consumers.py

import json

from fastapi import HTTPException


def create_delivery(state, event):
    data = json.loads(event.data)
    return {
        "id": event.delivery_id,
        "budget": int(data["budget"]),
        "notes": data["notes"],
        "status": "ready",
    }


def start_delivery(state, event):
    if state["status"] != "ready":
        raise HTTPException(status_code=400, detail="Delivery already started")

    return state | {"status": "active"}


def pickup_products(state, event):
    data = json.loads(event.data)
    new_budget = state["budget"] - int(data["purchase_price"]) * int(data["quantity"])
    new_quantity = state["quantity"] + int(data["quantity"])
    if new_budget < 0:
        raise HTTPException(status_code=400, detail="Not enough budget")

    return state | {
        "budget": new_budget,
        "purchase_price": int(data["purchase_price"]),
        "quantity": new_quantity,
        "status": "collected",
    }


def deliver_products(state, event):
    data = json.loads(event.data)
    new_budget = state["budget"] + int(data["sell_price"]) * int(data["quantity"])
    new_quantity = state["quantity"] - int(data["quantity"])

    if new_quantity < 0:
        raise HTTPException(status_code=400, detail="Not enough quantity")

    return state | {
        "budget": new_budget,
        "sell_price": int(data["sell_price"]),
        "quantity": new_quantity,
        "status": "completed",
    }


def increase_budget(state, event):
    data = json.loads(event.data)
    state["budget"] += int(data["budget"])
    return state


CONSUMERS = {
    "CREATE_DELIVERY": create_delivery,
    "START_DELIVERY": start_delivery,
    "PICKUP_PRODUCTS": pickup_products,
    "DELIVER_PRODUCTS": deliver_products,
    "INCREASE_BUDGET": increase_budget,
}