PyZipline/pyzipline/rest_adapter.py

import logging
from typing import Dict
from json import JSONDecodeError

import requests
from urllib3 import disable_warnings

from pyzipline.errors import KwargConflict, HTTPFailure, PyZiplineError
from pyzipline.models import Result

class RestAdapter:
    def __init__(self, hostname: str, token: str = '', ssl: bool = True, enforced_signing: bool = True, logger: logging.Logger = None):
        """Constructor for RestAdapter

        :param hostname: The hostname of your Zipline instance, WITHOUT https or http.
        :type hostname: str
        :param token: (optional) String used for authentication when making requests.
        :param token: str
        :param ssl: (optional) Normally set to True, but if your Zipline instance doesn't use SSL/TLS, set this to False.
        :type ssl: bool
        :param enforced_signing: (optional) Normally set to True, but if having SSL/TLS cert validation issues, can turn off with False.
        :type enforced_signing: bool
        :param logger: (optional) If your app has a logger, pass it in here.
        :type logger: logging.Logger
        :raise KwargConflict: Raised when the keyword arguments passed to a function conflict.
        """
        self._url = f"http{'s' if ssl else ''}://{hostname}/api/"
        self._token = token
        self._ssl = ssl
        self._enforced_signing = enforced_signing
        self._logger = logger or logging.getLogger(__name__)

        if ssl is False and enforced_signing is True:
            raise KwargConflict("Cannot enforce signing without SSL")

        if not ssl and not enforced_signing:
            disable_warnings()

    def _do(self, http_method: str, endpoint: str, params: Dict = None, data: Dict = None) -> Result:
        """Internal method to make a request to the Zipline server. You shouldn't use this directly.

        :param http_method: The HTTP method to use (GET, POST, DELETE)
        :type http_method: str
        :param endpoint: The endpoint to make the request to.
        :type endpoint: str
        :param params: (optional) Python dictionary of query parameters to send with the request.
        :type params: Dict
        :param data: (optional) Python dictionary of data to send with the request.
        :type data: Dict
        :raise HTTPFailure: Raised when an HTTP request fails.
        :raise PyZiplineError: Raised when an error occurs in the PyZipline library.
        :return: Result object
        :rtype: Result"""
        full_url = self._url + endpoint
        headers = {'Authorization': self._token}

        log_line_pre = f"method={http_method}, url={full_url}, params={params}"
        log_line_post = ', '.join((log_line_pre, "success={}, status_code={}, message={}"))

        try: # Log HTTP params and perform an HTTP request, catching and re-raising any exceptions
            self._logger.debug(msg=log_line_pre)
            # will eventually refactor this to use asyncio/aiohttp instead for async operation
            response = requests.request(method=http_method, url=full_url, verify=self._enforced_signing, params=params, headers=headers, json=data)
        except requests.exceptions.RequestException as e:
            self._logger.error(msg=(str(e)))
            raise HTTPFailure("Could not connect to Zipline server") from e

        try: # Deserialize JSON output to Python object, or return failed Result on exception
            data_out = response.json()
        except (ValueError, JSONDecodeError) as e:
            self._logger.error(msg=log_line_post.format(False, None, e))
            raise PyZiplineError("Could not decode response from Zipline server") from e

        # If status_code in 200-299 range, return success Result with data, otherwise raise exception
        is_success = 299 >= response.status_code >= 200
        log_line = log_line_post.format(is_success, response.status_code, response.reason)

        if is_success:
            self._logger.debug(msg=log_line_post.format(is_success, response.status_code, response.reason))
            return Result(status_code=response.status_code, message=response.reason, data=data_out)

        self._logger.error(msg=log_line)

        raise PyZiplineError(f"{response.status_code}: {response.reason}")

    def get(self, endpoint: str, params: Dict = None) -> Result:
        """Make a GET request to the Zipline server. You should almost never have to use this directly.

        :param endpoint: The endpoint to make the request to.
        :type endpoint: str
        :param params: (optional) Python dictionary of query parameters to send with the request.
        :type params: Dict
        :return: Result object
        :rtype: Result"""
        return self._do(http_method='GET', endpoint=endpoint, params=params)

    def post(self, endpoint: str, params: Dict = None, data: Dict = None) -> Result:
        """Make a POST request to the Zipline server. You should almost never have to use this directly.

        :param endpoint: The endpoint to make the request to.
        :type endpoint: str
        :param params: (optional) Python dictionary of query parameters to send with the request.
        :type params: Dict
        :param data: (optional) Python dictionary of data to send with the request.
        :type data: Dict
        :return: Result object
        :rtype: Result"""
        return self._do(http_method='POST', endpoint=endpoint, params=params, data=data)

    def delete(self, endpoint: str, params: Dict = None, data: Dict = None) -> Result:
        """Make a DELETE request to the Zipline server. You should almost never have to use this directly.

        :param endpoint: The endpoint to make the request to.
        :type endpoint: str
        :param params: (optional) Python dictionary of query parameters to send with the request.
        :type params: Dict
        :param data: (optional) Python dictionary of data to send with the request.
        :type data: Dict
        :return: Result object
        :rtype: Result"""
        return self._do(http_method='DELETE', endpoint=endpoint, params=params, data=data)