#!/usr/bin/python3

try:
    import requests
    import json
    import tempfile
    import tldextract
    import os
except ModuleNotFoundError:
    print("Missing module, see requirements.txt")
    exit(1)

def getZone(email, apiKey, host):
    listZones = requests.get(f"https://api.cloudflare.com/client/v4/zones/", 
         headers={"X-Auth-Email": f"{email}","X-Auth-Key": f"{apiKey}","Content-Type": "application/json"}).json()

    if listZones["success"] != True:
        print("Could not get Zone ID from Cloudflare. Errors were: " + str(listZones["errors"]))
        exit(1)

    # Extract the root domain from the full host.
    extractedHost = tldextract.extract(host)
    domain = (extractedHost.domain + "." + extractedHost.suffix)

    for zone in listZones["result"]:
        if zone["name"] == domain:
            return zone["id"]
    
    print("Could not find a Zone ID for the specified domain.")
    exit(1)
        
def storeIP(ip, scriptDir):
    # Store the given IP in the lastip file.
    file = open(scriptDir + 'updateCloudflare.lastip', 'w+')
    file.write(ip)

def checkCloudflare(zone, email, apiKey, host):
    # Get all the records in the zone.
    allRecords = requests.get(f"https://api.cloudflare.com/client/v4/zones/{zone}/dns_records", 
         headers={"X-Auth-Email": f"{email}","X-Auth-Key": f"{apiKey}","Content-Type": "application/json"}).json()

    # Search for the defined zone in the list and get it's IP.
    for currentRecord in allRecords["result"]:
        if currentRecord["name"] == host:
            recordIP = currentRecord["content"]
            print(f"IP of {host} is " + recordIP)
            return(recordIP)

def updateCloudflare(zone, email, apiKey, host, ip):
    # Get all records for the given zone.
    allRecords = requests.get(f"https://api.cloudflare.com/client/v4/zones/{zone}/dns_records", 
        headers={"X-Auth-Email": f"{email}","X-Auth-Key": f"{apiKey}","Content-Type": "application/json"}).json()

    # Find the record for the domain we want to work on.
    for currentRecord in allRecords["result"]:
        if currentRecord["name"] == host:
            recordID = currentRecord["id"]
            print(f"ID for {host} is " + recordID)

    # Update our record with the new IP.
    result = requests.patch(f"https://api.cloudflare.com/client/v4/zones/{zone}/dns_records/" + recordID, 
        headers={"X-Auth-Email": f"{email}","X-Auth-Key": f"{apiKey}","Content-Type": "application/json"}, 
        data='{"content":"%s"}' % ip).json()

    # Check if Cloudflare returned any errors.
    if result["success"] == True:
        print("Cloudflare was successfully updated")
    else:
        print("Updating failed, errors were: " + str(result["errors"]))

def main():
    print(
        '''
        ------------------------------
        Cloudflare updater
        www.jakecharman.co.uk
        ------------------------------
        '''
    )

    # Get the directory of the script.
    scriptDir = os.path.dirname(os.path.realpath(__file__)) + "/"

    # Read in parameters from the config file.
    try:
        configFile = open(scriptDir + "updateCloudflare.conf", "r")
    except FileNotFoundError:
        print("Configuration file does not exist.")
        exit(1)

    configLines = configFile.readlines()
    for line in configLines:
        if line[0] == "#":
            continue
        # Remove any spaces from the line then split it to an array on the = sign.
        splitLn = line.replace(" ", "").strip().split('#')[0].split("=")

        # Pull in the known config lines.
        if (splitLn[0] == "email"):
            authEmail = splitLn[1]
        elif (splitLn[0] == "apiKey"):
            apiKey = splitLn[1]
        elif (splitLn[0] == "host"):
            hostToUpdate = splitLn[1]
        else:
            # Error out on an unknown config line.
            print("Unknown config: " + splitLn[0])
            exit(1)

    # Get the Zone ID for the given hostname.
    zoneID = getZone(authEmail, apiKey, hostToUpdate)

    # Open the temp file.
    try:
        file = open(scriptDir + 'updateCloudflare.lastip', 'r')
        lastip = file.read()
    except FileNotFoundError:
        lastip = ""

    if lastip == "":
        storedIP = False
        print("No stored IP... checking Cloudflare API")
        cloudflareIP = checkCloudflare(zoneID, authEmail, apiKey, hostToUpdate)
    else:
        storedIP = lastip
        print("Stored IP is " + lastip)

    # Get our external IP
    ip = requests.get('https://api.ipify.org').text
    print("Our current IP is " + ip)
    if storedIP:    
        if ip == storedIP:
            print("IP has not changed since last run... Exiting")
            exit(0)
        else: 
            print("IP has changed since last run... Updating Cloudflare")
            storeIP(ip, scriptDir)
            updateCloudflare(zoneID, authEmail, apiKey, hostToUpdate, ip)
    else:
        storeIP(ip, scriptDir)
        if ip == cloudflareIP:
            print("Cloudflare matches our current IP... Exiting")
            exit(0)
        else:
            print("Cloudflare IP does not match our current IP... Updating Cloudflare.")
            updateCloudflare(zoneID, authEmail, apiKey, hostToUpdate, ip)

if __name__ == "__main__":
    main()