# Copyright 2013, Big Switch Networks, Inc.
#
# LoxiGen is licensed under the Eclipse Public License, version 1.0 (EPL), with
# the following special exception:
#
# LOXI Exception
#
# As a special exception to the terms of the EPL, you may distribute libraries
# generated by LoxiGen (LoxiGen Libraries) under the terms of your choice, provided
# that copyright and licensing notices generated by LoxiGen are not altered or removed
# from the LoxiGen Libraries and the notice provided below is (i) included in
# the LoxiGen Libraries, if distributed in source code form and (ii) included in any
# documentation for the LoxiGen Libraries, if distributed in binary form.
#
# Notice: "Copyright 2013, Big Switch Networks, Inc. This library was generated by the LoxiGen Compiler."
#
# You may not use this file except in compliance with the EPL or LOXI Exception. You may obtain
# a copy of the EPL at:
#
# http://www.eclipse.org/legal/epl-v10.html
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# EPL for the specific language governing permissions and limitations
# under the EPL.

from generic_utils import *
import c_gen.loxi_utils_legacy as loxi_utils
import loxi_globals

inheritance_roots = [
    'of_instruction',
    'of_instruction_id',
    'of_action',
    'of_action_id',
    'of_oxm',
    'of_queue_prop',
    'of_hello_elem',
    'of_table_feature_prop',
    'of_meter_band',
    'of_bsn_vport',
    'of_bsn_tlv',
]

def class_is_virtual(cls):
    """
    Returns True if cls is a virtual class
    """
    if cls.endswith("header"):
        return True
    if loxi_utils.class_is_list(cls):
        return True
    return loxi_globals.unified.class_by_name(cls).virtual

def class_is_inheritance_root(cls):
    return cls in inheritance_roots

# map from parent class name to set of subclass names
inheritance_map = dict()

def generate_maps():
    def inheritance_root(ofclass):
        if not ofclass.superclass:
            if ofclass.name in inheritance_roots:
                return ofclass
            else:
                return None
        else:
            return inheritance_root(ofclass.superclass)

    for version, protocol in loxi_globals.ir.items():
        wire_version = version.wire_version
        for ofclass in protocol.classes:
            root = inheritance_root(ofclass)
            if not root or root == ofclass:
                continue

            if root.name not in inheritance_map:
                inheritance_map[root.name] = set()
            inheritance_map[root.name].add(ofclass.name)

def sub_class_map(base_type, version):
    """
    Returns an iterable object giving the instance nameys and subclass types
    for the base_type, version values
    """
    rv = []
    if base_type not in inheritance_map:
        return rv

    for subcls in inheritance_map[base_type]:
        if not loxi_utils.class_in_version(subcls, version):
            continue
        instance = loxi_utils.class_to_instance(subcls, base_type)
        rv.append((instance, subcls))

    return rv