file serving, and error handling.
+
+Routes:
+- `/app-ads.txt`: Serves the `app-ads.txt` file.
+- `/robots.txt`: Serves the `robots.txt` file.
+- `/wallpaper/today`: Served by the wallpaper router, fetches today's wallpaper.
+- `/wallpaper/{day}`: Served by the wallpaper router, fetches the wallpaper for a specific day.
+"""
+
 import http
 
 import uvicorn

src/middleware/plausible_analytics.py

@@ -1,13 +1,40 @@
+"""
+This module contains the PlausibleAnalytics middleware for sending analytics events
+to Plausible Analytics after processing each request.
+
+The middleware collects information about the request, such as the HTTP method, status code,
+user agent, and source, and sends this data to the Plausible Analytics API.
+
+In case of any client-side or server-side errors, no event is sent, 
+and the response is returned as usual.
+"""
+
 import httpx
 import yaml
-
 from http import HTTPStatus
 from user_agents import parse as ua_parse
 
 config = yaml.safe_load(open('./config.yaml'))
 
 class PlausibleAnalytics:
+    """
+    Middleware for sending analytics data to Plausible Analytics
+    after processing each request.
+    """
+    
     async def __call__(self, request, call_next):
+        """
+        Called for each request, sends an event to Plausible with
+        information about the request and user.
+
+        Args:
+            request: FastAPI request object.
+            call_next: Function to call the next request handler.
+
+        Returns:
+            Response: FastAPI response object.
+        """
+        
         response = await call_next(request)
 
         user_agent = request.headers.get('user-agent', 'unknown')
@@ -29,18 +56,18 @@ class PlausibleAnalytics:
             },
         }
 
-        async with httpx.AsyncClient() as client:
-            try:
+        try:
+            async with httpx.AsyncClient() as client:
                 await client.post(
                     config['analytics']['endpoint'],
                     json=event,
                     headers={
                         "Authorization": f"Bearer {config['analytics']['token']}",
                         "Content-Type": "application/json",
-                        "User-Agent": request.headers.get('user-agent', 'unknown'),
+                        "User-Agent": user_agent,
                     },
                 )
-            except Exception as e:
-                print(f"Error sending event to Plausible: {e}")
+        except Exception as e:
+            print(f"Error sending event to Plausible: {e}")
 
-        return response
+        return response

src/routes/index.py

@@ -1,9 +1,13 @@
-from fastapi import APIRouter, Request
+"""
+This module defines API routes for serving static HTML files.
+"""
+
+from fastapi import APIRouter
 from fastapi.responses import FileResponse
 
 router = APIRouter()
 
-
 @router.get('/')
 async def main():
+    """Returns the main HTML page."""
     return FileResponse('./src/web/html/index.html')

src/routes/wallpaper.py

@@ -1,3 +1,13 @@
+"""
+This module contains routes for serving wallpapers using FastAPI.
+
+Routes:
+- `/wallpaper/today`: Fetches the wallpaper of the day and renders it using a template.
+- `/wallpaper/{day}`: Fetches a specific wallpaper by day and renders it using a template.
+
+In case of any client or server errors or empty data, a 404 error page is returned.
+"""
+
 from http import HTTPStatus
 
 import requests
@@ -12,6 +22,16 @@ template = Jinja2Templates(directory='./src/web/html')
 
 @router.get('/wallpaper/today', response_class=HTMLResponse)
 async def today_wallpaper(request: Request):
+    """
+    Fetches the wallpaper of the day and renders it using a template.
+    Returns a 404 page in case of client or server errors.
+
+    Args:
+        request: The FastAPI request object.
+
+    Returns:
+        HTMLResponse: The wallpaper page or 404 error page.
+    """
     res = requests.get(f'https://api.starlio.space/last')
 
     if HTTPStatus(res.status_code).is_server_error or HTTPStatus(res.status_code).is_client_error:
@@ -26,6 +46,17 @@ async def today_wallpaper(request: Request):
 
 @router.get('/wallpaper/{day}', response_class=HTMLResponse)
 async def wallpaper(request: Request, day):
+    """
+    Fetches a specific wallpaper by day and renders it using a template.
+    Returns a 404 page in case of client or server errors or if the wallpaper data is empty.
+
+    Args:
+        request: The FastAPI request object.
+        day: The day parameter used to fetch the wallpaper.
+
+    Returns:
+        HTMLResponse: The wallpaper page or 404 error page.
+    """
     res = requests.get(f'https://api.starlio.space/wallpaper/{day}')
 
     if (HTTPStatus(res.status_code).is_server_error