<?php

namespace App\Http\Controllers;

use App\Models\PurchaseOrder;
use App\Models\PurchaseOrderItem;
use App\Models\ReceivingOrder;
use App\Models\ReceivingOrderItem;
use App\Services\PurchaseService;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Validator;

class PurchaseOrderController extends Controller
{
    protected $purchaseService;

    public function __construct(PurchaseService $purchaseService)
    {
        $this->purchaseService = $purchaseService;
    }

    /**
     * 采购单列表
     */
    public function index(Request $request)
    {
        $query = PurchaseOrder::with(['supplier', 'warehouse', 'items']);

        // 筛选条件
        if ($request->has('po_no')) {
            $query->where('po_no', 'like', '%' . $request->po_no . '%');
        }
        if ($request->has('supplier_id')) {
            $query->where('supplier_id', $request->supplier_id);
        }
        if ($request->has('warehouse_id')) {
            $query->where('warehouse_id', $request->warehouse_id);
        }
        if ($request->has('status')) {
            $query->where('status', $request->status);
        }
        if ($request->has('date_from')) {
            $query->whereDate('created_at', '>=', $request->date_from);
        }
        if ($request->has('date_to')) {
            $query->whereDate('created_at', '<=', $request->date_to);
        }

        $perPage = $request->get('per_page', 15);
        $orders = $query->orderBy('id', 'desc')->paginate($perPage);

        return response()->json([
            'code' => 200,
            'data' => $orders,
            'message' => 'success'
        ]);
    }

    /**
     * 创建采购单
     */
    public function store(Request $request)
    {
        $validator = Validator::make($request->all(), [
            'warehouse_id' => 'required|exists:warehouses,id',
            'supplier_id' => 'required|exists:suppliers,id',
            'expected_arrival' => 'nullable|date',
            'shipping_method' => 'nullable|string|max:50',
            'freight' => 'nullable|numeric|min:0',
            'category' => 'nullable|string|max:100',
            'remark' => 'nullable|string',
            'items' => 'required|array|min:1',
            'items.*.sku_code' => 'required|string',
            'items.*.sku_name' => 'required|string',
            'items.*.quantity' => 'required|integer|min:1',
            'items.*.price' => 'required|numeric|min:0',
        ]);

        if ($validator->fails()) {
            return response()->json([
                'code' => 422,
                'message' => '验证失败',
                'errors' => $validator->errors()
            ], 422);
        }

        try {
            DB::beginTransaction();

            // 生成采购单号
            $poNo = 'PO' . date('Ymd') . str_pad(mt_rand(1, 99999), 5, '0', STR_PAD_LEFT);

            $purchaseOrder = PurchaseOrder::create([
                'po_no' => $poNo,
                'warehouse_id' => $request->warehouse_id,
                'supplier_id' => $request->supplier_id,
                'expected_arrival' => $request->expected_arrival,
                'shipping_method' => $request->shipping_method,
                'freight' => $request->freight ?? 0,
                'category' => $request->category,
                'remark' => $request->remark,
                'status' => 'draft',
            ]);

            foreach ($request->items as $item) {
                PurchaseOrderItem::create([
                    'purchase_order_id' => $purchaseOrder->id,
                    'sku_code' => $item['sku_code'],
                    'sku_name' => $item['sku_name'],
                    'quantity' => $item['quantity'],
                    'received_quantity' => 0,
                    'price' => $item['price'],
                ]);
            }

            DB::commit();

            return response()->json([
                'code' => 201,
                'data' => $purchaseOrder->load('items'),
                'message' => '采购单创建成功'
            ], 201);

        } catch (\Exception $e) {
            DB::rollBack();
            return response()->json([
                'code' => 500,
                'message' => '创建失败：' . $e->getMessage()
            ], 500);
        }
    }

    /**
     * 采购单详情
     */
    public function show($id)
    {
        $order = PurchaseOrder::with(['supplier', 'warehouse', 'items'])->find($id);
        if (!$order) {
            return response()->json([
                'code' => 404,
                'message' => '采购单不存在'
            ], 404);
        }
        return response()->json([
            'code' => 200,
            'data' => $order,
            'message' => 'success'
        ]);
    }

    /**
     * 更新采购单（仅草稿状态可更新）
     */
    public function update(Request $request, $id)
    {
        $purchaseOrder = PurchaseOrder::find($id);
        if (!$purchaseOrder) {
            return response()->json(['code' => 404, 'message' => '采购单不存在'], 404);
        }

        if ($purchaseOrder->status !== 'draft') {
            return response()->json(['code' => 403, 'message' => '仅草稿状态可修改'], 403);
        }

        $validator = Validator::make($request->all(), [
            'warehouse_id' => 'sometimes|exists:warehouses,id',
            'supplier_id' => 'sometimes|exists:suppliers,id',
            'expected_arrival' => 'nullable|date',
            'shipping_method' => 'nullable|string|max:50',
            'freight' => 'nullable|numeric|min:0',
            'category' => 'nullable|string|max:100',
            'remark' => 'nullable|string',
            'items' => 'sometimes|array|min:1',
            'items.*.sku_code' => 'required_with:items|string',
            'items.*.sku_name' => 'required_with:items|string',
            'items.*.quantity' => 'required_with:items|integer|min:1',
            'items.*.price' => 'required_with:items|numeric|min:0',
        ]);

        if ($validator->fails()) {
            return response()->json(['code' => 422, 'message' => '验证失败', 'errors' => $validator->errors()], 422);
        }

        DB::beginTransaction();
        try {
            $purchaseOrder->update($request->only([
                'warehouse_id', 'supplier_id', 'expected_arrival',
                'shipping_method', 'freight', 'category', 'remark'
            ]));

            if ($request->has('items')) {
                $purchaseOrder->items()->delete();
                foreach ($request->items as $item) {
                    $purchaseOrder->items()->create([
                        'sku_code' => $item['sku_code'],
                        'sku_name' => $item['sku_name'],
                        'quantity' => $item['quantity'],
                        'received_quantity' => 0,
                        'price' => $item['price'],
                    ]);
                }
            }

            DB::commit();
            return response()->json([
                'code' => 200,
                'data' => $purchaseOrder->load('items'),
                'message' => '更新成功'
            ]);
        } catch (\Exception $e) {
            DB::rollBack();
            return response()->json(['code' => 500, 'message' => '更新失败：' . $e->getMessage()], 500);
        }
    }

    /**
     * 提交审核
     */
    public function submitReview($id)
    {
        $purchaseOrder = PurchaseOrder::find($id);
        if (!$purchaseOrder) {
            return response()->json(['code' => 404, 'message' => '采购单不存在'], 404);
        }
        if ($purchaseOrder->status !== 'draft') {
            return response()->json(['code' => 403, 'message' => '仅草稿状态可提交审核'], 403);
        }

        $purchaseOrder->status = 'under_review';
        $purchaseOrder->save();

        return response()->json(['code' => 200, 'message' => '提交审核成功']);
    }

    /**
     * 审核通过
     */
    public function approve($id)
    {
        \Log::info('approve method entered', ['id' => $id, 'time' => now()]);

        $purchaseOrder = PurchaseOrder::with('items')->find($id);
        if (!$purchaseOrder) {
            return response()->json(['code' => 404, 'message' => '采购单不存在'], 404);
        }
        if ($purchaseOrder->status !== 'under_review') {
            return response()->json(['code' => 403, 'message' => '仅待审核状态可审核通过'], 403);
        }

        DB::beginTransaction();
        try {
            $purchaseOrder->status = 'approved';
            // 临时注释掉以下两行，避免字段缺失错误
            // $purchaseOrder->approved_at = now();
            // $purchaseOrder->approved_by = auth()->id() ?? 1;
            $purchaseOrder->save();

            // 计算总数量
            $totalQuantity = $purchaseOrder->items->sum('quantity');

            // 自动生成收货单
            $receivingOrder = ReceivingOrder::create([
                'receiving_no' => 'RO' . date('Ymd') . str_pad(mt_rand(1, 99999), 5, '0', STR_PAD_LEFT),
                'po_id' => $purchaseOrder->id,
                'warehouse_id' => $purchaseOrder->warehouse_id,
                'total_quantity' => $totalQuantity,
                'received_quantity' => 0,
                'status' => 'pending',
                'is_cloud_warehouse' => false, // 默认为false
                // 其他可选字段：'receiver', 'remark' 暂不设置
            ]);

            foreach ($purchaseOrder->items as $item) {
                ReceivingOrderItem::create([
                    'receiving_order_id' => $receivingOrder->id,
                    'sku_code' => $item->sku_code,
                    'sku_name' => $item->sku_name,
                    'order_quantity' => $item->quantity,
                    'received_quantity' => 0,
                ]);
            }

            DB::commit();
            return response()->json(['code' => 200, 'message' => '审核通过，已生成收货单']);
        } catch (\Exception $e) {
            DB::rollBack();
            \Log::error('Approve failed', [
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString()
            ]);
            return response()->json(['code' => 500, 'message' => '审核失败：' . $e->getMessage()], 500);
        }
    }

    /**
     * 驳回审核
     */
    public function reject(Request $request, $id)
    {
        $purchaseOrder = PurchaseOrder::find($id);
        if (!$purchaseOrder) {
            return response()->json(['code' => 404, 'message' => '采购单不存在'], 404);
        }
        if ($purchaseOrder->status !== 'under_review') {
            return response()->json(['code' => 403, 'message' => '仅待审核状态可驳回'], 403);
        }

        $validator = Validator::make($request->all(), [
            'reason' => 'required|string'
        ]);
        if ($validator->fails()) {
            return response()->json(['code' => 422, 'message' => '请填写驳回原因', 'errors' => $validator->errors()], 422);
        }

        $purchaseOrder->status = 'rejected';
        $purchaseOrder->reject_reason = $request->reason;
        $purchaseOrder->save();

        return response()->json(['code' => 200, 'message' => '已驳回']);
    }

    /**
     * 推送云仓（模拟）
     */
    public function pushCloud($id)
    {
        $purchaseOrder = PurchaseOrder::find($id);
        if (!$purchaseOrder) {
            return response()->json(['code' => 404, 'message' => '采购单不存在'], 404);
        }
        if ($purchaseOrder->status !== 'approved') {
            return response()->json(['code' => 403, 'message' => '仅审核通过的采购单可推送云仓'], 403);
        }

        $result = $this->purchaseService->pushToCloud($purchaseOrder);

        if ($result['success']) {
            $purchaseOrder->cloud_push_status = 'pushed';
            $purchaseOrder->cloud_push_time = now();
            $purchaseOrder->save();
            return response()->json(['code' => 200, 'message' => '推送成功', 'data' => $result]);
        } else {
            return response()->json(['code' => 500, 'message' => '推送失败', 'error' => $result['error']], 500);
        }
    }

    /**
     * 删除采购单（仅草稿）
     */
    public function destroy($id)
    {
        $purchaseOrder = PurchaseOrder::find($id);
        if (!$purchaseOrder) {
            return response()->json(['code' => 404, 'message' => '采购单不存在'], 404);
        }
        if ($purchaseOrder->status !== 'draft') {
            return response()->json(['code' => 403, 'message' => '仅草稿状态可删除'], 403);
        }

        DB::transaction(function () use ($purchaseOrder) {
            $purchaseOrder->items()->delete();
            $purchaseOrder->delete();
        });

        return response()->json(['code' => 200, 'message' => '删除成功']);
    }
}