<?php

namespace App\Http\Controllers\Api\Admin\Invoice;

use App\Enums\Invoice\InvoiceStatus;
use App\Helpers\OrderHelper;
use App\Http\Controllers\Controller;
use App\Http\Requests\InvoiceRequest;
use App\Exports\BrandedReportWriter;
use App\Http\Requests\BillingExportRequest;
use App\Exports\InvoicesExport;
use App\Http\Resources\Api\Admin\InvoiceResource;
use Symfony\Component\HttpFoundation\BinaryFileResponse;
use App\Http\Resources\Api\Admin\OrderItemServiceResource;
use App\Models\Invoice;
use App\Models\InvoiceItem;
use App\Models\Order;
use App\Repositories\Invoice\InvoiceRepositoryInterface;
use App\Repositories\InvoiceAttachment\InvoiceAttachmentRepositoryInterface;
use App\Services\InvoicePaymentService;
use App\Services\InvoicePdfService;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Mail;
use App\Http\Controllers\Api\Admin\Invoice\Concerns\HandlesInvoicePayments;
use App\Http\Controllers\Api\Admin\Invoice\Concerns\HandlesInvoiceAttachments;
use App\Http\Controllers\Api\Admin\Invoice\Concerns\SendsInvoiceNotifications;

class InvoiceController extends Controller
{
    use HandlesInvoicePayments;
    use HandlesInvoiceAttachments;
    use SendsInvoiceNotifications;

    public function __construct(
        private readonly InvoiceRepositoryInterface $invoiceRepository,
        private readonly InvoiceAttachmentRepositoryInterface $attachmentRepository,
        private readonly InvoicePdfService $invoicePdfService,
        private readonly InvoicePaymentService $invoicePaymentService,
    ) {}

    public function index(Request $request): JsonResponse
    {
        $query = $this->invoiceRepository->filter(
            $request->all(),
            [
                'payment',
                'customer',
                'order',
                ...OrderItemServiceResource::relationsFor('order.orderItems'),
            ],
            [],
            ['*'],
            true
        );

        return response()->json([
            'error' => false,
            'data' => [
                'items' => InvoiceResource::collection($query->get())->resolve(),
                'total' => $query->count(),
            ],
        ]);
    }

    public function export(BillingExportRequest $request, BrandedReportWriter $writer): BinaryFileResponse
    {
        $query = $this->invoiceRepository->filter(
            array_filter($request->validated(), fn ($value) => $value !== null && $value !== []),
            ['payment', 'customer', 'order', ...OrderItemServiceResource::relationsFor('order.orderItems')],
            [],
            ['*'],
            true
        );

        return $writer->download(new InvoicesExport($query), 'hoa-don-' . now()->format('Y-m-d-His') . '.xlsx');
    }

    /**
     * Admin tạo thêm 1 invoice thủ công cho 1 order đã tồn tại — chỉ dùng cho phụ
     * phí/điều chỉnh thuộc CHÍNH dịch vụ trong order đó (vd. phạt trễ hạn, phí xử lý).
     * Order cố định: không dùng endpoint này để bán thêm dịch vụ mới — dịch vụ mới phải
     * là 1 Order riêng (qua OrderController::store). Đi qua cùng convention với renewal
     * invoice ở nơi khác trong codebase: gắn order_id vào order gốc, tự sinh invoice_number.
     */
    public function store(Request $request): JsonResponse
    {
        $validated = $request->validate([
            'order_id' => 'required|integer|exists:orders,id',
            'invoice_type' => 'nullable|integer|in:1,2,3',
            'description' => 'nullable|string|max:500',
            'due_date' => 'nullable|date',
            'sub_total' => 'required|numeric|min:0',
            'tax' => 'nullable|numeric|min:0',
        ]);

        $order = Order::find($validated['order_id']);
        $subTotal = (int) $validated['sub_total'];
        $tax = (int) ($validated['tax'] ?? 0);
        $total = $subTotal + $tax;

        try {
            $invoice = DB::transaction(function () use ($order, $validated, $subTotal, $tax, $total) {
                $invoice = Invoice::create([
                    'invoice_number' => OrderHelper::generateOrderNumber('INV'),
                    'customer_id' => $order->customer_id,
                    'order_id' => $order->id,
                    'invoice_type' => $validated['invoice_type'] ?? 3,
                    'sub_total' => $subTotal,
                    'discount_amount' => 0,
                    'tax' => $tax,
                    'total' => $total,
                    'status' => InvoiceStatus::UNPAID->value,
                    'due_date' => $validated['due_date'] ?? now()->addDays(7)->toDateString(),
                ]);

                InvoiceItem::create([
                    'invoice_id' => $invoice->id,
                    'type' => 'service',
                    'description' => $validated['description'] ?: 'Hóa đơn bổ sung',
                    'months' => 0,
                    'quantity' => 1,
                    'unit_price' => $subTotal,
                    'total_price' => $subTotal,
                ]);

                return $invoice;
            });

            return response()->json([
                'error' => false,
                'message' => 'Đã tạo hóa đơn',
                'data' => new InvoiceResource($invoice->load('invoiceItems')),
            ], 201);
        } catch (\Exception $e) {
            return response()->json([
                'error' => true,
                'message' => $e->getMessage()
            ], 500);
        }
    }

    public function show(int $id): JsonResponse
    {
        $invoice = $this->invoiceRepository->findWithRelationships($id, ['payment', 'invoiceItem', 'customer']);

        if (!$invoice) {
            return response()->json([
                'error' => true,
                'message' => "Can't find invoice by ID #" . $id
            ], 404);
        }

        return response()->json([
            'error' => false,
            'data' => new InvoiceResource($invoice)
        ]);
    }

    public function update(InvoiceRequest $request, int $id): JsonResponse
    {
        $invoice = $this->invoiceRepository->find($id);

        if (!$invoice) {
            return response()->json([
                'error' => true,
                'message' => "Can't find invoice by ID #" . $id
            ], 404);
        }

        $request->validated();

        $action = strtolower((string) $request->get('action'));
        $status = match ($action) {
            'paid' => InvoiceStatus::PAID->value,
            'cancel' => InvoiceStatus::CANCELLED->value,
            default => null,
        };

        if ($status === null) {
            return response()->json([
                'error' => true,
                'message' => 'Invalid invoice action.',
            ], 422);
        }

        try {
            DB::beginTransaction();
            $invoice->load(['order', 'customer']);

            if ($status === InvoiceStatus::PAID->value) {
                $this->invoicePaymentService->markPaidByAdmin($invoice, auth()->id());
            } else {
                $this->assertCancellable($invoice);
                $invoice->update([
                    'status' => $status,
                    'paid_at' => null,
                ]);
            }

            DB::commit();

            return response()->json([
                'error' => false,
                'message' => 'Invoice updated successfully'
            ]);
        } catch (\InvalidArgumentException $e) {
            DB::rollBack();
            return response()->json([
                'error' => true,
                'message' => $e->getMessage()
            ], 422);
        } catch (\Exception $e) {
            DB::rollBack();
            return response()->json([
                'error' => true,
                'message' => $e->getMessage()
            ], 500);
        }
    }

    public function destroy(int $id): JsonResponse
    {
        $invoice = $this->invoiceRepository->find($id);

        if (!$invoice) {
            return response()->json([
                'error' => true,
                'message' => "Can't find invoice by ID #" . $id
            ], 404);
        }

        // Hoá đơn đã thu tiền là chứng từ gốc: xoá đi thì Transaction và số dư đã trừ vẫn còn,
        // sổ sách lệch mà không còn dấu vết. Muốn đảo thì phải đi qua luồng hoàn tiền.
        if (in_array((int) $invoice->status, [InvoiceStatus::PAID->value, InvoiceStatus::REFUNDED->value], true)) {
            return response()->json([
                'error' => true,
                'message' => 'Không thể xoá hoá đơn đã thanh toán hoặc đã hoàn tiền. Hãy dùng chức năng hoàn tiền nếu cần đảo giao dịch.',
            ], 422);
        }

        try {
            // Note: `orders` has no `invoice_id` column (the FK runs the other way —
            // invoices.order_id -> orders.id), so there's nothing to clean up there. Any
            // `services.invoice_id` pointing at this invoice is already handled by the
            // FK's onDelete('set null').
            $this->invoiceRepository->delete($id);

            return response()->json([
                'error' => false,
                'message' => 'Invoice deleted successfully'
            ]);
        } catch (\Exception $e) {
            return response()->json([
                'error' => true,
                'message' => $e->getMessage()
            ], 500);
        }
    }

    // ─── Attachments ────────────────────────────────────────────────────────────

    // ─── Send Mail ───────────────────────────────────────────────────────────────
}