feat: make registration procedure a conversation

fix: use ApplicationBuilder.post_init() to add_commands
refactor: rename login to register

main.py

@@ -1,7 +1,7 @@
 """
     main module
 """
-from module.commands import start, report, help, login
+from module.commands import start, report, help, register_conv_handler
 from module.data import HELP, REPORT
 
 from telegram import BotCommand, Update
@@ -18,7 +18,7 @@ async def add_commands(app: Application) -> None:
         BotCommand("start", "messaggio di benvenuto"),
         BotCommand("help", "ricevi aiuto sui comandi"),
         BotCommand("report", "segnala un problema"),
-        BotCommand("login", "procedura di autenticazione")
+        BotCommand("register", "procedura di registrazione")
     ]
 
     await app.bot.set_my_commands(commands)
@@ -43,14 +43,13 @@ async def chatid(update: Update, context: ContextTypes.DEFAULT_TYPE):
         MessageHandler(filters.Regex(HELP) & filters.ChatType.PRIVATE, help),
         CommandHandler("report", report),
         MessageHandler(filters.Regex(REPORT) & filters.ChatType.PRIVATE, report),
-        CommandHandler("login", login)
+        register_conv_handler()
     ]
 
     app.add_handlers(handlers)
 
 def main():
-    app = ApplicationBuilder().token("TOKEN").build()
-    add_commands(app)
+    app = ApplicationBuilder().token("TOKEN").post_init(add_commands).build()
     add_handlers(app)
 
     app.run_polling()

module/commands/__init__.py

@@ -4,4 +4,4 @@
 from .start import start
 from .help import help
 from .report import report
-from .login import login
+from .register import register_conv_handler

module/commands/register.py

@@ -0,0 +1,174 @@
+"""
+    /register command
+"""
+import re
+import hashlib
+from enum import Enum
+
+from telegram import Update
+from telegram.ext import ContextTypes, MessageHandler, CommandHandler, ConversationHandler, filters
+
+from sqlalchemy import select
+from data.db import Session
+from data.db.models import User
+
+class State(Enum):
+    """
+        States of the register procedure
+    """
+    EMAIL = 1
+    OTP = 2
+
+async def register_entry(update: Update, context: ContextTypes.DEFAULT_TYPE) -> State:
+    """
+        Called by the /register command.
+
+        Starts the registration procedure.
+
+        Args:
+            update: Update event
+            context: context passed by the handler
+
+        Returns:
+            State: the next state of the conversation
+    """
+
+    await context.bot.send_message(
+        chat_id=update.effective_chat.id,
+        text="Invia la tua email studium"
+    )
+
+    return State.EMAIL
+
+async def email_checker(update: Update, context: ContextTypes.DEFAULT_TYPE) -> State | int:
+    """
+        Checks if the user isn't already registered.
+
+        Args:
+            update: Update event
+            context: context passed by the handler
+
+        Returns:
+            State: the next state of the conversation
+            int: constant ConversationHandler.END (if the user is already registered)
+    """
+    email = update.message.text.strip()
+    email_digest = hashlib.sha256(email.encode()).hexdigest()
+
+    with Session() as session:
+        stmt = select(User).where((User.chat_id == update.effective_chat.id) | (User.email == email_digest))
+        result = session.scalars(stmt).first()
+
+    if result is not None:
+        await context.bot.send_message(
+            chat_id=update.effective_chat.id,
+            text="Sei gia' registrato!"
+        )
+
+        return ConversationHandler.END
+
+    context.user_data["email"] = email
+    context.user_data["otp"] = "123456"
+    context.user_data["tries"] = 0
+
+    await context.bot.send_message(
+        chat_id=update.effective_chat.id,
+        text="Invia l'OTP che ti e' stato inviato all'email da te indicata"
+    )
+
+    return State.OTP
+
+async def otp_checker(update: Update, context: ContextTypes.DEFAULT_TYPE) -> State | int:
+    """
+        Checks if the OTP sent to the email is valid.
+
+        Args:
+            update: Update event
+            context: context passed by the handler
+
+        Returns:
+            State: returns State.OTP if the OTP wasn't correct.
+            int: constant ConversationHandler.END (if the OTP was correct or too many wrong tries)
+    """
+    if context.user_data["tries"] >= 3:
+        await context.bot.send_message(
+            chat_id=update.effective_chat.id,
+            text="Hai esaurito il numero di tentativi, riprova piu' tardi"
+        )
+
+        return ConversationHandler.END
+
+    otp = update.message.text.strip()
+    if otp != context.user_data["otp"]:
+        context.user_data["tries"] += 1
+
+        await context.bot.send_message(
+            chat_id=update.effective_chat.id,
+            text="OTP non corretto, controlla la tua mail"
+        )
+
+        return State.OTP
+
+    with Session() as session:
+        session.add(User=context.user_data["email"], chat_id=update.effective_chat.id)
+        session.commit()
+
+    await context.bot.send_message(
+        chat_id=update.effective_chat.id,
+        text="Registrazione completata!"
+    )
+
+    return ConversationHandler.END
+
+def register_conv_handler() -> ConversationHandler:
+    """
+        Creates the /register ConversationHandler.
+
+        States of the command:
+            - State.EMAIL: Waits for a text message containing the email (should match the regex)
+            - State.OTP: Waits for a text message containing the OTP sent to the email address.
+
+        Returns:
+            ConversationHandler: the created handler
+    """
+    email_regex = re.compile(r"^[a-z]+\.[a-z]+@studium\.unict\.it$")
+    otp_regex = re.compile(r"^\d{6}$")
+
+    async def invalid_email(update: Update, context: ContextTypes.DEFAULT_TYPE) -> State:
+        await context.bot.send_message(
+            chat_id=update.effective_chat.id,
+            text="Email non valida, riprova"
+        )
+
+        return State.EMAIL
+
+    async def invalid_otp(update: Update, context: ContextTypes.DEFAULT_TYPE) -> State:
+        await context.bot.send_message(
+            chat_id=update.effective_chat.id,
+            text="OTP non valido, riprova"
+        )
+
+        return State.OTP
+
+    async def cancel(update: Update, context: ContextTypes.DEFAULT_TYPE) -> int:
+        context.bot.send_message(
+            chat_id=update.effective_chat.id,
+            text="Registrazione annullata!"
+        )
+
+        return ConversationHandler.END
+
+    return ConversationHandler(
+        entry_points=[CommandHandler("register", register_entry)],
+        states={
+            State.EMAIL: [
+                MessageHandler(filters.Regex(email_regex), email_checker),
+                MessageHandler(filters.TEXT & ~filters.Regex(email_regex), invalid_email)
+            ],
+            State.OTP: [
+                MessageHandler(filters.Regex(otp_regex), otp_checker),
+                MessageHandler(filters.TEXT & ~filters.Regex(otp_regex), invalid_otp)
+            ]
+        },
+        fallbacks=[CommandHandler("cancel", cancel)]
+    )

module/data/constants.py

@@ -4,7 +4,7 @@
 
 HELP_CMD_TEXT = '\n'.join((
     "📬 /report Fornisce la possibilità di poter inviare una segnalazione agli sviluppatori riguardante qualsiasi disservizio",
-    "🔑 /login Permette di effettuare il login al sistema"
+    "🔑 /register Permette di effettuare la registrazione al sistema"
 ))
 
 REPORT = "Segnalazioni Rappresentanti 📬"