[feature] List replies policy, refactor async workers (#2087)

* Add/update some DB functions.

* move async workers into subprocessor

* rename FromFederator -> FromFediAPI

* update home timeline check to include check for current status first before moving to parent status

* change streamMap to pointer to mollify linter

* update followtoas func signature

* fix merge

* remove errant debug log

* don't use separate errs.Combine() check to wrap errs

* wrap parts of workers functionality in sub-structs

* populate report using new db funcs

* embed federator (tiny bit tidier)

* flesh out error msg, add continue(!)

* fix other error messages to be more specific

* better, nicer

* give parseURI util function a bit more util

* missing headers

* use pointers for subprocessors

1 files changed, 119 insertions, 0 deletions

diff --git a/internal/processing/workers/wipestatus.go b/internal/processing/workers/wipestatus.go
new file mode 100644
index 000000000..0891d9e24
--- /dev/null
+++ b/internal/processing/workers/wipestatus.go
@@ -0,0 +1,119 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// 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 workers
+
+import (
+	"context"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtscontext"
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+	"github.com/superseriousbusiness/gotosocial/internal/processing/media"
+	"github.com/superseriousbusiness/gotosocial/internal/state"
+)
+
+// wipeStatus encapsulates common logic used to totally delete a status
+// + all its attachments, notifications, boosts, and timeline entries.
+type wipeStatus func(context.Context, *gtsmodel.Status, bool) error
+
+// wipeStatusF returns a wipeStatus util function.
+func wipeStatusF(state *state.State, media *media.Processor, surface *surface) wipeStatus {
+	return func(
+		ctx context.Context,
+		statusToDelete *gtsmodel.Status,
+		deleteAttachments bool,
+	) error {
+		errs := new(gtserror.MultiError)
+
+		// Either delete all attachments for this status,
+		// or simply unattach + clean them separately later.
+		//
+		// Reason to unattach rather than delete is that
+		// the poster might want to reattach them to another
+		// status immediately (in case of delete + redraft)
+		if deleteAttachments {
+			// todo:state.DB.DeleteAttachmentsForStatus
+			for _, a := range statusToDelete.AttachmentIDs {
+				if err := media.Delete(ctx, a); err != nil {
+					errs.Appendf("error deleting media: %w", err)
+				}
+			}
+		} else {
+			// todo:state.DB.UnattachAttachmentsForStatus
+			for _, a := range statusToDelete.AttachmentIDs {
+				if _, err := media.Unattach(ctx, statusToDelete.Account, a); err != nil {
+					errs.Appendf("error unattaching media: %w", err)
+				}
+			}
+		}
+
+		// delete all mention entries generated by this status
+		// todo:state.DB.DeleteMentionsForStatus
+		for _, id := range statusToDelete.MentionIDs {
+			if err := state.DB.DeleteMentionByID(ctx, id); err != nil {
+				errs.Appendf("error deleting status mention: %w", err)
+			}
+		}
+
+		// delete all notification entries generated by this status
+		if err := state.DB.DeleteNotificationsForStatus(ctx, statusToDelete.ID); err != nil {
+			errs.Appendf("error deleting status notifications: %w", err)
+		}
+
+		// delete all bookmarks that point to this status
+		if err := state.DB.DeleteStatusBookmarksForStatus(ctx, statusToDelete.ID); err != nil {
+			errs.Appendf("error deleting status bookmarks: %w", err)
+		}
+
+		// delete all faves of this status
+		if err := state.DB.DeleteStatusFavesForStatus(ctx, statusToDelete.ID); err != nil {
+			errs.Appendf("error deleting status faves: %w", err)
+		}
+
+		// delete all boosts for this status + remove them from timelines
+		boosts, err := state.DB.GetStatusBoosts(
+			// we MUST set a barebones context here,
+			// as depending on where it came from the
+			// original BoostOf may already be gone.
+			gtscontext.SetBarebones(ctx),
+			statusToDelete.ID)
+		if err != nil {
+			errs.Appendf("error fetching status boosts: %w", err)
+		}
+		for _, b := range boosts {
+			if err := surface.deleteStatusFromTimelines(ctx, b.ID); err != nil {
+				errs.Appendf("error deleting boost from timelines: %w", err)
+			}
+			if err := state.DB.DeleteStatusByID(ctx, b.ID); err != nil {
+				errs.Appendf("error deleting boost: %w", err)
+			}
+		}
+
+		// delete this status from any and all timelines
+		if err := surface.deleteStatusFromTimelines(ctx, statusToDelete.ID); err != nil {
+			errs.Appendf("error deleting status from timelines: %w", err)
+		}
+
+		// finally, delete the status itself
+		if err := state.DB.DeleteStatusByID(ctx, statusToDelete.ID); err != nil {
+			errs.Appendf("error deleting status: %w", err)
+		}
+
+		return errs.Combine()
+	}
+}