# -*- coding: utf8 -*-
import requests
import json
import hashlib
import base64
import hmac
import datetime
import uuid

METHOD_GET = 'GET'
METHOD_POST = 'POST'

# 官网accessKey
AK = '3d98d123d633xxxxxxxxxxx5a60d4bb3'
# 官网securityKey
SK = '173615ae4177xxxxxxxxxxxd17b1c3ed'


def hmac_sha256(secret, data):
    secret = bytearray(secret)
    data = bytearray(data)
    return hmac.new(secret, data, digestmod=hashlib.sha256).digest()


def base64_of_hmac(data):
    return base64.b64encode(data)


def get_request_uuid():
    return str(uuid.uuid1())


def get_sorted_str(data):
    """
    鉴权用的参数整理
    :param data: dict 需要整理的参数
    :return: str
    """
    sorted_data = sorted(data.items(), key=lambda item: item[0])
    str_list = map(lambda x_y: '%s=%s' % (x_y[0], x_y[1]), sorted_data)
    return '&'.join(str_list)


def build_sign(query_params, body_params, eop_date, request_uuid):
    """
    计算鉴权字段
    :param query_params: dict get请求中的参数
    :param body_params: dict post请求中的参数
    :param eop_date: str 请求时间，格式为：'%Y%m%dT%H%M%SZ'
    :return: str
    """
    # body_str = json.dumps(body_params) if body_params else ''
    body_str = json.dumps(body_params)
    body_digest = hashlib.sha256(body_str.encode('utf-8')).hexdigest()
    # 请求头中必要的两个参数
    header_str = 'ctyun-eop-request-id:%s\neop-date:%s\n' % (request_uuid, eop_date)
    # url中的参数，或get参数
    query_str = get_sorted_str(query_params)

    signature_str = '%s\n%s\n%s' % (header_str, query_str, body_digest)

    print_log(repr('signature_str is: %s' % signature_str))
    sign_date = eop_date.split('T')[0]

    # 计算鉴权密钥
    k_time = hmac_sha256(SK, eop_date)
    k_ak = hmac_sha256(k_time, AK)
    k_date = hmac_sha256(k_ak, sign_date)

    signature_base64 = base64_of_hmac(hmac_sha256(k_date, signature_str))
    # 构建请求头的鉴权字段值
    sign_header = '%s Headers=ctyun-eop-request-id;eop-date Signature=%s' % (AK, signature_base64)
    return sign_header


def get_sign_headers(query_params, body):
    """
    获取鉴权用的请求头参数
    :param query_params: dict get请求中的参数
    :param body: dict post请求中的参数
    :return:
    """
    now = datetime.datetime.now()
    eop_date = datetime.datetime.strftime(now, '%Y%m%dT%H%M%SZ')
    request_uuid = get_request_uuid()
    headers = {  # 三个鉴权用的参数
        'eop-date': eop_date,
        'ctyun-eop-request-id': request_uuid,
        'Eop-Authorization': build_sign(query_params=query_params, body_params=body, eop_date=eop_date,
                                        request_uuid=request_uuid),
    }
    return headers


def get(url, params=None, header_params=None, get_body=None):
    return execute(url, method=METHOD_GET, params=params, header_params=header_params, get_body=get_body)


def post(url, params=None, header_params=None):
    return execute(url, method=METHOD_POST, params=params, header_params=header_params)


def execute(url, method, params=None, header_params=None, get_body=None):
    get_body = get_body or {}
    params = params or {}
    header_params = header_params or {}
    query_params, body = (params, get_body) if method == METHOD_GET else ({}, params)
    headers = get_sign_headers(query_params, body)
    headers.update(header_params)

    print_log(u'url: %s' % url)
    print_log(u'请求方式: %s' % method)
    print_log(u'请求头: %s' % headers)
    print_log(u'请求参数: %s' % params)

    if method == METHOD_GET:
        res = requests.get(url, params=params, headers=headers, verify=False, json=get_body)
    else:
        res = requests.post(url, json=params, headers=headers, verify=False)

    print_log(u'返回状态码: %s' % res.status_code)
    print_log(u'返回: %s' % res.text)
    return res


def print_log(log_info):
    now = datetime.datetime.now()
    log_info = u'[%s]: %s' % (str(now), log_info)
    print log_info

# 操作类示例
post("https://ebs-global.ctapi.ctyun.cn/v4/ebs/attach",
     params={
         "resourceID": "eff436exxxxxxxxx306ab3a14530f02",
         "regionID": "41f64827xxxxxxxxxffa3a5deb5d15d",
         "instanceUUID": "xxxxxxxxx"
     })

# 查询类示例
get("https://ebs-global.ctapi.ctyun.cn/v4/ebs/info-by-name",
     params={
        "regionID": "81f7728662dd11ec810800155d307d5b",
        "name": "yue4test"
    })