text: from __future__ import unicode_literals
  
  import weakref
  from datetime import date, datetime
  from functools import wraps
  from ..compat import string_types, quote, PY2
  
  # parts of URL to be omitted
  SKIP_IN_PATH = (None, "", b"", [], ())
  
  
  def _escape(value):
      """
      Escape a single value of a URL string or a query parameter. If it is a list
      or tuple, turn it into a comma-separated string first.
      """
  
      # make sequences into comma-separated stings
      if isinstance(value, (list, tuple)):
          value = ",".join(value)
  
      # dates and datetimes into isoformat
      elif isinstance(value, (date, datetime)):
          value = value.isoformat()
  
      # make bools into true/false strings
      elif isinstance(value, bool):
          value = str(value).lower()
  
      # don't decode bytestrings
      elif isinstance(value, bytes):
          return value
  
      # encode strings to utf-8
      if isinstance(value, string_types):
          if PY2 and isinstance(value, unicode):  # noqa: F821
              return value.encode("utf-8")
          if not PY2 and isinstance(value, str):
              return value.encode("utf-8")
  
      return str(value)
  
  
  def _make_path(*parts):
      """
      Create a URL string from parts, omit all `None` values and empty strings.
      Convert lists and tuples to comma separated values.
      """
      # TODO: maybe only allow some parts to be lists/tuples ?
      return "/" + "/".join(
          # preserve ',' and '*' in url for nicer URLs in logs
          quote(_escape(p), b",*")
          for p in parts
          if p not in SKIP_IN_PATH
      )
  
  
  # parameters that apply to all methods
  GLOBAL_PARAMS = ("pretty", "human", "error_trace", "format", "filter_path")
  
  
  def query_params(*es_query_params):
      """
      Decorator that pops all accepted parameters from method's kwargs and puts
      them in the params argument.
      """
  
      def _wrapper(func):
          @wraps(func)
          def _wrapped(*args, **kwargs):
              params = {}
              headers = {}
              if "params" in kwargs:
                  params = kwargs.pop("params").copy()
              if "headers" in kwargs:
                  headers = {
                      k.lower(): v for k, v in (kwargs.pop("headers") or {}).items()
                  }
              if "opaque_id" in kwargs:
                  headers["x-opaque-id"] = kwargs.pop("opaque_id")
  
              for p in es_query_params + GLOBAL_PARAMS:
                  if p in kwargs:
                      v = kwargs.pop(p)
                      if v is not None:
                          params[p] = _escape(v)
  
              # don't treat ignore, request_timeout, and opaque_id as other params to avoid escaping
              for p in ("ignore", "request_timeout"):
                  if p in kwargs:
                      params[p] = kwargs.pop(p)
              return func(*args, params=params, headers=headers, **kwargs)
  
          return _wrapped
  
      return _wrapper
  
  
  def _bulk_body(serializer, body):
      # if not passed in a string, serialize items and join by newline
      if not isinstance(body, string_types):
          body = "\n".join(map(serializer.dumps, body))
  
      # bulk body must end with a newline
      if not body.endswith("\n"):
          body += "\n"
  
      return body
  
  
  class NamespacedClient(object):
      def __init__(self, client):
          self.client = client
  
      @property
      def transport(self):
          return self.client.transport
  
  
  class AddonClient(NamespacedClient):
      @classmethod
      def infect_client(cls, client):
          addon = cls(weakref.proxy(client))
          setattr(client, cls.namespace, addon)
          return client
  