<?php

namespace App\Modules\Production\Controllers;

use App\Http\Controllers\Controller;

use App\Modules\Production\Models\ProductionOrder;
use App\Modules\Production\Models\ProductionOrderItem;
use App\Modules\Inventory\Contracts\InventoryServiceInterface;
use App\Modules\Core\Models\User;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Inertia\Inertia;
use Inertia\Response;

class ProductionOrderController extends Controller
{
    protected $inventoryService;

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

    /**
     * 生產工單列表
     */
    public function index(Request $request): Response
    {
        // 不再使用 with()，避免跨模組 Eager Loading
        $query = ProductionOrder::query();

        // 搜尋 (此處 orWhereHas 暫時保留，因 Laravel query builder 仍可作用於資料表層級，
        // 但實務上若模組完全隔離，應考慮搜尋引擎或 ID 預選)
        if ($request->filled('search')) {
            $search = $request->search;
            $query->where(function ($q) use ($search) {
                $q->where('code', 'like', "%{$search}%")
                  ->orWhere('output_batch_number', 'like', "%{$search}%");
                // 若要搜尋產品名稱，現在需先從 Inventory 查出 IDs
                $productIds = \App\Modules\Inventory\Models\Product::where('name', 'like', "%{$search}%")->pluck('id');
                $q->orWhereIn('product_id', $productIds);
            });
        }

        // 狀態篩選
        if ($request->filled('status') && $request->status !== 'all') {
            $query->where('status', $request->status);
        }

        // 排除軟刪除
        $query->orderBy($request->input('sort_field', 'created_at'), $request->input('sort_direction', 'desc'));

        // 分頁
        $perPage = $request->input('per_page', 10);
        $productionOrders = $query->paginate($perPage)->withQueryString();

        // --- 手動資料水和 (Manual Hydration) ---
        $productIds = $productionOrders->pluck('product_id')->unique()->filter()->toArray();
        $warehouseIds = $productionOrders->pluck('warehouse_id')->unique()->filter()->toArray();
        $userIds = $productionOrders->pluck('user_id')->unique()->filter()->toArray();

        $products = $this->inventoryService->getProductsByIds($productIds)->keyBy('id');
        $warehouses = $this->inventoryService->getAllWarehouses()->whereIn('id', $warehouseIds)->keyBy('id');
        $users = User::whereIn('id', $userIds)->get()->keyBy('id'); // Core 模組暫由 Model 直接獲取

        $productionOrders->getCollection()->transform(function ($order) use ($products, $warehouses, $users) {
            $order->product = $products->get($order->product_id);
            $order->warehouse = $warehouses->get($order->warehouse_id);
            $order->user = $users->get($order->user_id);
            return $order;
        });

        return Inertia::render('Production/Index', [
            'productionOrders' => $productionOrders,
            'filters' => $request->only(['search', 'status', 'per_page', 'sort_field', 'sort_direction']),
        ]);
    }

    /**
     * 新增生產單表單
     */
    public function create(): Response
    {
        return Inertia::render('Production/Create', [
            'products' => $this->inventoryService->getAllProducts(),
            'warehouses' => $this->inventoryService->getAllWarehouses(),
            'units' => $this->inventoryService->getUnits(),
        ]);
    }

    /**
     * 儲存生產單（含自動扣料與成品入庫）
     */
    public function store(Request $request)
    {
        $status = $request->input('status', 'draft');

        $baseRules = [
            'product_id' => 'required',
            'output_batch_number' => 'required|string|max:50',
            'status' => 'nullable|in:draft,completed',
        ];

        $completedRules = [
            'warehouse_id' => 'required',
            'output_quantity' => 'required|numeric|min:0.01',
            'production_date' => 'required|date',
            'items' => 'required|array|min:1',
            'items.*.inventory_id' => 'required',
            'items.*.quantity_used' => 'required|numeric|min:0.0001',
        ];

        $rules = $status === 'completed' ? array_merge($baseRules, $completedRules) : $baseRules;

        $validated = $request->validate($rules);

        DB::transaction(function () use ($validated, $request, $status) {
            // 1. 建立生產工單
            $productionOrder = ProductionOrder::create([
                'code' => ProductionOrder::generateCode(),
                'product_id' => $validated['product_id'],
                'warehouse_id' => $validated['warehouse_id'] ?? null,
                'output_quantity' => $validated['output_quantity'] ?? 0,
                'output_batch_number' => $validated['output_batch_number'],
                'output_box_count' => $request->output_box_count,
                'production_date' => $validated['production_date'] ?? now()->toDateString(),
                'expiry_date' => $request->expiry_date,
                'user_id' => auth()->id(),
                'status' => $status,
                'remark' => $request->remark,
            ]);

            activity()
                ->performedOn($productionOrder)
                ->causedBy(auth()->user())
                ->log('created');

            // 2. 處理明細
            if (!empty($request->items)) {
                foreach ($request->items as $item) {
                    ProductionOrderItem::create([
                        'production_order_id' => $productionOrder->id,
                        'inventory_id' => $item['inventory_id'],
                        'quantity_used' => $item['quantity_used'] ?? 0,
                        'unit_id' => $item['unit_id'] ?? null,
                    ]);

                    if ($status === 'completed') {
                        $this->inventoryService->decreaseInventoryQuantity(
                            $item['inventory_id'], 
                            $item['quantity_used'], 
                            "生產單 #{$productionOrder->code} 耗料",
                            ProductionOrder::class,
                            $productionOrder->id
                        );
                    }
                }
            }

            // 3. 成品入庫
            if ($status === 'completed') {
                $this->inventoryService->createInventoryRecord([
                    'warehouse_id' => $validated['warehouse_id'],
                    'product_id' => $validated['product_id'],
                    'quantity' => $validated['output_quantity'],
                    'batch_number' => $validated['output_batch_number'],
                    'box_number' => $request->output_box_count,
                    'arrival_date' => $validated['production_date'],
                    'expiry_date' => $request->expiry_date,
                    'reason' => "生產單 #{$productionOrder->code} 成品入庫",
                    'reference_type' => ProductionOrder::class,
                    'reference_id' => $productionOrder->id,
                ]);

                activity()
                    ->performedOn($productionOrder)
                    ->causedBy(auth()->user())
                    ->log('completed');
            }
        });

        return redirect()->route('production-orders.index')
            ->with('success', $status === 'completed' ? '生產單已完成並入庫' : '草稿已儲存');
    }

    /**
     * 檢視生產單詳情
     */
    public function show(ProductionOrder $productionOrder): Response
    {
        // 手動水和主表資料
        $productionOrder->product = $this->inventoryService->getProduct($productionOrder->product_id);
        if ($productionOrder->product) {
            $productionOrder->product->base_unit = $this->inventoryService->getUnits()->where('id', $productionOrder->product->base_unit_id)->first();
        }
        $productionOrder->warehouse = $this->inventoryService->getWarehouse($productionOrder->warehouse_id);
        $productionOrder->user = User::find($productionOrder->user_id);

        // 手動水和明細資料
        $items = $productionOrder->items;
        $inventoryIds = $items->pluck('inventory_id')->unique()->filter()->toArray();
        $inventories = $this->inventoryService->getInventoriesByIds(
            $inventoryIds, 
            ['product.baseUnit', 'sourcePurchaseOrder.vendor']
        )->keyBy('id');
        
        $units = $this->inventoryService->getUnits()->keyBy('id');

        foreach ($items as $item) {
            $item->inventory = $inventories->get($item->inventory_id);
            $item->unit = $units->get($item->unit_id);
        }

        return Inertia::render('Production/Show', [
            'productionOrder' => $productionOrder,
        ]);
    }

    /**
     * 取得倉庫內可用庫存
     */
    public function getWarehouseInventories($warehouseId)
    {
        $inventories = $this->inventoryService->getInventoriesByWarehouse($warehouseId);
        
        $data = $inventories->map(function ($inv) {
            return [
                'id' => $inv->id,
                'product_id' => $inv->product_id,
                'product_name' => $inv->product->name ?? '未知商品',
                'product_code' => $inv->product->code ?? '',
                'batch_number' => $inv->batch_number,
                'box_number' => $inv->box_number,
                'quantity' => $inv->quantity,
                'arrival_date' => $inv->arrival_date ? $inv->arrival_date->format('Y-m-d') : null,
                'expiry_date' => $inv->expiry_date ? $inv->expiry_date->format('Y-m-d') : null,
                'unit_name' => $inv->product->baseUnit->name ?? '',
                'base_unit_id' => $inv->product->base_unit_id ?? null,
                'large_unit_id' => $inv->product->large_unit_id ?? null,
                'conversion_rate' => $inv->product->conversion_rate ?? 1,
            ];
        });

        return response()->json($data);
    }

    /**
     * 編輯生產單
     */
    public function edit(ProductionOrder $productionOrder): Response
    {
        if ($productionOrder->status !== 'draft') {
            return redirect()->route('production-orders.show', $productionOrder->id)
                ->with('error', '只有草稿狀態的生產單可以編輯');
        }

        // 基本水和
        $productionOrder->product = $this->inventoryService->getProduct($productionOrder->product_id);
        $productionOrder->warehouse = $this->inventoryService->getWarehouse($productionOrder->warehouse_id);
        
        // 手動水和明細資料
        $items = $productionOrder->items;
        $inventoryIds = $items->pluck('inventory_id')->unique()->filter()->toArray();
        $inventories = $this->inventoryService->getInventoriesByIds(
            $inventoryIds, 
            ['product.baseUnit']
        )->keyBy('id');
        
        $units = $this->inventoryService->getUnits()->keyBy('id');

        foreach ($items as $item) {
            $item->inventory = $inventories->get($item->inventory_id);
            $item->unit = $units->get($item->unit_id);
        }

        return Inertia::render('Production/Edit', [
            'productionOrder' => $productionOrder,
            'products' => $this->inventoryService->getAllProducts(),
            'warehouses' => $this->inventoryService->getAllWarehouses(),
            'units' => $this->inventoryService->getUnits(),
        ]);
    }

    /**
     * 更新生產單
     */
    public function update(Request $request, ProductionOrder $productionOrder)
    {
        if ($productionOrder->status !== 'draft') {
             return redirect()->route('production-orders.show', $productionOrder->id)
                ->with('error', '只有草稿可以修改');
        }

        $status = $request->input('status', 'draft');

        // 基礎驗證規則
        $baseRules = [
            'product_id' => 'required|exists:products,id',
            'output_batch_number' => 'required|string|max:50',
            'status' => 'required|in:draft,completed',
            'remark' => 'nullable|string',
        ];

        // 完工時的嚴格驗證規則
        $completedRules = [
            'warehouse_id' => 'required|exists:warehouses,id',
            'output_quantity' => 'required|numeric|min:0.01',
            'production_date' => 'required|date',
            'expiry_date' => 'nullable|date',
            'items' => 'required|array|min:1',
            'items.*.inventory_id' => 'required|exists:inventories,id',
            'items.*.quantity_used' => 'required|numeric|min:0.0001',
        ];

        // 若狀態切換為 completed，需合併驗證規則
        $rules = $status === 'completed' ? array_merge($baseRules, $completedRules) : $baseRules;
        
        $validated = $request->validate($rules);

        DB::transaction(function () use ($validated, $request, $status, $productionOrder) {
            $productionOrder->update([
                'product_id' => $validated['product_id'],
                'warehouse_id' => $validated['warehouse_id'] ?? $productionOrder->warehouse_id,
                'output_quantity' => $validated['output_quantity'] ?? 0,
                'output_batch_number' => $validated['output_batch_number'],
                'output_box_count' => $request->output_box_count,
                'production_date' => $validated['production_date'] ?? now()->toDateString(),
                'expiry_date' => $request->expiry_date,
                'status' => $status,
                'remark' => $request->remark,
            ]);

            activity()
                ->performedOn($productionOrder)
                ->causedBy(auth()->user())
                ->log('updated');

            // 重新建立明細
            $productionOrder->items()->delete();

            if (!empty($request->items)) {
                foreach ($request->items as $item) {
                    ProductionOrderItem::create([
                        'production_order_id' => $productionOrder->id,
                        'inventory_id' => $item['inventory_id'],
                        'quantity_used' => $item['quantity_used'] ?? 0,
                        'unit_id' => $item['unit_id'] ?? null,
                    ]);

                    if ($status === 'completed') {
                        $this->inventoryService->decreaseInventoryQuantity(
                            $item['inventory_id'], 
                            $item['quantity_used'], 
                            "生產單 #{$productionOrder->code} 耗料",
                            ProductionOrder::class,
                            $productionOrder->id
                        );
                    }
                }
            }

            if ($status === 'completed') {
                $this->inventoryService->createInventoryRecord([
                    'warehouse_id' => $validated['warehouse_id'],
                    'product_id' => $validated['product_id'],
                    'quantity' => $validated['output_quantity'],
                    'batch_number' => $validated['output_batch_number'],
                    'box_number' => $request->output_box_count,
                    'arrival_date' => $validated['production_date'],
                    'expiry_date' => $request->expiry_date,
                    'reason' => "生產單 #{$productionOrder->code} 成品入庫",
                    'reference_type' => ProductionOrder::class,
                    'reference_id' => $productionOrder->id,
                ]);

                activity()
                    ->performedOn($productionOrder)
                    ->causedBy(auth()->user())
                    ->log('completed');
            }
        });

        return redirect()->route('production-orders.index')
            ->with('success', '生產單已更新');
    }

    /**
     * 刪除生產單
     */
    public function destroy(ProductionOrder $productionOrder)
    {
        if ($productionOrder->status === 'completed') {
            return redirect()->back()->with('error', '已完工的生產單無法刪除');
        }

        DB::transaction(function () use ($productionOrder) {
            // 紀錄刪除動作 (需在刪除前或使用軟刪除)
            activity()
                ->performedOn($productionOrder)
                ->causedBy(auth()->user())
                ->log('deleted');

            $productionOrder->items()->delete();
            $productionOrder->delete();
        });

        return redirect()->route('production-orders.index')->with('success', '生產單已刪除');
    }
}