import boto3
import botocore.exceptions

GP3_MIN_IOPS = 3000
GP3_MIN_THROUGHPUT = 125
GP3_MAX_THROUGHPUT = 250


if __name__ == "__main__":
    region = "us-west-2"
    client = boto3.client("ec2", region_name=region)
    dry_run = True

    response = client.describe_volumes()

    for result in response["Volumes"]:
        if result["VolumeType"] == "gp2":
            VolumeId = result["VolumeId"]

            Iops = result["Iops"] if result["Iops"] >= GP3_MIN_IOPS else GP3_MIN_IOPS
            CalculatedThroughput = int(result["Iops"] * result["Size"] / 1024)
            if CalculatedThroughput >= GP3_MAX_THROUGHPUT:
                Throughput = GP3_MAX_THROUGHPUT
            elif CalculatedThroughput < GP3_MIN_THROUGHPUT:
                Throughput = GP3_MIN_THROUGHPUT
            else:
                Throughput = CalculatedThroughput

            report = (
                f"{result['VolumeId']} gp2: {result['Size']}gb {result['Iops']}"
                + f" {CalculatedThroughput} {Throughput} ||| "
                + f"gp3: {result['Size']}gb {Iops} {Throughput}"
            )
            print(report)
            try:
                modify = client.modify_volume(
                    VolumeId=result["VolumeId"],
                    VolumeType="gp3",
                    Iops=Iops,
                    Throughput=Throughput,
                    DryRun=dry_run,
                )
            except botocore.exceptions.ClientError as error:
                if error.response["Error"]["Code"] == "DryRunOperation":
                    print("DryRun operation")
                else:
                    raise error