hub/app/Services/InvoiceService.php

<?php

declare(strict_types=1);

namespace App\Services;

use App\Models\Invoice;
use App\Models\Order;
use Illuminate\Support\Str;
use Spatie\LaravelPdf\Facades\Pdf;
use Illuminate\Support\Facades\Storage;

class InvoiceService
{
    /**
     * Generate an invoice from an order.
     */
    public function generateFromOrder(Order $order): Invoice
    {
        // Check if invoice already exists for this order
        if ($order->invoice) {
            return $order->invoice;
        }

        $invoiceNumber = $this->generateInvoiceNumber();

        $invoice = Invoice::create([
            'invoice_number' => $invoiceNumber,
            'order_id' => $order->id,
            'company_id' => $order->company_id,
            'subtotal' => $order->subtotal,
            'tax' => $order->tax,
            'total' => $order->total,
            'payment_status' => 'unpaid',
            'amount_paid' => 0,
            'amount_due' => $order->total,
            'invoice_date' => now(),
            'due_date' => $order->due_date ?? now()->addDays(30),
            'notes' => $order->notes,
        ]);

        return $invoice;
    }

    /**
     * Generate a unique invoice number.
     */
    private function generateInvoiceNumber(): string
    {
        do {
            $number = 'INV-' . strtoupper(Str::random(12));
        } while (Invoice::where('invoice_number', $number)->exists());

        return $number;
    }

    /**
     * Record a payment against an invoice.
     */
    public function recordPayment(Invoice $invoice, float $amount, string $paymentMethod = null, string $notes = null): bool
    {
        if ($amount <= 0) {
            return false;
        }

        // Update invoice payment status
        $success = $invoice->recordPayment($amount);

        // TODO: In future, create Payment record to track payment history
        // Payment::create([
        //     'invoice_id' => $invoice->id,
        //     'amount' => $amount,
        //     'payment_method' => $paymentMethod,
        //     'notes' => $notes,
        // ]);

        return $success;
    }

    /**
     * Update payment status based on current amounts.
     */
    public function updatePaymentStatus(Invoice $invoice): void
    {
        $invoice->amount_due = bcsub((string) $invoice->total, (string) $invoice->amount_paid, 2);

        if (bccomp((string) $invoice->amount_due, '0', 2) <= 0) {
            $invoice->payment_status = 'paid';
            $invoice->amount_due = 0;
        } elseif (bccomp((string) $invoice->amount_paid, '0', 2) > 0) {
            $invoice->payment_status = 'partially_paid';
        } else {
            $invoice->payment_status = 'unpaid';
        }

        // Check if overdue
        if ($invoice->payment_status !== 'paid' && $invoice->due_date->isPast()) {
            $invoice->payment_status = 'overdue';
        }

        $invoice->save();
    }

    /**
     * Generate PDF document for invoice.
     */
    public function generatePdf(Invoice $invoice): string
    {
        // Load all necessary relationships
        $invoice->load([
            'order.items.product.brand',
            'order.company',
            'order.user',
            'company',
        ]);

        // Generate PDF using Blade view with Spatie Laravel PDF
        $pdf = Pdf::view('pdfs.invoice', [
            'invoice' => $invoice,
            'order' => $invoice->order,
            'company' => $invoice->company,
            'items' => $invoice->order->items,
        ])
        ->format('letter'); // Use letter format for US standard

        // Generate filename
        $filename = "invoices/{$invoice->invoice_number}.pdf";

        // Ensure directory exists
        $directory = Storage::disk('local')->path('invoices');
        if (!file_exists($directory)) {
            mkdir($directory, 0755, true);
        }

        // Save PDF to storage
        $pdf->save(Storage::disk('local')->path($filename));

        // Update invoice with PDF path
        $invoice->update(['pdf_path' => $filename]);

        return $filename;
    }

    /**
     * Regenerate PDF for an existing invoice.
     */
    public function regeneratePdf(Invoice $invoice): string
    {
        // Delete old PDF if exists
        if ($invoice->pdf_path && Storage::disk('local')->exists($invoice->pdf_path)) {
            Storage::disk('local')->delete($invoice->pdf_path);
        }

        return $this->generatePdf($invoice);
    }
}