# Twisted/Klein imports
from twisted.logger import Logger

# Other library imports
from json import dumps
from json.decoder import JSONDecodeError
import requests
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.backends import default_backend
import jwt

# Project imports
from settings import settings


class Revolut(object):
    """
    Class to handle Revolut API calls.
    """

    def __init__(self, irc):
        self.log = Logger("revolut")
        self.token = None
        self.irc = irc

    def setup_auth(self):
        self.create_new_jwt()
        self.get_access_token()

    def create_new_jwt(self):
        payload = {
            "iss": settings.Revolut.Domain,
            "sub": settings.Revolut.ClientID,
            "aud": "https://revolut.com",
            "exp": int(settings.Revolut.Expiry),
        }
        with open(settings.Revolut.PrivateKey, "rb") as f:
            pem_bytes = f.read()

        # payload = {jwt_header, jwt_body}
        private_key = serialization.load_pem_private_key(pem_bytes, password=None, backend=default_backend())
        encoded = jwt.encode(payload, private_key, algorithm="RS256")
        settings.Revolut.JWT = encoded
        settings.write()

    def get_access_token(self):
        headers = {"Content-Type": "application/x-www-form-urlencoded"}
        data = {
            "grant_type": "authorization_code",
            "code": settings.Revolut.AuthCode,
            "client_id": settings.Revolut.ClientID,
            "client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
            "client_assertion": settings.Revolut.JWT,
        }
        r = requests.post(f"{settings.Revolut.Base}/auth/token", data=data, headers=headers)
        try:
            parsed = r.json()
        except JSONDecodeError:
            return False
        if r.status_code == 200:
            try:
                settings.Revolut.RefreshToken = parsed["refresh_token"]
                settings.Revolut.SetupToken = "0"
                settings.write()
                self.log.info("Refreshed refresh token: {refresh_token}", refresh_token=settings.Revolut.RefreshToken)
                self.token = parsed["access_token"]
                self.log.info("Refreshed access token: {access_token}", access_token=self.token)
            except KeyError:
                self.log.error(f"Token authorization didn't contain refresh or access token: {parsed}", parsed=parsed)
                return False
        else:
            self.log.error(f"Cannot refresh token: {parsed}", parsed=parsed)
            return False

    def get_new_token(self):
        headers = {"Content-Type": "application/x-www-form-urlencoded"}
        data = {
            "grant_type": "refresh_token",
            "refresh_token": settings.Revolut.RefreshToken,
            "client_id": settings.Revolut.ClientID,
            "client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
            "client_assertion": settings.Revolut.JWT,
        }
        r = requests.post(f"{settings.Revolut.Base}/auth/token", data=data, headers=headers)
        try:
            parsed = r.json()
        except JSONDecodeError:
            return False
        if r.status_code == 200:
            if "access_token" in parsed.keys():
                self.token = parsed["access_token"]
                self.log.info("Refreshed access token: {access_token}", access_token=self.token)
                return True
            else:
                self.log.error(f"Token refresh didn't contain access token: {parsed}", parsed=parsed)
                return False
        else:
            self.log.error(f"Cannot refresh token: {parsed}", parsed=parsed)
            return False

    def setup_webhook(self):
        self.log.info("Setting up webhook: {url}", url=settings.Revolut.WebhookURL)
        headers = {"Authorization": f"Bearer {self.token}"}
        data = {"url": settings.Revolut.WebhookURL}
        r = requests.post(f"{settings.Revolut.Base}/webhook", data=dumps(data), headers=headers)
        if r.status_code == 204:
            self.log.info("Set up webhook: {url}", url=settings.Revolut.WebhookURL)
            return dumps({"success": True})
        else:
            parsed = r.json()
            self.log.info("Failed setting up webhook: {parsed}", parsed=parsed)