add return type hinting for pop3

mail4one/pop3.py

@@ -14,10 +14,10 @@ from .poputils import InvalidCommand, parse_command, err, Command, ClientQuit, C
     Request, MailEntry, get_mail, get_mails_list, MailList
 
 
-async def next_req():
+async def next_req() -> Request:
     for _ in range(InvalidCommand.RETRIES):
         line = await state().reader.readline()
-        logging.debug(f"Client: {line}")
+        # logging.debug(f"Client: {line}")
         if not line:
             continue
         try:
@@ -32,7 +32,7 @@ async def next_req():
         raise ClientError(f"Bad command {InvalidCommand.RETRIES} times")
 
 
-async def expect_cmd(*commands: Command):
+async def expect_cmd(*commands: Command) -> Request:
     req = await next_req()
     if req.cmd not in commands:
         logging.error(f"Unexpected command: {req.cmd} is not in {commands}")
@@ -40,12 +40,12 @@ async def expect_cmd(*commands: Command):
     return req
 
 
-def write(data):
+def write(data) -> None:
     logging.debug(f"Server: {data}")
     state().writer.write(data)
 
 
-def validate_password(username, password):
+def validate_password(username, password) -> None:
     try:
         pwinfo, mbox = config().users[username]
     except:
@@ -57,7 +57,7 @@ def validate_password(username, password):
     state().mbox = mbox
 
 
-async def handle_user_pass_auth(user_cmd):
+async def handle_user_pass_auth(user_cmd) -> None:
     username = user_cmd.arg1
     if not username:
         raise AuthError("Invalid USER command. username empty")
@@ -68,7 +68,7 @@ async def handle_user_pass_auth(user_cmd):
     logging.info(f"{username=} has logged in successfully")
 
 
-async def auth_stage():
+async def auth_stage() -> None:
     write(ok("Server Ready"))
     for _ in range(AuthError.RETRIES):
         try:
@@ -78,8 +78,8 @@ async def auth_stage():
                 write(msg("USER"))
                 write(end())
             else:
-                username = await handle_user_pass_auth(req)
+                await handle_user_pass_auth(req)
-                if username in config().loggedin_users:
+                if (username:=state().username) in config().loggedin_users:
                     logging.warning(
                         f"User: {username} already has an active session")
                     raise AuthError("Already logged in")
@@ -96,18 +96,18 @@ async def auth_stage():
         raise ClientError("Failed to authenticate")
 
 
-def trans_command_capa(_, __):
+def trans_command_capa(_, __) -> None:
     write(ok("CAPA follows"))
     write(msg("UIDL"))
     write(end())
 
 
-def trans_command_stat(mails: MailList, _):
+def trans_command_stat(mails: MailList, _) -> None:
     num, size = mails.compute_stat()
     write(ok(f"{num} {size}"))
 
 
-def trans_command_list(mails: MailList, req: Request):
+def trans_command_list(mails: MailList, req: Request) -> None:
     if req.arg1:
         entry = mails.get(req.arg1)
         if entry:
@@ -121,7 +121,7 @@ def trans_command_list(mails: MailList, req: Request):
         write(end())
 
 
-def trans_command_uidl(mails: MailList, req: Request):
+def trans_command_uidl(mails: MailList, req: Request) -> None:
     if req.arg1:
         entry = mails.get(req.arg1)
         if entry:
@@ -135,7 +135,7 @@ def trans_command_uidl(mails: MailList, req: Request):
         write(end())
 
 
-def trans_command_retr(mails: MailList, req: Request):
+def trans_command_retr(mails: MailList, req: Request) -> None:
     entry = mails.get(req.arg1)
     if entry:
         write(ok("Contents follow"))
@@ -146,7 +146,7 @@ def trans_command_retr(mails: MailList, req: Request):
         write(err("Not found"))
 
 
-def trans_command_dele(mails: MailList, req: Request):
+def trans_command_dele(mails: MailList, req: Request) -> None:
     entry = mails.get(req.arg1)
     if entry:
         mails.delete(req.arg1)
@@ -155,11 +155,11 @@ def trans_command_dele(mails: MailList, req: Request):
         write(err("Not found"))
 
 
-def trans_command_noop(_, __):
+def trans_command_noop(_, __) -> None:
     write(ok("Hmm"))
 
 
-async def process_transactions(mails_list: list[MailEntry]):
+async def process_transactions(mails_list: list[MailEntry]) -> set[str]:
     mails = MailList(mails_list)
 
     def reset(_, __):
@@ -194,19 +194,19 @@ async def process_transactions(mails_list: list[MailEntry]):
             await state().writer.drain()
 
 
-def get_deleted_items(deleted_items_path: Path):
+def get_deleted_items(deleted_items_path: Path) -> set[str]:
     if deleted_items_path.exists():
         with deleted_items_path.open() as f:
             return set(f.read().splitlines())
     return set()
 
 
-def save_deleted_items(deleted_items_path: Path, deleted_items: set[str]):
+def save_deleted_items(deleted_items_path: Path, deleted_items: set[str]) -> None:
     with deleted_items_path.open(mode="w") as f:
         f.writelines(f"{did}\n" for did in deleted_items)
 
 
-async def transaction_stage():
+async def transaction_stage() -> None:
     deleted_items_path = config().mails_path / state().mbox / state().username
     existing_deleted_items: set[str] = get_deleted_items(deleted_items_path)
     mails_list = [
@@ -215,7 +215,7 @@ async def transaction_stage():
         if entry.uid not in existing_deleted_items
     ]
 
-    new_deleted_items: Set = await process_transactions(mails_list)
+    new_deleted_items: set[str] = await process_transactions(mails_list)
     logging.info(f"completed transactions. Deleted:{len(new_deleted_items)}")
     if new_deleted_items:
         save_deleted_items(deleted_items_path,
@@ -224,7 +224,7 @@ async def transaction_stage():
     logging.info(f"Saved deleted items")
 
 
-async def start_session():
+async def start_session() -> None:
     logging.info("New session started")
     try:
         await auth_stage()
@@ -243,7 +243,7 @@ async def start_session():
             config().loggedin_users.remove(state().username)
 
 
-def parse_users(users: list[User]):
+def parse_users(users: list[User]) -> dict[str, tuple[PWInfo, str]]:
 
     def inner():
         for user in users:
@@ -315,7 +315,7 @@ async def create_pop_server(host: str,
                                       ssl=ssl_context)
 
 
-async def a_main(*args, **kwargs):
+async def a_main(*args, **kwargs) -> None:
     server = await create_pop_server(*args, **kwargs)
     await server.serve_forever()