#!/usr/bin/env python3
# Description: Monitor a website for changes.
# Usage: python3 diff-web.py --domain example.com --time 60 --email user@example.com
# Author: Justin Oros
# Source: https://github.com/JustinOros

import argparse
import hashlib
import os
import re
import sys
import time
from datetime import datetime
from getpass import getpass
from urllib.parse import urlparse

import requests
from bs4 import BeautifulSoup

def clean_text(text):
    junk_phrases = [
        r'\bMenu\b', r'\bClose\b', r'\bSign ?In\b', r'\bSign ?Out\b',
        r'\bLogin\b', r'\bLogout\b', r'\bBack\b', r'\bNext\b', r'\bMore\b',
        r'\bSearch\b', r'\bCart\b', r'\bSettings\b', r'\bHelp\b',
        r'\bContact\b', r'\bLanguage\b', r'\bProfile\b', r'\bAccount\b',
        r'\bSupport\b', r'\bUS\b', r'\bEN\b', r'\bFR\b', r'\bDE\b',
        r'\bJP\b', r'\bES\b', r'\bIT\b', r'\bCN\b', r'\b≡\b', r'\b×\b'
    ]

    text = re.sub(r'\b(?:US|EN|FR|DE|JP|ES|IT|CN)\b(\s*chevron_right\s*)+', '', text, flags=re.IGNORECASE)
    text = re.sub(r'(chevron_right\s*){2,}', '', text, flags=re.IGNORECASE)
    text = re.sub(r'\bchevron_right\b', '', text, flags=re.IGNORECASE)

    for pattern in junk_phrases:
        text = re.sub(pattern, '', text, flags=re.IGNORECASE)

    text = re.sub(r'\s+', ' ', text)
    return text.strip()

def fetch_content(url):
    response = requests.get(url, timeout=10)
    response.raise_for_status()
    soup = BeautifulSoup(response.text, 'html.parser')

    for tag in soup(["script", "style", "noscript", "iframe", "svg", "canvas", "header", "footer", "nav", "form", "button"]):
        tag.decompose()

    keep_tags = ['h1', 'h2', 'h3', 'h4', 'p', 'li', 'article', 'section', 'span', 'div']
    for tag in soup.find_all(True):
        if tag.name not in keep_tags:
            tag.decompose()

    raw_text = soup.get_text(separator=' ', strip=True)
    return clean_text(raw_text)

def hash_content(content):
    return hashlib.sha256(content.encode('utf-8')).hexdigest()

def save_log(domain, content):
    now = datetime.now()
    timestamp = now.strftime("%Y%m%d.%H%M%S")
    domain_name = domain.replace("https://", "").replace("http://", "").split("/")[0]
    filename = f"{domain_name}.{timestamp}.log"
    with open(filename, "w", encoding="utf-8") as f:
        f.write(content)
    print(f"[+] Change detected. Log saved to: {os.path.abspath(filename)}")

def prompt_credentials(args):
    try:
        # Prompt email if -e passed without value or empty string
        if args.email is not None and not args.email.strip():
            args.email = input("Enter your email: ").strip()

        # Prompt password only if email is set and password not provided
        if args.email and not args.password:
            args.password = getpass("Enter your password: ")

    except KeyboardInterrupt:
        print("\n[!] Input canceled by user. Exiting.")
        sys.exit(0)
    return args

def main():
    parser = argparse.ArgumentParser(description="Monitor a webpage for changes.")
    parser.add_argument("-d", "--domain", type=str, required=True, help="Domain to monitor (e.g., example.com)")
    parser.add_argument("--time", type=int, default=60, help="Polling interval in seconds (default: 60)")
    parser.add_argument("-e", "--email", nargs="?", const="", help="Your email address (optional prompt)")
    parser.add_argument("-p", "--password", nargs="?", const="", help="Your password (optional; will prompt if not provided)")

    args = parser.parse_args()
    args = prompt_credentials(args)

    domain = args.domain
    url = domain if domain.startswith("http") else "https://" + domain
    print(f"[+] Monitoring: {url} every {args.time} seconds")
    if args.email:
        print(f"[+] Email: {args.email}")

    previous_hash = None

    while True:
        try:
            content = fetch_content(url)
            current_hash = hash_content(content)

            if previous_hash and current_hash != previous_hash:
                save_log(url, content)
            else:
                print(f"[{datetime.now().strftime('%H:%M:%S')}] No change.")

            previous_hash = current_hash
        except Exception as e:
            print(f"[!] Error: {e}")

        try:
            time.sleep(args.time)
        except KeyboardInterrupt:
            print("\n[!] Monitoring stopped by user. Goodbye!")
            sys.exit(0)

if __name__ == "__main__":
    try:
        main()
    except KeyboardInterrupt:
        print("\n[!] Monitoring stopped by user. Goodbye!")
        sys.exit(0)