// Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
// SPDX-License-Identifier: MIT-0

import {
  EC2Client,
  DescribeInstancesCommand
} from '@aws-sdk/client-ec2'

// describe ec2 instances
// https://docs.aws.amazon.com/AWSJavaScriptSDK/v3/latest/clients/client-ec2/classes/describeinstancescommand.html
async function getInstances (region) {
  const instances = []
  const client = new EC2Client({
    region
  })
  const params = {}
  let res
  do {
    if (res && res.NextToken) {
      params.NextToken = res.NextToken
    }
    const command = new DescribeInstancesCommand(params)
    res = await client.send(command)
    for (const reserve of res.Reservations) {
      for (const instance of reserve.Instances) {
        instances.push({ id: instance.InstanceId, type: instance.InstanceType })
      }
    }
  } while (res.NextToken)
  return instances
}
export const handler = async (event) => {
  console.log(event)
  const instances = await getInstances(event.region)
  return { region: event.region, instanceTypes: event.instancesTypes, instances }
}