1 files changed, 247 insertions, 0 deletions

diff --git a/tap_google_sheets/client.py b/tap_google_sheets/client.py
new file mode 100644
index 0000000..12f0811
--- /dev/null
+++ b/tap_google_sheets/client.py
@@ -0,0 +1,247 @@
+from datetime import datetime, timedelta
+import backoff
+import requests
+from collections import OrderedDict
+
+import singer
+from singer import metrics
+from singer import utils
+
+BASE_URL = 'https://www.googleapis.com'
+GOOGLE_TOKEN_URI = 'https://oauth2.googleapis.com/token'
+LOGGER = singer.get_logger()
+
+
+class Server5xxError(Exception):
+    pass
+
+
+class Server429Error(Exception):
+    pass
+
+
+class GoogleError(Exception):
+    pass
+
+
+class GoogleBadRequestError(GoogleError):
+    pass
+
+
+class GoogleUnauthorizedError(GoogleError):
+    pass
+
+
+class GooglePaymentRequiredError(GoogleError):
+    pass
+
+
+class GoogleNotFoundError(GoogleError):
+    pass
+
+
+class GoogleMethodNotAllowedError(GoogleError):
+    pass
+
+
+class GoogleConflictError(GoogleError):
+    pass
+
+
+class GoogleGoneError(GoogleError):
+    pass
+
+
+class GooglePreconditionFailedError(GoogleError):
+    pass
+
+
+class GoogleRequestEntityTooLargeError(GoogleError):
+    pass
+
+
+class GoogleRequestedRangeNotSatisfiableError(GoogleError):
+    pass
+
+
+class GoogleExpectationFailedError(GoogleError):
+    pass
+
+
+class GoogleForbiddenError(GoogleError):
+    pass
+
+
+class GoogleUnprocessableEntityError(GoogleError):
+    pass
+
+
+class GooglePreconditionRequiredError(GoogleError):
+    pass
+
+
+class GoogleInternalServiceError(GoogleError):
+    pass
+
+
+# Error Codes: https://developers.google.com/webmaster-tools/search-console-api-original/v3/errors
+ERROR_CODE_EXCEPTION_MAPPING = {
+    400: GoogleBadRequestError,
+    401: GoogleUnauthorizedError,
+    402: GooglePaymentRequiredError,
+    403: GoogleForbiddenError,
+    404: GoogleNotFoundError,
+    405: GoogleMethodNotAllowedError,
+    409: GoogleConflictError,
+    410: GoogleGoneError,
+    412: GooglePreconditionFailedError,
+    413: GoogleRequestEntityTooLargeError,
+    416: GoogleRequestedRangeNotSatisfiableError,
+    417: GoogleExpectationFailedError,
+    422: GoogleUnprocessableEntityError,
+    428: GooglePreconditionRequiredError,
+    500: GoogleInternalServiceError}
+
+
+def get_exception_for_error_code(error_code):
+    return ERROR_CODE_EXCEPTION_MAPPING.get(error_code, GoogleError)
+
+def raise_for_error(response):
+    try:
+        response.raise_for_status()
+    except (requests.HTTPError, requests.ConnectionError) as error:
+        try:
+            content_length = len(response.content)
+            if content_length == 0:
+                # There is nothing we can do here since Google has neither sent
+                # us a 2xx response nor a response content.
+                return
+            response = response.json()
+            if ('error' in response) or ('errorCode' in response):
+                message = '%s: %s' % (response.get('error', str(error)),
+                                      response.get('message', 'Unknown Error'))
+                error_code = response.get('error', {}).get('code')
+                ex = get_exception_for_error_code(error_code)
+                raise ex(message)
+            else:
+                raise GoogleError(error)
+        except (ValueError, TypeError):
+            raise GoogleError(error)
+
+class GoogleClient: # pylint: disable=too-many-instance-attributes
+    def __init__(self,
+                 client_id,
+                 client_secret,
+                 refresh_token,
+                 user_agent=None):
+        self.__client_id = client_id
+        self.__client_secret = client_secret
+        self.__refresh_token = refresh_token
+        self.__user_agent = user_agent
+        self.__access_token = None
+        self.__expires = None
+        self.__session = requests.Session()
+        self.base_url = None
+
+
+    def __enter__(self):
+        self.get_access_token()
+        return self
+
+    def __exit__(self, exception_type, exception_value, traceback):
+        self.__session.close()
+
+    @backoff.on_exception(backoff.expo,
+                          Server5xxError,
+                          max_tries=5,
+                          factor=2)
+    def get_access_token(self):
+        # The refresh_token never expires and may be used many times to generate each access_token
+        # Since the refresh_token does not expire, it is not included in get access_token response
+        if self.__access_token is not None and self.__expires > datetime.utcnow():
+            return
+
+        headers = {}
+        if self.__user_agent:
+            headers['User-Agent'] = self.__user_agent
+
+        response = self.__session.post(
+            url=GOOGLE_TOKEN_URI,
+            headers=headers,
+            data={
+                'grant_type': 'refresh_token',
+                'client_id': self.__client_id,
+                'client_secret': self.__client_secret,
+                'refresh_token': self.__refresh_token,
+            })
+
+        if response.status_code >= 500:
+            raise Server5xxError()
+
+        if response.status_code != 200:
+            raise_for_error(response)
+
+        data = response.json()
+        self.__access_token = data['access_token']
+        self.__expires = datetime.utcnow() + timedelta(seconds=data['expires_in'])
+        LOGGER.info('Authorized, token expires = {}'.format(self.__expires))
+
+
+    @backoff.on_exception(backoff.expo,
+                          (Server5xxError, ConnectionError, Server429Error),
+                          max_tries=7,
+                          factor=3)
+    # Rate Limit:
+    #  https://developers.google.com/webmaster-tools/search-console-api-original/v3/limits
+    @utils.ratelimit(1200, 60)
+    def request(self, method, path=None, url=None, api=None, **kwargs):
+
+        self.get_access_token()
+        
+        self.base_url = 'https://sheets.googleapis.com/v4'
+        if api == 'files':
+            self.base_url = 'https://www.googleapis.com/drive/v3'
+
+        if not url and path:
+            url = '{}/{}'.format(self.base_url, path)
+
+        # endpoint = stream_name (from sync.py API call)
+        if 'endpoint' in kwargs:
+            endpoint = kwargs['endpoint']
+            del kwargs['endpoint']
+        else:
+            endpoint = None
+
+        if 'headers' not in kwargs:
+            kwargs['headers'] = {}
+        kwargs['headers']['Authorization'] = 'Bearer {}'.format(self.__access_token)
+
+        if self.__user_agent:
+            kwargs['headers']['User-Agent'] = self.__user_agent
+
+        if method == 'POST':
+            kwargs['headers']['Content-Type'] = 'application/json'
+
+        with metrics.http_request_timer(endpoint) as timer:
+            response = self.__session.request(method, url, **kwargs)
+            timer.tags[metrics.Tag.http_status_code] = response.status_code
+
+        if response.status_code >= 500:
+            raise Server5xxError()
+
+        #Use retry functionality in backoff to wait and retry if
+        #response code equals 429 because rate limit has been exceeded
+        if response.status_code == 429:
+            raise Server429Error()
+
+        if response.status_code != 200:
+            raise_for_error(response)
+
+        # Ensure keys and rows are ordered as received from API
+        return response.json(object_pairs_hook=OrderedDict)
+
+    def get(self, path, api, **kwargs):
+        return self.request(method='GET', path=path, api=api, **kwargs)
+
+    def post(self, path, api, **kwargs):
+        return self.request(method='POST', path=path, api=api, **kwargs)