import os
import string
import re
import io
import requests
import logging

from typing import (
    Any,
    Dict,
    Optional,
    Text,
)  # allows specifying explicit variable types

import pandas as pd
import numpy as np

from schematic.schemas.explorer import SchemaExplorer
from schematic import LOADER

from schematic.utils.validate_rules_utils import validate_schema_rules
from schematic.utils.df_utils import load_df

logger = logging.getLogger(__name__)


"""
Utility for converting csv file containing a data model definition schema (see scRNA-seq.csv for an example) into schema.org schema.
"""

# required headers for schema; may or may not abstract further; for now hardcode
required_headers = set(
    [
        "Attribute",
        "Description",
        "Valid Values",
        "DependsOn",
        "Required",
        "Parent",
        "Properties",
        "DependsOn Component",
        "Source",
        "Validation Rules",
    ]
)


def get_class(
    se: SchemaExplorer,
    class_display_name: str,
    description: str = None,
    subclass_of: list = [],
    requires_dependencies: list = None,
    requires_range: list = None,
    requires_components: list = None,
    required: bool = None,
    validation_rules: list = None,
) -> dict:

    """Constructs a new schema.org compliant class given a set of schema object attributes

    Args:
       se: a schema explorer object allowing the traversal and modification of a schema graph
       display_class_name: human readable label for the schema object/attribute: key characteristic X of the assay, related protocol, or downstream data that we want to record as metadata feature
       description: definition or a reference containing the definition of attribute X. Preferably provide a source ontology link or code in addition to the definition.
       subclass_of: *schema* label of this attribute/object's parent node in the schema
       requires_dependencies: important characteristics, if any, of attribute X that need to be recorded as metadata features given attribute X is specified. These characteristics are attributes themselves and need to pre-exist in the schema as such
       requires_range: a set/range of values that this attribute can be assigned to. this domain is stored in the rangeIncludes property of this object.
       requires_components: a set of associated components/categories that this object/entity requires for its full specification; each component is a high level ontology class in which entities/objects are categorized/componentized and it is an entity on its own that needs to exist in the schema.
       required: indicates if this attribute is required or optional in a schema
       validation_rules: a list of validation rules defined for this class (e.g. defining what is a valid object of this class)

    Returns: a json schema.org object
    """

    class_name = se.get_class_label_from_display_name(class_display_name)

    # setup biothings object template with mandatory elements
    class_attributes = {
        "@id": "bts:" + class_name,
        "@type": "rdfs:Class",
        "rdfs:comment": description
        if description and not pd.isnull(description)
        else "TBD",
        "rdfs:label": class_name,
        "schema:isPartOf": {"@id": "http://schema.biothings.io"},
    }

    # determine parent class of element and add subclass relationship to schema - required by biothings
    # if no subclass is provided, set a default to schema.org Thing
    if subclass_of:
        if len(subclass_of) == 1 and pd.isnull(subclass_of[0]):
            parent = {"rdfs:subClassOf": [{"@id": "schema:Thing"}]}
        else:
            parent = {
                "rdfs:subClassOf": [
                    {"@id": "bts:" + se.get_class_label_from_display_name(sub)}
                    for sub in subclass_of
                ]
            }
    else:
        parent = {"rdfs:subClassOf": [{"@id": "schema:Thing"}]}

    class_attributes.update(parent)

    # add optional attribute specifying attributes/objects that are required for the specification of this object
    # useful for specifying annotation requirements, for example
    if requires_dependencies:
        requirement = {
            "sms:requiresDependency": [
                {"@id": "bts:" + dep} for dep in requires_dependencies
            ]
        }
        class_attributes.update(requirement)

    # add optional attribute specifying the possible values this object can be set to; can be other objects, including primitives
    if requires_range:
        value_constraint = {
            "schema:rangeIncludes": [
                {"@id": "bts:" + se.get_class_label_from_display_name(val)}
                for val in requires_range
            ]
        }
        class_attributes.update(value_constraint)

    # add optional attribute specifying validation patterns associated with this object (e.g. precise definition of the object range)
    if validation_rules:
        class_attributes.update({"sms:validationRules": validation_rules})
    else:
        class_attributes.update({"sms:validationRules": []})

    # add optional attribute specifying the required components (i.e. high level ontology class in which entities/objects are categorized/componentized)
    # that are required for the specification of this object
    if requires_components:
        requirement = {
            "sms:requiresComponent": [{"@id": "bts:" + c} for c in requires_components]
        }
        class_attributes.update(requirement)

    if required:
        class_attributes.update({"sms:required": "sms:true"})
    else:
        class_attributes.update({"sms:required": "sms:false"})

    # ensure display name does not contain leading/trailing white spaces
    class_attributes.update({"sms:displayName": class_display_name.strip()})

    return class_attributes


def get_property(
    se: SchemaExplorer,
    property_display_name: str,
    property_class_names: list,
    description: str = None,
    requires_range: list = None,
    requires_dependencies: list = None,
    required: bool = None,
    validation_rules: str = None,
) -> dict:

    """Constructs a new schema.org compliant property of an existing schema.org object/class; note that the property itself is a schema.org object class.

    Args:
        se: a schema explorer object allowing the traversal and modification of a schema graph
        property_display_name: human readable label for the schema object/attribute: key characteristic X of the assay, related protocol, or downstream data that we want to record as metadata feature
        property_class_name: *schema* label of the classes/objects that this is a property of
        description: definition or a reference containing the definition of attribute X. Preferably provide a source ontology link or code in addition to the definition.
        requires_range: what is the set/domain of values that this attribute can be assigned to; currently only used to specify primitive types. TODO: extend to reg exp patterns
        requires_dependencies: important characteristics, if any, of property X that need to be recorded as metadata features given property X is specified. These characteristics are attributes themselves and need to pre-exist in the schema as such
        validation_rules: a list of validation rules defined for this class (e.g. defining what is a valid object of this property)


    Returns: a json schema.org  property object
    """
    property_name = se.get_property_label_from_display_name(property_display_name)
    
    property_attributes = {
        "@id": "bts:" + property_name,
        "@type": "rdf:Property",
        "rdfs:comment": description
        if description and not pd.isnull(description)
        else "TBD",
        "rdfs:label": property_name,
        "sms:displayName": property_display_name,
        "schema:isPartOf": {"@id": "http://schema.biothings.io"},
    }

    domain_includes = {
            "schema:domainIncludes": [
                {"@id": "bts:" + se.get_class_label_from_display_name(val)}
                for val in property_class_names
            ]
        }
    property_attributes.update(domain_includes)

    if requires_range:
        value_constraint = {
            "schema:rangeIncludes": [
                {"@id": "bts:" + se.get_class_label_from_display_name(val)}
                for val in requires_range
            ]
        }
        property_attributes.update(value_constraint)

    if requires_dependencies:
        requirement = {
            "sms:requiresDependency": [
                {"@id": "bts:" + dep} for dep in requires_dependencies
            ]
        }
        property_attributes.update(requirement)

    # add optional attribute specifying validation patterns associated with this object (e.g. precise definition of the object range)
    if validation_rules:
        property_attributes.update({"sms:validationRules": validation_rules})
    else:
        property_attributes.update({"sms:validationRules": []})

    if required:
        property_attributes.update({"sms:required": "sms:true"})
    else:
        property_attributes.update({"sms:required": "sms:false"})

    #'http://schema.org/domainIncludes':{'@id': 'bts:' + property_class_name},
    #'http://schema.org/rangeIncludes':{'@id': 'schema:' + allowed_values},

    # ensure display name does not contain leading/trailing white spaces
    property_attributes.update({"sms:displayName": property_display_name.strip()})

    return property_attributes


def attribute_exists(se: SchemaExplorer, attribute_label: str) -> bool:

    """Check if a given attribute exists already in schema

    Args:
       se: a schema explorer object allowing the traversal and modification of a schema graph
       attribute_label: a schema label for the attribute to check

    Returns:
       True/False indicating if attribute exists or not
    """
    schema_graph = se.get_nx_schema()

    if attribute_label in schema_graph.nodes:
        return True
    return False


def check_schema_definition(schema_definition: pd.DataFrame) -> bool:

    """Checks if a schema definition data frame contains the right required headers.

    See schema definition guide for more details
    TODO: post and link schema definition guide

    Args:
        schema_definition: a pandas dataframe containing schema definition; see example here: https://docs.google.com/spreadsheets/d/1J2brhqO4kpeHIkNytzlqrdIiRanXDr6KD2hqjOTC9hs/edit#gid=0
    Raises: Exception
    """

    if required_headers.issubset(set(list(schema_definition.columns))):
        return
    elif "Requires" in list(schema_definition.columns) or "Requires Component" in list(
        schema_definition.columns
    ):
        raise ValueError(
            "The input CSV schema file contains the 'Requires' and/or the 'Requires "
            "Component' column headers. These columns were renamed to 'DependsOn' and "
            "'DependsOn Component', respectively. Switch to the new column names."
        )

def _prop_2_classes(properties: dict) -> dict:
    
    """Create a dictionary linking all properties to their classes.
    Args:
        properties (dict): attributes and their properties (if applicable)
    Returns:
        Dictionary linking properties to all the classes in their domain.
    """
    prop_2_classes = {}
    for record in properties:
        if not pd.isnull(record["Properties"]):
            props = record["Properties"].strip().split(",")
            for pr in props:
                prop_2_classes.setdefault(pr.strip(),[]).append(record["Attribute"])
    
    return prop_2_classes

def create_nx_schema_objects(
    schema_extension: pd.DataFrame, se: SchemaExplorer
) -> SchemaExplorer:
    """Creates classes for all attributes and adds them to the schema.
    Args:
        schema_extension: a pandas dataframe containing schema definition; see example here: https://docs.google.com/spreadsheets/d/1J2brhqO4kpeHIkNytzlqrdIiRanXDr6KD2hqjOTC9hs/edit#gid=0
        se: a schema explorer object allowing the traversal and modification of a schema graph
        base_schema_path: a path to a json-ld file containing an existing schema
    Returns:
        An updated schema explorer object
    """

    try:
        check_schema_definition(schema_extension)
        logger.debug("Schema definition csv ready for processing!")
    except:
        raise ValueError(
            f"Schema extension headers: {set(list(schema_extension.columns))} "
            f"do not match required schema headers: {required_headers}"
        )

    rel_dict = {
        "rdfs:subClassOf": {"parentOf": "in"},
        "schema:domainIncludes": {"domainValue": "in"},
        "sms:requiresDependency": {"requiresDependency": "out"},
        "sms:requiresComponent": {"requiresComponent": "out"},
        "schema:rangeIncludes": {"rangeValue": "out"},
    }

    # get attributes from Attribute column
    attributes = schema_extension[list(required_headers)].to_dict("records")

    # get all properties across all attributes from Properties column
    props = set(schema_extension[["Properties"]].dropna().values.flatten())

    # clean properties strings
    all_properties = []
    for prop in props:
        all_properties += [p.strip() for p in prop.split(",")]

    # get both attributes and their properties (if any)
    properties = schema_extension[["Attribute", "Properties"]].to_dict("records")

    prop_2_classes = _prop_2_classes(properties)
    
    logger.debug("Adding attributes")
    for attribute in attributes:

        required = None
        if not pd.isnull(attribute["Required"]):
            required = attribute["Required"]

        if not attribute["Attribute"] in all_properties:
            # Attribute is not a property
            display_name = attribute["Attribute"]

            subclass_of = None
            if not pd.isnull(attribute["Parent"]):
                subclass_of = [
                    parent for parent in attribute["Parent"].strip().split(",")
                ]

            new_class = get_class(
                se,
                display_name,
                description=attribute["Description"],
                subclass_of=subclass_of,
                required=required,
            )

            se.add_schema_object_nx(new_class, **rel_dict)

            """
            print(se.get_nx_schema().nodes[new_class["rdfs:label"]])
            # check if attribute doesn't already exist and add it
            if not attribute_exists(se, new_class["rdfs:label"]):
                se.add_schema_object_nx(new_class, **rel_dict)
            else:
                print("ATTRIBUTE EXISTS")
                print(new_class)
            """
        
        else:
            # Attribute is a property
            display_name = attribute["Attribute"]

            new_property = get_property(
                se,
                display_name,
                prop_2_classes[display_name],
                description=attribute["Description"],
                required=required,
            )

            # check if attribute doesn't already exist and add it
            if not attribute_exists(se, new_property["rdfs:label"]):
                se.add_schema_object_nx(new_property, **rel_dict)

    logger.debug("Done adding attributes")

    # TODO check if schema already contains property - may require property context in csv schema definition

    logger.debug("Adding and editing properties")

    for prop in properties:
        if not pd.isnull(prop["Properties"]):  # a class may have or not have properties
            for p in (
                prop["Properties"].strip().split(",")
            ):  # a class may have multiple properties
                attribute = prop["Attribute"]

                # check if property is already present as attribute under attributes column
                # TODO: adjust logic below to compactify code
                p = p.strip()
                if p in list(schema_extension["Attribute"]):
                    description = schema_extension.loc[
                        schema_extension["Attribute"] == p
                    ]["Description"].values[0]
                    property_info = se.explore_property(
                        se.get_property_label_from_display_name(p)
                    )
                    range_values = (
                        property_info["range"] if "range" in property_info else None
                    )
                    requires_dependencies = (
                        property_info["dependencies"]
                        if "dependencies" in property_info
                        else None
                    )
                    required = (
                        property_info["required"]
                        if "required" in property_info
                        else None
                    )

                    new_property = get_property(
                        se,
                        p,
                        property_info["domain"],
                        description=description,
                        requires_range=range_values,
                        requires_dependencies=requires_dependencies,
                        required=required,
                    )
                    se.edit_schema_object_nx(new_property)
                else:
                    description = None
                    new_property = get_property(
                        se, p, attribute, description=description
                    )
                    se.add_schema_object_nx(new_property, **rel_dict)

    logger.debug("Done adding properties")

    # # set range values and dependency requirements for each attribute
    # # if not already added, add each attribute in required values and dependencies to the schema extension
    # print("Editing attributes and properties to add requirements and value ranges")
    # print("====================================================================================")

    for attribute in attributes:

        # TODO: refactor processing of multi-valued cells in columns and corresponding schema updates; it would compactify code below if class and property are encapsulated as objects inheriting from a common attribute parent object

        # get values in range for this attribute, if any are specified
        range_values = attribute["Valid Values"]
        if not pd.isnull(range_values):
            # prepare the range values list and split based on appropriate delimiter
            # if the string "range_values" starts with double quotes, then extract all "valid values" within double quotes
            range_values_list = []
            if range_values[0] == '"':
                range_values_list = re.findall(r'"([^"]*)"', range_values)
            else:
                range_values_list = range_values.strip().split(",")

            for val in range_values_list:
                # check if value is in attributes column; add it as a class if not
                if not val.strip() in list(schema_extension["Attribute"]):

                    # determine parent class of the new value class
                    # if this attribute is not a property, set it as a parent class
                    if not attribute["Attribute"] in all_properties:
                        parent = [attribute["Attribute"]]
                    else:
                        # this attribute is a property, set the parent to the domain class of this attribute
                        
                        parent = se.get_class_by_property(attribute["Attribute"])
                        
                        if not parent:
                            raise ValueError(
                                f"Listed valid value: {val}, for attribute: {attribute['Attribute']} "
                                "must have a class parent. The extension could not be added to the schema."
                            )
                    new_class = get_class(
                        se, val, description=None, subclass_of=parent
                    )

                    # check if attribute doesn't already exist and add it
                    if not attribute_exists(se, new_class["rdfs:label"]):
                        se.add_schema_object_nx(new_class, **rel_dict)

                # update rangeIncludes of attribute
                # if attribute is not a property, then assume it is a class
                if not attribute["Attribute"] in all_properties:
                    class_info = se.explore_class(
                        se.get_class_label_from_display_name(attribute["Attribute"])
                    )
                    class_info["range"].append(
                        se.get_class_label_from_display_name(val)
                    )

                    class_range_edit = get_class(
                        se,
                        attribute["Attribute"],
                        description=attribute["Description"],
                        subclass_of=[attribute["Parent"]],
                        requires_dependencies=class_info["dependencies"],
                        requires_range=class_info["range"],
                        required=class_info["required"],
                        validation_rules=class_info["validation_rules"],
                    )
                    se.edit_schema_object_nx(class_range_edit)

                else:
                    # the attribute is a property
                    property_info = se.explore_property(
                        se.get_property_label_from_display_name(attribute["Attribute"])
                    )
                    property_info["range"].append(
                        se.get_class_label_from_display_name(val)
                    )
                    
                    property_range_edit = get_property(
                        se,
                        attribute["Attribute"],
                        property_info["domain"],
                        description=property_info["description"],
                        requires_dependencies=property_info["dependencies"],
                        requires_range=property_info["range"],
                        required=property_info["required"],
                        validation_rules=property_info["validation_rules"],
                    )
                    se.edit_schema_object_nx(property_range_edit)

                logger.debug(val + " added to value range")

        # get validation rules for this attribute, if any are specified
        validation_rules = attribute["Validation Rules"]

        if not pd.isnull(validation_rules):
            
            # TODO: make validation rules delimiter configurable parameter
           
            validation_rules = [
                val_rule.strip() for val_rule in validation_rules.strip().split("::")
            ]

            validate_vr = validate_schema_rules(
                            validation_rules, 
                            attribute["Attribute"],
                            input_filetype = 'csv_schema')


            # update validation rules of attribute
            # if attribute is not a property, then assume it is a class
            if not attribute["Attribute"] in all_properties:
                class_info = se.explore_class(
                    se.get_class_label_from_display_name(attribute["Attribute"])
                )
                class_info["validation_rules"] = validation_rules
                class_val_rule_edit = get_class(
                    se,
                    attribute["Attribute"],
                    description=attribute["Description"],
                    subclass_of=[attribute["Parent"]],
                    requires_dependencies=class_info["dependencies"],
                    requires_range=class_info["range"],
                    required=class_info["required"],
                    validation_rules=class_info["validation_rules"],
                )
                se.edit_schema_object_nx(class_val_rule_edit)
            else:
                # the attribute is a property
                property_info = se.explore_property(
                    se.get_property_label_from_display_name(attribute["Attribute"])
                )
                property_info["validation_rules"] = validation_rules
                property_val_rule_edit = get_property(
                    se,
                    attribute["Attribute"],
                    property_info["domain"],
                    description=property_info["description"],
                    requires_dependencies=property_info["dependencies"],
                    requires_range=property_info["range"],
                    required=property_info["required"],
                    validation_rules=property_info["validation_rules"],
                )
                se.edit_schema_object_nx(property_val_rule_edit)
            try:
                logger.debug(val + "validation rules added")
            except:
                logger.debug("Validation rules added")

        # get dependencies for this attribute, if any are specified
        requires_dependencies = attribute["DependsOn"]

        if not pd.isnull(requires_dependencies):
            for dep in requires_dependencies.strip().split(","):
                # check if dependency is a property or not
                dep = dep.strip()
                dep_is_property = dep in all_properties
                dep_label = ""
                # set dependency label based on kind of dependency: class or property
                if dep_is_property:
                    dep_label = se.get_property_label_from_display_name(dep)
                else:
                    dep_label = se.get_class_label_from_display_name(dep)

                # check if dependency is in attributes column; add it to the list if not
                if not dep.strip() in list(schema_extension["Attribute"]):
                    # if dependency is a property create a new property; else create a new class
                    if not dep_is_property:
                        # if this attribute is not a property, set it as a parent class
                        if not attribute["Attribute"] in all_properties:
                            parent = attribute["Attribute"]
                        else:
                            # this attribute is a property, set the parent to the domain class of this attribute
                            parent = se.get_class_by_property(attribute["Attribute"])
                            if not parent:
                                raise ValueError(
                                    f"Listed required dependency: {dep}, for attribute: {attribute['Attribute']} "
                                    "must have a class parent. The extension could not be added to the schema."
                                )

                        new_class = get_class(
                            se, dep, description=None, subclass_of=[parent]
                        )
                        # se.add_schema_object_nx(new_class, **rel_dict)
                        # check if attribute doesn't already exist and add it
                        if not attribute_exists(se, new_class["rdfs:label"]):
                            se.add_schema_object_nx(new_class, **rel_dict)

                    else:
                        if not attribute["Attribute"] in all_properties:
                            domain_attribute = attribute["Attribute"]
                        else:
                            # this attribute is a property, set the domain of this property to the domain class of the attribute
                            domain_attribute = se.get_class_by_property(
                                attribute["Attribute"]
                            )
                            if not domain_attribute:
                                raise ValueError(
                                    f"Listed required dependency: {dep}, must have a class parent. "
                                    "The extension could not be added to the schema."
                                )

                        description = None
                        new_property = get_property(
                            se, dep, domain_attribute, description=description
                        )
                        # check if attribute doesn't already exist and add it
                        if not attribute_exists(se, new_property["rdfs:label"]):
                            se.add_schema_object_nx(new_property, **rel_dict)

                # update required dependencies of attribute
                # if attribute is not a property then assume it is a class
                if not attribute["Attribute"] in all_properties:
                    class_info = se.explore_class(
                        se.get_class_label_from_display_name(attribute["Attribute"])
                    )
                    class_info["dependencies"].append(dep_label)
                    class_dependencies_edit = get_class(
                        se,
                        attribute["Attribute"],
                        description=attribute["Description"],
                        subclass_of=[attribute["Parent"]],
                        requires_dependencies=class_info["dependencies"],
                        requires_range=class_info["range"],
                        required=class_info["required"],
                        validation_rules=class_info["validation_rules"],
                    )
                    se.edit_schema_object_nx(class_dependencies_edit)
                else:
                    # the attribute is a property then update as a property
                    property_info = se.explore_property(
                        se.get_property_label_from_display_name(attribute["Attribute"])
                    )
                    property_info["dependencies"].append(dep_label)
                    property_dependencies_edit = get_property(
                        se,
                        attribute["Attribute"],
                        property_info["domain"],
                        description=property_info["description"],
                        requires_dependencies=property_info["dependencies"],
                        requires_range=property_info["range"],
                        required=property_info["required"],
                        validation_rules=property_info["validation_rules"],
                    )
                    se.edit_schema_object_nx(property_dependencies_edit)

                logger.debug(dep + " added to dependencies")

            # TODO check for cycles in attribute dependencies schema subgraph

        # check if the attribute requires any components
        if not pd.isnull(attribute["DependsOn Component"]):
            component_dependencies = attribute["DependsOn Component"]
        else:
            continue

        # iterate over potentially multiple dependency components
        for comp_dep in component_dependencies.strip().split(","):

            # check if a component is already defined as an attribute; if not define it in the schema
            if not comp_dep.strip() in list(schema_extension["Attribute"]):

                # component is not in csv schema so try adding it as a class with a parent Thing
                new_class = get_class(se, comp_dep, description=None)

                # check if attribute doesn't already exist in schema.org schema and add it
                # (component may not be in csv schema, but could be in the base schema we are extending)
                if not attribute_exists(se, new_class["rdfs:label"]):
                    se.add_schema_object_nx(new_class, **rel_dict)

            # update this attribute requirements to include component
            class_info = se.explore_class(
                se.get_class_label_from_display_name(attribute["Attribute"])
            )
            class_info["component_dependencies"].append(
                se.get_class_label_from_display_name(comp_dep)
            )
            class_component_dependencies_edit = get_class(
                se,
                attribute["Attribute"],
                description=class_info["description"],
                subclass_of=class_info["subClassOf"],
                requires_dependencies=class_info["dependencies"],
                requires_range=class_info["range"],
                validation_rules=class_info["validation_rules"],
                requires_components=class_info["component_dependencies"],
            )
            se.edit_schema_object_nx(class_component_dependencies_edit)

        logger.debug(comp_dep + " added to dependencies")

        # TODO check for cycles in component dependencies schema subgraph

    logger.info("Done adding requirements and value ranges to attributes")

    return se


def _get_base_schema_path(base_schema: str = None) -> str:
    """Evaluate path to base schema.

    Args:
        base_schema: Path to base data model. BioThings data model is loaded by default.

    Returns:
        base_schema_path: Path to base schema based on provided argument.
    """
    biothings_schema_path = LOADER.filename("data_models/biothings.model.jsonld")
    base_schema_path = biothings_schema_path if base_schema is None else base_schema

    return base_schema_path


def _convert_csv_to_data_model(
    schema_csv: str, base_schema: str = None
) -> SchemaExplorer:
    """Convert provided CSV spec. in CSV format to data model in JSON-LD format.

    Args:
        schema_csv: Path to CSV file containing data to be translated to
                    JSON-LD data model. Can be path to local CSV or URL.

    Returns:
        base_se: SchemaExplorer object which has updated properties
                 (base_se.schema and base_se.schema_nx).
    """
    # create data model from provided RFC
    rfc_df = load_df(schema_csv, data_model=True)

    # instantiate schema explorer
    base_se = SchemaExplorer()

    # determine base schema path
    base_schema_path = _get_base_schema_path(base_schema)

    # load base schema (BioThings)
    base_se.load_schema(base_schema_path)

    # call parser code that converts a dataframe of the RFC
    # specs. into a JSON-LD data model
    base_se = create_nx_schema_objects(rfc_df, base_se)

    return base_se