2 files changed, 227 insertions, 3 deletions

diff --git a/internal/federation/dereferencing/status.go b/internal/federation/dereferencing/status.go
index 4dd6d3baf..1f09dedc0 100644
--- a/internal/federation/dereferencing/status.go
+++ b/internal/federation/dereferencing/status.go
@@ -365,12 +365,13 @@ func (d *Dereferencer) enrichStatus(
 
 	// Use existing status ID.
 	latestStatus.ID = status.ID
-
 	if latestStatus.ID == "" {
+
 		// Generate new status ID from the provided creation date.
 		latestStatus.ID, err = id.NewULIDFromTime(latestStatus.CreatedAt)
 		if err != nil {
-			return nil, nil, gtserror.Newf("invalid created at date: %w", err)
+			log.Errorf(ctx, "invalid created at date (falling back to 'now'): %v", err)
+			latestStatus.ID = id.NewULID() // just use "now"
 		}
 	}
 
@@ -379,6 +380,11 @@ func (d *Dereferencer) enrichStatus(
 	latestStatus.FetchedAt = time.Now()
 	latestStatus.Local = status.Local
 
+	// Ensure the status' poll remains consistent, else reset the poll.
+	if err := d.fetchStatusPoll(ctx, status, latestStatus); err != nil {
+		return nil, nil, gtserror.Newf("error populating poll for status %s: %w", uri, err)
+	}
+
 	// Ensure the status' mentions are populated, and pass in existing to check for changes.
 	if err := d.fetchStatusMentions(ctx, requestUser, status, latestStatus); err != nil {
 		return nil, nil, gtserror.Newf("error populating mentions for status %s: %w", uri, err)
@@ -533,7 +539,7 @@ func (d *Dereferencer) fetchStatusMentions(ctx context.Context, requestUser stri
 		//       support for edited status revision history.
 		mention.ID, err = id.NewULIDFromTime(status.CreatedAt)
 		if err != nil {
-			log.Errorf(ctx, "invalid created at date: %v", err)
+			log.Errorf(ctx, "invalid created at date (falling back to 'now'): %v", err)
 			mention.ID = id.NewULID() // just use "now"
 		}
 
@@ -681,6 +687,101 @@ func (d *Dereferencer) fetchStatusTags(ctx context.Context, existing, status *gt
 	return nil
 }
 
+func (d *Dereferencer) fetchStatusPoll(ctx context.Context, existing, status *gtsmodel.Status) error {
+	var (
+		// insertStatusPoll generates ID and inserts the poll attached to status into the database.
+		insertStatusPoll = func(ctx context.Context, status *gtsmodel.Status) error {
+			var err error
+
+			// Generate new ID for poll from the status CreatedAt.
+			// TODO: update this to use "edited_at" when we add
+			//       support for edited status revision history.
+			status.Poll.ID, err = id.NewULIDFromTime(status.CreatedAt)
+			if err != nil {
+				log.Errorf(ctx, "invalid created at date (falling back to 'now'): %v", err)
+				status.Poll.ID = id.NewULID() // just use "now"
+			}
+
+			// Update the status<->poll links.
+			status.PollID = status.Poll.ID
+			status.Poll.StatusID = status.ID
+			status.Poll.Status = status
+
+			// Insert this latest poll into the database.
+			err = d.state.DB.PutPoll(ctx, status.Poll)
+			if err != nil {
+				return gtserror.Newf("error putting in database: %w", err)
+			}
+
+			return nil
+		}
+
+		// deleteStatusPoll deletes the poll with ID, and all attached votes, from the database.
+		deleteStatusPoll = func(ctx context.Context, pollID string) error {
+			if err := d.state.DB.DeletePollByID(ctx, pollID); err != nil {
+				return gtserror.Newf("error deleting existing poll from database: %w", err)
+			}
+			if err := d.state.DB.DeletePollVotes(ctx, pollID); err != nil {
+				return gtserror.Newf("error deleting existing votes from database: %w", err)
+			}
+			return nil
+		}
+	)
+
+	switch {
+	case existing.Poll == nil && status.Poll == nil:
+		// no poll before or after, nothing to do.
+		return nil
+
+	case existing.Poll == nil && status.Poll != nil:
+		// no previous poll, insert new poll!
+		return insertStatusPoll(ctx, status)
+
+	case /*existing.Poll != nil &&*/ status.Poll == nil:
+		// existing poll has been deleted, remove this.
+		return deleteStatusPoll(ctx, existing.PollID)
+
+	case /*existing.Poll != nil && status.Poll != nil && */
+		!slices.Equal(existing.Poll.Options, status.Poll.Options) ||
+			!existing.Poll.ExpiresAt.Equal(status.Poll.ExpiresAt):
+		// poll has changed since original, delete and reinsert new.
+		if err := deleteStatusPoll(ctx, existing.PollID); err != nil {
+			return err
+		}
+		return insertStatusPoll(ctx, status)
+
+	case /*existing.Poll != nil && status.Poll != nil && */
+		!existing.Poll.ClosedAt.Equal(status.Poll.ClosedAt) ||
+			!slices.Equal(existing.Poll.Votes, status.Poll.Votes) ||
+			existing.Poll.Voters != status.Poll.Voters:
+		// Since we last saw it, the poll has updated!
+		// Whether that be stats, or close time.
+		poll := existing.Poll
+		poll.Closing = (!poll.Closed() && status.Poll.Closed())
+		poll.ClosedAt = status.Poll.ClosedAt
+		poll.Voters = status.Poll.Voters
+		poll.Votes = status.Poll.Votes
+
+		// Update poll model in the database (specifically only the possible changed columns).
+		if err := d.state.DB.UpdatePoll(ctx, poll, "closed_at", "voters", "votes"); err != nil {
+			return gtserror.Newf("error updating poll: %w", err)
+		}
+
+		// Update poll on status.
+		status.PollID = poll.ID
+		status.Poll = poll
+		return nil
+
+	default:
+		// latest and existing
+		// polls are up to date.
+		poll := existing.Poll
+		status.PollID = poll.ID
+		status.Poll = poll
+		return nil
+	}
+}
+
 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))
diff --git a/internal/federation/federatingdb/create.go b/internal/federation/federatingdb/create.go
index 0fb459190..3a8d8f0ac 100644
--- a/internal/federation/federatingdb/create.go
+++ b/internal/federation/federatingdb/create.go
@@ -28,6 +28,7 @@ import (
 	"github.com/superseriousbusiness/gotosocial/internal/ap"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
+	"github.com/superseriousbusiness/gotosocial/internal/gtscontext"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
 	"github.com/superseriousbusiness/gotosocial/internal/id"
@@ -141,6 +142,22 @@ func (f *federatingDB) activityCreate(
 	// Extract objects from create activity.
 	objects := ap.ExtractObjects(create)
 
+	// Extract PollOptionables (votes!) from objects slice.
+	optionables, objects := ap.ExtractPollOptionables(objects)
+
+	if len(optionables) > 0 {
+		// Handle provided poll vote(s) creation, this can
+		// be for single or multiple votes in the same poll.
+		err := f.createPollOptionables(ctx,
+			receivingAccount,
+			requestingAccount,
+			optionables,
+		)
+		if err != nil {
+			errs.Appendf("error creating poll vote(s): %w", err)
+		}
+	}
+
 	// Extract Statusables from objects slice (this must be
 	// done AFTER extracting options due to how AS typing works).
 	statusables, objects := ap.ExtractStatusables(objects)
@@ -169,6 +186,112 @@ func (f *federatingDB) activityCreate(
 	return errs.Combine()
 }
 
+// createPollOptionable handles a Create activity for a PollOptionable.
+// This function doesn't handle database insertion, only validation checks
+// before passing off to a worker for asynchronous processing.
+func (f *federatingDB) createPollOptionables(
+	ctx context.Context,
+	receiver *gtsmodel.Account,
+	requester *gtsmodel.Account,
+	options []ap.PollOptionable,
+) error {
+	var (
+		// the origin Status w/ Poll the vote
+		// options are in. This gets set on first
+		// iteration, relevant checks performed
+		// then re-used in each further iteration.
+		inReplyTo *gtsmodel.Status
+
+		// the resulting slices of Poll.Option
+		// choice indices passed into the new
+		// created PollVote object.
+		choices []int
+	)
+
+	for _, option := range options {
+		// Extract the "inReplyTo" property.
+		inReplyToURIs := ap.GetInReplyTo(option)
+		if len(inReplyToURIs) != 1 {
+			return gtserror.Newf("invalid inReplyTo property length: %d", len(inReplyToURIs))
+		}
+
+		// Stringify the inReplyTo URI.
+		statusURI := inReplyToURIs[0].String()
+
+		if inReplyTo == nil {
+			var err error
+
+			// This is the first object in the activity slice,
+			// check database for the poll source status by URI.
+			inReplyTo, err = f.state.DB.GetStatusByURI(ctx, statusURI)
+			if err != nil {
+				return gtserror.Newf("error getting poll source from database %s: %w", statusURI, err)
+			}
+
+			switch {
+			// The origin status isn't a poll?
+			case inReplyTo.PollID == "":
+				return gtserror.Newf("poll vote in status %s without poll", statusURI)
+
+			// We don't own the poll ...
+			case !*inReplyTo.Local:
+				return gtserror.Newf("poll vote in remote status %s", statusURI)
+			}
+
+			// Check whether user has already vote in this poll.
+			// (we only check this for the first object, as multiple
+			// may be sent in response to a multiple-choice poll).
+			vote, err := f.state.DB.GetPollVoteBy(
+				gtscontext.SetBarebones(ctx),
+				inReplyTo.PollID,
+				requester.ID,
+			)
+			if err != nil && !errors.Is(err, db.ErrNoEntries) {
+				return gtserror.Newf("error getting status %s poll votes from database: %w", statusURI, err)
+			}
+
+			if vote != nil {
+				log.Warnf(ctx, "%s has already voted in poll %s", requester.URI, statusURI)
+				return nil // this is a useful warning for admins to report to us from logs
+			}
+		}
+
+		if statusURI != inReplyTo.URI {
+			// All activity votes should be to the same poll per activity.
+			return gtserror.New("votes to multiple polls in single activity")
+		}
+
+		// Extract the poll option name.
+		name := ap.ExtractName(option)
+
+		// Check that this is a valid option name.
+		choice := inReplyTo.Poll.GetChoice(name)
+		if choice == -1 {
+			return gtserror.Newf("poll vote in status %s invalid: %s", statusURI, name)
+		}
+
+		// Append the option index to choices.
+		choices = append(choices, choice)
+	}
+
+	// Enqueue message to the fedi API worker with poll vote(s).
+	f.state.Workers.EnqueueFediAPI(ctx, messages.FromFediAPI{
+		APActivityType: ap.ActivityCreate,
+		APObjectType:   ap.ActivityQuestion,
+		GTSModel: &gtsmodel.PollVote{
+			ID:        id.NewULID(),
+			Choices:   choices,
+			AccountID: requester.ID,
+			Account:   requester,
+			PollID:    inReplyTo.PollID,
+			Poll:      inReplyTo.Poll,
+		},
+		ReceivingAccount: receiver,
+	})
+
+	return nil
+}
+
 // createStatusable handles a Create activity for a Statusable.
 // This function won't insert anything in the database yet,
 // but will pass the Statusable (if appropriate) through to