[chore] de-interface{} the federator and dereferencer structs (#2285)

* de-interface{} the federator and dereferencer structs

* fix broken type signatures

18 files changed, 103 insertions, 156 deletions

diff --git a/internal/federation/authenticate.go b/internal/federation/authenticate.go
index 12d6f459a..a42633b8f 100644
--- a/internal/federation/authenticate.go
+++ b/internal/federation/authenticate.go
@@ -109,7 +109,7 @@ type PubKeyAuth struct {
 // Also note that this function *does not* dereference the remote account that
 // the signature key is associated with. Other functions should use the returned
 // URL to dereference the remote account, if required.
-func (f *federator) AuthenticateFederatedRequest(ctx context.Context, requestedUsername string) (*PubKeyAuth, gtserror.WithCode) {
+func (f *Federator) AuthenticateFederatedRequest(ctx context.Context, requestedUsername string) (*PubKeyAuth, gtserror.WithCode) {
 	// Thanks to the signature check middleware,
 	// we should already have an http signature
 	// verifier set on the context. If we don't,
@@ -215,7 +215,7 @@ func (f *federator) AuthenticateFederatedRequest(ctx context.Context, requestedU
 //
 // In case an entry for the pubKey owner just doesn't
 // exist in the db (yet), will return nil, nil.
-func (f *federator) derefPubKeyDBOnly(
+func (f *Federator) derefPubKeyDBOnly(
 	ctx context.Context,
 	pubKeyIDStr string,
 ) (*PubKeyAuth, gtserror.WithCode) {
@@ -248,7 +248,7 @@ func (f *federator) derefPubKeyDBOnly(
 // checking in the database, and then (if no entry found, or entry
 // found but pubKey expired) calling the remote pub key URI and
 // extracting the key.
-func (f *federator) derefPubKey(
+func (f *Federator) derefPubKey(
 	ctx context.Context,
 	requestedUsername string,
 	pubKeyIDStr string,
@@ -363,7 +363,7 @@ func (f *federator) derefPubKey(
 // callForPubKey handles the nitty gritty of actually
 // making a request for the given pubKeyID with a
 // transport created on behalf of requestedUsername.
-func (f *federator) callForPubKey(
+func (f *Federator) callForPubKey(
 	ctx context.Context,
 	requestedUsername string,
 	pubKeyID *url.URL,
diff --git a/internal/federation/commonbehavior.go b/internal/federation/commonbehavior.go
index 4fbbe4b14..5ca704db7 100644
--- a/internal/federation/commonbehavior.go
+++ b/internal/federation/commonbehavior.go
@@ -51,7 +51,7 @@ import (
 // Finally, if the authentication and authorization succeeds, then
 // authenticated must be true and error nil. The request will continue
 // to be processed.
-func (f *federator) AuthenticateGetInbox(ctx context.Context, w http.ResponseWriter, r *http.Request) (context.Context, bool, error) {
+func (f *Federator) AuthenticateGetInbox(ctx context.Context, w http.ResponseWriter, r *http.Request) (context.Context, bool, error) {
 	// IMPLEMENTATION NOTE: For GoToSocial, we serve GETS to outboxes and inboxes through
 	// the CLIENT API, not through the federation API, so we just do nothing here.
 	return ctx, false, nil
@@ -76,7 +76,7 @@ func (f *federator) AuthenticateGetInbox(ctx context.Context, w http.ResponseWri
 // Finally, if the authentication and authorization succeeds, then
 // authenticated must be true and error nil. The request will continue
 // to be processed.
-func (f *federator) AuthenticateGetOutbox(ctx context.Context, w http.ResponseWriter, r *http.Request) (context.Context, bool, error) {
+func (f *Federator) AuthenticateGetOutbox(ctx context.Context, w http.ResponseWriter, r *http.Request) (context.Context, bool, error) {
 	// IMPLEMENTATION NOTE: For GoToSocial, we serve GETS to outboxes and inboxes through
 	// the CLIENT API, not through the federation API, so we just do nothing here.
 	return ctx, false, nil
@@ -90,7 +90,7 @@ func (f *federator) AuthenticateGetOutbox(ctx context.Context, w http.ResponseWr
 //
 // Always called, regardless whether the Federated Protocol or Social
 // API is enabled.
-func (f *federator) GetOutbox(ctx context.Context, r *http.Request) (vocab.ActivityStreamsOrderedCollectionPage, error) {
+func (f *Federator) GetOutbox(ctx context.Context, r *http.Request) (vocab.ActivityStreamsOrderedCollectionPage, error) {
 	// IMPLEMENTATION NOTE: For GoToSocial, we serve GETS to outboxes and inboxes through
 	// the CLIENT API, not through the federation API, so we just do nothing here.
 	return streams.NewActivityStreamsOrderedCollectionPage(), nil
diff --git a/internal/federation/dereferencing/account.go b/internal/federation/dereferencing/account.go
index 04efc464f..f94dbaffa 100644
--- a/internal/federation/dereferencing/account.go
+++ b/internal/federation/dereferencing/account.go
@@ -60,8 +60,10 @@ func accountUpToDate(account *gtsmodel.Account) bool {
 	return false
 }
 
-// GetAccountByURI: implements Dereferencer{}.GetAccountByURI.
-func (d *deref) GetAccountByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Account, ap.Accountable, error) {
+// GetAccountByURI will attempt to fetch an accounts by its URI, first checking the database. In the case of a newly-met remote model, or a remote model
+// whose last_fetched date is beyond a certain interval, the account will be dereferenced. In the case of dereferencing, some low-priority account information
+// may be enqueued for asynchronous fetching, e.g. featured account statuses (pins). An ActivityPub object indicates the account was dereferenced.
+func (d *Dereferencer) GetAccountByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Account, ap.Accountable, error) {
 	// Fetch and dereference account if necessary.
 	account, apubAcc, err := d.getAccountByURI(ctx,
 		requestUser,
@@ -84,7 +86,7 @@ func (d *deref) GetAccountByURI(ctx context.Context, requestUser string, uri *ur
 }
 
 // getAccountByURI is a package internal form of .GetAccountByURI() that doesn't bother dereferencing featured posts on update.
-func (d *deref) getAccountByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Account, ap.Accountable, error) {
+func (d *Dereferencer) getAccountByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Account, ap.Accountable, error) {
 	var (
 		account *gtsmodel.Account
 		uriStr  = uri.String()
@@ -157,8 +159,10 @@ func (d *deref) getAccountByURI(ctx context.Context, requestUser string, uri *ur
 	return latest, apubAcc, nil
 }
 
-// GetAccountByUsernameDomain: implements Dereferencer{}.GetAccountByUsernameDomain.
-func (d *deref) GetAccountByUsernameDomain(ctx context.Context, requestUser string, username string, domain string) (*gtsmodel.Account, ap.Accountable, error) {
+// GetAccountByUsernameDomain will attempt to fetch an accounts by its username@domain, first checking the database. In the case of a newly-met remote model,
+// or a remote model whose last_fetched date is beyond a certain interval, the account will be dereferenced. In the case of dereferencing, some low-priority
+// account information may be enqueued for asynchronous fetching, e.g. featured account statuses (pins). An ActivityPub object indicates the account was dereferenced.
+func (d *Dereferencer) GetAccountByUsernameDomain(ctx context.Context, requestUser string, username string, domain string) (*gtsmodel.Account, ap.Accountable, error) {
 	if domain == config.GetHost() || domain == config.GetAccountDomain() {
 		// We do local lookups using an empty domain,
 		// else it will fail the db search below.
@@ -224,8 +228,10 @@ func (d *deref) GetAccountByUsernameDomain(ctx context.Context, requestUser stri
 	return latest, apubAcc, nil
 }
 
-// RefreshAccount: implements Dereferencer{}.RefreshAccount.
-func (d *deref) RefreshAccount(ctx context.Context, requestUser string, account *gtsmodel.Account, apubAcc ap.Accountable, force bool) (*gtsmodel.Account, ap.Accountable, error) {
+// RefreshAccount updates the given account if remote and last_fetched is beyond fetch interval, or if force is set. An updated account model is returned,
+// but in the case of dereferencing, some low-priority account information may be enqueued for asynchronous fetching, e.g. featured account statuses (pins).
+// An ActivityPub object indicates the account was dereferenced (i.e. updated).
+func (d *Dereferencer) RefreshAccount(ctx context.Context, requestUser string, account *gtsmodel.Account, apubAcc ap.Accountable, force bool) (*gtsmodel.Account, ap.Accountable, error) {
 	// Check whether needs update (and not forced).
 	if accountUpToDate(account) && !force {
 		return account, nil, nil
@@ -264,8 +270,9 @@ func (d *deref) RefreshAccount(ctx context.Context, requestUser string, account
 	return latest, apubAcc, nil
 }
 
-// RefreshAccountAsync: implements Dereferencer{}.RefreshAccountAsync.
-func (d *deref) RefreshAccountAsync(ctx context.Context, requestUser string, account *gtsmodel.Account, apubAcc ap.Accountable, force bool) {
+// RefreshAccountAsync enqueues the given account for an asychronous update fetching, if last_fetched is beyond fetch interval, or if forcc is set.
+// This is a more optimized form of manually enqueueing .UpdateAccount() to the federation worker, since it only enqueues update if necessary.
+func (d *Dereferencer) RefreshAccountAsync(ctx context.Context, requestUser string, account *gtsmodel.Account, apubAcc ap.Accountable, force bool) {
 	// Check whether needs update (and not forced).
 	if accountUpToDate(account) && !force {
 		return
@@ -294,7 +301,7 @@ func (d *deref) RefreshAccountAsync(ctx context.Context, requestUser string, acc
 }
 
 // enrichAccount will enrich the given account, whether a new barebones model, or existing model from the database. It handles necessary dereferencing, webfingering etc.
-func (d *deref) enrichAccount(ctx context.Context, requestUser string, uri *url.URL, account *gtsmodel.Account, apubAcc ap.Accountable) (*gtsmodel.Account, ap.Accountable, error) {
+func (d *Dereferencer) enrichAccount(ctx context.Context, requestUser string, uri *url.URL, account *gtsmodel.Account, apubAcc ap.Accountable) (*gtsmodel.Account, ap.Accountable, error) {
 	// Pre-fetch a transport for requesting username, used by later deref procedures.
 	tsport, err := d.transportController.NewTransportForUsername(ctx, requestUser)
 	if err != nil {
@@ -472,7 +479,7 @@ func (d *deref) enrichAccount(ctx context.Context, requestUser string, uri *url.
 	return latestAcc, apubAcc, nil
 }
 
-func (d *deref) fetchRemoteAccountAvatar(ctx context.Context, tsport transport.Transport, existing, latestAcc *gtsmodel.Account) error {
+func (d *Dereferencer) fetchRemoteAccountAvatar(ctx context.Context, tsport transport.Transport, existing, latestAcc *gtsmodel.Account) error {
 	if latestAcc.AvatarRemoteURL == "" {
 		// No avatar set on newest model, leave
 		// latest avatar attachment ID empty.
@@ -562,7 +569,7 @@ func (d *deref) fetchRemoteAccountAvatar(ctx context.Context, tsport transport.T
 	return nil
 }
 
-func (d *deref) fetchRemoteAccountHeader(ctx context.Context, tsport transport.Transport, existing, latestAcc *gtsmodel.Account) error {
+func (d *Dereferencer) fetchRemoteAccountHeader(ctx context.Context, tsport transport.Transport, existing, latestAcc *gtsmodel.Account) error {
 	if latestAcc.HeaderRemoteURL == "" {
 		// No header set on newest model, leave
 		// latest header attachment ID empty.
@@ -652,7 +659,7 @@ func (d *deref) fetchRemoteAccountHeader(ctx context.Context, tsport transport.T
 	return nil
 }
 
-func (d *deref) fetchRemoteAccountEmojis(ctx context.Context, targetAccount *gtsmodel.Account, requestingUsername string) (bool, error) {
+func (d *Dereferencer) fetchRemoteAccountEmojis(ctx context.Context, targetAccount *gtsmodel.Account, requestingUsername string) (bool, error) {
 	maybeEmojis := targetAccount.Emojis
 	maybeEmojiIDs := targetAccount.EmojiIDs
 
@@ -766,7 +773,7 @@ func (d *deref) fetchRemoteAccountEmojis(ctx context.Context, targetAccount *gts
 
 // dereferenceAccountFeatured dereferences an account's featuredCollectionURI (if not empty). For each discovered status, this status will
 // be dereferenced (if necessary) and marked as pinned (if necessary). Then, old pins will be removed if they're not included in new pins.
-func (d *deref) dereferenceAccountFeatured(ctx context.Context, requestUser string, account *gtsmodel.Account) error {
+func (d *Dereferencer) dereferenceAccountFeatured(ctx context.Context, requestUser string, account *gtsmodel.Account) error {
 	uri, err := url.Parse(account.FeaturedCollectionURI)
 	if err != nil {
 		return err
diff --git a/internal/federation/dereferencing/announce.go b/internal/federation/dereferencing/announce.go
index e479e41b1..22c33685a 100644
--- a/internal/federation/dereferencing/announce.go
+++ b/internal/federation/dereferencing/announce.go
@@ -27,7 +27,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 )
 
-func (d *deref) DereferenceAnnounce(ctx context.Context, announce *gtsmodel.Status, requestingUsername string) error {
+func (d *Dereferencer) DereferenceAnnounce(ctx context.Context, announce *gtsmodel.Status, requestingUsername string) error {
 	if announce.BoostOf == nil {
 		// we can't do anything unfortunately
 		return errors.New("DereferenceAnnounce: no URI to dereference")
diff --git a/internal/federation/dereferencing/collectionpage.go b/internal/federation/dereferencing/collectionpage.go
index dc4ac7b4b..dc5c68273 100644
--- a/internal/federation/dereferencing/collectionpage.go
+++ b/internal/federation/dereferencing/collectionpage.go
@@ -30,7 +30,7 @@ import (
 )
 
 // dereferenceCollectionPage returns the activitystreams CollectionPage at the specified IRI, or an error if something goes wrong.
-func (d *deref) dereferenceCollectionPage(ctx context.Context, username string, pageIRI *url.URL) (ap.CollectionPageIterator, error) {
+func (d *Dereferencer) dereferenceCollectionPage(ctx context.Context, username string, pageIRI *url.URL) (ap.CollectionPageIterator, error) {
 	if blocked, err := d.state.DB.IsDomainBlocked(ctx, pageIRI.Host); blocked || err != nil {
 		return nil, gtserror.Newf("domain %s is blocked", pageIRI.Host)
 	}
diff --git a/internal/federation/dereferencing/dereferencer.go b/internal/federation/dereferencing/dereferencer.go
index 6248aa2c1..a5c68bd80 100644
--- a/internal/federation/dereferencing/dereferencer.go
+++ b/internal/federation/dereferencing/dereferencer.go
@@ -18,72 +18,19 @@
 package dereferencing
 
 import (
-	"context"
 	"net/url"
 	"sync"
 
 	"codeberg.org/gruf/go-mutexes"
-	"github.com/superseriousbusiness/gotosocial/internal/ap"
-	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/media"
 	"github.com/superseriousbusiness/gotosocial/internal/state"
 	"github.com/superseriousbusiness/gotosocial/internal/transport"
 	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
 )
 
-// Dereferencer wraps logic and functionality for doing dereferencing of remote accounts, statuses, etc, from federated instances.
-type Dereferencer interface {
-	// GetAccountByURI will attempt to fetch an accounts by its URI, first checking the database. In the case of a newly-met remote model, or a remote model
-	// whose last_fetched date is beyond a certain interval, the account will be dereferenced. In the case of dereferencing, some low-priority account information
-	// may be enqueued for asynchronous fetching, e.g. featured account statuses (pins). An ActivityPub object indicates the account was dereferenced.
-	GetAccountByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Account, ap.Accountable, error)
-
-	// GetAccountByUsernameDomain will attempt to fetch an accounts by its username@domain, first checking the database. In the case of a newly-met remote model,
-	// or a remote model whose last_fetched date is beyond a certain interval, the account will be dereferenced. In the case of dereferencing, some low-priority
-	// account information may be enqueued for asynchronous fetching, e.g. featured account statuses (pins). An ActivityPub object indicates the account was dereferenced.
-	GetAccountByUsernameDomain(ctx context.Context, requestUser string, username string, domain string) (*gtsmodel.Account, ap.Accountable, error)
-
-	// RefreshAccount updates the given account if remote and last_fetched is beyond fetch interval, or if force is set. An updated account model is returned,
-	// but in the case of dereferencing, some low-priority account information may be enqueued for asynchronous fetching, e.g. featured account statuses (pins).
-	// An ActivityPub object indicates the account was dereferenced (i.e. updated).
-	RefreshAccount(ctx context.Context, requestUser string, account *gtsmodel.Account, apubAcc ap.Accountable, force bool) (*gtsmodel.Account, ap.Accountable, error)
-
-	// RefreshAccountAsync enqueues the given account for an asychronous update fetching, if last_fetched is beyond fetch interval, or if forcc is set.
-	// This is a more optimized form of manually enqueueing .UpdateAccount() to the federation worker, since it only enqueues update if necessary.
-	RefreshAccountAsync(ctx context.Context, requestUser string, account *gtsmodel.Account, apubAcc ap.Accountable, force bool)
-
-	// GetStatusByURI will attempt to fetch a status by its URI, first checking the database. In the case of a newly-met remote model, or a remote model
-	// whose last_fetched date is beyond a certain interval, the status will be dereferenced. In the case of dereferencing, some low-priority status information
-	// may be enqueued for asynchronous fetching, e.g. dereferencing the remainder of the status thread. An ActivityPub object indicates the status was dereferenced.
-	GetStatusByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Status, ap.Statusable, error)
-
-	// RefreshStatus updates the given status if remote and last_fetched is beyond fetch interval, or if force is set. An updated status model is returned,
-	// but in the case of dereferencing, some low-priority status information may be enqueued for asynchronous fetching, e.g. dereferencing the remainder of the
-	// status thread. An ActivityPub object indicates the status was dereferenced (i.e. updated).
-	RefreshStatus(ctx context.Context, requestUser string, status *gtsmodel.Status, apubStatus ap.Statusable, force bool) (*gtsmodel.Status, ap.Statusable, error)
-
-	// RefreshStatusAsync enqueues the given status for an asychronous update fetching, if last_fetched is beyond fetch interval, or if force is set.
-	// This is a more optimized form of manually enqueueing .UpdateStatus() to the federation worker, since it only enqueues update if necessary.
-	RefreshStatusAsync(ctx context.Context, requestUser string, status *gtsmodel.Status, apubStatus ap.Statusable, force bool)
-
-	// DereferenceStatusAncestors iterates upwards from the given status, using InReplyToURI, to ensure that as many parent statuses as possible are dereferenced.
-	DereferenceStatusAncestors(ctx context.Context, requestUser string, status *gtsmodel.Status) error
-
-	// DereferenceStatusDescendents iterates downwards from the given status, using its replies, to ensure that as many children statuses as possible are dereferenced.
-	DereferenceStatusDescendants(ctx context.Context, requestUser string, statusIRI *url.URL, parent ap.Statusable) error
-
-	GetRemoteInstance(ctx context.Context, username string, remoteInstanceURI *url.URL) (*gtsmodel.Instance, error)
-
-	DereferenceAnnounce(ctx context.Context, announce *gtsmodel.Status, requestingUsername string) error
-
-	GetRemoteMedia(ctx context.Context, requestingUsername string, accountID string, remoteURL string, ai *media.AdditionalMediaInfo) (*media.ProcessingMedia, error)
-
-	GetRemoteEmoji(ctx context.Context, requestingUsername string, remoteURL string, shortcode string, domain string, id string, emojiURI string, ai *media.AdditionalEmojiInfo, refresh bool) (*media.ProcessingEmoji, error)
-
-	Handshaking(username string, remoteAccountID *url.URL) bool
-}
-
-type deref struct {
+// Dereferencer wraps logic and functionality for doing dereferencing
+// of remote accounts, statuses, etc, from federated instances.
+type Dereferencer struct {
 	state               *state.State
 	converter           *typeutils.Converter
 	transportController transport.Controller
@@ -99,8 +46,13 @@ type deref struct {
 }
 
 // NewDereferencer returns a Dereferencer initialized with the given parameters.
-func NewDereferencer(state *state.State, converter *typeutils.Converter, transportController transport.Controller, mediaManager *media.Manager) Dereferencer {
-	return &deref{
+func NewDereferencer(
+	state *state.State,
+	converter *typeutils.Converter,
+	transportController transport.Controller,
+	mediaManager *media.Manager,
+) Dereferencer {
+	return Dereferencer{
 		state:               state,
 		converter:           converter,
 		transportController: transportController,
diff --git a/internal/federation/dereferencing/emoji.go b/internal/federation/dereferencing/emoji.go
index 3ce3c7f10..2d86da663 100644
--- a/internal/federation/dereferencing/emoji.go
+++ b/internal/federation/dereferencing/emoji.go
@@ -30,7 +30,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/media"
 )
 
-func (d *deref) GetRemoteEmoji(ctx context.Context, requestingUsername string, remoteURL string, shortcode string, domain string, id string, emojiURI string, ai *media.AdditionalEmojiInfo, refresh bool) (*media.ProcessingEmoji, error) {
+func (d *Dereferencer) GetRemoteEmoji(ctx context.Context, requestingUsername string, remoteURL string, shortcode string, domain string, id string, emojiURI string, ai *media.AdditionalEmojiInfo, refresh bool) (*media.ProcessingEmoji, error) {
 	var (
 		shortcodeDomain = shortcode + "@" + domain
 		processingEmoji *media.ProcessingEmoji
@@ -88,7 +88,7 @@ func (d *deref) GetRemoteEmoji(ctx context.Context, requestingUsername string, r
 	return processingEmoji, nil
 }
 
-func (d *deref) populateEmojis(ctx context.Context, rawEmojis []*gtsmodel.Emoji, requestingUsername string) ([]*gtsmodel.Emoji, error) {
+func (d *Dereferencer) populateEmojis(ctx context.Context, rawEmojis []*gtsmodel.Emoji, requestingUsername string) ([]*gtsmodel.Emoji, error) {
 	// At this point we should know:
 	// * the AP uri of the emoji
 	// * the domain of the emoji
diff --git a/internal/federation/dereferencing/finger.go b/internal/federation/dereferencing/finger.go
index fff079327..a81afa5ea 100644
--- a/internal/federation/dereferencing/finger.go
+++ b/internal/federation/dereferencing/finger.go
@@ -30,7 +30,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
-func (d *deref) fingerRemoteAccount(ctx context.Context, transport transport.Transport, targetUsername string, targetHost string) (accountDomain string, accountURI *url.URL, err error) {
+func (d *Dereferencer) fingerRemoteAccount(ctx context.Context, transport transport.Transport, targetUsername string, targetHost string) (accountDomain string, accountURI *url.URL, err error) {
 	b, err := transport.Finger(ctx, targetUsername, targetHost)
 	if err != nil {
 		err = fmt.Errorf("fingerRemoteAccount: error fingering @%s@%s: %s", targetUsername, targetHost, err)
diff --git a/internal/federation/dereferencing/handshake.go b/internal/federation/dereferencing/handshake.go
index 96d8d349f..1180ff140 100644
--- a/internal/federation/dereferencing/handshake.go
+++ b/internal/federation/dereferencing/handshake.go
@@ -21,7 +21,7 @@ import (
 	"net/url"
 )
 
-func (d *deref) Handshaking(username string, remoteAccountID *url.URL) bool {
+func (d *Dereferencer) Handshaking(username string, remoteAccountID *url.URL) bool {
 	d.handshakesMu.Lock()
 	defer d.handshakesMu.Unlock()
 
@@ -51,7 +51,7 @@ func (d *deref) Handshaking(username string, remoteAccountID *url.URL) bool {
 	return false
 }
 
-func (d *deref) startHandshake(username string, remoteAccountID *url.URL) {
+func (d *Dereferencer) startHandshake(username string, remoteAccountID *url.URL) {
 	d.handshakesMu.Lock()
 	defer d.handshakesMu.Unlock()
 
@@ -68,7 +68,7 @@ func (d *deref) startHandshake(username string, remoteAccountID *url.URL) {
 	d.handshakes[username] = remoteIDs
 }
 
-func (d *deref) stopHandshake(username string, remoteAccountID *url.URL) {
+func (d *Dereferencer) stopHandshake(username string, remoteAccountID *url.URL) {
 	d.handshakesMu.Lock()
 	defer d.handshakesMu.Unlock()
 
diff --git a/internal/federation/dereferencing/instance.go b/internal/federation/dereferencing/instance.go
index 742239637..90ce074cd 100644
--- a/internal/federation/dereferencing/instance.go
+++ b/internal/federation/dereferencing/instance.go
@@ -25,7 +25,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 )
 
-func (d *deref) GetRemoteInstance(ctx context.Context, username string, remoteInstanceURI *url.URL) (*gtsmodel.Instance, error) {
+func (d *Dereferencer) GetRemoteInstance(ctx context.Context, username string, remoteInstanceURI *url.URL) (*gtsmodel.Instance, error) {
 	if blocked, err := d.state.DB.IsDomainBlocked(ctx, remoteInstanceURI.Host); blocked || err != nil {
 		return nil, fmt.Errorf("GetRemoteInstance: domain %s is blocked", remoteInstanceURI.Host)
 	}
diff --git a/internal/federation/dereferencing/media.go b/internal/federation/dereferencing/media.go
index 315da1c39..15aa4bb08 100644
--- a/internal/federation/dereferencing/media.go
+++ b/internal/federation/dereferencing/media.go
@@ -26,7 +26,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/media"
 )
 
-func (d *deref) GetRemoteMedia(ctx context.Context, requestingUsername string, accountID string, remoteURL string, ai *media.AdditionalMediaInfo) (*media.ProcessingMedia, error) {
+func (d *Dereferencer) GetRemoteMedia(ctx context.Context, requestingUsername string, accountID string, remoteURL string, ai *media.AdditionalMediaInfo) (*media.ProcessingMedia, error) {
 	if accountID == "" {
 		return nil, fmt.Errorf("GetRemoteMedia: account ID was empty")
 	}
diff --git a/internal/federation/dereferencing/status.go b/internal/federation/dereferencing/status.go
index 84316f3a9..bb6a8002c 100644
--- a/internal/federation/dereferencing/status.go
+++ b/internal/federation/dereferencing/status.go
@@ -52,8 +52,10 @@ func statusUpToDate(status *gtsmodel.Status) bool {
 	return false
 }
 
-// GetStatus: implements Dereferencer{}.GetStatus().
-func (d *deref) GetStatusByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Status, ap.Statusable, error) {
+// GetStatusByURI will attempt to fetch a status by its URI, first checking the database. In the case of a newly-met remote model, or a remote model
+// whose last_fetched date is beyond a certain interval, the status will be dereferenced. In the case of dereferencing, some low-priority status information
+// may be enqueued for asynchronous fetching, e.g. dereferencing the remainder of the status thread. An ActivityPub object indicates the status was dereferenced.
+func (d *Dereferencer) GetStatusByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Status, ap.Statusable, error) {
 	// Fetch and dereference status if necessary.
 	status, apubStatus, err := d.getStatusByURI(ctx,
 		requestUser,
@@ -74,7 +76,7 @@ func (d *deref) GetStatusByURI(ctx context.Context, requestUser string, uri *url
 }
 
 // getStatusByURI is a package internal form of .GetStatusByURI() that doesn't bother dereferencing the whole thread on update.
-func (d *deref) getStatusByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Status, ap.Statusable, error) {
+func (d *Dereferencer) getStatusByURI(ctx context.Context, requestUser string, uri *url.URL) (*gtsmodel.Status, ap.Statusable, error) {
 	var (
 		status *gtsmodel.Status
 		uriStr = uri.String()
@@ -146,8 +148,10 @@ func (d *deref) getStatusByURI(ctx context.Context, requestUser string, uri *url
 	return latest, apubStatus, nil
 }
 
-// RefreshStatus: implements Dereferencer{}.RefreshStatus().
-func (d *deref) RefreshStatus(ctx context.Context, requestUser string, status *gtsmodel.Status, apubStatus ap.Statusable, force bool) (*gtsmodel.Status, ap.Statusable, error) {
+// RefreshStatus updates the given status if remote and last_fetched is beyond fetch interval, or if force is set. An updated status model is returned,
+// but in the case of dereferencing, some low-priority status information may be enqueued for asynchronous fetching, e.g. dereferencing the remainder of the
+// status thread. An ActivityPub object indicates the status was dereferenced (i.e. updated).
+func (d *Dereferencer) RefreshStatus(ctx context.Context, requestUser string, status *gtsmodel.Status, apubStatus ap.Statusable, force bool) (*gtsmodel.Status, ap.Statusable, error) {
 	// Check whether needs update.
 	if !force && statusUpToDate(status) {
 		return status, nil, nil
@@ -178,8 +182,9 @@ func (d *deref) RefreshStatus(ctx context.Context, requestUser string, status *g
 	return latest, apubStatus, nil
 }
 
-// RefreshStatusAsync: implements Dereferencer{}.RefreshStatusAsync().
-func (d *deref) RefreshStatusAsync(ctx context.Context, requestUser string, status *gtsmodel.Status, apubStatus ap.Statusable, force bool) {
+// RefreshStatusAsync enqueues the given status for an asychronous update fetching, if last_fetched is beyond fetch interval, or if force is set.
+// This is a more optimized form of manually enqueueing .UpdateStatus() to the federation worker, since it only enqueues update if necessary.
+func (d *Dereferencer) RefreshStatusAsync(ctx context.Context, requestUser string, status *gtsmodel.Status, apubStatus ap.Statusable, force bool) {
 	// Check whether needs update.
 	if statusUpToDate(status) {
 		return
@@ -208,7 +213,7 @@ func (d *deref) RefreshStatusAsync(ctx context.Context, requestUser string, stat
 // enrichStatus will enrich the given status, whether a new
 // barebones model, or existing model from the database.
 // It handles necessary dereferencing, database updates, etc.
-func (d *deref) enrichStatus(
+func (d *Dereferencer) enrichStatus(
 	ctx context.Context,
 	requestUser string,
 	uri *url.URL,
@@ -329,7 +334,7 @@ func (d *deref) enrichStatus(
 	return latestStatus, apubStatus, nil
 }
 
-func (d *deref) fetchStatusMentions(ctx context.Context, requestUser string, existing, status *gtsmodel.Status) error {
+func (d *Dereferencer) fetchStatusMentions(ctx context.Context, requestUser string, existing, status *gtsmodel.Status) error {
 	// Allocate new slice to take the yet-to-be created mention IDs.
 	status.MentionIDs = make([]string, len(status.Mentions))
 
@@ -405,7 +410,7 @@ func (d *deref) fetchStatusMentions(ctx context.Context, requestUser string, exi
 	return nil
 }
 
-func (d *deref) fetchStatusTags(ctx context.Context, status *gtsmodel.Status) error {
+func (d *Dereferencer) fetchStatusTags(ctx context.Context, status *gtsmodel.Status) error {
 	// Allocate new slice to take the yet-to-be determined tag IDs.
 	status.TagIDs = make([]string, len(status.Tags))
 
@@ -455,7 +460,7 @@ func (d *deref) fetchStatusTags(ctx context.Context, status *gtsmodel.Status) er
 	return nil
 }
 
-func (d *deref) fetchStatusAttachments(ctx context.Context, tsport transport.Transport, existing, status *gtsmodel.Status) error {
+func (d *Dereferencer) fetchStatusAttachments(ctx context.Context, tsport transport.Transport, existing, status *gtsmodel.Status) error {
 	// Allocate new slice to take the yet-to-be fetched attachment IDs.
 	status.AttachmentIDs = make([]string, len(status.Attachments))
 
@@ -519,7 +524,7 @@ func (d *deref) fetchStatusAttachments(ctx context.Context, tsport transport.Tra
 	return nil
 }
 
-func (d *deref) fetchStatusEmojis(ctx context.Context, requestUser string, status *gtsmodel.Status) error {
+func (d *Dereferencer) fetchStatusEmojis(ctx context.Context, requestUser string, status *gtsmodel.Status) error {
 	// Fetch the full-fleshed-out emoji objects for our status.
 	emojis, err := d.populateEmojis(ctx, status.Emojis, requestUser)
 	if err != nil {
diff --git a/internal/federation/dereferencing/thread.go b/internal/federation/dereferencing/thread.go
index 6d8c913c7..5753ce4dd 100644
--- a/internal/federation/dereferencing/thread.go
+++ b/internal/federation/dereferencing/thread.go
@@ -38,7 +38,7 @@ import (
 // ancesters we are willing to follow before returning error.
 const maxIter = 1000
 
-func (d *deref) dereferenceThread(ctx context.Context, username string, statusIRI *url.URL, status *gtsmodel.Status, statusable ap.Statusable) {
+func (d *Dereferencer) dereferenceThread(ctx context.Context, username string, statusIRI *url.URL, status *gtsmodel.Status, statusable ap.Statusable) {
 	// Ensure that ancestors have been fully dereferenced
 	if err := d.DereferenceStatusAncestors(ctx, username, status); err != nil {
 		log.Error(ctx, err)
@@ -50,11 +50,8 @@ func (d *deref) dereferenceThread(ctx context.Context, username string, statusIR
 	}
 }
 
-func (d *deref) DereferenceStatusAncestors(
-	ctx context.Context,
-	username string,
-	status *gtsmodel.Status,
-) error {
+// DereferenceStatusAncestors iterates upwards from the given status, using InReplyToURI, to ensure that as many parent statuses as possible are dereferenced.
+func (d *Dereferencer) DereferenceStatusAncestors(ctx context.Context, username string, status *gtsmodel.Status) error {
 	// Start log entry with fields
 	l := log.WithContext(ctx).
 		WithFields(kv.Fields{
@@ -220,7 +217,8 @@ func (d *deref) DereferenceStatusAncestors(
 	return gtserror.Newf("reached %d ancestor iterations for %q", maxIter, status.URI)
 }
 
-func (d *deref) DereferenceStatusDescendants(ctx context.Context, username string, statusIRI *url.URL, parent ap.Statusable) error {
+// DereferenceStatusDescendents iterates downwards from the given status, using its replies, to ensure that as many children statuses as possible are dereferenced.
+func (d *Dereferencer) DereferenceStatusDescendants(ctx context.Context, username string, statusIRI *url.URL, parent ap.Statusable) error {
 	statusIRIStr := statusIRI.String()
 
 	// Start log entry with fields
diff --git a/internal/federation/federatingprotocol.go b/internal/federation/federatingprotocol.go
index ea19eb651..28dc145af 100644
--- a/internal/federation/federatingprotocol.go
+++ b/internal/federation/federatingprotocol.go
@@ -93,7 +93,7 @@ func newErrOtherIRIBlocked(
 // In this case, the DelegateActor implementation must not write a response
 // to the ResponseWriter as is expected that the caller to PostInbox will
 // do so when handling the error.
-func (f *federator) PostInboxRequestBodyHook(ctx context.Context, r *http.Request, activity pub.Activity) (context.Context, error) {
+func (f *Federator) PostInboxRequestBodyHook(ctx context.Context, r *http.Request, activity pub.Activity) (context.Context, error) {
 	// Extract any other IRIs involved in this activity.
 	otherIRIs := []*url.URL{}
 
@@ -186,7 +186,7 @@ func (f *federator) PostInboxRequestBodyHook(ctx context.Context, r *http.Reques
 // Finally, if the authentication and authorization succeeds, then
 // authenticated must be true and error nil. The request will continue
 // to be processed.
-func (f *federator) AuthenticatePostInbox(ctx context.Context, w http.ResponseWriter, r *http.Request) (context.Context, bool, error) {
+func (f *Federator) AuthenticatePostInbox(ctx context.Context, w http.ResponseWriter, r *http.Request) (context.Context, bool, error) {
 	log.Tracef(ctx, "received request to authenticate inbox %s", r.URL.String())
 
 	// Ensure this is an inbox path, and fetch the inbox owner
@@ -298,7 +298,7 @@ func (f *federator) AuthenticatePostInbox(ctx context.Context, w http.ResponseWr
 // Blocked should determine whether to permit a set of actors given by
 // their ids are able to interact with this particular end user due to
 // being blocked or other application-specific logic.
-func (f *federator) Blocked(ctx context.Context, actorIRIs []*url.URL) (bool, error) {
+func (f *Federator) Blocked(ctx context.Context, actorIRIs []*url.URL) (bool, error) {
 	// Fetch relevant items from request context.
 	// These should have been set further up the flow.
 	receivingAccount := gtscontext.ReceivingAccount(ctx)
@@ -498,7 +498,7 @@ func (f *federator) Blocked(ctx context.Context, actorIRIs []*url.URL) (bool, er
 //
 // Applications are not expected to handle every single ActivityStreams
 // type and extension. The unhandled ones are passed to DefaultCallback.
-func (f *federator) FederatingCallbacks(ctx context.Context) (wrapped pub.FederatingWrappedCallbacks, other []interface{}, err error) {
+func (f *Federator) FederatingCallbacks(ctx context.Context) (wrapped pub.FederatingWrappedCallbacks, other []interface{}, err error) {
 	wrapped = pub.FederatingWrappedCallbacks{
 		// OnFollow determines what action to take for this
 		// particular callback if a Follow Activity is handled.
@@ -537,7 +537,7 @@ func (f *federator) FederatingCallbacks(ctx context.Context) (wrapped pub.Federa
 // Applications are not expected to handle every single ActivityStreams
 // type and extension, so the unhandled ones are passed to
 // DefaultCallback.
-func (f *federator) DefaultCallback(ctx context.Context, activity pub.Activity) error {
+func (f *Federator) DefaultCallback(ctx context.Context, activity pub.Activity) error {
 	log.Debugf(ctx, "received unhandle-able activity type (%s) so ignoring it", activity.GetTypeName())
 	return nil
 }
@@ -546,7 +546,7 @@ func (f *federator) DefaultCallback(ctx context.Context, activity pub.Activity)
 // an activity to determine if inbox forwarding needs to occur.
 //
 // Zero or negative numbers indicate infinite recursion.
-func (f *federator) MaxInboxForwardingRecursionDepth(ctx context.Context) int {
+func (f *Federator) MaxInboxForwardingRecursionDepth(ctx context.Context) int {
 	// TODO
 	return 4
 }
@@ -556,7 +556,7 @@ func (f *federator) MaxInboxForwardingRecursionDepth(ctx context.Context) int {
 // delivery.
 //
 // Zero or negative numbers indicate infinite recursion.
-func (f *federator) MaxDeliveryRecursionDepth(ctx context.Context) int {
+func (f *Federator) MaxDeliveryRecursionDepth(ctx context.Context) int {
 	// TODO
 	return 4
 }
@@ -568,7 +568,7 @@ func (f *federator) MaxDeliveryRecursionDepth(ctx context.Context) int {
 //
 // The activity is provided as a reference for more intelligent
 // logic to be used, but the implementation must not modify it.
-func (f *federator) FilterForwarding(ctx context.Context, potentialRecipients []*url.URL, a pub.Activity) ([]*url.URL, error) {
+func (f *Federator) FilterForwarding(ctx context.Context, potentialRecipients []*url.URL, a pub.Activity) ([]*url.URL, error) {
 	// TODO
 	return []*url.URL{}, nil
 }
@@ -581,7 +581,7 @@ func (f *federator) FilterForwarding(ctx context.Context, potentialRecipients []
 //
 // Always called, regardless whether the Federated Protocol or Social
 // API is enabled.
-func (f *federator) GetInbox(ctx context.Context, r *http.Request) (vocab.ActivityStreamsOrderedCollectionPage, error) {
+func (f *Federator) GetInbox(ctx context.Context, r *http.Request) (vocab.ActivityStreamsOrderedCollectionPage, error) {
 	// IMPLEMENTATION NOTE: For GoToSocial, we serve GETS to outboxes and inboxes through
 	// the CLIENT API, not through the federation API, so we just do nothing here.
 	return streams.NewActivityStreamsOrderedCollectionPage(), nil
diff --git a/internal/federation/federator.go b/internal/federation/federator.go
index 1d1df4714..8377546a1 100644
--- a/internal/federation/federator.go
+++ b/internal/federation/federator.go
@@ -18,44 +18,22 @@
 package federation
 
 import (
-	"context"
-
 	"github.com/superseriousbusiness/activity/pub"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/federation/dereferencing"
 	"github.com/superseriousbusiness/gotosocial/internal/federation/federatingdb"
-	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/media"
 	"github.com/superseriousbusiness/gotosocial/internal/state"
 	"github.com/superseriousbusiness/gotosocial/internal/transport"
 	"github.com/superseriousbusiness/gotosocial/internal/typeutils"
 )
 
-// Federator wraps various interfaces and functions to manage activitypub federation from gotosocial
-type Federator interface {
-	// FederatingActor returns the underlying pub.FederatingActor, which can be used to send activities, and serve actors at inboxes/outboxes.
-	FederatingActor() pub.FederatingActor
-	// FederatingDB returns the underlying FederatingDB interface.
-	FederatingDB() federatingdb.DB
-	// TransportController returns the underlying transport controller.
-	TransportController() transport.Controller
-
-	// AuthenticateFederatedRequest can be used to check the authenticity of incoming http-signed requests for federating resources.
-	// The given username will be used to create a transport for making outgoing requests. See the implementation for more detailed comments.
-	//
-	// If the request is valid and passes authentication, the URL of the key owner ID will be returned, as well as true, and nil.
-	//
-	// If the request does not pass authentication, or there's a domain block, nil, false, nil will be returned.
-	//
-	// If something goes wrong during authentication, nil, false, and an error will be returned.
-	AuthenticateFederatedRequest(ctx context.Context, username string) (*PubKeyAuth, gtserror.WithCode)
-
+var _ interface {
 	pub.CommonBehavior
 	pub.FederatingProtocol
-	dereferencing.Dereferencer
-}
+} = &Federator{}
 
-type federator struct {
+type Federator struct {
 	db                  db.DB
 	federatingDB        federatingdb.DB
 	clock               pub.Clock
@@ -66,33 +44,40 @@ type federator struct {
 	dereferencing.Dereferencer
 }
 
-// NewFederator returns a new federator
-func NewFederator(state *state.State, federatingDB federatingdb.DB, transportController transport.Controller, converter *typeutils.Converter, mediaManager *media.Manager) Federator {
-	dereferencer := dereferencing.NewDereferencer(state, converter, transportController, mediaManager)
-
+// NewFederator returns a new federator instance.
+func NewFederator(
+	state *state.State,
+	federatingDB federatingdb.DB,
+	transportController transport.Controller,
+	converter *typeutils.Converter,
+	mediaManager *media.Manager,
+) *Federator {
 	clock := &Clock{}
-	f := &federator{
+	f := &Federator{
 		db:                  state.DB,
 		federatingDB:        federatingDB,
-		clock:               &Clock{},
+		clock:               clock,
 		converter:           converter,
 		transportController: transportController,
 		mediaManager:        mediaManager,
-		Dereferencer:        dereferencer,
+		Dereferencer:        dereferencing.NewDereferencer(state, converter, transportController, mediaManager),
 	}
 	actor := newFederatingActor(f, f, federatingDB, clock)
 	f.actor = actor
 	return f
 }
 
-func (f *federator) FederatingActor() pub.FederatingActor {
+// FederatingActor returns the underlying pub.FederatingActor, which can be used to send activities, and serve actors at inboxes/outboxes.
+func (f *Federator) FederatingActor() pub.FederatingActor {
 	return f.actor
 }
 
-func (f *federator) FederatingDB() federatingdb.DB {
+// FederatingDB returns the underlying FederatingDB interface.
+func (f *Federator) FederatingDB() federatingdb.DB {
 	return f.federatingDB
 }
 
-func (f *federator) TransportController() transport.Controller {
+// TransportController returns the underlying transport controller.
+func (f *Federator) TransportController() transport.Controller {
 	return f.transportController
 }
diff --git a/internal/federation/federator_test.go b/internal/federation/federator_test.go
index 7c57dfff1..bfc25fc74 100644
--- a/internal/federation/federator_test.go
+++ b/internal/federation/federator_test.go
@@ -39,7 +39,7 @@ type FederatorStandardTestSuite struct {
 	typeconverter       *typeutils.Converter
 	transportController transport.Controller
 	httpClient          *testrig.MockHTTPClient
-	federator           federation.Federator
+	federator           *federation.Federator
 
 	testAccounts   map[string]*gtsmodel.Account
 	testStatuses   map[string]*gtsmodel.Status
diff --git a/internal/federation/gone.go b/internal/federation/gone.go
index 7f0c34532..e0278765c 100644
--- a/internal/federation/gone.go
+++ b/internal/federation/gone.go
@@ -26,12 +26,12 @@ import (
 )
 
 // CheckGone checks if a tombstone exists in the database for AP Actor or Object with the given uri.
-func (f *federator) CheckGone(ctx context.Context, uri *url.URL) (bool, error) {
+func (f *Federator) CheckGone(ctx context.Context, uri *url.URL) (bool, error) {
 	return f.db.TombstoneExistsWithURI(ctx, uri.String())
 }
 
 // HandleGone puts a tombstone in the database, which marks an AP Actor or Object with the given uri as gone.
-func (f *federator) HandleGone(ctx context.Context, uri *url.URL) error {
+func (f *Federator) HandleGone(ctx context.Context, uri *url.URL) error {
 	tombstone := &gtsmodel.Tombstone{
 		ID:     id.NewULID(),
 		Domain: uri.Host,
diff --git a/internal/federation/transport.go b/internal/federation/transport.go
index 0116db4cb..b6f7a46c8 100644
--- a/internal/federation/transport.go
+++ b/internal/federation/transport.go
@@ -49,7 +49,7 @@ import (
 // Note that the library will not maintain a long-lived pointer to the
 // returned Transport so that any private credentials are able to be
 // garbage collected.
-func (f *federator) NewTransport(ctx context.Context, actorBoxIRI *url.URL, gofedAgent string) (pub.Transport, error) {
+func (f *Federator) NewTransport(ctx context.Context, actorBoxIRI *url.URL, gofedAgent string) (pub.Transport, error) {
 	var username string
 	var err error