import oss2

auth = oss2.Auth(settings.OSS_ACCESS_KEY_ID, settings.OSS_ACCESS_KEY_SECRET)
bucket = oss2.Bucket(auth, settings.OSS_ENDPOINT, settings.OSS_BUCKET_NAME)


def CalculateFolderLength(bucket, folder):
    length = 0
    for obj in oss2.ObjectIterator(bucket, prefix=folder, max_keys=1000):
        length 
 
+= obj.size
    return length


# ObjectIterator 會列舉所有的檔案或目錄，但每次迴圈列舉100個，可以通過 max_keys 來調整數目，最大值為 1000
def get_size():
    size = 0
    for obj in oss2.ObjectIterator(bucket, delimiter='/'):
        if obj.is_prefix():  # 資料夾
            length = CalculateFolderLength(bucket, obj.key)
            size += length
        
 
else:
            size += obj.size
    return size


def StrOfSize(size):
    '''
    遞迴實現，精確為最大單位值 + 小數點後三位
    '''
    def strofsize(integer, remainder, level):
        if integer >= 1024:
            remainder = integer % 1024
            integer //= 1024
            level += 1
            return strofsize(integer, remainder, level)
        
 
else:
            return integer, remainder, level

    units = ['B', 'KB', 'MB', 'GB', 'TB', 'PB']
    integer, remainder, level = strofsize(size, 0, 0)
    if level+1 > len(units):
        level = -1
    return ( '{}.{:>03d} {}'.format(integer, remainder, units[level]) )


print(StrOfSize(get_size()))