"""
    Python setup.py utilities
    ~~~~~~~~~~~~~~~~~~~~~~~~~

    Generate ReStructuredText README from README.creole.
    Usable for other python packages, too.

    More information:
        https://github.com/jedie/python-creole/wiki/Use-In-Setup

    :copyleft: 2011-2020 by the python-creole team, see AUTHORS for more details.
    :license: GNU GPL v3 or above, see LICENSE for more details.
"""

import codecs
import datetime
import os
import sys
import warnings
from pathlib import Path

from creole import creole2html, html2rest
from creole.shared.unknown_tags import raise_unknown_node, transparent_unknown_nodes


RAISE_ERRORS_ARGS = (
    'check', 'register', 'sdist', 'bdist', 'upload',
    '--long-description', '--restructuredtext',
)


def should_raise_errors():
    """
    Raise only errors, if one of RAISE_ERRORS_ARGS is in sys.argv
    or if no argument presents.
    """
    if len(sys.argv) == 1:
        return True

    for arg in RAISE_ERRORS_ARGS:
        if arg in sys.argv:
            return True
    return False


def get_long_description(package_root, filename='README.creole', raise_errors=None):
    """ read README file and convert it on-the-fly to ReStructuredText. """

    warnings.warn('get_long_description() will be removed in the future', DeprecationWarning)

    if raise_errors is None:
        raise_errors = should_raise_errors()

    if raise_errors:
        sys.stderr.write('Test creole2rest and raise an error, if rendering failed...\n')
        # raise a error if a unknown node found
        unknown_emit = raise_unknown_node
    else:
        # ignore unknown nodes
        unknown_emit = transparent_unknown_nodes

    filepath = os.path.join(package_root, filename)
    long_description_origin = ''
    try:
        # Read creole README
        f = codecs.open(filepath, 'r', encoding='utf-8')
        long_description_origin = f.read().strip()
        f.close()

        # convert creole into html
        long_description_html = creole2html(long_description_origin)

        # convert html to ReSt
        long_description_rest = html2rest(
            long_description_html,
            emitter_kwargs={'unknown_emit': unknown_emit}
        )
    except Exception:
        if raise_errors:
            raise
        # Don't raise the error e.g. in ./setup install process
        evalue = sys.exc_info()[1]
        long_description_rest = f'[Error: {evalue}]\n{long_description_origin}'
    else:
        if raise_errors:
            # Test created ReSt code like PyPi does it.
            from creole.rest_tools.pypi_rest2html import pypi_rest2html
            try:
                pypi_rest2html(long_description_rest)
            except SystemExit as e:
                msg = f'Error creole2rest self test failed: rest2html() exist with status code: {e.args[0]}\n'
                sys.stderr.write(msg)
                sys.exit(msg)
            except Exception as e:
                sys.exit(f'ReSt2html error: {e}')
            else:
                if 'check' in sys.argv:
                    print('Generating creole to ReSt to html, ok.')

    return long_description_rest


def update_rst_readme(package_root, filename='README.creole'):
    """
    Generate README.rst from README.creole
    """
    assert isinstance(package_root, Path)
    assert package_root.is_dir(), f'Directory not found: {package_root}'
    creole_readme_path = Path(package_root, filename)
    assert creole_readme_path.is_file(), f'File not found: {creole_readme_path}'

    rest_readme_path = creole_readme_path.with_suffix('.rst')
    print(
        f'Generate {rest_readme_path.name} from {creole_readme_path.name}',
        end='...', flush=True
    )

    with creole_readme_path.open('r') as f:
        creole_readme = f.read().strip()

    # convert creole into html
    html_readme = creole2html(creole_readme)

    # convert html to ReSt
    rest_readme = html2rest(
        html_readme,
        emitter_kwargs={
            'unknown_emit': raise_unknown_node  # raise a error if a unknown node found
        }
    )

    with rest_readme_path.open('w') as f:
        f.write(rest_readme)

        # Add a note about generation with modification time from source:

        f.write('\n\n------------\n\n')

        modification_time = creole_readme_path.stat().st_mtime
        dt = datetime.datetime.fromtimestamp(modification_time)
        dt = dt.replace(microsecond=0)
        dt = dt.isoformat(sep=' ')
        f.write(f'``Note: this file is generated from {filename} {dt} with "python-creole"``')

    print('done.')
    return rest_readme_path


def update_creole_rst_readme():
    return update_rst_readme(
        package_root=Path(__file__).parent.parent,
        filename='README.creole'
    )


if __name__ == '__main__':
    update_creole_rst_readme()