package ebs

import (
	"context"
	"fmt"
	"log"

	"github.com/aws/aws-sdk-go/service/ec2"
	awscommon "github.com/hashicorp/packer/builder/amazon/common"
	"github.com/hashicorp/packer/common/random"
	"github.com/hashicorp/packer/helper/multistep"
	"github.com/hashicorp/packer/packer"
)

type stepCreateAMI struct {
	image *ec2.Image
}

func (s *stepCreateAMI) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
	config := state.Get("config").(*Config)
	ec2conn := state.Get("ec2").(*ec2.EC2)
	instance := state.Get("instance").(*ec2.Instance)
	ui := state.Get("ui").(packer.Ui)

	// Create the image
	amiName := config.AMIName
	if config.AMIEncryptBootVolume {
		// to avoid having a temporary unencrypted
		// image named config.AMIName
		amiName = random.AlphaNum(7)
	}

	ui.Say(fmt.Sprintf("Creating unencrypted AMI %s from instance %s", amiName, *instance.InstanceId))
	createOpts := &ec2.CreateImageInput{
		InstanceId:          instance.InstanceId,
		Name:                &amiName,
		BlockDeviceMappings: config.BlockDevices.BuildAMIDevices(),
	}

	createResp, err := ec2conn.CreateImage(createOpts)
	if err != nil {
		err := fmt.Errorf("Error creating AMI: %s", err)
		state.Put("error", err)
		ui.Error(err.Error())
		return multistep.ActionHalt
	}

	// Set the AMI ID in the state
	ui.Message(fmt.Sprintf("AMI: %s", *createResp.ImageId))
	amis := make(map[string]string)
	amis[*ec2conn.Config.Region] = *createResp.ImageId
	state.Put("amis", amis)

	// Wait for the image to become ready
	ui.Say("Waiting for AMI to become ready...")
	if err := awscommon.WaitUntilAMIAvailable(ctx, ec2conn, *createResp.ImageId); err != nil {
		log.Printf("Error waiting for AMI: %s", err)
		imagesResp, err := ec2conn.DescribeImages(&ec2.DescribeImagesInput{ImageIds: []*string{createResp.ImageId}})
		if err != nil {
			log.Printf("Unable to determine reason waiting for AMI failed: %s", err)
			err = fmt.Errorf("Unknown error waiting for AMI.")
		} else {
			stateReason := imagesResp.Images[0].StateReason
			err = fmt.Errorf("Error waiting for AMI. Reason: %s", stateReason)
		}

		state.Put("error", err)
		ui.Error(err.Error())
		return multistep.ActionHalt
	}

	imagesResp, err := ec2conn.DescribeImages(&ec2.DescribeImagesInput{ImageIds: []*string{createResp.ImageId}})
	if err != nil {
		err := fmt.Errorf("Error searching for AMI: %s", err)
		state.Put("error", err)
		ui.Error(err.Error())
		return multistep.ActionHalt
	}
	s.image = imagesResp.Images[0]

	snapshots := make(map[string][]string)
	for _, blockDeviceMapping := range imagesResp.Images[0].BlockDeviceMappings {
		if blockDeviceMapping.Ebs != nil && blockDeviceMapping.Ebs.SnapshotId != nil {

			snapshots[*ec2conn.Config.Region] = append(snapshots[*ec2conn.Config.Region], *blockDeviceMapping.Ebs.SnapshotId)
		}
	}
	state.Put("snapshots", snapshots)

	return multistep.ActionContinue
}

func (s *stepCreateAMI) Cleanup(state multistep.StateBag) {
	if s.image == nil {
		return
	}

	_, cancelled := state.GetOk(multistep.StateCancelled)
	_, halted := state.GetOk(multistep.StateHalted)
	if !cancelled && !halted {
		return
	}

	ec2conn := state.Get("ec2").(*ec2.EC2)
	ui := state.Get("ui").(packer.Ui)

	ui.Say("Deregistering the AMI because cancellation or error...")
	deregisterOpts := &ec2.DeregisterImageInput{ImageId: s.image.ImageId}
	if _, err := ec2conn.DeregisterImage(deregisterOpts); err != nil {
		ui.Error(fmt.Sprintf("Error deregistering AMI, may still be around: %s", err))
		return
	}
}
