refactor(coderd): collapse activityBumpWorkspace into a single query (#9652)

* Adds unit-style tests for activityBumpWorkspace
* Ports logic of activityBumpWorkspace to a SQL query
* Updates activityBumpWorkspace to call above query

coderd/database/dbfake/dbfake.go

@@ -685,6 +685,13 @@ func (q *FakeQuerier) GetActiveDBCryptKeys(_ context.Context) ([]database.DBCryp
 	return ks, nil
 }
 
+func minTime(t, u time.Time) time.Time {
+	if t.Before(u) {
+		return t
+	}
+	return u
+}
+
 func (*FakeQuerier) AcquireLock(_ context.Context, _ int64) error {
 	return xerrors.New("AcquireLock must only be called within a transaction")
 }
@@ -744,6 +751,67 @@ func (q *FakeQuerier) AcquireProvisionerJob(_ context.Context, arg database.Acqu
 	return database.ProvisionerJob{}, sql.ErrNoRows
 }
 
+func (q *FakeQuerier) ActivityBumpWorkspace(ctx context.Context, workspaceID uuid.UUID) error {
+	err := validateDatabaseType(workspaceID)
+	if err != nil {
+		return err
+	}
+
+	q.mutex.Lock()
+	defer q.mutex.Unlock()
+
+	workspace, err := q.getWorkspaceByIDNoLock(ctx, workspaceID)
+	if err != nil {
+		return err
+	}
+	latestBuild, err := q.getLatestWorkspaceBuildByWorkspaceIDNoLock(ctx, workspaceID)
+	if err != nil {
+		return err
+	}
+
+	now := dbtime.Now()
+	for i := range q.workspaceBuilds {
+		if q.workspaceBuilds[i].BuildNumber != latestBuild.BuildNumber {
+			continue
+		}
+		// If the build is not active, do not bump.
+		if q.workspaceBuilds[i].Transition != database.WorkspaceTransitionStart {
+			return nil
+		}
+		// If the provisioner job is not completed, do not bump.
+		pj, err := q.getProvisionerJobByIDNoLock(ctx, q.workspaceBuilds[i].JobID)
+		if err != nil {
+			return err
+		}
+		if !pj.CompletedAt.Valid {
+			return nil
+		}
+		// Do not bump if the deadline is not set.
+		if q.workspaceBuilds[i].Deadline.IsZero() {
+			return nil
+		}
+		// Only bump if 5% of the deadline has passed.
+		ttlDur := time.Duration(workspace.Ttl.Int64)
+		ttlDur95 := ttlDur - (ttlDur / 20)
+		minBumpDeadline := q.workspaceBuilds[i].Deadline.Add(-ttlDur95)
+		if now.Before(minBumpDeadline) {
+			return nil
+		}
+
+		// Bump.
+		newDeadline := now.Add(ttlDur)
+		q.workspaceBuilds[i].UpdatedAt = now
+		if !q.workspaceBuilds[i].MaxDeadline.IsZero() {
+			q.workspaceBuilds[i].Deadline = minTime(newDeadline, q.workspaceBuilds[i].MaxDeadline)
+		} else {
+			q.workspaceBuilds[i].Deadline = newDeadline
+		}
+		return nil
+	}
+
+	return sql.ErrNoRows
+}
+
 func (*FakeQuerier) CleanTailnetCoordinators(_ context.Context) error {
 	return ErrUnimplemented
 }
@@ -4741,6 +4809,7 @@ func (q *FakeQuerier) InsertWorkspaceBuild(_ context.Context, arg database.Inser
 		JobID:             arg.JobID,
 		ProvisionerState:  arg.ProvisionerState,
 		Deadline:          arg.Deadline,
+		MaxDeadline:       arg.MaxDeadline,
 		Reason:            arg.Reason,
 	}
 	q.workspaceBuilds = append(q.workspaceBuilds, workspaceBuild)