Add logging

app.py

@@ -4,6 +4,10 @@ import requests
 from bs4 import BeautifulSoup
 from flask import Flask, Response
 from diskcache import Cache
+import logging
+
+logging.basicConfig(level=logging.INFO)
+logger = logging.getLogger(__name__)
 
 app = Flask(__name__)
 
@@ -15,7 +19,7 @@ cookie_jar = http.cookiejar.MozillaCookieJar('cookies.txt')
 try:
     cookie_jar.load(ignore_discard=True, ignore_expires=True)
 except FileNotFoundError:
-    print("cookies.txt not found, starting with empty cookie jar")
+    logger.warning("cookies.txt not found, starting with empty cookie jar")
 
 s = requests.Session()
 s.headers.update({
@@ -25,16 +29,21 @@ s.cookies = cookie_jar  # type: ignore
 
 @app.route("/watch/<video_id>")
 def proxy(video_id):
+    logger.info(f"Received request for video ID: {video_id}")
+
     cached_html = cache.get(video_id)
     if cached_html is not None:
+        logger.info(f"Using cached response for video ID: {video_id}")
         return Response(cached_html, mimetype="text/html")  # type: ignore
 
     # Not in cache or cache expired; fetch from nicovideo.jp
     real_url = f"https://www.nicovideo.jp/watch/{video_id}"
     try:
+        logger.info(f"Fetching content from URL: {real_url}")
         r = s.get(real_url, timeout=10)
     except requests.RequestException as e:
-        return Response(f"Error fetching the page: {e}", status=500)
+        logger.error(f"Error fetching the page for video ID '{video_id}': {e}")
+        return Response(status=500)
 
     soup = BeautifulSoup(r.text, "html.parser")
     thumbnail_url = None
@@ -49,7 +58,8 @@ def proxy(video_id):
                 params["video"]["thumbnail"].get("middleUrl") or
                 params["video"]["thumbnail"].get("url")
             )
-    except (KeyError, json.JSONDecodeError):
+    except (KeyError, json.JSONDecodeError) as e:
+        logger.warning(f"Failed to extract thumbnail info for video ID '{video_id}': {e}")
         pass
 
     og_tags = soup.find_all("meta", property=lambda x: x)  # type: ignore