# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
"""Helper to create tarballs.
"""
import copy
import glob
import os
import tarfile

from condprof import progress
from condprof.util import TASK_CLUSTER


def _tarinfo2mem(tar, tarinfo):
    metadata = copy.copy(tarinfo)
    try:
        data = tar.extractfile(tarinfo)
        if data is not None:
            data = data.read()
    except Exception:
        data = None

    return metadata, data


class Archiver(object):
    def __init__(self, scenario, profile_dir, archives_dir):
        self.profile_dir = profile_dir
        self.archives_dir = archives_dir
        self.scenario = scenario

    def _strftime(self, date, template="-%Y-%m-%d-hp.tar.gz"):
        return date.strftime(self.scenario + template)

    def _get_archive_path(self, when):
        archive = self._strftime(when)
        return os.path.join(self.archives_dir, archive), archive

    def create_archive(self, when, iterator=None):
        if iterator is None:

            def _files(tar):
                files = glob.glob(os.path.join(self.profile_dir, "*"))
                yield len(files)
                for filename in files:
                    try:
                        tar.add(filename, os.path.basename(filename))
                        yield filename
                    except FileNotFoundError:  # NOQA
                        # locks and such
                        pass

            iterator = _files

        if isinstance(when, str):
            archive = when
        else:
            archive, __ = self._get_archive_path(when)

        with tarfile.open(archive, "w:gz", dereference=True) as tar:
            it = iterator(tar)
            size = next(it)
            with progress.Bar(expected_size=size) as bar:
                for filename in it:
                    if not TASK_CLUSTER:
                        bar.show(bar.last_progress + 1)

        return archive

    def _read_tar(self, filename):
        files = {}
        with tarfile.open(filename, "r:gz") as tar:
            for tarinfo in tar:
                files[tarinfo.name] = _tarinfo2mem(tar, tarinfo)
        return files