# coding: utf-8
from urllib.request import quote
import hashlib, hmac
import base64
import sys
import datetime
import webbrowser

##argv = sys.argv
##argc = len(argv)
##if (argc < 2):
##    print('enter ean code')
##    quit()

#リクエスト項目列挙1
service='Service=AWSECommerceService'
key1='AWSAccessKeyId=xxxxxxxxxxxxxxxxxxxxxxx'
key2='xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx'
operation='Operation=ItemLookup'
version='Version=2010-10-01'
response='ResponseGroup=Medium'
searchindex='SearchIndex=All'
sign_head='GET\necs.amazonaws.jp\n/onca/xml\n'

#タイムスタンプ生成
ymd=datetime.datetime.utcnow().strftime("Timestamp=%Y-%m-%d")
hms=datetime.datetime.utcnow().strftime("T%H:%M:%SZ")
hms=quote(hms)
timestamp=ymd+hms

#リクエスト項目列挙2
idtype='IdType=EAN'
itemid='ItemId=%s' % 9784003361726 #EAN code
request=[timestamp, service, operation, version, response, idtype, itemid, searchindex]

#署名作成のためにソート、文字列連結
req_sorted =sorted(request)
req_joined=key1+'&'+'&'.join(req_sorted)
req_joined2=sign_head+req_joined

#署名作成
hmac_digest =hmac.new(key2.encode('utf-8'),req_joined2.encode('utf-8'),hashlib.sha256).digest()
base64_encoded = base64.b64encode(hmac_digest)
result = quote(base64_encoded)

#リクエスト作成
reqstr='http://ecs.amazonaws.jp/onca/xml?'+req_joined+'&Signature='+result
print(reqstr)

webbrowser.open_new_tab(reqstr)