Update documentation

bot.py

@@ -15,14 +15,15 @@
 logging.getLogger('telegram').setLevel(logging.WARNING)
 logging.getLogger('httpx').setLevel(logging.WARNING)
 
-#Read env variables
+# Read env variables
 TOKEN = os.environ['TOKEN']
 search_url = os.environ['search_url'] 
 affiliate_tag = os.environ['affiliate_tag']
 
-#Filtered URL schemes: dp/ASIN, gp/product/ASIN and gp/aw/d/ASIN
+# Filtered URL schemes: dp/ASIN, gp/product/ASIN and gp/aw/d/ASIN
 PRODUCT_PATTERN_CODE = re.compile(r'(?:dp\/[\w]*)|(?:gp\/product\/[\w]*)|(?:gp\/aw\/d\/[\w]*)')
 
+# Handle the search_url and ensure that it's correct
 if (not search_url.startswith("amazon.")):
     logger.error("Incorrect search URL. The URL must start with 'amazon.' followed by the country domain.")
 if (not search_url.endswith("/")):
@@ -31,47 +32,77 @@
 
 logger.info(f'Telegram bot started correctly with the affiliate_tag: {affiliate_tag}')
 
-# Define a few command handlers. These usually take the two arguments update and
-# context. Error handlers also receive the raised TelegramError object in error.
-async def start(update: Update, context: ContextTypes.DEFAULT_TYPE):
+
+async def start(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Command handler for the command start. Reply with a greeting when initializing the bot.
+    
+    Args:
+        update: The incoming update.
+        context: The context of the bot.
+    """
     await context.bot.send_message(chat_id=update.effective_chat.id, text="Hola! Este bot responde a los enlaces de amazon añadiendo un codigo de afiliado!")
 
-# Create the new URL with the refer tag
 def create_affiliate_url(product_code: str) -> str:
+    """Create a new URL with the the product code and the affiliate tag.
+
+    Args:
+        product_code: The product code that will be used to create the URL.
+    
+    Returns:
+        The new URL with the product code and the affiliate tag.
+    """
     return base_url+product_code+"?tag="+affiliate_tag
 
-#Expand shortened URL (amzn.to or amzn.eu links) to normal Amazon URL
 def expand_short_url(url: str) -> str:
+    """
+    Expand shortened URLs to the common Amazon URLs.
+
+    Args:
+        url: The shortened URL.
+    
+    Returns:
+        The expanded URL or empty string if the process fails. 
+    """
     try:
         response = requests.get("https://"+url)
         return response.url
     except requests.exceptions.RequestException:
         logger.error(f"Failed to expand URL: {url}")
         return ""  
-#Filter the msg text to extract the URL if found. Then send the corresponding reply
-# with the new affiliate URL
-async def filterText(update: Update, context: ContextTypes.DEFAULT_TYPE):
+
+async def filterText(update: Update, context: ContextTypes.DEFAULT_TYPE) -> None:
+    """Filter the incoming message text to extract the amazon URL if found. 
+       Then send the corresponding reply with the new URL with the affiliate tag.
+
+    Args:
+        update: The incoming update.
+        context: The context of the bot.
+    """
     pCode=""
     msg = update.message.text
+
+    # Search for a shortened URL and expand it.
     short_url_list = ["amzn.to", "amzn.eu"]
     for url in short_url_list:
         short_start_index = msg.find(url)
         if short_start_index!=-1:
             msg = expand_short_url(msg[short_start_index:].split()[0])
             break
 
+    # Search for the affiliate tag, send the same URL if found.
     if (msg.find(affiliate_tag)!=-1):
         logger.info(f"The affiliate tag was already in the URL: {msg}")
         await context.bot.sendMessage(chat_id=update.message.chat_id, reply_to_message_id=update.effective_message.id, text=msg)
         return
 
+    # Search the start of the amazon base url
     start_index = msg.find(search_url)
-
     if start_index != -1:
-        #Regular expression to extract the product code. Adjust if different URL schemes are found.
+        # Regular expression to extract the product code. Adjust if different URL schemes are found.
         m = re.search(PRODUCT_PATTERN_CODE,msg[start_index:].split(" ")[0]) 
         pCode = m.group(0) if m != None else ""
 
+        # Create and send the new url with the affiliate tag
         new_url = create_affiliate_url(pCode)
         logger.info(f"Filtered link: {msg} -> {new_url}" if m != None else f"Product code not found: {msg} -> {new_url}")
         await context.bot.sendMessage(chat_id=update.message.chat_id, reply_to_message_id=update.effective_message.id, text=new_url)