App\Http\Controllers\InvoiceController::invoiceHistory PHP Method

    public function invoiceHistory(InvoiceRequest $request)
    {
        $invoice = $request->entity();
        $invoice->load('user', 'invoice_items', 'documents', 'expenses', 'expenses.documents', 'account.country', 'client.contacts', 'client.country');
        $invoice->invoice_date = Utils::fromSqlDate($invoice->invoice_date);
        $invoice->due_date = Utils::fromSqlDate($invoice->due_date);
        $invoice->features = ['customize_invoice_design' => Auth::user()->hasFeature(FEATURE_CUSTOMIZE_INVOICE_DESIGN), 'remove_created_by' => Auth::user()->hasFeature(FEATURE_REMOVE_CREATED_BY), 'invoice_settings' => Auth::user()->hasFeature(FEATURE_INVOICE_SETTINGS)];
        $invoice->invoice_type_id = intval($invoice->invoice_type_id);
        $activityTypeId = $invoice->isType(INVOICE_TYPE_QUOTE) ? ACTIVITY_TYPE_UPDATE_QUOTE : ACTIVITY_TYPE_UPDATE_INVOICE;
        $activities = Activity::scope(false, $invoice->account_id)->where('activity_type_id', '=', $activityTypeId)->where('invoice_id', '=', $invoice->id)->orderBy('id', 'desc')->get(['id', 'created_at', 'user_id', 'json_backup']);
        $versionsJson = [];
        $versionsSelect = [];
        $lastId = false;
        foreach ($activities as $activity) {
            if ($backup = json_decode($activity->json_backup)) {
                $backup->invoice_date = Utils::fromSqlDate($backup->invoice_date);
                $backup->due_date = Utils::fromSqlDate($backup->due_date);
                $backup->features = ['customize_invoice_design' => Auth::user()->hasFeature(FEATURE_CUSTOMIZE_INVOICE_DESIGN), 'remove_created_by' => Auth::user()->hasFeature(FEATURE_REMOVE_CREATED_BY), 'invoice_settings' => Auth::user()->hasFeature(FEATURE_INVOICE_SETTINGS)];
                $backup->invoice_type_id = isset($backup->invoice_type_id) && intval($backup->invoice_type_id) == INVOICE_TYPE_QUOTE;
                $backup->account = $invoice->account->toArray();
                $versionsJson[$activity->id] = $backup;
                $key = Utils::timestampToDateTimeString(strtotime($activity->created_at)) . ' - ' . $activity->user->getDisplayName();
                $versionsSelect[$lastId ? $lastId : 0] = $key;
                $lastId = $activity->id;
            } else {
                Utils::logError('Failed to parse invoice backup');
            }
        }
        if ($lastId) {
            $versionsSelect[$lastId] = Utils::timestampToDateTimeString(strtotime($invoice->created_at)) . ' - ' . $invoice->user->getDisplayName();
        }
        $data = ['invoice' => $invoice, 'versionsJson' => json_encode($versionsJson), 'versionsSelect' => $versionsSelect, 'invoiceDesigns' => InvoiceDesign::getDesigns(), 'invoiceFonts' => Cache::get('fonts')];
        return View::make('invoices.history', $data);
    }