Merge pull request #1419 from bstasyszyn/1418

fix: Discover actor from service endpoint in orb-cli

cmd/orb-cli/common/activitypubclient.go

@@ -0,0 +1,186 @@
+/*
+Copyright SecureKey Technologies Inc. All Rights Reserved.
+
+SPDX-License-Identifier: Apache-2.0
+*/
+
+package common
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/spf13/cobra"
+	cmdutils "github.com/trustbloc/edge-core/pkg/utils/cmd"
+
+	"github.com/trustbloc/orb/pkg/activitypub/vocab"
+	orberrors "github.com/trustbloc/orb/pkg/errors"
+)
+
+// ActivityPubClient reads ActivityPub actors and collections from the service endpoint.
+type ActivityPubClient struct {
+	cmd          *cobra.Command
+	sendRequest  requestSender
+	overridesMap map[string]string
+}
+
+// NewActivityPubClient returns a new ActivityPub client.
+func NewActivityPubClient(cmd *cobra.Command) (*ActivityPubClient, error) {
+	httpClient, err := NewHTTPClient(cmd)
+	if err != nil {
+		return nil, err
+	}
+
+	headers := newAuthTokenHeader(cmd)
+
+	overridesMap := make(map[string]string)
+
+	const mappingParts = 2
+
+	for _, mapping := range cmdutils.GetUserSetOptionalVarFromArrayString(cmd, TargetOverrideFlagName,
+		TargetOverrideEnvKey) {
+		pair := strings.Split(mapping, "->")
+		if len(pair) != mappingParts {
+			return nil, fmt.Errorf("invalid target override %s", mapping)
+		}
+
+		overridesMap[pair[0]] = pair[1]
+	}
+
+	return &ActivityPubClient{
+		cmd:          cmd,
+		overridesMap: overridesMap,
+		sendRequest: func(req []byte, method, endpointURL string) ([]byte, error) {
+			return SendRequest(httpClient, req, headers, method, endpointURL)
+		},
+	}, nil
+}
+
+// ResolveActor returns the actor for the given endpoint.
+func (c *ActivityPubClient) ResolveActor(actorEndpoint string) (*vocab.ActorType, error) {
+	resp, err := c.sendRequest(nil, http.MethodGet, c.overrideTarget(actorEndpoint))
+	if err != nil {
+		return nil, fmt.Errorf("send http request: %w", err)
+	}
+
+	actor := &vocab.ActorType{}
+
+	if err := json.Unmarshal(resp, actor); err != nil {
+		return nil, fmt.Errorf("unmarshal actor: %w", err)
+	}
+
+	return actor, nil
+}
+
+// GetCollection returns an ActivityPub collection iterator for the given collection IRI.
+func (c *ActivityPubClient) GetCollection(collURI *url.URL) (*ActivityPubCollectionIterator, error) {
+	return newAPCollIterator(c.cmd, collURI.String(), c.sendRequest, c.overrideTarget)
+}
+
+// CollectionContains returns true if the given ActivityPub collection contains the given IRI.
+func (c *ActivityPubClient) CollectionContains(collURI *url.URL, iri string) (bool, error) {
+	it, err := c.GetCollection(collURI)
+	if err != nil {
+		return false, fmt.Errorf("get ActivityPub collection iterator: %w", err)
+	}
+
+	for {
+		item, err := it.Next()
+		if err != nil {
+			if errors.Is(err, orberrors.ErrContentNotFound) {
+				return false, nil
+			}
+
+			return false, err
+		}
+
+		if item.String() == iri {
+			return true, nil
+		}
+	}
+}
+
+// overrideTarget checks if there is an override for the given target (specified with the --target-override flag).
+// If so, a new target URL is returned, otherwise the same target is returned.
+func (c *ActivityPubClient) overrideTarget(targetURI string) string {
+	for oldTarget, newTarget := range c.overridesMap {
+		if strings.Contains(targetURI, "//"+oldTarget) {
+			return strings.Replace(targetURI, "//"+oldTarget, "//"+newTarget, 1)
+		}
+	}
+
+	return targetURI
+}
+
+// ActivityPubCollectionIterator iterates over an ActivityPub collection.
+type ActivityPubCollectionIterator struct {
+	cmd               *cobra.Command
+	sendRequest       requestSender
+	getTargetOverride targetOverrideFunc
+	nextPage          *url.URL
+	items             []*vocab.ObjectProperty
+	index             int
+}
+
+type requestSender func(req []byte, method, endpointURL string) ([]byte, error)
+
+type targetOverrideFunc func(targetURI string) string
+
+func newAPCollIterator(cmd *cobra.Command, collURI string, sendRequest requestSender,
+	getTargetOverride targetOverrideFunc) (*ActivityPubCollectionIterator, error) {
+	resp, err := sendRequest(nil, http.MethodGet, getTargetOverride(collURI))
+	if err != nil {
+		return nil, fmt.Errorf("failed to send http request: %w", err)
+	}
+
+	coll := &vocab.CollectionType{}
+
+	if err := json.Unmarshal(resp, coll); err != nil {
+		return nil, err
+	}
+
+	return &ActivityPubCollectionIterator{
+		cmd:               cmd,
+		sendRequest:       sendRequest,
+		getTargetOverride: getTargetOverride,
+		nextPage:          coll.First(),
+	}, nil
+}
+
+// Next returns the next item in the collection.
+func (it *ActivityPubCollectionIterator) Next() (*url.URL, error) {
+	if it.index >= len(it.items) {
+		if it.nextPage == nil {
+			return nil, orberrors.ErrContentNotFound
+		}
+
+		resp, err := it.sendRequest(nil, http.MethodGet, it.getTargetOverride(it.nextPage.String()))
+		if err != nil {
+			return nil, fmt.Errorf("send http request: %w", err)
+		}
+
+		collPage := &vocab.CollectionPageType{}
+
+		if err := json.Unmarshal(resp, collPage); err != nil {
+			return nil, err
+		}
+
+		it.items = collPage.Items()
+		it.index = 0
+		it.nextPage = collPage.Next()
+	}
+
+	i := it.index
+
+	it.index++
+
+	if i >= len(it.items) {
+		return nil, orberrors.ErrContentNotFound
+	}
+
+	return it.items[i].IRI(), nil
+}