oval_graph.oval_tree.oval_node

Complexity

Total Complexity

50

Size/Duplication

Total Lines	247
Duplicated Lines	0 %

Test Coverage

Coverage

97.12%

Importance

Changes

0

12 Methods

Rating	Name	Duplication	Size	Complexity
A	OvalNode.add_to_tree()	0	18	2
A	OvalNode.__repr__()	0	2	1
C	OvalNode._get_result_counts()	0	25	11
C	OvalNode.evaluate_tree()	0	33	10
A	OvalNode.add_child()	0	15	2
B	OvalNode.find_node_with_id()	0	18	6
A	OvalNode.change_tree_value()	0	26	2
A	OvalNode._validate_negation()	0	5	2
A	OvalNode.__init__()	0	40	4
A	OvalNode._validate_type()	0	6	2
A	OvalNode._check_missing_children_for_operator()	0	4	3
A	OvalNode._validate_value()	0	22	5

from .evaluate import (is_notapp_result, oval_operator_and, oval_operator_one,
                       oval_operator_or, oval_operator_xor)


class OvalNode():
    """The Oval Node object is one node of the OVAL tree.
       The graphic representation of the OVAL tree is the OVAL graph.

    Attributes:
        node_id (str): id of node
        node_type (str): type node
        value (str): value of node for operator and, or, one etc... and for value true,
        false, error etc...
        negation (bool): value indicating whether the node is negated
        comment (str): some comment about node
        tag (str): tag specifies if the node represents OVAL test,
        OVAL definition or XCCDF rule
        test_result_details (dict|None): information about test
        children ([OvalNode]): children of node
    """

    def __init__(self, **kwargs):
        """This metode construct OvalNode and validate values of parameteres.

        Required args:
            node_id (str|int): identifies node
            node_type (str): type of node (value or operator)
            value (str): value of node

        Optional args:
            negation (bool): value indicating whether the node is negated (empty eq False)
            comment (str): text about node (empty eq None)
            tag (str): tag specifies if the node represents OVAL test,
            OVAL definition or XCCDF rule (empty eq None)
            test_result_details (dict|None): information about test (empty eq None)
            children ([OvalNode]): array of children of node (empty eq empty array)

        Raises:
            KeyError, TypeError, ValueError
        """
        try:
            self.node_id = kwargs['node_id']
            self.node_type = self._validate_type(kwargs['node_type'])
            self.value = self._validate_value(self.node_type, kwargs['value'])

            self._check_missing_children_for_operator(
                kwargs.get('children', None))
            self.negation = self._validate_negation(
                kwargs.get('negation', False))
        except KeyError as key_error:
            raise Exception("Missing required argument!") from key_error

        self.comment = kwargs.get('comment', None)
        self.tag = kwargs.get('tag', None)
        self.test_result_details = kwargs.get('test_result_details', None)

        input_children = kwargs.get('children', None)
        self.children = []
        if input_children:
            for child in input_children:
                self.add_child(child)

    @staticmethod
    def _validate_negation(input_negation):
        if not isinstance(input_negation, bool):
            raise TypeError("Wrong value of negation argument!")
        return input_negation

    @staticmethod
    def _validate_type(input_node_type):
        node_type = input_node_type.lower()
        if node_type not in ("value", "operator"):
            raise TypeError("Wrong value of node_type argument!")
        return node_type

    @staticmethod
    def _validate_value(input_node_type, input_value):
        value = input_value.lower()

        allowed_values = [
            "true",
            "false",
            "error",
            "unknown",
            "noteval",
            "notappl"]
        allowed_operators = ["or", "and", "one", "xor"]

        if input_node_type == "value" and value not in allowed_values:
            raise TypeError(
                "Wrong value of argument value for value node!")

        if input_node_type == "operator" and value not in allowed_operators:
            raise TypeError(
                "Wrong value of argument value for operator node!")

        return value

    def _check_missing_children_for_operator(self, children):
        if children is None and self.node_type == "operator":
            raise ValueError(
                "The operator node must have a child!")

    def __repr__(self):
        return self.value

    def add_child(self, node):
        """Adds a OvalNode (node) as child of OvalNode.

        Args:
            node (OvalNode): New node

        Raises:
            ValueError
        """
        if self.node_type == "operator":
            assert isinstance(node, OvalNode)
            self.children.append(node)
            return
        raise ValueError(
            "The value node cannot contain any child!")

    def _get_result_counts(self):
        result = {
            'true_cnt': 0,
            'false_cnt': 0,
            'error_cnt': 0,
            'unknown_cnt': 0,
            'noteval_cnt': 0,
            'notappl_cnt': 0
        }

        for child in self.children:
            if child.value == 'true' and not child.negation:
                result['true_cnt'] += 1
            elif child.value == 'true' and child.negation:
                result['false_cnt'] += 1
            elif child.value == 'false' and not child.negation:
                result['false_cnt'] += 1
            elif child.value == 'false' and child.negation:
                result['true_cnt'] += 1
            else:
                if child.node_type == "operator":
                    result[child.evaluate_tree() + "_cnt"] += 1
                else:
                    result[child.value + "_cnt"] += 1
        return result

    def evaluate_tree(self):
        """Evaluates the entire OVAL tree.

        Returns:
            str. return values::

                true
                false
                error
                unknown
                noteval
                notappl
        """
        result = self._get_result_counts()
        out_result = None
        if is_notapp_result(result):
            out_result = "notappl"
        else:
            if self.value == "or":
                out_result = oval_operator_or(result)
            elif self.value == "and":
                out_result = oval_operator_and(result)
            elif self.value == "one":
                out_result = oval_operator_one(result)
            elif self.value == "xor":
                out_result = oval_operator_xor(result)

        if out_result == 'true' and self.negation:
            out_result = 'false'
        elif out_result == 'false' and self.negation:
            out_result = 'true'

        return out_result

    def find_node_with_id(self, node_id):
        """Finds an OVAL tree node by ID.

        Args:
            node_id (str): ID of node

        Returns:
            OvalNode or None.
        """
        if self.node_id == node_id:
            return self
        for child in self.children:
            if child.node_id == node_id:
                return child
        for child in self.children:
            if child.children != []:
                return child.find_node_with_id(node_id)
        return None

    def add_to_tree(self, node_id, new_node):
        """Adds a OvalNode (new_node) below OvalNode with node_id.

        Args:
            node_id (str): ID of node
            newNode (OvalNode): New node

        Returns:
            bool. The return values::

                true -- Success!
                false -- Not found.
        """
        node = self.find_node_with_id(node_id)
        if node is not None:
            node.add_child(new_node)
            return True
        return False

    def change_tree_value(self, node_id, value):
        """Changes the value of OvalNode with node_id.

        Args:
            node_id (str): ID of node
            value (str): value of node::

                true
                false
                error
                unknown
                noteval
                notappl

        Returns:
            bool. The return values::

                true -- Success!
                false -- Not found.
        """
        node = self.find_node_with_id(node_id)
        if node is not None:
            self._validate_value(node.node_type, value)
            node.value = value
            return True
        return False