"""
For dynamic completion.
"""
import parsing
import evaluate

# This is something like the sys.path, but only for searching params. It means
# that this is the order in which Jedi searches params.
search_param_modules = ['.']


class ParamListener(object):
    """
    This listener is used to get the params for a function.
    """
    def __init__(self):
        self.param_possibilities = []

    def execute(self, params):
        self.param_possibilities.append(params)


def search_params(param):
    """
    This is a dynamic search for params. If you try to complete a type:
    >>> def func(foo):
    >>>     # here is the completion
    >>>     foo
    >>> func(1)
    >>> func("")

    It is not known what the type is, because it cannot be guessed with
    recursive madness. Therefore one has to analyse the statements that are
    calling the function, as well as analyzing the incoming params.
    """
    def get_params_for_module(module):
        """
        Returns the values of a param, or an empty array.
        """
        try:
            possible_stmts = current_module.used_names[func_name]
        except KeyError:
            return []

        for stmt in possible_stmts:
            evaluate.follow_statement(stmt)

        result = []
        for params in listener.param_possibilities:
            for p in params:
                if str(p) == param_name:
                    result += evaluate.follow_statement(p.parent)
        #print listener.param_possibilities, param, result

        return result

    func = param.get_parent_until(parsing.Function)

    # add the listener
    listener = ParamListener()
    func.listeners.add(listener)

    func_name = str(func.name)

    # get the param name
    if param.assignment_details:
        arr = param.assignment_details[0][1]
    else:
        arr = param.get_assignment_calls()
    offset = 1 if arr[0][0] in ['*', '**'] else 0
    param_name = str(arr[0][offset].name)

    current_module = param.get_parent_until()

    result = get_params_for_module(current_module)

    # TODO check other modules
    # cleanup: remove the listener
    func.listeners.remove(listener)

    return result