package containerd

import (
	"context"
	"io"

	"github.com/containerd/containerd"
	"github.com/containerd/containerd/platforms"
	"github.com/docker/distribution"
	"github.com/docker/distribution/reference"
	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/backend"
	"github.com/docker/docker/api/types/filters"
	imagetype "github.com/docker/docker/api/types/image"
	registrytypes "github.com/docker/docker/api/types/registry"
	"github.com/docker/docker/builder"
	"github.com/docker/docker/container"
	"github.com/docker/docker/daemon/images"
	"github.com/docker/docker/errdefs"
	"github.com/docker/docker/image"
	"github.com/docker/docker/layer"
	"github.com/opencontainers/go-digest"
	specs "github.com/opencontainers/image-spec/specs-go/v1"
)

// ImageService implements daemon.ImageService
type ImageService struct {
	client *containerd.Client
}

// NewService creates a new ImageService.
func NewService(c *containerd.Client) *ImageService {
	return &ImageService{
		client: c,
	}
}

// PullImage initiates a pull operation. image is the repository name to pull, and
// tagOrDigest may be either empty, or indicate a specific tag or digest to pull.
func (cs *ImageService) PullImage(ctx context.Context, image, tagOrDigest string, platform *specs.Platform, metaHeaders map[string][]string, authConfig *types.AuthConfig, outStream io.Writer) error {
	var opts []containerd.RemoteOpt
	if platform != nil {
		opts = append(opts, containerd.WithPlatform(platforms.Format(*platform)))
	}
	ref, err := reference.ParseNormalizedNamed(image)
	if err != nil {
		return errdefs.InvalidParameter(err)
	}

	// TODO(thaJeztah) this could use a WithTagOrDigest() utility
	if tagOrDigest != "" {
		// The "tag" could actually be a digest.
		var dgst digest.Digest
		dgst, err = digest.Parse(tagOrDigest)
		if err == nil {
			ref, err = reference.WithDigest(reference.TrimNamed(ref), dgst)
		} else {
			ref, err = reference.WithTag(ref, tagOrDigest)
		}
		if err != nil {
			return errdefs.InvalidParameter(err)
		}
	}

	_, err = cs.client.Pull(ctx, ref.String(), opts...)
	return err
}

// Images returns a filtered list of images.
func (cs *ImageService) Images(ctx context.Context, opts types.ImageListOptions) ([]*types.ImageSummary, error) {
	imgs, err := cs.client.ListImages(ctx)
	if err != nil {
		return nil, err
	}

	var ret []*types.ImageSummary
	for _, img := range imgs {
		size, err := img.Size(ctx)
		if err != nil {
			return nil, err
		}

		ret = append(ret, &types.ImageSummary{
			RepoDigests: []string{img.Name() + "@" + img.Target().Digest.String()}, // "hello-world@sha256:bfea6278a0a267fad2634554f4f0c6f31981eea41c553fdf5a83e95a41d40c38"},
			RepoTags:    []string{img.Name()},
			Containers:  -1,
			ParentID:    "",
			SharedSize:  -1,
			VirtualSize: 10,
			ID:          img.Target().Digest.String(),
			Created:     img.Metadata().CreatedAt.Unix(),
			Size:        size,
		})
	}

	return ret, nil
}

// LogImageEvent generates an event related to an image with only the
// default attributes.
func (cs *ImageService) LogImageEvent(imageID, refName, action string) {
	panic("not implemented")
}

// LogImageEventWithAttributes generates an event related to an image with
// specific given attributes.
func (cs *ImageService) LogImageEventWithAttributes(imageID, refName, action string, attributes map[string]string) {
	panic("not implemented")
}

// GetLayerFolders returns the layer folders from an image RootFS.
func (cs *ImageService) GetLayerFolders(img *image.Image, rwLayer layer.RWLayer) ([]string, error) {
	panic("not implemented")
}

// GetLayerByID returns a layer by ID
// called from daemon.go Daemon.restore(), and Daemon.containerExport().
func (cs *ImageService) GetLayerByID(string) (layer.RWLayer, error) {
	panic("not implemented")
}

// GetLayerMountID returns the mount ID for a layer
// called from daemon.go Daemon.Shutdown(), and Daemon.Cleanup() (cleanup is actually continerCleanup)
// TODO: needs to be refactored to Unmount (see callers), or removed and replaced with GetLayerByID
func (cs *ImageService) GetLayerMountID(string) (string, error) {
	panic("not implemented")
}

// Cleanup resources before the process is shutdown.
// called from daemon.go Daemon.Shutdown()
func (cs *ImageService) Cleanup() error {
	return nil
}

// GraphDriverName returns the name of the graph drvier
// moved from Daemon.GraphDriverName, used by:
// - newContainer
// - to report an error in Daemon.Mount(container)
func (cs *ImageService) GraphDriverName() string {
	return ""
}

// CommitBuildStep is used by the builder to create an image for each step in
// the build.
//
// This method is different from CreateImageFromContainer:
//   - it doesn't attempt to validate container state
//   - it doesn't send a commit action to metrics
//   - it doesn't log a container commit event
//
// This is a temporary shim. Should be removed when builder stops using commit.
func (cs *ImageService) CommitBuildStep(c backend.CommitConfig) (image.ID, error) {
	panic("not implemented")
}

// CreateImage creates a new image by adding a config and ID to the image store.
// This is similar to LoadImage() except that it receives JSON encoded bytes of
// an image instead of a tar archive.
func (cs *ImageService) CreateImage(config []byte, parent string) (builder.Image, error) {
	panic("not implemented")
}

// GetImageAndReleasableLayer returns an image and releaseable layer for a
// eference or ID. Every call to GetImageAndReleasableLayer MUST call
// releasableLayer.Release() to prevent leaking of layers.
func (cs *ImageService) GetImageAndReleasableLayer(ctx context.Context, refOrID string, opts backend.GetImageAndLayerOptions) (builder.Image, builder.ROLayer, error) {
	panic("not implemented")
}

// MakeImageCache creates a stateful image cache.
func (cs *ImageService) MakeImageCache(sourceRefs []string) builder.ImageCache {
	panic("not implemented")
}

// TagImageWithReference adds the given reference to the image ID provided.
func (cs *ImageService) TagImageWithReference(imageID image.ID, newTag reference.Named) error {
	panic("not implemented")
}

// SquashImage creates a new image with the diff of the specified image and
// the specified parent. This new image contains only the layers from its
// parent + 1 extra layer which contains the diff of all the layers in between.
// The existing image(s) is not destroyed. If no parent is specified, a new
// image with the diff of all the specified image's layers merged into a new
// layer that has no parents.
func (cs *ImageService) SquashImage(id, parent string) (string, error) {
	panic("not implemented")
}

// ExportImage exports a list of images to the given output stream. The
// exported images are archived into a tar when written to the output
// stream. All images with the given tag and all versions containing
// the same tag are exported. names is the set of tags to export, and
// outStream is the writer which the images are written to.
func (cs *ImageService) ExportImage(names []string, outStream io.Writer) error {
	panic("not implemented")
}

// ImageDelete deletes the image referenced by the given imageRef from this
// daemon. The given imageRef can be an image ID, ID prefix, or a repository
// reference (with an optional tag or digest, defaulting to the tag name
// "latest"). There is differing behavior depending on whether the given
// imageRef is a repository reference or not.
//
// If the given imageRef is a repository reference then that repository
// reference will be removed. However, if there exists any containers which
// were created using the same image reference then the repository reference
// cannot be removed unless either there are other repository references to the
// same image or force is true. Following removal of the repository reference,
// the referenced image itself will attempt to be deleted as described below
// but quietly, meaning any image delete conflicts will cause the image to not
// be deleted and the conflict will not be reported.
//
// There may be conflicts preventing deletion of an image and these conflicts
// are divided into two categories grouped by their severity:
//
// Hard Conflict:
//   - a pull or build using the image.
//   - any descendant image.
//   - any running container using the image.
//
// Soft Conflict:
//   - any stopped container using the image.
//   - any repository tag or digest references to the image.
//
// The image cannot be removed if there are any hard conflicts and can be
// removed if there are soft conflicts only if force is true.
//
// If prune is true, ancestor images will each attempt to be deleted quietly,
// meaning any delete conflicts will cause the image to not be deleted and the
// conflict will not be reported.
func (cs *ImageService) ImageDelete(imageRef string, force, prune bool) ([]types.ImageDeleteResponseItem, error) {
	panic("not implemented")
}

// ImageHistory returns a slice of ImageHistory structures for the specified
// image name by walking the image lineage.
func (cs *ImageService) ImageHistory(name string) ([]*imagetype.HistoryResponseItem, error) {
	panic("not implemented")
}

// ImagesPrune removes unused images
func (cs *ImageService) ImagesPrune(ctx context.Context, pruneFilters filters.Args) (*types.ImagesPruneReport, error) {
	panic("not implemented")
}

// ImportImage imports an image, getting the archived layer data either from
// inConfig (if src is "-"), or from a URI specified in src. Progress output is
// written to outStream. Repository and tag names can optionally be given in
// the repo and tag arguments, respectively.
func (cs *ImageService) ImportImage(src string, repository string, platform *specs.Platform, tag string, msg string, inConfig io.ReadCloser, outStream io.Writer, changes []string) error {
	panic("not implemented")
}

// LoadImage uploads a set of images into the repository. This is the
// complement of ExportImage.  The input stream is an uncompressed tar
// ball containing images and metadata.
func (cs *ImageService) LoadImage(inTar io.ReadCloser, outStream io.Writer, quiet bool) error {
	panic("not implemented")
}

// PushImage initiates a push operation on the repository named localName.
func (cs *ImageService) PushImage(ctx context.Context, image, tag string, metaHeaders map[string][]string, authConfig *types.AuthConfig, outStream io.Writer) error {
	panic("not implemented")
}

// SearchRegistryForImages queries the registry for images matching
// term. authConfig is used to login.
//
// TODO: this could be implemented in a registry service instead of the image
// service.
func (cs *ImageService) SearchRegistryForImages(ctx context.Context, searchFilters filters.Args, term string, limit int, authConfig *types.AuthConfig, metaHeaders map[string][]string) (*registrytypes.SearchResults, error) {
	panic("not implemented")
}

// TagImage creates the tag specified by newTag, pointing to the image named
// imageName (alternatively, imageName can also be an image ID).
func (cs *ImageService) TagImage(imageName, repository, tag string) (string, error) {
	panic("not implemented")
}

// GetRepository returns a repository from the registry.
func (cs *ImageService) GetRepository(context.Context, reference.Named, *types.AuthConfig) (distribution.Repository, error) {
	panic("not implemented")
}

// ImageDiskUsage returns information about image data disk usage.
func (cs *ImageService) ImageDiskUsage(ctx context.Context) ([]*types.ImageSummary, error) {
	panic("not implemented")
}

// LayerDiskUsage returns the number of bytes used by layer stores
// called from disk_usage.go
func (cs *ImageService) LayerDiskUsage(ctx context.Context) (int64, error) {
	panic("not implemented")
}

// ReleaseLayer releases a layer allowing it to be removed
// called from delete.go Daemon.cleanupContainer(), and Daemon.containerExport()
func (cs *ImageService) ReleaseLayer(rwlayer layer.RWLayer) error {
	panic("not implemented")
}

// CommitImage creates a new image from a commit config.
func (cs *ImageService) CommitImage(c backend.CommitConfig) (image.ID, error) {
	panic("not implemented")
}

// GetImage returns an image corresponding to the image referred to by refOrID.
func (cs *ImageService) GetImage(refOrID string, platform *specs.Platform) (retImg *image.Image, retErr error) {
	panic("not implemented")
}

// CreateLayer creates a filesystem layer for a container.
// called from create.go
// TODO: accept an opt struct instead of container?
func (cs *ImageService) CreateLayer(container *container.Container, initFunc layer.MountInit) (layer.RWLayer, error) {
	panic("not implemented")
}

// DistributionServices return services controlling daemon image storage.
func (cs *ImageService) DistributionServices() images.DistributionServices {
	return images.DistributionServices{}
}

// CountImages returns the number of images stored by ImageService
// called from info.go
func (cs *ImageService) CountImages() int {
	imgs, err := cs.client.ListImages(context.TODO())
	if err != nil {
		return 0
	}

	return len(imgs)
}

// LayerStoreStatus returns the status for each layer store
// called from info.go
func (cs *ImageService) LayerStoreStatus() [][2]string {
	return [][2]string{}
}

// GetContainerLayerSize returns the real size & virtual size of the container.
func (cs *ImageService) GetContainerLayerSize(containerID string) (int64, int64) {
	panic("not implemented")
}

// UpdateConfig values
//
// called from reload.go
func (cs *ImageService) UpdateConfig(maxDownloads, maxUploads int) {
	panic("not implemented")
}

// Children returns the children image.IDs for a parent image.
// called from list.go to filter containers
// TODO: refactor to expose an ancestry for image.ID?
func (cs *ImageService) Children(id image.ID) []image.ID {
	panic("not implemented")
}