from __future__ import print_function
import boto3 
import json
import botocore.exceptions as exceptions
import urllib3
SUCCESS = "SUCCESS"
FAILED = "FAILED"
http = urllib3.PoolManager()
def send(event, context, responseStatus, responseData, reason=None, physicalResourceId=None, noEcho=False):
    responseUrl = event['ResponseURL']

    print(responseUrl)

    responseBody = {
        'Status' : responseStatus,
        'Reason' : reason or "See the details in CloudWatch Log Stream: {}".format(context.log_stream_name),
        'PhysicalResourceId' : physicalResourceId or context.log_stream_name,
        'StackId' : event['StackId'],
        'RequestId' : event['RequestId'],
        'LogicalResourceId' : event['LogicalResourceId'],
        'NoEcho' : noEcho,
        'Data' : responseData
    }

    json_responseBody = json.dumps(responseBody)

    print("Response body:")
    print(json_responseBody)

    headers = {
        'content-type' : '',
        'content-length' : str(len(json_responseBody))
    }

    try:
        response = http.request('PUT', responseUrl, headers=headers, body=json_responseBody)
        print("Status code:", response.status)


    except Exception as e:
        print("send(..) failed executing http.request(..):", e)
        
def getSubnetZoneId():
    SubnetAZIdList = []

    ec2 = boto3.client('ec2')
    Subnets = ec2.describe_subnets(
        Filters = []
        )

    for i in Subnets['Subnets']:
        SubnetAZIdDict={}
        SubnetAZIdDict['AvailabilityZoneId']=i['AvailabilityZoneId']
        SubnetAZIdDict['CidrBlock']=i['CidrBlock']
        SubnetAZIdDict['SubnetId'] = i['SubnetId']
        SubnetAZIdList.append(SubnetAZIdDict)
    return SubnetAZIdList

def load_az(azs,central_account_role):
    table={}
    if central_account_role == 'NoValue':
        dynamodb = boto3.resource('dynamodb')
        table = dynamodb.Table('AZsMapping')
    else:
        sts_connection = boto3.client('sts')
        acct_b = sts_connection.assume_role(
            RoleArn=central_account_role,
            RoleSessionName="cross_acct_lambda"
        )
        
        ACCESS_KEY = acct_b['Credentials']['AccessKeyId']
        SECRET_KEY = acct_b['Credentials']['SecretAccessKey']
        SESSION_TOKEN = acct_b['Credentials']['SessionToken']

        ddb = boto3.resource(
            'dynamodb',
            aws_access_key_id=ACCESS_KEY,
            aws_secret_access_key=SECRET_KEY,
            aws_session_token=SESSION_TOKEN,
        )
        table = ddb.Table('AZsMapping')
        
    for az in azs:
        azCode = az['AvailabilityZoneId']
        cidrRange = az['CidrBlock']
        print("Adding record:", azCode, cidrRange)
        print(az,type(az))
        table.put_item(Item=az)

def lambda_handler(event, context):
    try: 
        responseData = {}
        print ('REQUEST BODY:n' + str(event))
        CentralAccountRoles = event['ResourceProperties']['CentralAccountRoles']
        SubnetAZIdList = getSubnetZoneId()
        print(SubnetAZIdList)
        load_az(SubnetAZIdList,CentralAccountRoles)
        responseStatus = SUCCESS
    except Exception as e:
        print (e)
        responseStatus = FAILED
    send(event, context, responseStatus, responseData)