App/Messages/MessagesRoute.py

# App/Messages/Routes.py
from fastapi import APIRouter, HTTPException, Request
from .Model import Message
from .Schema import MessageCreate, MessageResponse, TransactionSchema
from uuid import UUID
from typing import List, Optional
import re
from datetime import datetime
from decimal import Decimal
from App.Payments.PaymentsRoutes import create_payment
from App.Payments.Schema import CreatePaymentRequest
from App.Users.Model import User
from App.Payments.Schema import PaymentMethod
from App.Payments.Model import Payment
from App.Plans.Model import Plan
from tortoise.contrib.pydantic import pydantic_model_creator

message_router = APIRouter(tags=["Messages"], prefix="/messages")


@message_router.post("/sms_received", response_model=MessageResponse)
async def receive_message(message_data: MessageCreate):
    message = Message.get_or_none(message_id=message_data.id)
    Message_Pydantic = pydantic_model_creator(Message)
    try:
        # Extract data from the message content using regex
        text = message_data.payload.message
        parsed_data = parse_message_content(text)

        # Process Mpesa Payments and prevent double entry from the sms gateway app (message_id must be unique)
        if parsed_data and not message:
            user: User = User.get_or_none(phoneNumber=parsed_data.phone_number)

            # if the user sent an exact amount
            data_plan: Plan = Plan.get_or_none(
                amount=Decimal(parsed_data.amount_received)
            )
            payment_details = CreatePaymentRequest(
                user_id=user.id,
                plan_id=data_plan.id,
                amount=Decimal(parsed_data.amount_received),
                payment_method=PaymentMethod.MPESA,
                transaction_id=parsed_data.transaction_id,
            )

            payment: Payment = await create_payment(payment_details)
            await payment.create_subscription_or_balance()

        # prevent double entries
        if not message:
            # Create a new message record with parsed_data
            message = await Message.create(
                device_id=message_data.deviceId,
                event=message_data.event,
                message_id=message_data.id,
                webhook_id=message_data.webhookId,
                message_content=text,
                phone_number=message_data.payload.phoneNumber,
                received_at=message_data.payload.receivedAt,
                sim_number=message_data.payload.simNumber,
                parsed_data=parsed_data,
            )
        print(message.__dict__)
        if type(message) == Message:
            data = await Message_Pydantic.from_tortoise_orm(message)
        else:
            data = await Message_Pydantic.from_queryset_single(message)

        return data
    except Exception as e:
        raise HTTPException(status_code=400, detail=str(e))


def parse_message_content(text: str) -> Optional[TransactionSchema]:
    # Regular expression to capture the data from the message, allowing for different types of spaces
    pattern = r"(\w+)\sConfirmed\.You have received Tsh([\d,]+\.\d{2}) from (\d{12}) - ([A-Z ]+) on (\d{1,2}/\d{1,2}/\d{2}) at ([\d:]+ [APM]+).*?balance\sis\sTsh([\d,]+\.\d{2})"

    # Replace non-breaking spaces and other whitespace characters with regular spaces in the input text
    text = re.sub(r"\s+", " ", text)

    matches: TransactionSchema = re.search(pattern, text)
    if matches:
        data = {
            "transaction_id": matches.group(1),
            "amount_received": parse_decimal(matches.group(2)),
            "phone_number": matches.group(3),
            "name": matches.group(4).strip(),
            "date": parse_date(matches.group(5), matches.group(6)),
            "new_balance": parse_decimal(matches.group(7)),
        }
        return data
    else:
        # Return None if the message doesn't match the expected format
        return None


def parse_decimal(amount_str: str) -> float:
    # Remove commas and convert to Decimal
    amount_str = amount_str.replace(",", "")
    return float(Decimal(amount_str))


def parse_date(date_str: str, time_str: str) -> str:
    # Combine date and time strings and parse into ISO format
    datetime_str = f"{date_str} {time_str}"
    try:
        dt = datetime.strptime(datetime_str, "%d/%m/%y %I:%M %p")
        return dt.isoformat()
    except ValueError:
        return datetime_str  # Return as-is if parsing fails