package images

import (
	"fmt"
	"io"
	"os"

	"github.com/containerd/containerd/cmd/ctr/commands"
	"github.com/containerd/containerd/images"
	oci "github.com/containerd/containerd/images/oci"
	"github.com/containerd/containerd/log"
	"github.com/urfave/cli"
)

var importCommand = cli.Command{
	Name:      "import",
	Usage:     "import images",
	ArgsUsage: "[flags] <in>",
	Description: `Import images from a tar stream.
Implemented formats:
- oci.v1     (default)


For oci.v1 format, you need to specify --oci-name because an OCI archive contains image refs (tags)
but does not contain the base image name.

e.g.
  $ ctr images import --format oci.v1 --oci-name foo/bar foobar.tar

If foobar.tar contains an OCI ref named "latest" and anonymous ref "sha256:deadbeef", the command will create
"foo/bar:latest" and "foo/bar@sha256:deadbeef" images in the containerd store.
`,
	Flags: append([]cli.Flag{
		cli.StringFlag{
			Name:  "format",
			Value: "oci.v1",
			Usage: "image format. See DESCRIPTION.",
		},
		cli.StringFlag{
			Name:  "oci-name",
			Value: "unknown/unknown",
			Usage: "prefix added to either oci.v1 ref annotation or digest",
		},
		// TODO(AkihiroSuda): support commands.LabelFlag (for all children objects)
	}, commands.SnapshotterFlags...),

	Action: func(context *cli.Context) error {
		var (
			in            = context.Args().First()
			imageImporter images.Importer
		)

		switch format := context.String("format"); format {
		case "oci.v1":
			imageImporter = &oci.V1Importer{
				ImageName: context.String("oci-name"),
			}
		default:
			return fmt.Errorf("unknown format %s", format)
		}

		client, ctx, cancel, err := commands.NewClient(context)
		if err != nil {
			return err
		}
		defer cancel()

		var r io.ReadCloser
		if in == "-" {
			r = os.Stdin
		} else {
			r, err = os.Open(in)
			if err != nil {
				return err
			}
		}
		imgs, err := client.Import(ctx, imageImporter, r)
		if err != nil {
			return err
		}
		if err = r.Close(); err != nil {
			return err
		}

		log.G(ctx).Debugf("unpacking %d images", len(imgs))

		for _, img := range imgs {
			// TODO: Show unpack status
			fmt.Printf("unpacking %s (%s)...", img.Name(), img.Target().Digest)
			err = img.Unpack(ctx, context.String("snapshotter"))
			if err != nil {
				return err
			}
			fmt.Println("done")
		}
		return nil
	},
}