# -*- coding: utf-8 -*-
'''
声明：
这个函数针对文件和文件夹命名编码是如下格式：
1. mac/linux 系统， 默认是utf-8
2. windows 系统， 默认是gb2312， 也可以是utf-8
对于其他编码，我们这里尝试使用chardet这个库进行编码判断，但是这个并不能保证100% 正确，
建议用户先调试函数，如果有必要再改写函数，并保证调试通过。
Statement:
This function names and encodes files and folders as follows:
1. MAC/Linux system, default is utf-8
2. For Windows, the default is gb2312 or utf-8
For other encodings, we try to use the chardet library for coding judgment here, 
but this is not guaranteed to be 100% correct. 
If necessary to rewrite this function, and ensure that the debugging pass
'''
import helper
import oss2
import json
import os
import time
import logging
import chardet
import concurrent.futures
"""
When a source/ prefix object is placed in an OSS, it is hoped that the object will be decompressed and then stored in the OSS as processed/ prefixed.
For example, source/a.zip will be processed as processed/a/... 
"Source /", "processed/" can be changed according to the user's requirements.
"""
# Close the info log printed by the oss SDK
logging.getLogger("oss2.api").setLevel(logging.ERROR)
logging.getLogger("oss2.auth").setLevel(logging.ERROR)
LOGGER = logging.getLogger()
# a decorator for print the excute time of a function
def print_excute_time(func):
    def wrapper(*args, **kwargs):
        local_time = time.time()
        ret = func(*args, **kwargs)
        LOGGER.info('current Function [%s] excute time is %.2f' %
                    (func.__name__, time.time() - local_time))
        return ret
    return wrapper
def get_zipfile_name(origin_name):  # 解决中文乱码问题
    name = origin_name
    try:
        name_bytes = origin_name.encode(encoding="cp437")
    except:
        name_bytes = origin_name.encode(encoding="utf-8")
    # the string to be detect is long enough, the detection result accuracy is higher
    detect = chardet.detect(name_bytes)
    confidence = detect["confidence"]
    detect_encoding = detect["encoding"]
    if confidence > 0.75 and (detect_encoding.lower() in ["gb2312", "gbk", "gb18030", "ascii", "utf-8"]):
        try:
            if detect_encoding.lower() in ["gb2312", "gbk", "gb18030"]:
                detect_encoding = "gb18030"
            name = name_bytes.decode(detect_encoding)
        except:
            name = name_bytes.decode(encoding="gb18030")
    else:
        try:
            name = name_bytes.decode(encoding="gb18030")
        except:
            name = name_bytes.decode(encoding="utf-8")
    # fix windows \\ as dir segment
    name = name.replace("\\", "/")
    return name
@print_excute_time
def handler(event, context):
    """
    The object from OSS will be decompressed automatically .
    param: event:   The OSS event json string. Including oss object uri and other information.
        For detail info, please refer https://help.aliyun.com/document_detail/70140.html?spm=a2c4g.11186623.6.578.5eb8cc74AJCA9p#OSS
    param: context: The function context, including credential and runtime info.
        For detail info, please refer to https://help.aliyun.com/document_detail/56316.html#using-context
    """
    evt_lst = json.loads(event)
    creds = context.credentials
    auth = oss2.StsAuth(
        creds.access_key_id,
        creds.access_key_secret,
        creds.security_token)
    evt = evt_lst['events'][0]
    bucket_name = evt['oss']['bucket']['name']
    endpoint = 'oss-' + evt['region'] + '-internal.aliyuncs.com'
    bucket = oss2.Bucket(auth, endpoint, bucket_name)
    object_name = evt['oss']['object']['key']
    if "ObjectCreated:PutSymlink" == evt['eventName']:
        object_name = bucket.get_symlink(object_name).target_key
        if object_name == "":
            raise RuntimeError('{} is invalid symlink file'.format(
                evt['oss']['object']['key']))
    file_type = os.path.splitext(object_name)[1]
    if file_type != ".zip":
        raise RuntimeError('{} filetype is not zip'.format(object_name))
    LOGGER.info("start to decompress zip file = {}".format(object_name))
    lst = object_name.split("/")
    zip_name = lst[-1]
    PROCESSED_DIR = os.environ.get("PROCESSED_DIR", "")
    RETAIN_FILE_NAME = os.environ.get("RETAIN_FILE_NAME", "")
    if PROCESSED_DIR and PROCESSED_DIR[-1] != "/":
        PROCESSED_DIR += "/"
    if RETAIN_FILE_NAME == "false":
        newKey = PROCESSED_DIR
    else:
        newKey = PROCESSED_DIR + zip_name
    zip_fp = helper.OssStreamFileLikeObject(bucket, object_name)
    newKey = newKey.replace(".zip", "/")
    with helper.zipfile_support_oss.ZipFile(zip_fp) as zip_file:
        with concurrent.futures.ThreadPoolExecutor() as executor:
            futures = []
            for name in zip_file.namelist():
                with zip_file.open(name) as file_obj:
                    name = get_zipfile_name(name)
                    new_object_key = newKey + name
                    futures.append(executor.submit(bucket.put_object, new_object_key, file_obj))
            # 等待所有任务完成
            concurrent.futures.wait(futures)