<?php

namespace App\Modules\Integration\Controllers;

use App\Http\Controllers\Controller;
use Illuminate\Http\Request;
use App\Modules\Integration\Models\SalesOrder;
use App\Modules\Integration\Models\SalesOrderItem;
use App\Modules\Inventory\Contracts\InventoryServiceInterface;
use App\Modules\Inventory\Contracts\ProductServiceInterface;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;

class OrderSyncController extends Controller
{
    protected $inventoryService;
    protected $productService;

    public function __construct(
        InventoryServiceInterface $inventoryService,
        ProductServiceInterface $productService
    ) {
        $this->inventoryService = $inventoryService;
        $this->productService = $productService;
    }

    public function store(Request $request)
    {
        // 冪等性處理：若訂單已存在，回傳已建立的訂單資訊
        $existingOrder = SalesOrder::where('external_order_id', $request->external_order_id)->first();
        if ($existingOrder) {
            return response()->json([
                'message' => 'Order already exists',
                'order_id' => $existingOrder->id,
            ], 200);
        }

        $request->validate([
            'external_order_id' => 'required|string|unique:sales_orders,external_order_id',
            'warehouse' => 'nullable|string',
            'warehouse_id' => 'nullable|integer',
            'payment_method' => 'nullable|string|in:cash,credit_card,line_pay,ecpay,transfer,other',
            'sold_at' => 'nullable|date',
            'items' => 'required|array|min:1',
            'items.*.pos_product_id' => 'required|string',
            'items.*.qty' => 'required|numeric|min:0.0001',
            'items.*.price' => 'required|numeric|min:0',
        ]);

        try {
            return DB::transaction(function () use ($request) {
                // 1. 建立訂單
                $order = SalesOrder::create([
                    'external_order_id' => $request->external_order_id,
                    'status' => 'completed',
                    'payment_method' => $request->payment_method ?? 'cash',
                    'total_amount' => 0,
                    'sold_at' => $request->sold_at ?? now(),
                    'raw_payload' => $request->all(),
                ]);

                // 2. 查找或建立倉庫
                $warehouseId = $request->warehouse_id;

                if (empty($warehouseId)) {
                    $warehouseName = $request->warehouse ?: '銷售倉庫';
                    $warehouse = $this->inventoryService->findOrCreateWarehouseByName($warehouseName);
                    $warehouseId = $warehouse->id;
                }

                $totalAmount = 0;

                // 3. 處理訂單明細
                foreach ($request->items as $itemData) {
                    // 透過介面查找產品
                    $product = $this->productService->findByExternalPosId($itemData['pos_product_id']);

                    if (!$product) {
                        throw new \Exception(
                            "Product not found for POS ID: " . $itemData['pos_product_id'] . ". Please sync product first."
                        );
                    }

                    $qty = $itemData['qty'];
                    $price = $itemData['price'];
                    $lineTotal = $qty * $price;
                    $totalAmount += $lineTotal;

                    // 建立訂單明細
                    SalesOrderItem::create([
                        'sales_order_id' => $order->id,
                        'product_id' => $product->id,
                        'product_name' => $product->name,
                        'quantity' => $qty,
                        'price' => $price,
                        'total' => $lineTotal,
                    ]);

                    // 4. 扣除庫存（強制模式，允許負庫存）
                    $this->inventoryService->decreaseStock(
                        $product->id,
                        $warehouseId,
                        $qty,
                        "POS Order: " . $order->external_order_id,
                        true
                    );
                }

                $order->update(['total_amount' => $totalAmount]);

                return response()->json([
                    'message' => 'Order synced and stock deducted successfully',
                    'order_id' => $order->id,
                ], 201);
            });

        } catch (\Exception $e) {
            Log::error('Order Sync Failed', ['error' => $e->getMessage(), 'payload' => $request->all()]);
            return response()->json(['message' => 'Sync failed: ' . $e->getMessage()], 400);
        }
    }
}