# Copyright 2017 The Rudders Authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# 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 License for the specific language governing permissions and
# limitations under the License.
"""Utils file for graph analisis"""

import networkx as nx


def get_largest_connected_component(graph, verbose=False):
    connected_components = list(nx.connected_components(graph))
    if len(connected_components) == 0:
        raise ValueError("Graph is empty ergo does not have connected components")
    if verbose:
        print(f"Graph has {len(connected_components)} connected components")
    return graph.subgraph(max(connected_components, key=len))
