# Host a Website at Home 
# Iffy Books | June 2025 | wtfpl
# https://iffybooks.net/host-a-website-at-home

# This script checks whether your external IP address has 
# changed since last time it ran. If there's been a change, 
# we'll update the namecheap API with our new IP address.

# Log in to namecheap and go to Domain List > Manage > Advanced DNS
# Scroll down and select Dynamic DNS to get your DDNS password.
# Run a command like this to save your DDNS password to a text file:
#   echo 'yourddnspass23j82d938j' > ~/ddns_pass.txt

import os
import subprocess
import time
from datetime import datetime

# Change to user home directory
os.chdir(os.path.expanduser('~/'))

# Store date and time as a string
current_time_string = str(datetime.now())

# Read DDNS password from ddns_pass.txt
with open('ddns_pass.txt') as fi:
	ddns_pass = fi.read().strip()

# Check current IP address using icanhazip.com
current_ip_address = subprocess.check_output(["curl", "--ipv4", "icanhazip.com"]).decode('utf-8').strip()
print("Current IP address: " + current_ip_address)

# Read old IP address from a text file if it's available
if 'old_ip_address.txt' in os.listdir():
	with open('old_ip_address.txt') as fi:
		old_ip_address = fi.read().strip()

	# Add code to check whether this is a valid IP address
	print("Old IP address: " + old_ip_address)

# If old IP address isn't available, write the current address to old_ip_address.txt
else:
	print("No previous IP address found. Writing current IP address to disk")
	with open('old_ip_address.txt','w') as fi:
		fi.write(current_ip_address)

# If the IP address has changed, update namecheap API
if current_ip_address != old_ip_address:
	print("Your IP address has changed!")
	host = '@'
	domain_name = '40404.net'
	api_url = f"https://dynamicdns.park-your-domain.com/update?host={host}&domain={domain_name}&password={ddns_pass}&ip={current_ip_address}"
	print(api_url)
	# Calling API URL to update IP address
	subprocess.call(['curl', api_url])
	# Write current IP address to disk
	with open('old_ip_address.txt','w') as fi:
		fi.write(current_ip_address)

# If the IP address hasn't changed, do nothing
else: 
	print(f"IP address is unchanged at {current_time_string}. Moving on.")


# More details on the namecheap DDNS API here: 
# https://www.namecheap.com/support/knowledgebase/article.aspx/29/11/how-to-dynamically-update-the-hosts-ip-with-an-https-request/