from core.builtin_concepts import ParserResultConcept, ReturnValueConcept
from core.concept import Concept
from evaluators.BaseEvaluator import OneReturnValueEvaluator
from parsers.DefaultParser import DefConceptNode
import logging

from parsers.PythonParser import PythonGetNamesVisitor, PythonNode

log = logging.getLogger(__name__)


class AddConceptEvaluator(OneReturnValueEvaluator):
    """
    Used to add a new concept
    """
    NAME = "AddNewConcept"

    def __init__(self):
        super().__init__(self.NAME, 50)

    def matches(self, context, return_value):
        return return_value.status and \
               isinstance(return_value.value, ParserResultConcept) and \
               isinstance(return_value.value.value, DefConceptNode)

    def eval(self, context, return_value):
        log.debug("Adding a new concept")
        def_concept_node = return_value.value.value
        sheerka = context.sheerka

        # validate the node
        props_found = set()

        concept = Concept(def_concept_node.name)
        for prop in ("where", "pre", "post", "body"):
            # put back the sources
            part_ret_val = getattr(def_concept_node, prop)
            if not isinstance(part_ret_val, ReturnValueConcept) or not part_ret_val.status:
                continue  # not quite sure that it's possible

            # update the parts
            source = self.get_source(part_ret_val)
            setattr(concept, prop, source)

            # try to find what can be a property
            for p in self.get_props(part_ret_val):
                props_found.add(p)

        # Auto discovered properties must be referenced in the name
        # Note that with this method, the variables will be created in the order of appearance
        for token in def_concept_node.name.tokens:
            if token.value in props_found:
                concept.set_prop(token.value, None)

        # finish initialisation
        concept.init_key(def_concept_node.name.tokens)
        concept.add_codes(def_concept_node.get_codes())

        ret = sheerka.create_new_concept(context, concept)
        return sheerka.ret(self.name, ret.status, ret.value, parents=[return_value])

    @staticmethod
    def get_source(ret_value):
        return ret_value.value.source if isinstance(ret_value.value, ParserResultConcept) \
            else ret_value.value.name

    @staticmethod
    def get_props(ret_value):
        if isinstance(ret_value.value, ParserResultConcept) and isinstance(ret_value.value.value, PythonNode):
            get_names_visitor = PythonGetNamesVisitor()
            get_names_visitor.visit(ret_value.value.value.ast_)
            return get_names_visitor.names

        if isinstance(ret_value.value, Concept):
            return list(ret_value.value.props.keys())

        return []