<?php

namespace App\Integrations\Whmcs\Transformers;

use App\Integrations\Whmcs\DTOs\InvoiceItemData;
use App\Integrations\Whmcs\Support\ProductIdResolver;
use Illuminate\Support\Facades\DB;

class InvoiceItemTransformer
{
    public function __construct(private ProductIdResolver $products)
    {
    }

    /**
     * Returns null for WHMCS tax/manual lines (blank `type`) — those are already
     * reflected in invoices.tax on the header, keeping them would double-count.
     * Also returns null for discount lines (negative amount) — invoice_items.unit_price
     * is unsigned; those are rolled into invoices.discount_amount instead, see InvoiceTransformer.
     */
    public function transform(array|object $row): ?InvoiceItemData
    {
        $row = (array) $row;

        $whmcsType = trim((string) ($row['type'] ?? ''));
        if ($whmcsType === '') {
            return null;
        }

        $amount = (int) round((float) $row['amount']);
        if ($amount < 0) {
            return null;
        }

        return new InvoiceItemData(
            legacyId: (int) $row['id'],
            type: $this->mapType($whmcsType),
            description: $row['description'] ? substr($row['description'], 0, 500) : null,
            unitPrice: $amount,
            totalPrice: $amount,
            productId: $this->resolveProductId($whmcsType, (int) $row['relid']),
        );
    }

    /**
     * Only 'Hosting' line items carry a resolvable product: relid -> tblhosting.id -> packageid -> products.legacy_id.
     * Domain/Addon relids point at tbldomains/tblhostingaddons, which don't map onto the products table.
     */
    private function resolveProductId(string $whmcsType, int $relid): ?int
    {
        if ($whmcsType !== 'Hosting' || $relid <= 0) {
            return null;
        }

        $packageId = DB::connection('whmcs')->table('tblhosting')->where('id', $relid)->value('packageid');

        return $packageId ? $this->products->resolve((int) $packageId) : null;
    }

    private function mapType(string $whmcsType): string
    {
        if ($whmcsType === 'Addon') {
            return 'addon';
        }

        if (str_contains($whmcsType, 'Upgrade')) {
            return 'upgrade';
        }

        return 'service';
    }
}