#! /usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright 2014 Hamilton Kibbe <ham@hamiltonkib.be>

# 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.


def read(filename):
    """ Read a gerber or excellon file and return a representative object.

    Parameters
    ----------
    filename : string
        Filename of the file to read.

    Returns
    -------
    file : CncFile subclass
        CncFile object representing the file, either GerberFile or
        ExcellonFile. Returns None if file is not an Excellon or Gerber file.
    """
    import gerber
    import excellon
    from utils import detect_file_format
    fmt = detect_file_format(filename)
    if fmt == 'rs274x':
        return gerber.read(filename)
    elif fmt == 'excellon':
        return excellon.read(filename)
    else:
        return None