// Push a local image to the registry
func (r *Session) PushImageJSONRegistry(imgData *ImgData, jsonRaw []byte, registry string) error {

	u := registry + "images/" + imgData.ID + "/json"

	logrus.Debugf("[registry] Calling PUT %s", u)

	req, err := http.NewRequest("PUT", u, bytes.NewReader(jsonRaw))
	if err != nil {
		return err
	}
	req.Header.Add("Content-type", "application/json")

	res, err := r.client.Do(req)
	if err != nil {
		return fmt.Errorf("Failed to upload metadata: %s", err)
	}
	defer res.Body.Close()
	if res.StatusCode == 401 && strings.HasPrefix(registry, "http://") {
		return httputils.NewHTTPRequestError("HTTP code 401, Docker will not send auth headers over HTTP.", res)
	}
	if res.StatusCode != 200 {
		errBody, err := ioutil.ReadAll(res.Body)
		if err != nil {
			return httputils.NewHTTPRequestError(fmt.Sprintf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err), res)
		}
		var jsonBody map[string]string
		if err := json.Unmarshal(errBody, &jsonBody); err != nil {
			errBody = []byte(err.Error())
		} else if jsonBody["error"] == "Image already exists" {
			return ErrAlreadyExists
		}
		return httputils.NewHTTPRequestError(fmt.Sprintf("HTTP code %d while uploading metadata: %q", res.StatusCode, errBody), res)
	}
	return nil
}

func (r *Session) GetRepositoryData(remote string) (*RepositoryData, error) {
	repositoryTarget := fmt.Sprintf("%srepositories/%s/images", r.indexEndpoint.VersionString(1), remote)

	logrus.Debugf("[registry] Calling GET %s", repositoryTarget)

	req, err := http.NewRequest("GET", repositoryTarget, nil)
	if err != nil {
		return nil, err
	}
	// this will set basic auth in r.client.Transport and send cached X-Docker-Token headers for all subsequent requests
	req.Header.Set("X-Docker-Token", "true")
	res, err := r.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode == 401 {
		return nil, errLoginRequired
	}
	// TODO: Right now we're ignoring checksums in the response body.
	// In the future, we need to use them to check image validity.
	if res.StatusCode == 404 {
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("HTTP code: %d", res.StatusCode), res)
	} else if res.StatusCode != 200 {
		errBody, err := ioutil.ReadAll(res.Body)
		if err != nil {
			logrus.Debugf("Error reading response body: %s", err)
		}
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("Error: Status %d trying to pull repository %s: %q", res.StatusCode, remote, errBody), res)
	}

	var endpoints []string
	if res.Header.Get("X-Docker-Endpoints") != "" {
		endpoints, err = buildEndpointsList(res.Header["X-Docker-Endpoints"], r.indexEndpoint.VersionString(1))
		if err != nil {
			return nil, err
		}
	} else {
		// Assume the endpoint is on the same host
		endpoints = append(endpoints, fmt.Sprintf("%s://%s/v1/", r.indexEndpoint.URL.Scheme, req.URL.Host))
	}

	remoteChecksums := []*ImgData{}
	if err := json.NewDecoder(res.Body).Decode(&remoteChecksums); err != nil {
		return nil, err
	}

	// Forge a better object from the retrieved data
	imgsData := make(map[string]*ImgData)
	for _, elem := range remoteChecksums {
		imgsData[elem.ID] = elem
	}

	return &RepositoryData{
		ImgList:   imgsData,
		Endpoints: endpoints,
	}, nil
}

// Retrieve an image from the Registry.
func (r *Session) GetRemoteImageJSON(imgID, registry string, token []string) ([]byte, int, error) {
	// Get the JSON
	req, err := r.reqFactory.NewRequest("GET", registry+"images/"+imgID+"/json", nil)
	if err != nil {
		return nil, -1, fmt.Errorf("Failed to download json: %s", err)
	}
	setTokenAuth(req, token)
	res, _, err := r.doRequest(req)
	if err != nil {
		return nil, -1, fmt.Errorf("Failed to download json: %s", err)
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		return nil, -1, httputils.NewHTTPRequestError(fmt.Sprintf("HTTP code %d", res.StatusCode), res)
	}
	// if the size header is not present, then set it to '-1'
	imageSize := -1
	if hdr := res.Header.Get("X-Docker-Size"); hdr != "" {
		imageSize, err = strconv.Atoi(hdr)
		if err != nil {
			return nil, -1, err
		}
	}

	jsonString, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, -1, fmt.Errorf("Failed to parse downloaded json: %s (%s)", err, jsonString)
	}
	return jsonString, imageSize, nil
}

func (r *Session) GetV2ImageBlobReader(ep *Endpoint, imageName string, dgst digest.Digest, auth *RequestAuthorization) (io.ReadCloser, int64, error) {
	routeURL, err := getV2Builder(ep).BuildBlobURL(imageName, dgst)
	if err != nil {
		return nil, 0, err
	}

	method := "GET"
	logrus.Debugf("[registry] Calling %q %s", method, routeURL)
	req, err := http.NewRequest(method, routeURL, nil)
	if err != nil {
		return nil, 0, err
	}
	if err := auth.Authorize(req); err != nil {
		return nil, 0, err
	}
	res, err := r.client.Do(req)
	if err != nil {
		return nil, 0, err
	}
	if res.StatusCode != 200 {
		if res.StatusCode == 401 {
			return nil, 0, errLoginRequired
		}
		return nil, 0, httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to pull %s blob - %s", res.StatusCode, imageName, dgst), res)
	}
	lenStr := res.Header.Get("Content-Length")
	l, err := strconv.ParseInt(lenStr, 10, 64)
	if err != nil {
		return nil, 0, err
	}

	return res.Body, l, err
}

func (r *Session) GetV2ImageBlob(ep *Endpoint, imageName string, dgst digest.Digest, blobWrtr io.Writer, auth *RequestAuthorization) error {
	routeURL, err := getV2Builder(ep).BuildBlobURL(imageName, dgst)
	if err != nil {
		return err
	}

	method := "GET"
	logrus.Debugf("[registry] Calling %q %s", method, routeURL)
	req, err := http.NewRequest(method, routeURL, nil)
	if err != nil {
		return err
	}
	if err := auth.Authorize(req); err != nil {
		return err
	}
	res, err := r.client.Do(req)
	if err != nil {
		return err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		if res.StatusCode == 401 {
			return errLoginRequired
		}
		return httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to pull %s blob", res.StatusCode, imageName), res)
	}

	_, err = io.Copy(blobWrtr, res.Body)
	return err
}

// - Succeeded to head image blob (already exists)
// - Failed with no error (continue to Push the Blob)
// - Failed with error
func (r *Session) HeadV2ImageBlob(ep *Endpoint, imageName string, dgst digest.Digest, auth *RequestAuthorization) (bool, error) {
	routeURL, err := getV2Builder(ep).BuildBlobURL(imageName, dgst)
	if err != nil {
		return false, err
	}

	method := "HEAD"
	logrus.Debugf("[registry] Calling %q %s", method, routeURL)

	req, err := http.NewRequest(method, routeURL, nil)
	if err != nil {
		return false, err
	}
	if err := auth.Authorize(req); err != nil {
		return false, err
	}
	res, err := r.client.Do(req)
	if err != nil {
		return false, err
	}
	res.Body.Close() // close early, since we're not needing a body on this call .. yet?
	switch {
	case res.StatusCode >= 200 && res.StatusCode < 400:
		// return something indicating no push needed
		return true, nil
	case res.StatusCode == 401:
		return false, errLoginRequired
	case res.StatusCode == 404:
		// return something indicating blob push needed
		return false, nil
	}

	return false, httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying head request for %s - %s", res.StatusCode, imageName, dgst), res)
}

// Retrieve the history of a given image from the Registry.
// Return a list of the parent's json (requested image included)
func (r *Session) GetRemoteHistory(imgID, registry string, token []string) ([]string, error) {
	req, err := r.reqFactory.NewRequest("GET", registry+"images/"+imgID+"/ancestry", nil)
	if err != nil {
		return nil, err
	}
	setTokenAuth(req, token)
	res, _, err := r.doRequest(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		if res.StatusCode == 401 {
			return nil, errLoginRequired
		}
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to fetch remote history for %s", res.StatusCode, imgID), res)
	}

	jsonString, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return nil, fmt.Errorf("Error while reading the http response: %s", err)
	}

	logrus.Debugf("Ancestry: %s", jsonString)
	history := new([]string)
	if err := json.Unmarshal(jsonString, history); err != nil {
		return nil, err
	}
	return *history, nil
}

func (r *Session) PushImageLayerRegistry(imgID string, layer io.Reader, registry string, jsonRaw []byte) (checksum string, checksumPayload string, err error) {

	u := registry + "images/" + imgID + "/layer"

	logrus.Debugf("[registry] Calling PUT %s", u)

	tarsumLayer, err := tarsum.NewTarSum(layer, false, tarsum.Version0)
	if err != nil {
		return "", "", err
	}
	h := sha256.New()
	h.Write(jsonRaw)
	h.Write([]byte{'\n'})
	checksumLayer := io.TeeReader(tarsumLayer, h)

	req, err := http.NewRequest("PUT", u, checksumLayer)
	if err != nil {
		return "", "", err
	}
	req.Header.Add("Content-Type", "application/octet-stream")
	req.ContentLength = -1
	req.TransferEncoding = []string{"chunked"}
	res, err := r.client.Do(req)
	if err != nil {
		return "", "", fmt.Errorf("Failed to upload layer: %v", err)
	}
	if rc, ok := layer.(io.Closer); ok {
		if err := rc.Close(); err != nil {
			return "", "", err
		}
	}
	defer res.Body.Close()

	if res.StatusCode != 200 {
		errBody, err := ioutil.ReadAll(res.Body)
		if err != nil {
			return "", "", httputils.NewHTTPRequestError(fmt.Sprintf("HTTP code %d while uploading metadata and error when trying to parse response body: %s", res.StatusCode, err), res)
		}
		return "", "", httputils.NewHTTPRequestError(fmt.Sprintf("Received HTTP code %d while uploading layer: %q", res.StatusCode, errBody), res)
	}

	checksumPayload = "sha256:" + hex.EncodeToString(h.Sum(nil))
	return tarsumLayer.Sum(jsonRaw), checksumPayload, nil
}

// Check if an image exists in the Registry
func (r *Session) LookupRemoteImage(imgID, registry string) error {
	res, err := r.client.Get(registry + "images/" + imgID + "/json")
	if err != nil {
		return err
	}
	res.Body.Close()
	if res.StatusCode != 200 {
		return httputils.NewHTTPRequestError(fmt.Sprintf("HTTP code %d", res.StatusCode), res)
	}
	return nil
}

// Finally Push the (signed) manifest of the blobs we've just pushed
func (r *Session) PutV2ImageManifest(ep *Endpoint, imageName, tagName string, signedManifest, rawManifest []byte, auth *RequestAuthorization) (digest.Digest, error) {
	routeURL, err := getV2Builder(ep).BuildManifestURL(imageName, tagName)
	if err != nil {
		return "", err
	}

	method := "PUT"
	logrus.Debugf("[registry] Calling %q %s", method, routeURL)
	req, err := http.NewRequest(method, routeURL, bytes.NewReader(signedManifest))
	if err != nil {
		return "", err
	}
	if err := auth.Authorize(req); err != nil {
		return "", err
	}
	res, err := r.client.Do(req)
	if err != nil {
		return "", err
	}
	defer res.Body.Close()

	// All 2xx and 3xx responses can be accepted for a put.
	if res.StatusCode >= 400 {
		if res.StatusCode == 401 {
			return "", errLoginRequired
		}
		errBody, err := ioutil.ReadAll(res.Body)
		if err != nil {
			return "", err
		}
		logrus.Debugf("Unexpected response from server: %q %#v", errBody, res.Header)
		return "", httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to push %s:%s manifest", res.StatusCode, imageName, tagName), res)
	}

	hdrDigest, err := digest.ParseDigest(res.Header.Get(DockerDigestHeader))
	if err != nil {
		return "", fmt.Errorf("invalid manifest digest from registry: %s", err)
	}

	dgstVerifier, err := digest.NewDigestVerifier(hdrDigest)
	if err != nil {
		return "", fmt.Errorf("invalid manifest digest from registry: %s", err)
	}

	dgstVerifier.Write(rawManifest)

	if !dgstVerifier.Verified() {
		computedDigest, _ := digest.FromBytes(rawManifest)
		return "", fmt.Errorf("unable to verify manifest digest: registry has %q, computed %q", hdrDigest, computedDigest)
	}

	return hdrDigest, nil
}

// GetV2ImageManifest simply fetches the bytes of a manifest and the remote
// digest, if available in the request. Note that the application shouldn't
// rely on the untrusted remoteDigest, and should also verify against a
// locally provided digest, if applicable.
func (r *Session) GetV2ImageManifest(ep *Endpoint, imageName, tagName string, auth *RequestAuthorization) (remoteDigest digest.Digest, p []byte, err error) {
	routeURL, err := getV2Builder(ep).BuildManifestURL(imageName, tagName)
	if err != nil {
		return "", nil, err
	}

	method := "GET"
	logrus.Debugf("[registry] Calling %q %s", method, routeURL)

	req, err := http.NewRequest(method, routeURL, nil)
	if err != nil {
		return "", nil, err
	}

	if err := auth.Authorize(req); err != nil {
		return "", nil, err
	}

	res, err := r.client.Do(req)
	if err != nil {
		return "", nil, err
	}
	defer res.Body.Close()

	if res.StatusCode != 200 {
		if res.StatusCode == 401 {
			return "", nil, errLoginRequired
		} else if res.StatusCode == 404 {
			return "", nil, ErrDoesNotExist
		}
		return "", nil, httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to fetch for %s:%s", res.StatusCode, imageName, tagName), res)
	}

	p, err = ioutil.ReadAll(res.Body)
	if err != nil {
		return "", nil, fmt.Errorf("Error while reading the http response: %s", err)
	}

	dgstHdr := res.Header.Get(DockerDigestHeader)
	if dgstHdr != "" {
		remoteDigest, err = digest.ParseDigest(dgstHdr)
		if err != nil {
			// NOTE(stevvooe): Including the remote digest is optional. We
			// don't need to verify against it, but it is good practice.
			remoteDigest = ""
			logrus.Debugf("error parsing remote digest when fetching %v: %v", routeURL, err)
		}
	}

	return
}

func (r *Session) SearchRepositories(term string) (*SearchResults, error) {
	logrus.Debugf("Index server: %s", r.indexEndpoint)
	u := r.indexEndpoint.VersionString(1) + "search?q=" + url.QueryEscape(term)
	res, err := r.client.Get(u)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("Unexpected status code %d", res.StatusCode), res)
	}
	result := new(SearchResults)
	return result, json.NewDecoder(res.Body).Decode(result)
}

// Check if an image exists in the Registry
func (r *Session) LookupRemoteImage(imgID, registry string, token []string) error {
	req, err := r.reqFactory.NewRequest("GET", registry+"images/"+imgID+"/json", nil)
	if err != nil {
		return err
	}
	setTokenAuth(req, token)
	res, _, err := r.doRequest(req)
	if err != nil {
		return err
	}
	res.Body.Close()
	if res.StatusCode != 200 {
		return httputils.NewHTTPRequestError(fmt.Sprintf("HTTP code %d", res.StatusCode), res)
	}
	return nil
}

// initiateBlobUpload gets the blob upload location for the given image name.
func (r *Session) initiateBlobUpload(ep *Endpoint, imageName string, auth *RequestAuthorization) (location string, err error) {
	routeURL, err := getV2Builder(ep).BuildBlobUploadURL(imageName)
	if err != nil {
		return "", err
	}

	logrus.Debugf("[registry] Calling %q %s", "POST", routeURL)
	req, err := http.NewRequest("POST", routeURL, nil)
	if err != nil {
		return "", err
	}

	if err := auth.Authorize(req); err != nil {
		return "", err
	}
	res, err := r.client.Do(req)
	if err != nil {
		return "", err
	}

	if res.StatusCode != http.StatusAccepted {
		if res.StatusCode == http.StatusUnauthorized {
			return "", errLoginRequired
		}
		if res.StatusCode == http.StatusNotFound {
			return "", ErrDoesNotExist
		}

		errBody, err := ioutil.ReadAll(res.Body)
		if err != nil {
			return "", err
		}

		logrus.Debugf("Unexpected response from server: %q %#v", errBody, res.Header)
		return "", httputils.NewHTTPRequestError(fmt.Sprintf("Server error: unexpected %d response status trying to initiate upload of %s", res.StatusCode, imageName), res)
	}

	if location = res.Header.Get("Location"); location == "" {
		return "", fmt.Errorf("registry did not return a Location header for resumable blob upload for image %s", imageName)
	}

	return
}

// push a tag on the registry.
// Remote has the format '<user>/<repo>
func (r *Session) PushRegistryTag(remote, revision, tag, registry string) error {
	// "jsonify" the string
	revision = "\"" + revision + "\""
	path := fmt.Sprintf("repositories/%s/tags/%s", remote, tag)

	req, err := http.NewRequest("PUT", registry+path, strings.NewReader(revision))
	if err != nil {
		return err
	}
	req.Header.Add("Content-type", "application/json")
	req.ContentLength = int64(len(revision))
	res, err := r.client.Do(req)
	if err != nil {
		return err
	}
	res.Body.Close()
	if res.StatusCode != 200 && res.StatusCode != 201 {
		return httputils.NewHTTPRequestError(fmt.Sprintf("Internal server error: %d trying to push tag %s on %s", res.StatusCode, tag, remote), res)
	}
	return nil
}

// Retrieve the history of a given image from the Registry.
// Return a list of the parent's json (requested image included)
func (r *Session) GetRemoteHistory(imgID, registry string) ([]string, error) {
	res, err := r.client.Get(registry + "images/" + imgID + "/ancestry")
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		if res.StatusCode == 401 {
			return nil, errLoginRequired
		}
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to fetch remote history for %s", res.StatusCode, imgID), res)
	}

	var history []string
	if err := json.NewDecoder(res.Body).Decode(&history); err != nil {
		return nil, fmt.Errorf("Error while reading the http response: %v", err)
	}

	logrus.Debugf("Ancestry: %v", history)
	return history, nil
}

// SearchRepositories performs a search against the remote repository
func (r *Session) SearchRepositories(term string) (*SearchResults, error) {
	logrus.Debugf("Index server: %s", r.indexEndpoint)
	u := r.indexEndpoint.VersionString(1) + "search?q=" + url.QueryEscape(term)

	req, err := http.NewRequest("GET", u, nil)
	if err != nil {
		return nil, fmt.Errorf("Error while getting from the server: %v", err)
	}
	// Have the AuthTransport send authentication, when logged in.
	req.Header.Set("X-Docker-Token", "true")
	res, err := r.client.Do(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("Unexpected status code %d", res.StatusCode), res)
	}
	result := new(SearchResults)
	return result, json.NewDecoder(res.Body).Decode(result)
}

func (r *Session) SearchRepositories(term string) (*SearchResults, error) {
	logrus.Debugf("Index server: %s", r.indexEndpoint)
	u := r.indexEndpoint.VersionString(1) + "search?q=" + url.QueryEscape(term)
	req, err := r.reqFactory.NewRequest("GET", u, nil)
	if err != nil {
		return nil, err
	}
	if r.authConfig != nil && len(r.authConfig.Username) > 0 {
		req.SetBasicAuth(r.authConfig.Username, r.authConfig.Password)
	}
	req.Header.Set("X-Docker-Token", "true")
	res, _, err := r.doRequest(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("Unexpected status code %d", res.StatusCode), res)
	}
	result := new(SearchResults)
	return result, json.NewDecoder(res.Body).Decode(result)
}

// Given a repository name, returns a json array of string tags
func (r *Session) GetV2RemoteTags(ep *Endpoint, imageName string, auth *RequestAuthorization) ([]string, error) {
	routeURL, err := getV2Builder(ep).BuildTagsURL(imageName)
	if err != nil {
		return nil, err
	}

	method := "GET"
	logrus.Debugf("[registry] Calling %q %s", method, routeURL)

	req, err := r.reqFactory.NewRequest(method, routeURL, nil)
	if err != nil {
		return nil, err
	}
	if err := auth.Authorize(req); err != nil {
		return nil, err
	}
	res, _, err := r.doRequest(req)
	if err != nil {
		return nil, err
	}
	defer res.Body.Close()
	if res.StatusCode != 200 {
		if res.StatusCode == 401 {
			return nil, errLoginRequired
		} else if res.StatusCode == 404 {
			return nil, ErrDoesNotExist
		}
		return nil, httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to fetch for %s", res.StatusCode, imageName), res)
	}

	decoder := json.NewDecoder(res.Body)
	var remote remoteTags
	err = decoder.Decode(&remote)
	if err != nil {
		return nil, fmt.Errorf("Error while decoding the http response: %s", err)
	}
	return remote.Tags, nil
}

// Push the image to the server for storage.
// 'layer' is an uncompressed reader of the blob to be pushed.
// The server will generate it's own checksum calculation.
func (r *Session) PutV2ImageBlob(ep *Endpoint, imageName string, dgst digest.Digest, blobRdr io.Reader, auth *RequestAuthorization) error {
	location, err := r.initiateBlobUpload(ep, imageName, auth)
	if err != nil {
		return err
	}

	method := "PUT"
	logrus.Debugf("[registry] Calling %q %s", method, location)
	req, err := http.NewRequest(method, location, ioutil.NopCloser(blobRdr))
	if err != nil {
		return err
	}
	queryParams := req.URL.Query()
	queryParams.Add("digest", dgst.String())
	req.URL.RawQuery = queryParams.Encode()
	if err := auth.Authorize(req); err != nil {
		return err
	}
	res, err := r.client.Do(req)
	if err != nil {
		return err
	}
	defer res.Body.Close()

	if res.StatusCode != 201 {
		if res.StatusCode == 401 {
			return errLoginRequired
		}
		errBody, err := ioutil.ReadAll(res.Body)
		if err != nil {
			return err
		}
		logrus.Debugf("Unexpected response from server: %q %#v", errBody, res.Header)
		return httputils.NewHTTPRequestError(fmt.Sprintf("Server error: %d trying to push %s blob - %s", res.StatusCode, imageName, dgst), res)
	}

	return nil
}