added pydrive files

resources/lib/pydrive/settings.py

@@ -0,0 +1,190 @@
+from yaml import load
+from yaml import YAMLError
+try:
+  from yaml import CLoader as Loader
+except ImportError:
+  from yaml import Loader
+
+SETTINGS_FILE = 'settings.yaml'
+SETTINGS_STRUCT = {
+    'client_config_backend': {
+        'type': str,
+        'required': True,
+        'default': 'file',
+        'dependency': [
+            {
+                'value': 'file',
+                'attribute': ['client_config_file']
+            },
+            {
+                'value': 'settings',
+                'attribute': ['client_config']
+            }
+        ]
+    },
+    'save_credentials': {
+        'type': bool,
+        'required': True,
+        'default': False,
+        'dependency': [
+            {
+                'value': True,
+                'attribute': ['save_credentials_backend']
+            }
+        ]
+    },
+    'get_refresh_token': {
+        'type': bool,
+        'required': False,
+        'default': False
+    },
+    'client_config_file': {
+        'type': str,
+        'required': False,
+        'default': 'client_secrets.json'
+    },
+    'save_credentials_backend': {
+        'type': str,
+        'required': False,
+        'dependency': [
+            {
+                'value': 'file',
+                'attribute': ['save_credentials_file']
+            }
+        ]
+    },
+    'client_config': {
+        'type': dict,
+        'required': False,
+        'struct': {
+            'client_id': {
+                'type': str,
+                'required': True
+            },
+            'client_secret': {
+                'type': str,
+                'required': True
+            },
+            'auth_uri': {
+                'type': str,
+                'required': True,
+                'default': 'https://accounts.google.com/o/oauth2/auth'
+            },
+            'token_uri': {
+                'type': str,
+                'required': True,
+                'default': 'https://accounts.google.com/o/oauth2/token'
+            },
+            'redirect_uri': {
+                'type': str,
+                'required': True,
+                'default': 'urn:ietf:wg:oauth:2.0:oob'
+            },
+            'revoke_uri': {
+                'type': str,
+                'required': True,
+                'default': None
+            }
+        }
+    },
+    'oauth_scope': {
+        'type': list,
+        'required': True,
+        'struct': str,
+        'default': ['https://www.googleapis.com/auth/drive']
+    },
+    'save_credentials_file': {
+        'type': str,
+        'required': False,
+    }
+}
+
+
+class SettingsError(IOError):
+  """Error while loading/saving settings"""
+
+
+class InvalidConfigError(IOError):
+  """Error trying to read client configuration."""
+
+
+def LoadSettingsFile(filename=SETTINGS_FILE):
+  """Loads settings file in yaml format given file name.
+
+  :param filename: path for settings file. 'settings.yaml' by default.
+  :type filename: str.
+  :raises: SettingsError
+  """
+  try:
+    stream = file(filename, 'r')
+    data = load(stream, Loader=Loader)
+  except (YAMLError, IOError), e:
+    raise SettingsError(e)
+  return data
+
+
+def ValidateSettings(data):
+  """Validates if current settings is valid.
+
+  :param data: dictionary containing all settings.
+  :type data: dict.
+  :raises: InvalidConfigError
+  """
+  _ValidateSettingsStruct(data, SETTINGS_STRUCT)
+
+
+def _ValidateSettingsStruct(data, struct):
+  """Validates if provided data fits provided structure.
+
+  :param data: dictionary containing settings.
+  :type data: dict.
+  :param struct: dictionary containing structure information of settings.
+  :type struct: dict.
+  :raises: InvalidConfigError
+  """
+  # Validate required elements of the setting.
+  for key in struct:
+    if struct[key]['required']:
+      _ValidateSettingsElement(data, struct, key)
+
+
+def _ValidateSettingsElement(data, struct, key):
+  """Validates if provided element of settings data fits provided structure.
+
+  :param data: dictionary containing settings.
+  :type data: dict.
+  :param struct: dictionary containing structure information of settings.
+  :type struct: dict.
+  :param key: key of the settings element to validate.
+  :type key: str.
+  :raises: InvalidConfigError
+  """
+  # Check if data exists. If not, check if default value exists.
+  value = data.get(key)
+  data_type = struct[key]['type']
+  if value is None:
+    try:
+      default = struct[key]['default']
+    except KeyError:
+      raise InvalidConfigError('Missing required setting %s' % key)
+    else:
+      data[key] = default
+  # If data exists, Check type of the data
+  elif type(value) is not data_type:
+    raise InvalidConfigError('Setting %s should be type %s' % (key, data_type))
+  # If type of this data is dict, check if structure of the data is valid.
+  if data_type is dict:
+    _ValidateSettingsStruct(data[key], struct[key]['struct'])
+  # If type of this data is list, check if all values in the list is valid.
+  elif data_type is list:
+    for element in data[key]:
+      if type(element) is not struct[key]['struct']:
+        raise InvalidConfigError('Setting %s should be list of %s' %
+                                 (key, struct[key]['struct']))
+  # Check dependency of this attribute.
+  dependencies = struct[key].get('dependency')
+  if dependencies:
+    for dependency in dependencies:
+      if value == dependency['value']:
+        for reqkey in dependency['attribute']:
+          _ValidateSettingsElement(data, struct, reqkey)