text: """Utilities for generating OpenAPI Specification (fka Swagger) entities from
  :class:`Fields <marshmallow.fields.Field>`.
  
  .. warning::
  
      This module is treated as private API.
      Users should not need to use this module directly.
  """
  import re
  import functools
  import operator
  import warnings
  
  import marshmallow
  from marshmallow.orderedset import OrderedSet
  
  
  RegexType = type(re.compile(""))
  
  # marshmallow field => (JSON Schema type, format)
  DEFAULT_FIELD_MAPPING = {
      marshmallow.fields.Integer: ("integer", None),
      marshmallow.fields.Number: ("number", None),
      marshmallow.fields.Float: ("number", None),
      marshmallow.fields.Decimal: ("number", None),
      marshmallow.fields.String: ("string", None),
      marshmallow.fields.Boolean: ("boolean", None),
      marshmallow.fields.UUID: ("string", "uuid"),
      marshmallow.fields.DateTime: ("string", "date-time"),
      marshmallow.fields.Date: ("string", "date"),
      marshmallow.fields.Time: ("string", None),
      marshmallow.fields.TimeDelta: ("integer", None),
      marshmallow.fields.Email: ("string", "email"),
      marshmallow.fields.URL: ("string", "url"),
      marshmallow.fields.Dict: ("object", None),
      marshmallow.fields.Field: (None, None),
      marshmallow.fields.Raw: (None, None),
      marshmallow.fields.List: ("array", None),
  }
  
  
  # Properties that may be defined in a field's metadata that will be added to the output
  # of field2property
  # https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#schemaObject
  _VALID_PROPERTIES = {
      "format",
      "title",
      "description",
      "default",
      "multipleOf",
      "maximum",
      "exclusiveMaximum",
      "minimum",
      "exclusiveMinimum",
      "maxLength",
      "minLength",
      "pattern",
      "maxItems",
      "minItems",
      "uniqueItems",
      "maxProperties",
      "minProperties",
      "required",
      "enum",
      "type",
      "items",
      "allOf",
      "oneOf",
      "anyOf",
      "not",
      "properties",
      "additionalProperties",
      "readOnly",
      "writeOnly",
      "xml",
      "externalDocs",
      "example",
      "nullable",
      "deprecated",
  }
  
  
  _VALID_PREFIX = "x-"
  
  
  class FieldConverterMixin:
      """Adds methods for converting marshmallow fields to an OpenAPI properties."""
  
      field_mapping = DEFAULT_FIELD_MAPPING
  
      def init_attribute_functions(self):
          self.attribute_functions = [
              # self.field2type_and_format should run first
              # as other functions may rely on its output
              self.field2type_and_format,
              self.field2default,
              self.field2choices,
              self.field2read_only,
              self.field2write_only,
              self.field2nullable,
              self.field2range,
              self.field2length,
              self.field2pattern,
              self.metadata2properties,
              self.nested2properties,
              self.pluck2properties,
              self.list2properties,
              self.dict2properties,
              self.timedelta2properties,
          ]
  
      def map_to_openapi_type(self, *args):
          """Decorator to set mapping for custom fields.
  
          ``*args`` can be:
  
          - a pair of the form ``(type, format)``
          - a core marshmallow field type (in which case we reuse that type's mapping)
          """
          if len(args) == 1 and args[0] in self.field_mapping:
              openapi_type_field = self.field_mapping[args[0]]
          elif len(args) == 2:
              openapi_type_field = args
          else:
              raise TypeError("Pass core marshmallow field type or (type, fmt) pair.")
  
          def inner(field_type):
              self.field_mapping[field_type] = openapi_type_field
              return field_type
  
          return inner
  
      def add_attribute_function(self, func):
          """Method to add an attribute function to the list of attribute functions
          that will be called on a field to convert it from a field to an OpenAPI
          property.
  
          :param func func: the attribute function to add
              The attribute function will be bound to the
              `OpenAPIConverter <apispec.ext.marshmallow.openapi.OpenAPIConverter>`
              instance.
              It will be called for each field in a schema with
              `self <apispec.ext.marshmallow.openapi.OpenAPIConverter>` and a
              `field <marshmallow.fields.Field>` instance
              positional arguments and `ret <dict>` keyword argument.
              Must return a dictionary of OpenAPI properties that will be shallow
              merged with the return values of all other attribute functions called on the field.
              User added attribute functions will be called after all built-in attribute
              functions in the order they were added. The merged results of all
              previously called attribute functions are accessable via the `ret`
              argument.
          """
          bound_func = func.__get__(self)
          setattr(self, func.__name__, bound_func)
          self.attribute_functions.append(bound_func)
  
      def field2property(self, field):
          """Return the JSON Schema property definition given a marshmallow
          :class:`Field <marshmallow.fields.Field>`.
  
          Will include field metadata that are valid properties of OpenAPI schema objects
          (e.g. "description", "enum", "example").
  
          https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#schemaObject
  
          :param Field field: A marshmallow field.
          :rtype: dict, a Property Object
          """
          ret = {}
  
          for attr_func in self.attribute_functions:
              ret.update(attr_func(field, ret=ret))
  
          return ret
  
      def field2type_and_format(self, field, **kwargs):
          """Return the dictionary of OpenAPI type and format based on the field type.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          # If this type isn't directly in the field mapping then check the
          # hierarchy until we find something that does.
          for field_class in type(field).__mro__:
              if field_class in self.field_mapping:
                  type_, fmt = self.field_mapping[field_class]
                  break
          else:
              warnings.warn(
                  "Field of type {} does not inherit from marshmallow.Field.".format(
                      type(field)
                  ),
                  UserWarning,
              )
              type_, fmt = "string", None
  
          ret = {}
          if type_:
              ret["type"] = type_
          if fmt:
              ret["format"] = fmt
  
          return ret
  
      def field2default(self, field, **kwargs):
          """Return the dictionary containing the field's default value.
  
          Will first look for a `default` key in the field's metadata and then
          fall back on the field's `missing` parameter. A callable passed to the
          field's missing parameter will be ignored.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          ret = {}
          if "default" in field.metadata:
              ret["default"] = field.metadata["default"]
          else:
              default = field.load_default
              if default is not marshmallow.missing and not callable(default):
                  default = field._serialize(default, None, None)
                  ret["default"] = default
          return ret
  
      def field2choices(self, field, **kwargs):
          """Return the dictionary of OpenAPI field attributes for valid choices definition.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          attributes = {}
  
          comparable = [
              validator.comparable
              for validator in field.validators
              if hasattr(validator, "comparable")
          ]
          if comparable:
              attributes["enum"] = comparable
          else:
              choices = [
                  OrderedSet(validator.choices)
                  for validator in field.validators
                  if hasattr(validator, "choices")
              ]
              if choices:
                  attributes["enum"] = list(functools.reduce(operator.and_, choices))
  
          return attributes
  
      def field2read_only(self, field, **kwargs):
          """Return the dictionary of OpenAPI field attributes for a dump_only field.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          attributes = {}
          if field.dump_only:
              attributes["readOnly"] = True
          return attributes
  
      def field2write_only(self, field, **kwargs):
          """Return the dictionary of OpenAPI field attributes for a load_only field.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          attributes = {}
          if field.load_only and self.openapi_version.major >= 3:
              attributes["writeOnly"] = True
          return attributes
  
      def field2nullable(self, field, ret):
          """Return the dictionary of OpenAPI field attributes for a nullable field.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          attributes = {}
          if field.allow_none:
              if self.openapi_version.major < 3:
                  attributes["x-nullable"] = True
              elif self.openapi_version.minor < 1:
                  attributes["nullable"] = True
              else:
                  attributes["type"] = [*make_type_list(ret.get("type")), "null"]
          return attributes
  
      def field2range(self, field, ret):
          """Return the dictionary of OpenAPI field attributes for a set of
          :class:`Range <marshmallow.validators.Range>` validators.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          validators = [
              validator
              for validator in field.validators
              if (
                  hasattr(validator, "min")
                  and hasattr(validator, "max")
                  and not hasattr(validator, "equal")
              )
          ]
  
          min_attr, max_attr = (
              ("minimum", "maximum")
              if set(make_type_list(ret.get("type"))) & {"number", "integer"}
              else ("x-minimum", "x-maximum")
          )
          return make_min_max_attributes(validators, min_attr, max_attr)
  
      def field2length(self, field, **kwargs):
          """Return the dictionary of OpenAPI field attributes for a set of
          :class:`Length <marshmallow.validators.Length>` validators.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          validators = [
              validator
              for validator in field.validators
              if (
                  hasattr(validator, "min")
                  and hasattr(validator, "max")
                  and hasattr(validator, "equal")
              )
          ]
  
          is_array = isinstance(
              field, (marshmallow.fields.Nested, marshmallow.fields.List)
          )
          min_attr = "minItems" if is_array else "minLength"
          max_attr = "maxItems" if is_array else "maxLength"
  
          equal_list = [
              validator.equal for validator in validators if validator.equal is not None
          ]
          if equal_list:
              return {min_attr: equal_list[0], max_attr: equal_list[0]}
  
          return make_min_max_attributes(validators, min_attr, max_attr)
  
      def field2pattern(self, field, **kwargs):
          """Return the dictionary of OpenAPI field attributes for a
          :class:`Regexp <marshmallow.validators.Regexp>` validator.
  
          If there is more than one such validator, only the first
          is used in the output spec.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          regex_validators = (
              v
              for v in field.validators
              if isinstance(getattr(v, "regex", None), RegexType)
          )
          v = next(regex_validators, None)
          attributes = {} if v is None else {"pattern": v.regex.pattern}
  
          if next(regex_validators, None) is not None:
              warnings.warn(
                  "More than one regex validator defined on {} field. Only the "
                  "first one will be used in the output spec.".format(type(field)),
                  UserWarning,
              )
  
          return attributes
  
      def metadata2properties(self, field, **kwargs):
          """Return a dictionary of properties extracted from field metadata.
  
          Will include field metadata that are valid properties of `OpenAPI schema
          objects
          <https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#schemaObject>`_
          (e.g. "description", "enum", "example").
  
          In addition, `specification extensions
          <https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#specification-extensions>`_
          are supported.  Prefix `x_` to the desired extension when passing the
          keyword argument to the field constructor. apispec will convert `x_` to
          `x-` to comply with OpenAPI.
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          # Dasherize metadata that starts with x_
          metadata = {
              key.replace("_", "-") if key.startswith("x_") else key: value
              for key, value in field.metadata.items()
              if isinstance(key, str)
          }
  
          # Avoid validation error with "Additional properties not allowed"
          ret = {
              key: value
              for key, value in metadata.items()
              if key in _VALID_PROPERTIES or key.startswith(_VALID_PREFIX)
          }
          return ret
  
      def nested2properties(self, field, ret):
          """Return a dictionary of properties from :class:`Nested <marshmallow.fields.Nested` fields.
  
          Typically provides a reference object and will add the schema to the spec
          if it is not already present
          If a custom `schema_name_resolver` function returns `None` for the nested
          schema a JSON schema object will be returned
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          # Pluck is a subclass of Nested but is in essence a single field; it
          # is treated separately by pluck2properties.
          if isinstance(field, marshmallow.fields.Nested) and not isinstance(
              field, marshmallow.fields.Pluck
          ):
              schema_dict = self.resolve_nested_schema(field.schema)
              if ret and "$ref" in schema_dict:
                  ret.update({"allOf": [schema_dict]})
              else:
                  ret.update(schema_dict)
          return ret
  
      def pluck2properties(self, field, **kwargs):
          """Return a dictionary of properties from :class:`Pluck <marshmallow.fields.Pluck` fields.
  
          Pluck effectively trans-includes a field from another schema into this,
          possibly wrapped in an array (`many=True`).
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          if isinstance(field, marshmallow.fields.Pluck):
              plucked_field = field.schema.fields[field.field_name]
              ret = self.field2property(plucked_field)
              return {"type": "array", "items": ret} if field.many else ret
          return {}
  
      def list2properties(self, field, **kwargs):
          """Return a dictionary of properties from :class:`List <marshmallow.fields.List>` fields.
  
          Will provide an `items` property based on the field's `inner` attribute
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          ret = {}
          if isinstance(field, marshmallow.fields.List):
              ret["items"] = self.field2property(field.inner)
          return ret
  
      def dict2properties(self, field, **kwargs):
          """Return a dictionary of properties from :class:`Dict <marshmallow.fields.Dict>` fields.
  
          Only applicable for Marshmallow versions greater than 3. Will provide an
          `additionalProperties` property based on the field's `value_field` attribute
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          ret = {}
          if isinstance(field, marshmallow.fields.Dict):
              value_field = field.value_field
              if value_field:
                  ret["additionalProperties"] = self.field2property(value_field)
          return ret
  
      def timedelta2properties(self, field, **kwargs):
          """Return a dictionary of properties from :class:`TimeDelta <marshmallow.fields.TimeDelta>` fields.
  
          Adds a `x-unit` vendor property based on the field's `precision` attribute
  
          :param Field field: A marshmallow field.
          :rtype: dict
          """
          ret = {}
          if isinstance(field, marshmallow.fields.TimeDelta):
              ret["x-unit"] = field.precision
          return ret
  
  
  def make_type_list(types):
      """Return a list of types from a type attribute
  
      Since OpenAPI 3.1.0, "type" can be a single type as string or a list of
      types, including 'null'. This function takes a "type" attribute as input
      and returns it as a list, be it an empty or single-element list.
      This is useful to factorize type-conditional code or code adding a type.
      """
      if types is None:
          return []
      if isinstance(types, str):
          return [types]
      return types
  
  
  def make_min_max_attributes(validators, min_attr, max_attr):
      """Return a dictionary of minimum and maximum attributes based on a list
      of validators. If either minimum or maximum values are not present in any
      of the validator objects that attribute will be omitted.
  
      :param validators list: A list of `Marshmallow` validator objects. Each
          objct is inspected for a minimum and maximum values
      :param min_attr string: The OpenAPI attribute for the minimum value
      :param max_attr string: The OpenAPI attribute for the maximum value
      """
      attributes = {}
      min_list = [validator.min for validator in validators if validator.min is not None]
      max_list = [validator.max for validator in validators if validator.max is not None]
      if min_list:
          attributes[min_attr] = max(min_list)
      if max_list:
          attributes[max_attr] = min(max_list)
      return attributes
  