[chore] Deinterface processor and subprocessors (#1501)

* [chore] Deinterface processor and subprocessors

* expose subprocessors via function calls

* missing license header

1 files changed, 224 insertions, 0 deletions

diff --git a/internal/processing/fedi/collections.go b/internal/processing/fedi/collections.go
new file mode 100644
index 000000000..62fc9d7b8
--- /dev/null
+++ b/internal/processing/fedi/collections.go
@@ -0,0 +1,224 @@
+/*
+   GoToSocial
+   Copyright (C) 2021-2023 GoToSocial Authors admin@gotosocial.org
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Affero General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Affero General Public License for more details.
+
+   You should have received a copy of the GNU Affero General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+package fedi
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"net/url"
+
+	"github.com/superseriousbusiness/activity/streams"
+	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/transport"
+)
+
+// FollowersGet handles the getting of a fedi/activitypub representation of a user/account's followers, performing appropriate
+// authentication before returning a JSON serializable interface to the caller.
+func (p *Processor) FollowersGet(ctx context.Context, requestedUsername string, requestURL *url.URL) (interface{}, gtserror.WithCode) {
+	// get the account the request is referring to
+	requestedAccount, err := p.db.GetAccountByUsernameDomain(ctx, requestedUsername, "")
+	if err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("database error getting account with username %s: %s", requestedUsername, err))
+	}
+
+	// authenticate the request
+	requestingAccountURI, errWithCode := p.federator.AuthenticateFederatedRequest(ctx, requestedUsername)
+	if errWithCode != nil {
+		return nil, errWithCode
+	}
+
+	requestingAccount, err := p.federator.GetAccountByURI(
+		transport.WithFastfail(ctx), requestedUsername, requestingAccountURI, false,
+	)
+	if err != nil {
+		return nil, gtserror.NewErrorUnauthorized(err)
+	}
+
+	blocked, err := p.db.IsBlocked(ctx, requestedAccount.ID, requestingAccount.ID, true)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	if blocked {
+		return nil, gtserror.NewErrorUnauthorized(fmt.Errorf("block exists between accounts %s and %s", requestedAccount.ID, requestingAccount.ID))
+	}
+
+	requestedAccountURI, err := url.Parse(requestedAccount.URI)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error parsing url %s: %s", requestedAccount.URI, err))
+	}
+
+	requestedFollowers, err := p.federator.FederatingDB().Followers(ctx, requestedAccountURI)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error fetching followers for uri %s: %s", requestedAccountURI.String(), err))
+	}
+
+	data, err := streams.Serialize(requestedFollowers)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return data, nil
+}
+
+// FollowingGet handles the getting of a fedi/activitypub representation of a user/account's following, performing appropriate
+// authentication before returning a JSON serializable interface to the caller.
+func (p *Processor) FollowingGet(ctx context.Context, requestedUsername string, requestURL *url.URL) (interface{}, gtserror.WithCode) {
+	// get the account the request is referring to
+	requestedAccount, err := p.db.GetAccountByUsernameDomain(ctx, requestedUsername, "")
+	if err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("database error getting account with username %s: %s", requestedUsername, err))
+	}
+
+	// authenticate the request
+	requestingAccountURI, errWithCode := p.federator.AuthenticateFederatedRequest(ctx, requestedUsername)
+	if errWithCode != nil {
+		return nil, errWithCode
+	}
+
+	requestingAccount, err := p.federator.GetAccountByURI(
+		transport.WithFastfail(ctx), requestedUsername, requestingAccountURI, false,
+	)
+	if err != nil {
+		return nil, gtserror.NewErrorUnauthorized(err)
+	}
+
+	blocked, err := p.db.IsBlocked(ctx, requestedAccount.ID, requestingAccount.ID, true)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	if blocked {
+		return nil, gtserror.NewErrorUnauthorized(fmt.Errorf("block exists between accounts %s and %s", requestedAccount.ID, requestingAccount.ID))
+	}
+
+	requestedAccountURI, err := url.Parse(requestedAccount.URI)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error parsing url %s: %s", requestedAccount.URI, err))
+	}
+
+	requestedFollowing, err := p.federator.FederatingDB().Following(ctx, requestedAccountURI)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(fmt.Errorf("error fetching following for uri %s: %s", requestedAccountURI.String(), err))
+	}
+
+	data, err := streams.Serialize(requestedFollowing)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return data, nil
+}
+
+// OutboxGet returns the activitypub representation of a local user's outbox.
+// This contains links to PUBLIC posts made by this user.
+func (p *Processor) OutboxGet(ctx context.Context, requestedUsername string, page bool, maxID string, minID string, requestURL *url.URL) (interface{}, gtserror.WithCode) {
+	// get the account the request is referring to
+	requestedAccount, err := p.db.GetAccountByUsernameDomain(ctx, requestedUsername, "")
+	if err != nil {
+		return nil, gtserror.NewErrorNotFound(fmt.Errorf("database error getting account with username %s: %s", requestedUsername, err))
+	}
+
+	// authenticate the request
+	requestingAccountURI, errWithCode := p.federator.AuthenticateFederatedRequest(ctx, requestedUsername)
+	if errWithCode != nil {
+		return nil, errWithCode
+	}
+
+	requestingAccount, err := p.federator.GetAccountByURI(
+		transport.WithFastfail(ctx), requestedUsername, requestingAccountURI, false,
+	)
+	if err != nil {
+		return nil, gtserror.NewErrorUnauthorized(err)
+	}
+
+	// authorize the request:
+	// 1. check if a block exists between the requester and the requestee
+	blocked, err := p.db.IsBlocked(ctx, requestedAccount.ID, requestingAccount.ID, true)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+	if blocked {
+		return nil, gtserror.NewErrorUnauthorized(fmt.Errorf("block exists between accounts %s and %s", requestedAccount.ID, requestingAccount.ID))
+	}
+
+	var data map[string]interface{}
+	// now there are two scenarios:
+	// 1. we're asked for the whole collection and not a page -- we can just return the collection, with no items, but a link to 'first' page.
+	// 2. we're asked for a specific page; this can be either the first page or any other page
+
+	if !page {
+		/*
+			scenario 1: return the collection with no items
+			we want something that looks like this:
+			{
+				"@context": "https://www.w3.org/ns/activitystreams",
+				"id": "https://example.org/users/whatever/outbox",
+				"type": "OrderedCollection",
+				"first": "https://example.org/users/whatever/outbox?page=true",
+				"last": "https://example.org/users/whatever/outbox?min_id=0&page=true"
+			}
+		*/
+		collection, err := p.tc.OutboxToASCollection(ctx, requestedAccount.OutboxURI)
+		if err != nil {
+			return nil, gtserror.NewErrorInternalError(err)
+		}
+
+		data, err = streams.Serialize(collection)
+		if err != nil {
+			return nil, gtserror.NewErrorInternalError(err)
+		}
+
+		return data, nil
+	}
+
+	// scenario 2 -- get the requested page
+	// limit pages to 30 entries per page
+	publicStatuses, err := p.db.GetAccountStatuses(ctx, requestedAccount.ID, 30, true, true, maxID, minID, false, false, true)
+	if err != nil && err != db.ErrNoEntries {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	outboxPage, err := p.tc.StatusesToASOutboxPage(ctx, requestedAccount.OutboxURI, maxID, minID, publicStatuses)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+	data, err = streams.Serialize(outboxPage)
+	if err != nil {
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	return data, nil
+}
+
+// InboxPost handles POST requests to a user's inbox for new activitypub messages.
+//
+// InboxPost returns true if the request was handled as an ActivityPub POST to an actor's inbox.
+// If false, the request was not an ActivityPub request and may still be handled by the caller in another way, such as serving a web page.
+//
+// If the error is nil, then the ResponseWriter's headers and response has already been written. If a non-nil error is returned, then no response has been written.
+//
+// If the Actor was constructed with the Federated Protocol enabled, side effects will occur.
+//
+// If the Federated Protocol is not enabled, writes the http.StatusMethodNotAllowed status code in the response. No side effects occur.
+func (p *Processor) InboxPost(ctx context.Context, w http.ResponseWriter, r *http.Request) (bool, error) {
+	return p.federator.FederatingActor().PostInbox(ctx, w, r)
+}