main.py

import logging
import json
import requests
from datetime import datetime

from telegram import Update, ReplyKeyboardMarkup, KeyboardButton, LabeledPrice, InlineKeyboardButton, InlineKeyboardMarkup
from telegram.ext import Updater, CommandHandler, MessageHandler, Filters, CallbackContext, CallbackQueryHandler, ConversationHandler, PreCheckoutQueryHandler

import const as keys
import response as R

logging.basicConfig(
    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s', level=logging.INFO
)

logger = logging.getLogger(__name__)    

def help_command(update: Update, context: CallbackContext) -> None:
    update.message.reply_text('/start 🛒 - start shopping\n /help ❓ - display commands help')

def start_command(update: Update, context: CallbackContext) -> None:
    categoriesurl = "https://fakestoreapi.com/products/categories"
    categoriesresponse = requests.get(categoriesurl)
    categories = json.loads(categoriesresponse.text)
    button_list = []
    for each in categories:
        button_list.append(InlineKeyboardButton(each, callback_data = 'c+' + each))
    reply_markup = InlineKeyboardMarkup(build_menu(button_list,n_cols=2))
    context.bot.send_message(chat_id=update.message.chat_id, text='Choose from the following',reply_markup=reply_markup)

def build_menu(buttons,n_cols,header_buttons=None,footer_buttons=None):
    menu = [buttons[i:i + n_cols] for i in range(0, len(buttons), n_cols)]
    if header_buttons:
        menu.insert(0, header_buttons)
    if footer_buttons:
        menu.append(footer_buttons)
    return menu

def category_callback(update: Update, context: CallbackContext):
    query = update.callback_query

    productsUrl = "https://fakestoreapi.com/products/category/" + query.data[2:]
    productsResponse = requests.get(productsUrl)
    products = json.loads(productsResponse.text)
    button_list = []
    for each in products:
        button_list.append(InlineKeyboardButton(each['title'], callback_data = 'p+' + str(each['id'])))
    reply_markup = InlineKeyboardMarkup(build_menu(button_list,n_cols=2))

    context.bot.edit_message_reply_markup(
        chat_id=query.message.chat_id,
        message_id=query.message.message_id,
        reply_markup=reply_markup)

def products_callback(update: Update, context: CallbackContext) :
    query = update.callback_query
    productUrl = "https://fakestoreapi.com/products/" + query.data[2:]
    productResponse = requests.get(productUrl)
    product = json.loads(productResponse.text)
    def num(s):
        try:
            return int(s)
        except ValueError:
            return float(s)
    context.bot.send_invoice(
        chat_id = query.message.chat_id, 
        title = product['title'], 
        description = product['description'], 
        payload = 'Payload', 
        provider_token = keys.paymentToken,
        currency = "USD",
        prices = [LabeledPrice(label = product['title'], amount = num(product['price']) * 100)],
        start_parameter = "test-payment",
        photo_url = product['image'],
        photo_height = 512,
        photo_width = 512,
        need_shipping_address = True)

def successful_payment_callback(update, context):
    update.message.reply_text("Thank you for your payment!")


def precheckout_callback(update: Update, context: CallbackContext) -> None:
    query = update.pre_checkout_query
    if query.invoice_payload != 'Payload':
        query.answer(ok=False, error_message="Something went wrong...")
    else:
        query.answer(ok=True)

def handle_message(update: Update, context: CallbackContext) -> None:
    text=str(update.message.text).lower()
    response = R.request_message(text)
    update.message.reply_text(response)

def main():
    updater=Updater(keys.apiKey)
    dp = updater.dispatcher
    dp.add_handler(CommandHandler("start", start_command))
    dp.add_handler(CommandHandler("help", help_command))
    dp.add_handler(CallbackQueryHandler(category_callback, pattern='^(c+)'))
    dp.add_handler(CallbackQueryHandler(products_callback, pattern='^(p+)'))
    dp.add_handler(MessageHandler(Filters.text,handle_message))
    dp.add_handler(MessageHandler(Filters.successful_payment, successful_payment_callback))
    dp.add_handler(PreCheckoutQueryHandler(callback=precheckout_callback))
    updater.start_polling()
    updater.is_idle

main()