main.py

from abc import ABC, abstractmethod
from helium import start_chrome, kill_browser
from bs4 import BeautifulSoup
from datetime import datetime
import smtplib
import validators
from time import sleep
from threading import Thread
import re
import requests
import os
import json


class PriceTracker(ABC):
    """
    Base class for Price Trackers.
    """
    with open("credentials.json") as f:
        fc = f.read()
        parser = json.loads(fc)
    email = parser["email"]
    password = parser["password"]
    removals = re.compile(r"₹|,|[$]")

    def __init__(self, product_name: str, product_url: str, desired_price: int) -> None:
        """
        Constructor.
        """
        if not validators.url(product_url):
            raise Exception("Invalid URL!")

        self.product_url = product_url
        self.set_price = desired_price
        self.product_name = product_name
        self.price = None

    @abstractmethod
    def get_price(self):
        """
        Fetches the latest price of the product.
        """
        pass

    @staticmethod
    def send_mail(your_email:str, your_password:str, subject: str, body: str):
        """
        Sends mail for the given price.
        """
        server = smtplib.SMTP('smtp.mail.yahoo.com', 587)
        server.ehlo()
        server.starttls()
        server.login(your_email, your_password)
        server.sendmail(your_email,
                        your_email, f"Subject: {subject}\n\n{body}")
        server.quit()
        print("Mail sent")

    @abstractmethod
    def write_to_file(self):
        """
        Write content to a text file.
        """
        pass

    def track_price(self):
        """
        Tracks price for a given product against the set price.
        """
        while True:
            self.get_price()
            if self.price == None:
                print("Unable to fetch the latest price!")
                os._exit(1)

            if self.set_price >= self.price:
                print("Price low for", self.product_name)
                self.write_to_file()
                self.send_mail(self.email, self.password, f"Price down for {self.product_name}",f"Dear sir,\nThe price for `{self.product_name}` is now {self.price} which is less than or equal to what you desired, {self.set_price}! Visit {self.product_url} for more info.")
                os._exit(0)

            else:
                self.write_to_file()

            sleep(60)


class AmazonPriceTracker(PriceTracker):
    """
    Helps poor people by notifying them when the price for their favorite product on Amazon is less than what they desired.
    """

    def get_price(self):
        """
        Fetches price for given product on Amazon.
        """
        driver = start_chrome(self.product_url)
        html = driver.page_source.replace(" ", "")
        kill_browser()
        soup = BeautifulSoup(html, "html5lib")
        price = soup.find("span", {"id": "priceblock_ourprice"})
        if price == None:
            price = soup.find("span", {"id": "priceblock_dealprice"}).string
        price = (re.sub(self.removals, "", price)).replace("\\xa", "")
        self.price = int(float(price))

    def write_to_file(self):
        """
        Writes datetime and price to a file.
        """
        now = datetime.now().strftime("%d-%m-%y %H:%M")
        content = f"{now} --> Amazon --> {self.price}\n"
        print(content)
        with open(f"{self.product_name}.prices", "a") as f:
            f.write(content)

    def run(self):
        self.track_price()


class FlipkartPriceTracker(PriceTracker):
    """
    Helps poor people by notifying them when the price of their favorite product on Flipkart is less than what they desired.
    """

    def get_price(self):
        """
        Fetches price for given product on Flipkart.
        """
        r = requests.get(self.product_url)
        soup = BeautifulSoup(r.content, "html5lib")
        price = soup.find("div", {"class": "_30jeq3 _16Jk6d"}).string
        price = re.sub(self.removals, "", price)
        self.price = int(price)

    def write_to_file(self):
        """
        Writes datetime and price to a file.
        """
        now = datetime.now().strftime("%d-%m-%y %H:%M")
        content = f"{now} --> Flipkart --> {self.price}\n"
        print(content)
        with open(f"{self.product_name}.prices", "a") as f:
            f.write(content)

    def run(self):
        self.track_price()


class MultipleStorePriceTracker():
    """
    Tracks prices for two stores at a time (Amazon and Flipkart) and notifies when either of them is less than the desired price.
    """

    def __init__(self, product_name:str, amazon_url:str, flipkart_url:str, desired_price:int) -> None:
        self.product = product_name
        self.fkturl = flipkart_url
        self.azurl = amazon_url
        self.set_price = desired_price

    def track_multiple(self):
        fktt = FlipkartPriceTracker(self.product, self.fkturl, self.set_price)
        azt = AmazonPriceTracker(self.product, self.azurl, self.set_price)
        t1 = Thread(target=fktt.run)
        t2 = Thread(target=azt.run)
        t1.start()
        t2.start()


def check_internet():
    try:
        requests.get("https://google.com")
    
    except Exception:
        print("Make sure you're connected to the internet!")
        quit()



if __name__ == "__main__":
    check_internet()
    print("Welcome to the Ecommerce Price Tracker! A tool which you can use to track prices for a given product on Amazon and Flipkart.\n")

    track_opt = input("Where to track prices?\n 1. Amazon \n 2. Flipkart \n 3. Both\n")

    if track_opt == "1":
        try:
            product_name = input("Enter product name: ")
            product_url = input("Enter the product url: ")
            desired_price = int(input("Enter the desired price (you'll be notified when this price is lower than the product price): "))
            azt = AmazonPriceTracker(product_name, product_url, desired_price)
            azt.run()

        except Exception as e:
            print(e)

    elif track_opt == "2":
        try:
            product_name = input("Enter product name: ")
            product_url = input("Enter the product url: ")
            desired_price = int(input("Enter the desired price (you'll be notified when this price is lower than the product price): "))
            fkt = FlipkartPriceTracker(product_name, product_url, desired_price)
            fkt.run()
        
        except Exception as e:
            print(e)

    elif track_opt == "3":
        try:
            product_name = input("Enter product name: ")
            azurl = input("Enter the product url on Amazon: ")
            fkturl = input("Enter the product url on Flipkart: ")
            desired_price = int(input("Enter the desired price (you'll be notified when this price is lower than the product price): "))
            mspt = MultipleStorePriceTracker(product_name, azurl, fkturl, desired_price)
            mspt.track_multiple()

        except Exception as e:
            print(e)

    else:
        print("Invalid input!")