#!/usr/bin/env python3

"""extract_odf_links.py - Tool to extract links from ODF documents

Given one or more ODF documents, this tool finds links that refer to the local

filesystem, and writes their full paths to stdout.

"""

# Copyright © 2020 Brett Smith

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU Affero General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU Affero General Public License for more details.

#

# You should have received a copy of the GNU Affero General Public License

# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import argparse

import logging

import os

import sys

import urllib.parse

from pathlib import Path

from zipfile import BadZipFile

import odf.opendocument  # type:ignore[import]

import odf.text  # type:ignore[import]

from typing import (

    Iterator,

    Optional,

    Sequence,

    Set,

    TextIO,

)

from .. import cliutil

PROGNAME = 'extract-odf-links'

logger = logging.getLogger('conservancy_beancount.tools.extract_odf_links')

def parse_delimiter(arg: str) -> str:

    try:

        retval = eval('"{}"'.format(arg.replace('"', r'\"')), {})

    except SyntaxError:

        retval = None

    if isinstance(retval, str):

        return retval

    else:

        raise ValueError(f"not a valid string: {arg!r}")

def parse_arguments(arglist: Optional[Sequence[str]]=None) -> argparse.Namespace:

    parser = argparse.ArgumentParser(prog=PROGNAME)

    cliutil.add_version_argument(parser)

    cliutil.add_loglevel_argument(parser)

    parser.add_argument(

        '--delimiter', '-d',

        metavar='STR',

        type=parse_delimiter,

        default='\\n',

        help="""String to output between links. Accepts all backslash escapes

supported in Python like \\n, \\t, \\0, \\u, etc. Default '\\n'.

""")

    parser.add_argument(

        '--zero', '--null', '-z', '-0',

        action='store_const',

        dest='delimiter',

        const='\0',

        help="""Shortcut for --delimiter=\\0

""")

    parser.add_argument(

        'odf_paths',

        metavar='ODF_PATH',

        type=Path,

        nargs=argparse.ONE_OR_MORE,

        help="""ODF file(s) to extract links from. Note that %(prog)s cannot

read from stdin because it needs to know document paths to resolve links.

""")

    return parser.parse_args(arglist)

def extract_links(odf_path: Path) -> Iterator[Path]:

    odf_root = odf_path.parent.resolve()

    with odf_path.open('rb') as odf_file:

        odf_doc = odf.opendocument.load(odf_file)

    for a_elem in odf_doc.getElementsByType(odf.text.A):

        parts = urllib.parse.urlparse(a_elem.getAttribute('href') or '')

        if (parts.scheme and parts.scheme != 'file') or not parts.path:

            continue

        path = Path(urllib.parse.unquote(parts.path))

        if not path.is_absolute():

            path = (odf_path / path).resolve()

            try:

                path.relative_to(odf_root)

            except ValueError:

                logger.warning(f"link {path} is neither absolute nor relative to {odf_path}")

        yield path

def main(arglist: Optional[Sequence[str]]=None,

         stdout: TextIO=sys.stdout,

         stderr: TextIO=sys.stderr,

) -> int:

    args = parse_arguments(arglist)

    cliutil.set_loglevel(logger, args.loglevel)

    returncode = 0

    links: Set[Path] = set()

    for odf_path in args.odf_paths:

        try:

            links.update(extract_links(odf_path))

        except IOError as error:

            logger.error("error reading %s: %s", odf_path, error.strerror)

            returncode = os.EX_DATAERR

        except BadZipFile as error:

            logger.error("error parsing %s: %s", odf_path, error.args[0])

            returncode = os.EX_DATAERR

    for link in links:

        if not link.exists():

            logger.warning("path %s not found", link)

        print(link, end=args.delimiter, file=stdout)

    return returncode

entry_point = cliutil.make_entry_point(__name__, PROGNAME)

if __name__ == '__main__':

    exit(entry_point())

    version='1.7.0',

            'extract-odf-links = conservancy_beancount.tools.extract_odf_links:entry_point',

"""test_extract_odf_links.py - Unit tests for ODF link extraction"""

# Copyright © 2020  Brett Smith

#

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU Affero General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU Affero General Public License for more details.

#

# You should have received a copy of the GNU Affero General Public License

# along with this program.  If not, see <https://www.gnu.org/licenses/>.

import io

import pytest

from . import testutil

from conservancy_beancount.tools import extract_odf_links

SRC_PATH = testutil.test_path('repository/LinksReport.ods')

EXPECTED_FILE_LINKS = {

    '/repository/Projects/project-data.yml',

    str(testutil.test_path('repository/Projects/project-data.yml')),

    str(testutil.test_path('repository/Projects/Bad Link.txt')),

}

@pytest.mark.parametrize('arglist,sep', [

    (['-0'], '\0'),

    (['-d', '\\v'], '\v'),

    ([str(SRC_PATH)], '\n'),  # Test that links aren't duplicated

])

def test_extract_file_links(arglist, sep, caplog):

    arglist.append(str(SRC_PATH))

    stdout = io.StringIO()

    stderr = io.StringIO()

    exitcode = extract_odf_links.main(arglist, stdout, stderr)

    assert exitcode == 0

    assert not stderr.getvalue()

    actual = stdout.getvalue().split(sep)

    if actual and not actual[-1]:

        actual.pop()

    assert len(actual) == len(EXPECTED_FILE_LINKS)

    assert set(actual) == EXPECTED_FILE_LINKS

    assert caplog.records

    assert any(

        log.levelname == 'WARNING'

        and log.message.endswith('/Bad Link.txt not found')

        for log in caplog.records

    )