// GetRemoteTags retrieves all tags from the given repository. It queries each
// of the registries supplied in the registries argument, and returns data from
// the first one that answers the query successfully. It returns a map with
// tag names as the keys and image IDs as the values.
func (r *Session) GetRemoteTags(registries []string, repositoryRef reference.Named) (map[string]string, error) {
	repository := repositoryRef.RemoteName()

	if strings.Count(repository, "/") == 0 {
		// This will be removed once the registry supports auto-resolution on
		// the "library" namespace
		repository = "library/" + repository
	}
	for _, host := range registries {
		endpoint := fmt.Sprintf("%srepositories/%s/tags", host, repository)
		res, err := r.client.Get(endpoint)
		if err != nil {
			return nil, err
		}

		logrus.Debugf("Got status code %d from %s", res.StatusCode, endpoint)
		defer res.Body.Close()

		if res.StatusCode == 404 {
			return nil, ErrRepoNotFound
		}
		if res.StatusCode != 200 {
			continue
		}

		result := make(map[string]string)
		if err := json.NewDecoder(res.Body).Decode(&result); err != nil {
			return nil, err
		}
		return result, nil
	}
	return nil, fmt.Errorf("Could not reach any registry endpoint")
}

// GetTag returns the tag associated with the given reference name.
func GetTag(ref reference.Named) string {
	tag := DefaultTag
	if ref, ok := ref.(reference.NamedTagged); ok {
		tag = ref.Tag()
	}
	return tag
}

// ReferencesByName returns the references for a given repository name.
// If there are no references known for this repository name,
// ReferencesByName returns nil.
func (store *repoCache) ReferencesByName(ref reference.Named) []Association {
	defer trace.End(trace.Begin(""))

	store.mu.RLock()
	defer store.mu.RUnlock()

	repository, exists := store.Repositories[ref.Name()]
	if !exists {
		return nil
	}

	var associations []Association
	for refStr, refID := range repository {
		ref, err := reference.ParseNamed(refStr)
		if err != nil {
			// Should never happen
			return nil
		}
		associations = append(associations,
			Association{
				Ref:     ref,
				ImageID: refID,
			})
	}

	sort.Sort(lexicalAssociations(associations))

	return associations
}

// getRepositoryMountCandidates returns an array of v2 metadata items belonging to the given registry. The
// array is sorted from youngest to oldest. If requireReigstryMatch is true, the resulting array will contain
// only metadata entries having registry part of SourceRepository matching the part of repoInfo.
func getRepositoryMountCandidates(
	repoInfo reference.Named,
	hmacKey []byte,
	max int,
	v2Metadata []metadata.V2Metadata,
) []metadata.V2Metadata {
	candidates := []metadata.V2Metadata{}
	for _, meta := range v2Metadata {
		sourceRepo, err := reference.ParseNamed(meta.SourceRepository)
		if err != nil || repoInfo.Hostname() != sourceRepo.Hostname() {
			continue
		}
		// target repository is not a viable candidate
		if meta.SourceRepository == repoInfo.FullName() {
			continue
		}
		candidates = append(candidates, meta)
	}

	sortV2MetadataByLikenessAndAge(repoInfo, hmacKey, candidates)
	if max >= 0 && len(candidates) > max {
		// select the youngest metadata
		candidates = candidates[:max]
	}

	return candidates
}

func (t *mockTagAdder) AddTag(ref reference.Named, id digest.Digest, force bool) error {
	if t.refs == nil {
		t.refs = make(map[string]string)
	}
	t.refs[ref.String()] = id.String()
	return nil
}

// Looks up image by reference.Named
func (c *ImageCache) GetImageByNamed(named reference.Named) (*metadata.ImageConfig, error) {
	c.m.RLock()
	defer c.m.RUnlock()

	if CacheNotUpdated {
		return nil, ErrCacheNotUpdated
	}

	var config *metadata.ImageConfig

	if tagged, ok := named.(reference.NamedTagged); ok {
		taggedName := tagged.Name() + ":" + tagged.Tag()
		config = c.cacheByName[taggedName]
	} else {
		// First try just the name.
		config = c.cacheByName[named.Name()]
		if config == nil {
			// try with the default docker tag
			taggedName := named.Name() + ":" + reference.DefaultTag
			config = c.cacheByName[taggedName]
		}
	}

	return config, nil
}

// TagImageWithReference adds the given reference to the image ID provided.
func (daemon *Daemon) TagImageWithReference(imageID image.ID, newTag reference.Named) error {
	if err := daemon.referenceStore.AddTag(newTag, imageID.Digest(), true); err != nil {
		return err
	}

	daemon.LogImageEvent(imageID.String(), newTag.String(), "tag")
	return nil
}

// newRepositoryInfo validates and breaks down a repository name into a RepositoryInfo
func newRepositoryInfo(config *serviceConfig, name reference.Named) (*RepositoryInfo, error) {
	index, err := newIndexInfo(config, name.Hostname())
	if err != nil {
		return nil, err
	}
	official := !strings.ContainsRune(name.Name(), '/')
	return &RepositoryInfo{name, index, official}, nil
}

func (p *v1Puller) pullRepository(ctx context.Context, ref reference.Named) error {
	progress.Message(p.config.ProgressOutput, "", "Pulling repository "+p.repoInfo.FullName())

	tagged, isTagged := ref.(reference.NamedTagged)

	repoData, err := p.session.GetRepositoryData(p.repoInfo)
	if err != nil {
		if strings.Contains(err.Error(), "HTTP code: 404") {
			if isTagged {
				return fmt.Errorf("Error: image %s:%s not found", p.repoInfo.RemoteName(), tagged.Tag())
			}
			return fmt.Errorf("Error: image %s not found", p.repoInfo.RemoteName())
		}
		// Unexpected HTTP error
		return err
	}

	logrus.Debug("Retrieving the tag list")
	var tagsList map[string]string
	if !isTagged {
		tagsList, err = p.session.GetRemoteTags(repoData.Endpoints, p.repoInfo)
	} else {
		var tagID string
		tagsList = make(map[string]string)
		tagID, err = p.session.GetRemoteTag(repoData.Endpoints, p.repoInfo, tagged.Tag())
		if err == registry.ErrRepoNotFound {
			return fmt.Errorf("Tag %s not found in repository %s", tagged.Tag(), p.repoInfo.FullName())
		}
		tagsList[tagged.Tag()] = tagID
	}
	if err != nil {
		logrus.Errorf("unable to get remote tags: %s", err)
		return err
	}

	for tag, id := range tagsList {
		repoData.ImgList[id] = &registry.ImgData{
			ID:       id,
			Tag:      tag,
			Checksum: "",
		}
	}

	layersDownloaded := false
	for _, imgData := range repoData.ImgList {
		if isTagged && imgData.Tag != tagged.Tag() {
			continue
		}

		err := p.downloadImage(ctx, repoData, imgData, &layersDownloaded)
		if err != nil {
			return err
		}
	}

	writeStatus(ref.String(), p.config.ProgressOutput, layersDownloaded)
	return nil
}

// trustedPush handles content trust pushing of an image
func trustedPush(ctx context.Context, cli *command.DockerCli, repoInfo *registry.RepositoryInfo, ref reference.Named, authConfig types.AuthConfig, requestPrivilege types.RequestPrivilegeFunc) error {
	responseBody, err := imagePushPrivileged(ctx, cli, authConfig, ref.String(), requestPrivilege)
	if err != nil {
		return err
	}

	defer responseBody.Close()

	return PushTrustedReference(cli, repoInfo, ref, authConfig, responseBody)
}

// TagImage creates a tag in the repository reponame, pointing to the image named
// imageName.
func (daemon *Daemon) TagImage(newTag reference.Named, imageName string) error {
	imageID, err := daemon.GetImageID(imageName)
	if err != nil {
		return err
	}
	if err := daemon.referenceStore.AddTag(newTag, imageID, true); err != nil {
		return err
	}
	daemon.EventsService.Log("tag", newTag.String(), "")
	return nil
}

func sortV2MetadataByLikenessAndAge(repoInfo reference.Named, hmacKey []byte, marr []metadata.V2Metadata) {
	// reverse the metadata array to shift the newest entries to the beginning
	for i := 0; i < len(marr)/2; i++ {
		marr[i], marr[len(marr)-i-1] = marr[len(marr)-i-1], marr[i]
	}
	// keep equal entries ordered from the youngest to the oldest
	sort.Stable(byLikeness{
		arr:            marr,
		hmacKey:        hmacKey,
		pathComponents: getPathComponents(repoInfo.FullName()),
	})
}

func (p *v2Puller) pullV2Repository(ctx context.Context, ref reference.Named) (err error) {
	var layersDownloaded bool
	if !reference.IsNameOnly(ref) {
		var err error
		layersDownloaded, err = p.pullV2Tag(ctx, ref)
		if err != nil {
			return err
		}
	} else {
		manSvc, err := p.repo.Manifests(ctx)
		if err != nil {
			return err
		}

		tags, err := manSvc.Tags()
		if err != nil {
			// If this repository doesn't exist on V2, we should
			// permit a fallback to V1.
			return allowV1Fallback(err)
		}

		// The v2 registry knows about this repository, so we will not
		// allow fallback to the v1 protocol even if we encounter an
		// error later on.
		p.confirmedV2 = true

		// This probably becomes a lot nicer after the manifest
		// refactor...
		for _, tag := range tags {
			tagRef, err := reference.WithTag(ref, tag)
			if err != nil {
				return err
			}
			pulledNew, err := p.pullV2Tag(ctx, tagRef)
			if err != nil {
				// Since this is the pull-all-tags case, don't
				// allow an error pulling a particular tag to
				// make the whole pull fall back to v1.
				if fallbackErr, ok := err.(fallbackError); ok {
					return fallbackErr.err
				}
				return err
			}
			// pulledNew is true if either new layers were downloaded OR if existing images were newly tagged
			// TODO(tiborvass): should we change the name of `layersDownload`? What about message in WriteStatus?
			layersDownloaded = layersDownloaded || pulledNew
		}
	}

	writeStatus(ref.String(), p.config.ProgressOutput, layersDownloaded)

	return nil
}

func (i *Image) PullImage(ctx context.Context, ref reference.Named, metaHeaders map[string][]string, authConfig *types.AuthConfig, outStream io.Writer) error {
	defer trace.End(trace.Begin("PullImage"))

	log.Printf("PullImage: ref = %+v, metaheaders = %+v\n", ref, metaHeaders)

	var cmdArgs []string

	cmdArgs = append(cmdArgs, "-reference", ref.String())

	if authConfig != nil {
		if len(authConfig.Username) > 0 {
			cmdArgs = append(cmdArgs, "-username", authConfig.Username)
		}
		if len(authConfig.Password) > 0 {
			cmdArgs = append(cmdArgs, "-password", authConfig.Password)
		}
	}

	portLayerServer := PortLayerServer()

	if portLayerServer != "" {
		cmdArgs = append(cmdArgs, "-host", portLayerServer)
	}

	// intruct imagec to use os.TempDir
	cmdArgs = append(cmdArgs, "-destination", os.TempDir())

	log.Printf("PullImage: cmd = %s %+v\n", Imagec, cmdArgs)

	cmd := exec.Command(Imagec, cmdArgs...)
	cmd.Stdout = outStream
	cmd.Stderr = outStream

	// Execute
	err := cmd.Start()

	if err != nil {
		log.Printf("Error starting %s - %s\n", Imagec, err)
		return fmt.Errorf("Error starting %s - %s\n", Imagec, err)
	}

	err = cmd.Wait()

	if err != nil {
		log.Println("imagec exit code:", err)
		return err
	}

	client := PortLayerClient()
	ImageCache().Update(client)
	return nil
}

func (s *Service) lookupV1Endpoints(repoName reference.Named) (endpoints []APIEndpoint, err error) {
	var cfg = tlsconfig.ServerDefault
	tlsConfig := &cfg
	nameString := repoName.FullName()
	if strings.HasPrefix(nameString, DefaultNamespace+"/") {
		endpoints = append(endpoints, APIEndpoint{
			URL:          DefaultV1Registry,
			Version:      APIVersion1,
			Official:     true,
			TrimHostname: true,
			TLSConfig:    tlsConfig,
		})
		return endpoints, nil
	}

	slashIndex := strings.IndexRune(nameString, '/')
	if slashIndex <= 0 {
		return nil, fmt.Errorf("invalid repo name: missing '/':  %s", nameString)
	}
	hostname := nameString[:slashIndex]

	tlsConfig, err = s.TLSConfig(hostname)
	if err != nil {
		return nil, err
	}

	endpoints = []APIEndpoint{
		{
			URL: &url.URL{
				Scheme: "https",
				Host:   hostname,
			},
			Version:      APIVersion1,
			TrimHostname: true,
			TLSConfig:    tlsConfig,
		},
	}

	if tlsConfig.InsecureSkipVerify {
		endpoints = append(endpoints, APIEndpoint{ // or this
			URL: &url.URL{
				Scheme: "http",
				Host:   hostname,
			},
			Version:      APIVersion1,
			TrimHostname: true,
			// used to check if supposed to be secure via InsecureSkipVerify
			TLSConfig: tlsConfig,
		})
	}
	return endpoints, nil
}

func digestFromManifest(m *schema1.SignedManifest, name reference.Named) (digest.Digest, int, error) {
	payload, err := m.Payload()
	if err != nil {
		// If this failed, the signatures section was corrupted
		// or missing. Treat the entire manifest as the payload.
		payload = m.Raw
	}
	manifestDigest, err := digest.FromBytes(payload)
	if err != nil {
		logrus.Infof("Could not compute manifest digest for %s:%s : %v", name.Name(), m.Tag, err)
	}
	return manifestDigest, len(payload), nil
}

func (pm *Manager) newPlugin(ref reference.Named, id string) *plugin {
	p := &plugin{
		PluginObj: types.Plugin{
			Name: ref.Name(),
			ID:   id,
		},
		runtimeSourcePath: filepath.Join(pm.runRoot, id),
	}
	if ref, ok := ref.(reference.NamedTagged); ok {
		p.PluginObj.Tag = ref.Tag()
	}
	return p
}

func (p *v2Puller) pullV2Repository(ctx context.Context, ref reference.Named) (err error) {
	var refs []reference.Named
	if !reference.IsNameOnly(ref) {
		refs = []reference.Named{ref}
	} else {
		manSvc, err := p.repo.Manifests(ctx)
		if err != nil {
			return err
		}

		tags, err := manSvc.Tags()
		if err != nil {
			return err
		}

		// If this call succeeded, we can be confident that the
		// registry on the other side speaks the v2 protocol.
		p.confirmedV2 = true

		// This probably becomes a lot nicer after the manifest
		// refactor...
		for _, tag := range tags {
			tagRef, err := reference.WithTag(ref, tag)
			if err != nil {
				return err
			}
			refs = append(refs, tagRef)
		}
	}

	var layersDownloaded bool
	for _, pullRef := range refs {
		// pulledNew is true if either new layers were downloaded OR if existing images were newly tagged
		// TODO(tiborvass): should we change the name of `layersDownload`? What about message in WriteStatus?
		pulledNew, err := p.pullV2Tag(ctx, pullRef)
		if err != nil {
			return err
		}
		layersDownloaded = layersDownloaded || pulledNew
	}

	writeStatus(ref.String(), p.config.ProgressOutput, layersDownloaded)

	return nil
}

// Looks up image by reference.Named
func (ic *ICache) getImageByNamed(named reference.Named) (*metadata.ImageConfig, error) {

	var config *metadata.ImageConfig

	if tagged, ok := named.(reference.NamedTagged); ok {
		taggedName := tagged.Name() + ":" + tagged.Tag()
		config = ic.cacheByName[taggedName]
	} else {
		// First try just the name.
		if config, ok = ic.cacheByName[named.Name()]; !ok {
			// try with the default docker tag
			taggedName := named.Name() + ":" + reference.DefaultTag
			config = ic.cacheByName[taggedName]
		}
	}

	return copyImageConfig(config), nil
}

// Get returns the imageID for a parsed reference
func (store *repoCache) Get(ref reference.Named) (string, error) {
	defer trace.End(trace.Begin(""))
	ref = reference.WithDefaultTag(ref)

	store.mu.RLock()
	defer store.mu.RUnlock()

	repository, exists := store.Repositories[ref.Name()]
	if !exists || repository == nil {
		return "", ErrDoesNotExist
	}
	imageID, exists := repository[ref.String()]
	if !exists {
		return "", ErrDoesNotExist
	}

	return imageID, nil
}