"""Pylint plugin for cubicweb"""

from astroid import MANAGER, InferenceError, nodes, scoped_nodes, ClassDef, FunctionDef

from astroid.builder import AstroidBuilder

def turn_function_to_class(node):

    """turn a Function node into a Class node (in-place)"""

    node.__class__ = ClassDef

    node.bases = ()

    # remove return nodes so that we don't get warned about 'return outside

    # function' by pylint

    for rnode in node.nodes_of_class(nodes.Return):

        rnode.parent.body.remove(rnode)

    # that seems to be enough :)

def cubicweb_transform(module):

    # handle objectify_predicate decorator (and its former name until bw compat

    # is kept). Only look at module level functions, should be enough.

    for assnodes in module.locals.values():

        for node in assnodes:

            if isinstance(node, FunctionDef) and node.decorators:

                for decorator in node.decorators.nodes:

                    try:

                        for infered in decorator.infer():

                            if infered.name in ('objectify_predicate', 'objectify_selector'):

                                turn_function_to_class(node)

                                break

                        else:

                            continue

                        break

                    except InferenceError:

                        continue

    # add yams base types into 'yams.buildobjs', astng doesn't grasp globals()

    # magic in there

    if module.name == 'yams.buildobjs':

        from yams import BASE_TYPES

        for etype in BASE_TYPES:

            module.locals[etype] = [scoped_nodes.Class(etype, None)]

    # add data() to uiprops module

    if module.name.split('.')[-1] == 'uiprops':

        fake = AstroidBuilder(MANAGER).string_build('''

def data(string):

  return u''

''')

        module.locals['data'] = fake.locals['data']

def register(linter):

    """called when loaded by pylint --load-plugins, nothing to do here"""

    MANAGER.register_transform(nodes.Module, cubicweb_transform)