<?php

namespace App\Integrations\Whmcs\Transformers;

use App\Integrations\Whmcs\DTOs\InvoiceData;
use App\Integrations\Whmcs\Extractors\InvoiceExtractor;
use App\Integrations\Whmcs\Support\CustomerIdResolver;
use App\Integrations\Whmcs\Support\OrderIdResolver;
use Illuminate\Support\Carbon;

class InvoiceTransformer
{
    public function __construct(
        private CustomerIdResolver $customers,
        private OrderIdResolver $orders,
        private InvoiceExtractor $extractor,
        private InvoiceItemTransformer $itemTransformer,
    ) {
    }

    public function transform(array|object $row): InvoiceData
    {
        $row = (array) $row;
        $legacyId = (int) $row['id'];

        $dueDate = $this->nullableDate($row['duedate'] ?? null);
        $status = $this->mapStatus($row['status'], $dueDate);
        $total = (int) round((float) $row['total']);
        $whmcsOrderId = $this->extractor->orderIdFor($legacyId);

        $rawItems = $this->extractor->items($legacyId);

        // WHMCS records discounts as negative-amount line items; invoice_items.unit_price
        // is unsigned, so fold them into the header's discount_amount instead.
        $discountAmount = (int) round(-$rawItems->sum(fn ($item) => min(0, (float) $item->amount)));

        $items = $rawItems
            ->map(fn ($item) => $this->itemTransformer->transform($item))
            ->filter()
            ->all();

        return new InvoiceData(
            legacyId: $legacyId,
            invoiceNumber: $row['invoicenum'] ?: "WHMCS-{$legacyId}",
            customerId: $this->customers->resolveFor('invoice', $row['invoicenum'] ?: $row['id'], (int) $row['userid']),
            orderId: $whmcsOrderId ? $this->orders->resolve($whmcsOrderId) : null,
            date: $this->nullableDate($row['date'] ?? null),
            subTotal: (int) round((float) $row['subtotal']),
            discountAmount: $discountAmount,
            tax: (int) round((float) $row['tax'] + (float) $row['tax2']),
            total: $total,
            // Không có amount_paid thì mọi hoá đơn WHMCS đã thanh toán sẽ hiện "chưa thu"
            // và outstanding = total trên toàn bộ dữ liệu import.
            amountPaid: $status === 2 ? $total : (int) round((float) ($row['credit'] ?? 0)),
            status: $status,
            paymentMethod: $row['paymentmethod'] ?: null,
            dueDate: $dueDate,
            paidAt: $this->nullableDate($row['datepaid'] ?? null),
            note: $row['notes'] ?: null,
            createdAt: $this->nullableDate($row['created_at'] ?? null),
            items: $items,
        );
    }

    /**
     * invoices.status: 1=unpaid, 2=paid, 3=cancelled, 4=overdue, 5=refunded.
     */
    private function mapStatus(string $status, ?string $dueDate): int
    {
        return match ($status) {
            'Paid' => 2,
            'Cancelled' => 3,
            'Refunded' => 5,
            'Collections' => 4,
            default => ($dueDate && Carbon::parse($dueDate)->isPast()) ? 4 : 1,
        };
    }

    /**
     * WHMCS has zero-dates ('0000-00-00...') and, in this data, at least one bogus
     * year (e.g. '0004-04-22') — both invalid for MySQL strict mode, so nullify them.
     */
    private function nullableDate(?string $value): ?string
    {
        if (! $value || (int) substr($value, 0, 4) < 1970) {
            return null;
        }

        return $value;
    }
}