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

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

# Imports
import boto3
import concurrent.futures
from openpyxl import load_workbook
from openpyxl.worksheet.worksheet import Worksheet
import projectlib.aws


def getResources(region_name: str) -> list[list[str | int]]:
    return_data = []
    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']:
            return_data.append([i['SubnetId'], i['VpcId'], i['CidrBlock'], i['AvailabilityZone'], v['IsDefault']])
    return return_data

# Main function
def main() -> None:
    # Open spreadsheet and add a sheet
    wb = load_workbook('aws-inventory.xlsx')
    ws = wb.create_sheet("Subnets")

    ws.append(["SubnetId", "VpcId", "CidrBlock", "AvailabilityZone", "InDefaultVpc"])
    with concurrent.futures.ThreadPoolExecutor(max_workers=8) as executor:
        results = executor.map(getResources, projectlib.aws.getRegions())
        for region_rows in results:
            # append to worksheet only if resoruces are found in the region
            if region_rows:
                for row in region_rows:
                    ws.append(row)

    wb.save('aws-inventory.xlsx')

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