# -*- coding: utf-8 -*-
import hashlib
import hmac
import json
import sys
import time
import base64
from datetime import datetime
if sys.version_info[0] <= 2:
    from httplib import HTTPSConnection
else:
    from http.client import HTTPSConnection


def sign(key, msg):
    return hmac.new(key, msg.encode("utf-8"), hashlib.sha256).digest()


with open("C:/Users/ec-users/Downloads/test.m4a", "rb") as f:
    content = f.read()
    encoded_audio = base64.b64encode(content)

# 在平台上查找对应key
secret_id = ""
secret_key = ""
token = ""

service = "asr"
host = "asr.tencentcloudapi.com"
region = ""
version = "2019-06-14"
action = "CreateRecTask"
payload = '{\"EngineModelType\":\"16k_zh\",\"ChannelNum\":1,\"ResTextFormat\":0,\"SourceType\":1,\"Data\":\"' + \
    encoded_audio.decode("utf8") + '\"}'
params = json.loads(payload)
endpoint = "https://asr.tencentcloudapi.com"
algorithm = "TC3-HMAC-SHA256"
timestamp = int(time.time())
date = datetime.utcfromtimestamp(timestamp).strftime("%Y-%m-%d")

# ************* 步骤 1：拼接规范请求串 *************
http_request_method = "POST"
canonical_uri = "/"
canonical_querystring = ""
ct = "application/json; charset=utf-8"
canonical_headers = "content-type:%s\nhost:%s\nx-tc-action:%s\n" % (
    ct, host, action.lower())
signed_headers = "content-type;host;x-tc-action"
hashed_request_payload = hashlib.sha256(payload.encode("utf-8")).hexdigest()
canonical_request = (http_request_method + "\n" +
                     canonical_uri + "\n" +
                     canonical_querystring + "\n" +
                     canonical_headers + "\n" +
                     signed_headers + "\n" +
                     hashed_request_payload)

# ************* 步骤 2：拼接待签名字符串 *************
credential_scope = date + "/" + service + "/" + "tc3_request"
hashed_canonical_request = hashlib.sha256(
    canonical_request.encode("utf-8")).hexdigest()
string_to_sign = (algorithm + "\n" +
                  str(timestamp) + "\n" +
                  credential_scope + "\n" +
                  hashed_canonical_request)

# ************* 步骤 3：计算签名 *************
secret_date = sign(("TC3" + secret_key).encode("utf-8"), date)
secret_service = sign(secret_date, service)
secret_signing = sign(secret_service, "tc3_request")
signature = hmac.new(secret_signing, string_to_sign.encode(
    "utf-8"), hashlib.sha256).hexdigest()

# ************* 步骤 4：拼接 Authorization *************
authorization = (algorithm + " " +
                 "Credential=" + secret_id + "/" + credential_scope + ", " +
                 "SignedHeaders=" + signed_headers + ", " +
                 "Signature=" + signature)

# ************* 步骤 5：构造并发起请求 *************
headers = {
    "Authorization": authorization,
    "Content-Type": "application/json; charset=utf-8",
    "Host": host,
    "X-TC-Action": action,
    "X-TC-Timestamp": timestamp,
    "X-TC-Version": version
}
if region:
    headers["X-TC-Region"] = region
if token:
    headers["X-TC-Token"] = token

try:
    req = HTTPSConnection(host)
    req.request("POST", "/", headers=headers, body=payload.encode("utf-8"))
    resp = req.getresponse()
    print(resp.read())
except Exception as err:
    print(err)