# Copyright (C) 2016-2023 RhodeCode GmbH
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License, version 3
# (only), as published by the Free Software Foundation.
#
# 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 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 <http://www.gnu.org/licenses/>.
#
# This program is dual-licensed. If you wish to learn more about the
# RhodeCode Enterprise Edition, including its added features, Support services,
# and proprietary license terms, please see https://rhodecode.com/licenses/

import io
import uuid
import pathlib
import s3fs

from rhodecode.lib.hash_utils import sha256_safe
from rhodecode.apps.file_store import config_keys


file_store_meta = None


def get_filestore_config(config) -> dict:

    final_config = {}

    for k, v in config.items():
        if k.startswith('file_store'):
            final_config[k] = v

    return final_config


def get_filestore_backend(config, always_init=False):
    """

    usage::
        from rhodecode.apps.file_store import get_filestore_backend
        f_store = get_filestore_backend(config=CONFIG)

    :param config:
    :param always_init:
    :return:
    """

    global file_store_meta
    if file_store_meta is not None and not always_init:
        return file_store_meta

    config = get_filestore_config(config)
    backend = config[config_keys.backend_type]

    match backend:
        case config_keys.backend_legacy_filesystem:
            # Legacy backward compatible storage
            from rhodecode.apps.file_store.backends.filesystem_legacy import LegacyFileSystemBackend
            d_cache = LegacyFileSystemBackend(
                settings=config
            )
        case config_keys.backend_filesystem:
            from rhodecode.apps.file_store.backends.filesystem import FileSystemBackend
            d_cache = FileSystemBackend(
                settings=config
            )
        case config_keys.backend_objectstore:
            from rhodecode.apps.file_store.backends.objectstore import ObjectStoreBackend
            d_cache = ObjectStoreBackend(
                settings=config
            )
        case _:
            raise ValueError(
                f'file_store.backend.type only supports "{config_keys.backend_types}" got {backend}'
            )

    cache_meta = d_cache
    return cache_meta


def splitext(filename):
    final_ext = []
    for suffix in pathlib.Path(filename).suffixes:
        if not suffix.isascii():
            continue

        suffix = " ".join(suffix.split()).replace(" ", "")
        final_ext.append(suffix)
    ext = ''.join(final_ext)
    return filename, ext


def get_uid_filename(filename, randomized=True):
    """
    Generates a randomized or stable (uuid) filename,
    preserving the original extension.

    :param filename: the original filename
    :param randomized: define if filename should be stable (sha1 based) or randomized
    """

    _, ext = splitext(filename)
    if randomized:
        uid = uuid.uuid4()
    else:
        store_suffix = "store"
        hash_key = f'{filename}.{store_suffix}'
        uid = uuid.uuid5(uuid.NAMESPACE_URL, hash_key)
    return str(uid) + ext.lower()


def bytes_to_file_obj(bytes_data):
    return io.BytesIO(bytes_data)


class ShardFileReader:

    def __init__(self, file_like_reader):
        self._file_like_reader = file_like_reader

    def __getattr__(self, item):
        if isinstance(self._file_like_reader, s3fs.core.S3File):
            match item:
                case 'name':
                    # S3 FileWrapper doesn't support name attribute, and we use it
                    return self._file_like_reader.full_name
                case _:
                    return getattr(self._file_like_reader, item)
        else:
            return getattr(self._file_like_reader, item)


def archive_iterator(_reader, block_size: int = 4096 * 512):
    # 4096 * 64 = 64KB
    while 1:
        data = _reader.read(block_size)
        if not data:
            break
        yield data