#!/usr/bin/env python3
# This directly follows the OAuth login flow that is opaquely described
# https://github.com/openid/AppAuth-Android
# A really nice walk through of how it works is:
# https://auth0.com/docs/get-started/authentication-and-authorization-flow/call-your-api-using-the-authorization-code-flow-with-pkce
import requests
from urllib.parse import urlparse, parse_qs, urlencode, urlunparse
from lxml import html
import io
import re
import sys
import json
from time import time
from base64 import b64decode as base64_decode
from base64 import urlsafe_b64encode as base64url_encode
from bs4 import BeautifulSoup
from Crypto.Random import get_random_bytes
from Crypto.Hash import SHA256
from zipfile import ZipFile
from HCxml2json import xml2json

import logging

# These two lines enable debugging at httplib level (requests->urllib3->http.client)
# You will see the REQUEST, including HEADERS and DATA, and RESPONSE with HEADERS but without DATA.
# The only thing missing will be the response.body which is not logged.
import http.client as http_client
#http_client.HTTPConnection.debuglevel = 1

# You must initialize logging, otherwise you'll not see debug output.
#logging.basicConfig()
#logging.getLogger().setLevel(logging.DEBUG)
#requests_log = logging.getLogger("requests.packages.urllib3")
#requests_log.setLevel(logging.DEBUG)
#requests_log.propagate = True

def debug(*args):
	print(*args, file=sys.stderr)

email = sys.argv[1]
password = sys.argv[2]

headers = {"User-Agent": "hc-login/1.0"}

session = requests.Session()
session.headers.update(headers)

base_url = 'https://api.home-connect.com/security/oauth/'
asset_url = 'https://prod.reu.rest.homeconnectegw.com/'

##############3
#
# Start by fetching the old login page, which gives
# us the verifier and challenge for getting the token,
# even after the singlekey detour.
#
# The app_id and scope are hardcoded in the application
app_id = '9B75AC9EC512F36C84256AC47D813E2C1DD0D6520DF774B020E1E6E2EB29B1F3'
scope = ["ReadAccount","Settings","IdentifyAppliance","Control","DeleteAppliance","WriteAppliance","ReadOrigApi","Monitor","WriteOrigApi","Images"]
scope = ["ReadOrigApi",]

def b64(b):
	return re.sub(r'=', '', base64url_encode(b).decode('UTF-8'))
def b64random(num):
	return b64(base64url_encode(get_random_bytes(num)))

verifier = b64(get_random_bytes(32))

login_query = {
	"response_type": "code",
	"prompt": "login",
	"code_challenge": b64(SHA256.new(verifier.encode('UTF-8')).digest()),
	"code_challenge_method": "S256",
	"client_id": app_id,
	"scope": ' '.join(scope),
	"nonce": b64random(16),
	"state": b64random(16),
	"redirect_uri": 'hcauth://auth/prod',
	"redirect_target": 'icore',
}

loginpage_url = base_url + 'authorize?' + urlencode(login_query)
token_url = base_url + 'token'

debug(f"{loginpage_url=}")
r = session.get(loginpage_url)
if r.status_code != requests.codes.ok:
	print("error fetching login url!", loginpage_url, r.text, file=sys.stderr)
	exit(1)

# get the session from the text
if not (match := re.search(r'"sessionId" value="(.*?)"', r.text)):
	print("Unable to find session id in login page")
	exit(1)
session_id = match[1]
if not (match := re.search(r'"sessionData" value="(.*?)"', r.text)):
	print("Unable to find session data in login page")
	exit(1)
session_data = match[1]

debug("--------")

# now that we have a session id, contact the 
# single key host to start the new login flow
singlekey_host = 'https://singlekey-id.com'
login_url = singlekey_host + '/auth/en-us/log-in/'

preauth_url = singlekey_host + "/auth/connect/authorize"
preauth_query = {
	"client_id": "11F75C04-21C2-4DA9-A623-228B54E9A256",
	"redirect_uri": "https://api.home-connect.com/security/oauth/redirect_target",
	"response_type": "code",
	"scope": "openid email profile offline_access homeconnect.general",
	"prompt": "login",
	"style_id": "bsh_hc_01",
	"state": '{"session_id":"' + session_id + '"}', # important: no spaces!
}

# fetch the preauth state to get the final callback url
preauth_url += "?" + urlencode(preauth_query)

# loop until we have the callback url
while True:
	debug(f"next {preauth_url=}")
	r = session.get(preauth_url, allow_redirects=False)
	if r.status_code == 200:
		break
	if r.status_code > 300 and r.status_code < 400:
		preauth_url = r.headers["location"]
		# Make relative locations absolute
		if not bool(urlparse(preauth_url).netloc):
			preauth_url = singlekey_host + preauth_url
		continue
	print(f"2: {preauth_url=}: failed to fetch {r} {r.text}", file=sys.stderr)
	exit(1)

# get the ReturnUrl from the response
query = parse_qs(urlparse(preauth_url).query)
return_url = query["ReturnUrl"][0]
debug(f"{return_url=}")

if "X-CSRF-FORM-TOKEN" in r.cookies:
	headers["RequestVerificationToken"] = r.cookies["X-CSRF-FORM-TOKEN"]
session.headers.update(headers)

debug("--------")

soup = BeautifulSoup(r.text, 'html.parser')
requestVerificationToken = soup.find('input', {'name': '__RequestVerificationToken'}).get('value')
r = session.post(preauth_url, data={"UserIdentifierInput.EmailInput.StringValue": email, "__RequestVerificationToken": requestVerificationToken }, allow_redirects=False)

password_url = r.headers['location']
if not bool(urlparse(password_url).netloc):
	password_url = singlekey_host + password_url

r = session.get(password_url, allow_redirects=False)
soup = BeautifulSoup(r.text, 'html.parser')
requestVerificationToken = soup.find('input', {'name': '__RequestVerificationToken'}).get('value')

r = session.post(password_url, data={"Password": password, "RememberMe": "false", "__RequestVerificationToken": requestVerificationToken }, allow_redirects=False)

if return_url.startswith("/"):
	return_url = singlekey_host + return_url

while True:
	r = session.get(return_url, allow_redirects=False)
	debug(f"{return_url=}, {r} {r.text}")
	if r.status_code != 302:
		break
	return_url = r.headers["location"]
	if return_url.startswith("hcauth://"):
		break
debug(f"{return_url=}")

debug("--------")

url = urlparse(return_url)
query = parse_qs(url.query)
code = query.get("code")[0]
state = query.get("state")[0]
grant_type = query.get("grant_type")[0] # "authorization_code"

debug(f"{code=} {grant_type=} {state=}")

auth_url = base_url + 'login'
token_url = base_url + 'token'

token_fields = {
	"grant_type": grant_type,
	"client_id": app_id,
	"code_verifier": verifier,
	"code": code,
	"redirect_uri": login_query["redirect_uri"],
}

debug(f"{token_url=} {token_fields=}")

r = requests.post(token_url, data=token_fields, allow_redirects=False)
if r.status_code != requests.codes.ok:
	print("Bad code?", file=sys.stderr)
	print(r.headers, r.text)
	exit(1)

debug('--------- got token page ----------')

token = json.loads(r.text)["access_token"]
debug(f"Received access {token=}")

headers = {
	"Authorization": "Bearer " + token,
}

# now we can fetch the rest of the account info
r = requests.get(asset_url + "account/details", headers=headers)
if r.status_code != requests.codes.ok:
	print("unable to fetch account details", file=sys.stderr)
	print(r.headers, r.text)
	exit(1)

#print(r.text)
account = json.loads(r.text)
configs = []

print(account, file=sys.stderr)

for app in account["data"]["homeAppliances"]:
	app_brand = app["brand"]
	app_type = app["type"]
	app_id = app["identifier"]

	config = {
		"name": app_type.lower(),
	}

	configs.append(config)

	if "tls" in app:
		# fancy machine with TLS support
		config["host"] =app_brand + "-" + app_type + "-" + app_id
		config["key"] = app["tls"]["key"]
	else:
		# less fancy machine with HTTP support
		config["host"] = app_id
		config["key"] = app["aes"]["key"]
		config["iv"] = app["aes"]["iv"]

	# Fetch the XML zip file for this device
	app_url = asset_url + "api/iddf/v1/iddf/" + app_id
	print("fetching", app_url, file=sys.stderr)
	r = requests.get(app_url, headers=headers)
	if r.status_code != requests.codes.ok:
		print(app_id, ": unable to fetch machine description?")
		next

	# we now have a zip file with XML, let's unpack them
	content = r.content
	print(app_url + ": " + app_id + ".zip", file=sys.stderr)
	with open(app_id + ".zip", "wb") as f:
		f.write(content)
	z = ZipFile(io.BytesIO(content))
	#print(z.infolist())
	features = z.open(app_id + "_FeatureMapping.xml").read()
	description = z.open(app_id + "_DeviceDescription.xml").read()

	machine = xml2json(features, description)
	config["description"] = machine["description"]
	config["features"] = machine["features"]

print(json.dumps(configs, indent=4))