import io
import pytest

from ucc import *
from ucc.s3 import *
from .conftest import MULTIPART_UPLOAD_THRESHOLD, MULTIPART_PART_SIZE

TEST_FOLDER = '/test_s3'


@pytest.fixture(scope='module', autouse=True)
def set_globals(path_client):
    global c
    c = path_client


@pytest.fixture(scope='session', autouse=True)
def test_folder(request, path_client):
    c = path_client
    c.mkdir(TEST_FOLDER)

    def fin():
        c.rmdirs(TEST_FOLDER)
    request.addfinalizer(fin)
    return TEST_FOLDER


def upload_file(fp: io.BytesIO, path: str = None) -> Metadata:
    if path is None:
        path = f'{TEST_FOLDER}/upload_{time.time()}'
    meta = c.upload(path, fp)
    fp.seek(0)
    return meta


def compute_md5(fp):
    _hash = hashlib.md5()
    _compute_hash(fp, _hash)
    fp.seek(0)
    return _hash.hexdigest()


def compute_awss3_multipart_etag(fp, part_size, part_num):
    _hash = AmazonS3MultipartHasher(part_size)
    _compute_hash(fp, _hash)
    local_etag_value = _hash.hexdigest()
    return f'"{local_etag_value}-{part_num}"'


def _compute_hash(fp, hashobj, buf_size=65536):
    assert hasattr(fp, 'read')
    while True:
        data = fp.read(buf_size)
        if not data:
            break
        hashobj.update(data)
    fp.seek(0)


def test_zero_size_etag():
    fp = io.BytesIO(b"")
    meta = upload_file(fp)
    etag = meta.hash['etag']
    expected_etag = f'"{compute_md5(fp)}"'

    assert expected_etag == etag, f'Expected ETag: {expected_etag}, Actual ETag: {etag}'


def test_normal_upload_etag():
    fp = io.BytesIO(b".")
    meta = upload_file(fp)
    etag = meta.hash['etag']
    expected_etag = f'"{compute_md5(fp)}"'

    assert expected_etag == etag, f'Expected ETag: {expected_etag}, Actual ETag: {etag}'


def test_multipart_upload_etag():
    fp = io.BytesIO(b"."*(MULTIPART_UPLOAD_THRESHOLD+1))
    meta = upload_file(fp)
    etag = meta.hash['etag']
    assert '-' in etag, f'ETag: {etag} do not contains "-"'
    _, part_num = etag.strip('"').split('-')
    expected_etag = compute_awss3_multipart_etag(fp, MULTIPART_PART_SIZE, part_num)

    assert expected_etag == etag, f'Expected ETag: {expected_etag}, Actual ETag: {etag}'

def test_normal_upload_etag_is_equal_to_list_etag():
    fp = io.BytesIO(b".")
    meta = upload_file(fp)
    upload_etag = meta.hash['etag']
    list_etag = get_etag_from_list(meta.path)

    assert upload_etag == list_etag, f'{upload_etag} is not equal to {list_etag}'


def get_etag_from_list(path):
    for m in c.listdir(os.path.dirname(path)):
        if m.path == path:
            return m.hash['etag']


def test_multipart_upload_etag_is_equal_to_list_etag():
    fp = io.BytesIO(b"."*(MULTIPART_UPLOAD_THRESHOLD+1))
    meta = upload_file(fp)
    upload_etag = meta.hash['etag']
    list_etag = get_etag_from_list(meta.path)

    assert upload_etag == list_etag, f'{upload_etag} is not equal to {list_etag}'


def test_unicode_delete_multi():
    path = '/Ã'
    result = c.delete_multi([path])
    assert path == result['deleted'][0]