wip

app/Filament/Company/Resources/Purchases/BillResource.php

                             Forms\Components\Group::make([
                                 Forms\Components\TextInput::make('bill_number')
                                     ->label('Bill Number')
-                                    ->default(fn () => Bill::getNextDocumentNumber()),
+                                    ->default(fn () => Bill::getNextDocumentNumber())
+                                    ->required(),
                                 Forms\Components\TextInput::make('order_number')
                                     ->label('P.O/S.O Number'),
                                 Forms\Components\DatePicker::make('date')
                                     ->label('Bill Date')
-                                    ->default(now()),
+                                    ->default(now())
+                                    ->disabled(function (?Bill $record) {
+                                        return $record?->hasPayments();
+                                    })
+                                    ->required(),
                                 Forms\Components\DatePicker::make('due_date')
                                     ->label('Due Date')
                                     ->default(function () use ($company) {
                                         return now()->addDays($company->defaultBill->payment_terms->getDays());
-                                    }),
+                                    })
+                                    ->required(),
                             ])->grow(true),
                         ])->from('md'),
                         TableRepeater::make('lineItems')

app/Filament/Company/Resources/Sales/InvoiceResource.php

                                     ->label('Invoice Date')
                                     ->live()
                                     ->default(now())
+                                    ->disabled(function (?Invoice $record) {
+                                        return $record?->hasPayments();
+                                    })
                                     ->afterStateUpdated(function (Forms\Set $set, Forms\Get $get, $state) {
                                         $date = $state;
                                         $dueDate = $get('due_date');

app/Models/Accounting/Bill.php

         ]);
     }
 
+    public function hasPayments(): bool
+    {
+        return $this->payments->isNotEmpty();
+    }
+
     public static function getNextDocumentNumber(): string
     {
         $company = auth()->user()->currentCompany;

app/Models/Accounting/Invoice.php

         return in_array($this->status, InvoiceStatus::canBeOverdue());
     }
 
+    public function hasPayments(): bool
+    {
+        return $this->payments->isNotEmpty();
+    }
+
     public static function getNextDocumentNumber(): string
     {
         $company = auth()->user()->currentCompany;

app/Observers/TransactionObserver.php

     {
         $this->transactionService->createJournalEntries($transaction);
 
-        if (! $transaction->is_payment) {
+        if (! $transaction->transactionable) {
             return;
         }
 
 
         $this->transactionService->updateJournalEntries($transaction);
 
-        if (! $transaction->is_payment) {
+        if (! $transaction->transactionable) {
             return;
         }
 
         DB::transaction(function () use ($transaction) {
             $this->transactionService->deleteJournalEntries($transaction);
 
-            if (! $transaction->is_payment) {
+            if (! $transaction->transactionable) {
                 return;
             }
 
 
     protected function updateInvoiceTotals(Invoice $invoice, ?Transaction $excludedTransaction = null): void
     {
+        if (! $invoice->hasPayments()) {
+            return;
+        }
+
         $depositTotal = (int) $invoice->deposits()
             ->when($excludedTransaction, fn (Builder $query) => $query->whereKeyNot($excludedTransaction->getKey()))
             ->sum('amount');
 
     protected function updateBillTotals(Bill $bill, ?Transaction $excludedTransaction = null): void
     {
+        if (! $bill->hasPayments()) {
+            return;
+        }
+
         $withdrawalTotal = (int) $bill->withdrawals()
             ->when($excludedTransaction, fn (Builder $query) => $query->whereKeyNot($excludedTransaction->getKey()))
             ->sum('amount');