main.py

from fastapi import FastAPI
from fastapi import Request
from fastapi.responses import JSONResponse
import db_helper
import generic_helper

app = FastAPI()

inprogress_orders={}

@app.post("/")
async def handle_request(request: Request):
    # Retrieve the JSON data from the request
    payload = await request.json()

    # Extract the necessary information from the payload
    # based on the structure of the WebhookRequest from Dialogflow
    intent = payload['queryResult']['intent']['displayName']
    parameters = payload['queryResult']['parameters']
    output_contexts = payload['queryResult']['outputContexts']
    session_id=generic_helper.extract_session_id(output_contexts[0]['name'])


    intent_handler_dict={"order.add-context:Ongoing Order":add_to_order,
                         "order.remove-context:ongoing-order":remove_from_order,
                         "order.complete-context:ongoing-order":complete_order,
                         "track.order-context:ongoing tracking":track_order
    }

    return intent_handler_dict[intent](parameters,session_id)


def remove_from_order(parameters:dict,session_id:str):
    if session_id not in inprogress_orders:
        return JSONResponse(content=
                            {"fulfillmentText":"Sorry, I didn't find your order. Can you place order again?." })
    else:
        current_order=inprogress_orders[session_id]
        food_items=parameters["food-item"]
        removed_items=[]
        no_such_items=[]
        for item in food_items:
            if item not in current_order:
                no_such_items.append(item)
            else:
                removed_items.append(item)
                del current_order[item]
        if len(removed_items)>0:
            fulfillment_text=f'Removed {",".join(removed_items)} from your order!'
        if len(no_such_items) > 0:
            fulfillment_text = f' Your current order does not have {",".join(no_such_items)}'
        if len(current_order.keys()) == 0:
            fulfillment_text = " Your order is empty!"
        else:
            order_str = generic_helper.get_str_from_food_dict(current_order)
            fulfillment_text = f" Here is what is left in your order: {order_str}"

        return JSONResponse(content={
            "fulfillmentText": fulfillment_text
        })



def add_to_order(parameters:dict,session_id:str):
    food_items=parameters["Food-item"]
    quantities=parameters["number"]

    if len(food_items)!=len(quantities):
        fulfillment_text="Sorry I didn't understand. Can you please specify food items and quantities"
    else:
        new_food_dict=dict(zip(food_items,quantities))

        if session_id in inprogress_orders:
            current_food_dict=inprogress_orders[session_id]
            current_food_dict.update(new_food_dict)
            inprogress_orders[session_id]=current_food_dict
        else:
            inprogress_orders[session_id]=new_food_dict


        order_str=generic_helper.get_str_from_food_dict(inprogress_orders[session_id])

        fulfillment_text=f"So far you have: {order_str}. Do you have anything else?"

    return JSONResponse(content=
                        {"fulfillmentText": fulfillment_text})

def complete_order(parameters:dict,session_id:str):
    if session_id not in inprogress_orders:
        fulfillment_text="I'm having a trouble finding your order. Sorry! can you place a new order"
    else:
        order=inprogress_orders[session_id]
        order_id=save_to_db(order)

        if order_id==-1:
            fulfillment_text="Sorry, I couldn't process your order. Please try again later"
        else:
            order_total=db_helper.get_total_order_price(order_id)
            fulfillment_text=f"Awesome. we have placed your order." \
                             f"Here is your order id #: {order_id}." \
                             f"Your order total is {order_total} which you can pay at the time of delivery!"
        del inprogress_orders[session_id]
    return JSONResponse(content=
                        {"fulfillmentText": fulfillment_text})

def save_to_db(order:dict):

    next_order_id=db_helper.get_next_order_id()

    for food_item,quantity in order.items():
        rcode=db_helper.insert_order_item(food_item,quantity,next_order_id)

        if rcode==-1:
            return -1
    db_helper.insert_order_tracking(next_order_id,"in progress")
    return next_order_id


def track_order(parameters: dict,session_id:str):
    order_id=int(parameters['number'])
    order_status=db_helper.get_order_status(order_id)

    if order_status:
        fulfillment_text=f"The order status for order id: {order_id} is :{order_status}"
    else:
        fulfillment_text = f"No order found with order id: {order_id}"

    return JSONResponse(content=
                        {"fulfillmentText": fulfillment_text})