#!/usr/bin/env python3

# `ipynb_filter.py`:
# This is a git filters that strips out the outputs and
# meta data of a Jupyer notebook using `nbconvert`.
# Execute the following line in order to activate this filter:
# python ipynb_filter.py
#
# The following line should be in `.gitattributes`:
# *.ipynb filter=ipynb_filter

from nbconvert.preprocessors import Preprocessor


class RemoveMetadata(Preprocessor):
    def preprocess(self, nb, resources):
        nb.metadata = {"language_info": {"name":"python",
                                         "pygments_lexer": "ipython3"}}
        return nb, resources


if __name__ == '__main__':
    # The filter is getting activated
    import os
    git_cmd = 'git config filter.ipynb_filter.clean "jupyter nbconvert --to notebook --config ipynb_filter.py --stdin --stdout"'
    os.system(git_cmd)
else:
    # This script is used as config
    c.Exporter.preprocessors = [RemoveMetadata]
    c.ClearOutputPreprocessor.enabled = True
    c.ClearOutputPreprocessor.remove_metadata_fields = [
        "deletable", "editable", "collapsed", "scrolled"]