#!/usr/bin/env python3
r"""
Documentation

License: This program is released under the MIT License
"""

# Imports
import boto3
import concurrent.futures

def getRegions(all_regions=False):
    ec2 = boto3.client('ec2')
    response = ec2.describe_regions(AllRegions=all_regions)
    return [region['RegionName'] for region in response['Regions']]

def printResources(region_name: str):
    client = boto3.client('ec2', region_name=region_name)
    response = client.describe_subnets()
    for i in response['Subnets']:
        default_vpc_check = client.describe_vpcs(VpcIds=[i['VpcId']])
        for v in default_vpc_check['Vpcs']:
            print(f"{i['SubnetId']}, {i['VpcId']}, {i['CidrBlock']}, {i['AvailabilityZone']}, {v['IsDefault']}")

# Main function
def main() -> None:
    print("SubnetId, VpcId, CidrBlock, AvailabilityZone, InDefaultVpc")
    with concurrent.futures.ProcessPoolExecutor(max_workers=6) as executor:
        futures = [executor.submit(printResources, region_name=r) for r in getRegions()]
        results = [future.result() for future in concurrent.futures.wait(futures).done]

# Call main function
if __name__ == '__main__':
    main()