package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"os"

	"github.com/containers/image/directory"
	dockerarchive "github.com/containers/image/docker/archive"
	ociarchive "github.com/containers/image/oci/archive"
	"github.com/containers/libpod/cmd/podman/libpodruntime"
	"github.com/containers/libpod/libpod/image"
	"github.com/pkg/errors"
	"github.com/urfave/cli"
)

var (
	loadFlags = []cli.Flag{
		cli.StringFlag{
			Name:  "input, i",
			Usage: "Read from archive file, default is STDIN",
			Value: "/dev/stdin",
		},
		cli.BoolFlag{
			Name:  "quiet, q",
			Usage: "Suppress the output",
		},
		cli.StringFlag{
			Name:  "signature-policy",
			Usage: "`pathname` of signature policy file (not usually used)",
		},
	}
	loadDescription = "Loads the image from docker-archive stored on the local machine."
	loadCommand     = cli.Command{
		Name:         "load",
		Usage:        "Load an image from docker archive",
		Description:  loadDescription,
		Flags:        sortFlags(loadFlags),
		Action:       loadCmd,
		ArgsUsage:    "",
		OnUsageError: usageErrorHandler,
	}
)

// loadCmd gets the image/file to be loaded from the command line
// and calls loadImage to load the image to containers-storage
func loadCmd(c *cli.Context) error {

	args := c.Args()
	var imageName string

	if len(args) == 1 {
		imageName = args[0]
	}
	if len(args) > 1 {
		return errors.New("too many arguments. Requires exactly 1")
	}
	if err := validateFlags(c, loadFlags); err != nil {
		return err
	}

	runtime, err := libpodruntime.GetRuntime(c)
	if err != nil {
		return errors.Wrapf(err, "could not get runtime")
	}
	defer runtime.Shutdown(false)

	input := c.String("input")

	if input == "/dev/stdin" {
		fi, err := os.Stdin.Stat()
		if err != nil {
			return err
		}
		// checking if loading from pipe
		if !fi.Mode().IsRegular() {
			outFile, err := ioutil.TempFile("/var/tmp", "podman")
			if err != nil {
				return errors.Errorf("error creating file %v", err)
			}
			defer os.Remove(outFile.Name())
			defer outFile.Close()

			inFile, err := os.OpenFile(input, 0, 0666)
			if err != nil {
				return errors.Errorf("error reading file %v", err)
			}
			defer inFile.Close()

			_, err = io.Copy(outFile, inFile)
			if err != nil {
				return errors.Errorf("error copying file %v", err)
			}

			input = outFile.Name()
		}
	}
	if err := validateFileName(input); err != nil {
		return err
	}

	var writer io.Writer
	if !c.Bool("quiet") {
		writer = os.Stderr
	}

	ctx := getContext()

	var newImages []*image.Image
	src, err := dockerarchive.ParseReference(input) // FIXME? We should add dockerarchive.NewReference()
	if err == nil {
		newImages, err = runtime.ImageRuntime().LoadFromArchiveReference(ctx, src, c.String("signature-policy"), writer)
	}
	if err != nil {
		// generate full src name with specified image:tag
		src, err := ociarchive.NewReference(input, imageName) // imageName may be ""
		if err == nil {
			newImages, err = runtime.ImageRuntime().LoadFromArchiveReference(ctx, src, c.String("signature-policy"), writer)
		}
		if err != nil {
			src, err := directory.NewReference(input)
			if err == nil {
				newImages, err = runtime.ImageRuntime().LoadFromArchiveReference(ctx, src, c.String("signature-policy"), writer)
			}
			if err != nil {
				return errors.Wrapf(err, "error pulling %q", input)
			}
		}
	}
	fmt.Println("Loaded image(s): " + getImageNames(newImages))
	return nil
}

func getImageNames(images []*image.Image) string {
	var names string
	for i := range images {
		if i == 0 {
			names = images[i].InputName
		} else {
			names += ", " + images[i].InputName
		}
	}
	return names
}