feat(inventory): 新增庫存分析模組

- 實作 InventoryAnalysisController 與 TurnoverService
- 新增庫存分析前端頁面 (Inventory/Analysis/Index.tsx)
- 整合路由與選單
- 統一分頁邏輯與狀態顯示
- 更新 UI Consistency Skill 文件

app/Modules/Inventory/Controllers/InventoryAnalysisController.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace App\Modules\Inventory\Controllers;
+
+use App\Http\Controllers\Controller;
+use App\Modules\Inventory\Models\Category;
+use App\Modules\Inventory\Models\Warehouse;
+use App\Modules\Inventory\Services\TurnoverService;
+use Illuminate\Http\Request;
+use Inertia\Inertia;
+
+class InventoryAnalysisController extends Controller
+{
+    protected $turnoverService;
+
+    public function __construct(TurnoverService $turnoverService)
+    {
+        $this->turnoverService = $turnoverService;
+    }
+
+    public function index(Request $request)
+    {
+        $filters = $request->only([
+            'warehouse_id', 'category_id', 'search', 'per_page', 'sort_by', 'sort_order', 'status'
+        ]);
+
+        $analysisData = $this->turnoverService->getAnalysisData($filters, $request->input('per_page', 10));
+        $kpis = $this->turnoverService->getKPIs($filters);
+
+        return Inertia::render('Inventory/Analysis/Index', [
+            'analysisData' => $analysisData,
+            'kpis' => $kpis,
+            'warehouses' => Warehouse::select('id', 'name')->get(),
+            'categories' => Category::select('id', 'name')->get(),
+            'filters' => $filters,
+        ]);
+    }
+}

app/Modules/Inventory/Routes/web.php

@@ -14,6 +14,7 @@ use App\Modules\Inventory\Controllers\AdjustDocController;
 use App\Modules\Inventory\Controllers\InventoryReportController;
 
 use App\Modules\Inventory\Controllers\StockQueryController;
+use App\Modules\Inventory\Controllers\InventoryAnalysisController;
 
 Route::middleware('auth')->group(function () {
     
@@ -32,6 +33,11 @@ Route::middleware('auth')->group(function () {
         Route::get('/inventory/report/{product}', [InventoryReportController::class, 'show'])->name('inventory.report.show');
     });
 
+    // 庫存分析 (Inventory Analysis)
+    Route::middleware('permission:inventory_report.view')->group(function () {
+        Route::get('/inventory/analysis', [InventoryAnalysisController::class, 'index'])->name('inventory.analysis.index');
+    });
+
     // 類別管理 (用於商品對話框) - 需要商品權限
     Route::middleware('permission:products.view')->group(function () {
         Route::get('/categories', [CategoryController::class, 'index'])->name('categories.index');

app/Modules/Inventory/Services/TurnoverService.php

@@ -0,0 +1,247 @@
+<?php
+
+namespace App\Modules\Inventory\Services;
+
+use App\Modules\Inventory\Models\InventoryTransaction;
+use App\Modules\Inventory\Models\Product;
+use Illuminate\Support\Facades\DB;
+use Carbon\Carbon;
+
+class TurnoverService
+{
+    /**
+     * Get inventory turnover analysis data
+     */
+    public function getAnalysisData(array $filters, int $perPage = 20)
+    {
+        $warehouseId = $filters['warehouse_id'] ?? null;
+        $categoryId = $filters['category_id'] ?? null;
+        $search = $filters['search'] ?? null;
+        $statusFilter = $filters['status'] ?? null; // 'dead', 'slow', 'normal'
+
+        // Base query for products with their current inventory sum
+        $query = Product::query()
+            ->select([
+                'products.id',
+                'products.code',
+                'products.name',
+                'categories.name as category_name',
+                'products.cost_price', // Assuming cost_price exists for value calculation
+            ])
+            ->leftJoin('categories', 'products.category_id', '=', 'categories.id')
+            ->leftJoin('inventories', 'products.id', '=', 'inventories.product_id')
+            ->groupBy(['products.id', 'products.code', 'products.name', 'categories.name', 'products.cost_price']);
+
+        // Filter by Warehouse (Current Inventory)
+        if ($warehouseId) {
+             $query->where('inventories.warehouse_id', $warehouseId);
+        }
+        
+        // Filter by Category
+        if ($categoryId) {
+            $query->where('products.category_id', $categoryId);
+        }
+
+        // Filter by Search
+        if ($search) {
+            $query->where(function($q) use ($search) {
+                $q->where('products.name', 'like', "%{$search}%")
+                  ->orWhere('products.code', 'like', "%{$search}%");
+            });
+        }
+        
+        // Add Aggregated Columns
+        
+        // 1. Current Inventory Quantity
+        $query->addSelect(DB::raw('COALESCE(SUM(inventories.quantity), 0) as current_stock'));
+
+        // 2. Sales in last 30 days (Outbound)
+        // We need a subquery or join for this to be efficient, or we use a separate query and map.
+        // Given potentially large data, subquery per row might be slow, but for pagination it's okay-ish.
+        // Better approach: Join with a subquery of aggregated transactions.
+        
+        $thirtyDaysAgo = Carbon::now()->subDays(30);
+        
+        // Subquery for 30-day sales
+        $salesSubquery = InventoryTransaction::query()
+            ->select('inventories.product_id', DB::raw('ABS(SUM(inventory_transactions.quantity)) as sales_qty_30d'))
+            ->join('inventories', 'inventory_transactions.inventory_id', '=', 'inventories.id')
+            ->where('inventory_transactions.type', '出庫') // Adjust type as needed based on actual data
+            ->where('inventory_transactions.actual_time', '>=', $thirtyDaysAgo)
+            ->groupBy('inventories.product_id');
+            
+        if ($warehouseId) {
+            $salesSubquery->where('inventories.warehouse_id', $warehouseId);
+        }
+
+        $query->leftJoinSub($salesSubquery, 'sales_30d', function ($join) {
+            $join->on('products.id', '=', 'sales_30d.product_id');
+        });
+        $query->addSelect(DB::raw('COALESCE(sales_30d.sales_qty_30d, 0) as sales_30d'));
+
+        // 3. Last Sale Date
+        // Use max actual_time from outbound transactions
+        $lastSaleSubquery = InventoryTransaction::query()
+            ->select('inventories.product_id', DB::raw('MAX(actual_time) as last_sale_date'))
+            ->join('inventories', 'inventory_transactions.inventory_id', '=', 'inventories.id')
+            ->where('inventory_transactions.type', '出庫')
+            ->groupBy('inventories.product_id');
+
+        if ($warehouseId) {
+             $lastSaleSubquery->where('inventories.warehouse_id', $warehouseId);
+        }
+
+        $query->leftJoinSub($lastSaleSubquery, 'last_sales', function ($join) {
+            $join->on('products.id', '=', 'last_sales.product_id');
+        });
+        $query->addSelect('last_sales.last_sale_date');
+
+        // Apply Status Filter (Dead Stock etc) requires having clauses or wrapper query.
+        // Dead Stock: stock > 0 AND (last_sale_date < 90 days ago OR last_sale_date IS NULL)
+        // Slow Moving: turnover days > X? 
+        
+        // Let's modify query to handle ordering and filtering on calculated fields if possible.
+        // For simplicity in Laravel, we might fetch and transform, but pagination breaks.
+        // We'll use HAVING for status filtering if needed.
+
+        // Order by
+        $sortBy = $filters['sort_by'] ?? 'turnover_days'; // Default sort
+        $sortOrder = $filters['sort_order'] ?? 'desc';
+        
+        // Turnover Days Calculation in SQL: (stock / (sales_30d / 30)) => (stock * 30) / sales_30d
+        // Handle division by zero: if sales_30d is 0, turnover is 'Inf' (or very high number like 9999)
+        $turnoverDaysSql = "CASE WHEN COALESCE(sales_30d.sales_qty_30d, 0) > 0 
+                            THEN (COALESCE(SUM(inventories.quantity), 0) * 30) / sales_30d.sales_qty_30d 
+                            ELSE 9999 END";
+        
+        $query->addSelect(DB::raw("$turnoverDaysSql as turnover_days"));
+
+        // Only show items with stock > 0 ? User might want to see out of stock items too? 
+        // Usually analysis focuses on what IS in stock. But Dead Stock needs items with stock.
+        // Stock-out analysis needs items with 0 stock.
+        // Let's filter stock > 0 by default for "Turnover Analysis".
+        // $query->havingRaw('current_stock > 0'); 
+        // Wait, better to let user filter? 
+        // For dead stock, definitive IS stock > 0.
+        
+        if ($statusFilter === 'dead') {
+            $ninetyDaysAgo = Carbon::now()->subDays(90);
+            $query->havingRaw("current_stock > 0 AND (last_sale_date < ? OR last_sale_date IS NULL)", [$ninetyDaysAgo]);
+        }
+
+        // Apply Sorting
+        if ($sortBy === 'turnover_days') {
+             $query->orderByRaw("$turnoverDaysSql $sortOrder");
+        } else if (in_array($sortBy, ['current_stock', 'sales_30d', 'last_sale_date'])) {
+             $query->orderBy($sortBy, $sortOrder);
+        } else {
+             $query->orderBy('products.code', 'asc');
+        }
+
+        return $query->paginate($perPage)->withQueryString()->through(function($item) {
+            // Post-processing for display
+            $item->turnover_days_display = $item->turnover_days >= 9999 ? '∞' : number_format($item->turnover_days, 1);
+            
+            // Determine Status Label
+            $lastSale = $item->last_sale_date ? Carbon::parse($item->last_sale_date) : null;
+            $daysSinceSale = $lastSale ? $lastSale->diffInDays(Carbon::now()) : 9999;
+            
+            if ($item->current_stock > 0 && $daysSinceSale > 90) {
+                $item->status = 'dead'; // 滯銷
+                $item->status_label = '滯銷';
+            } elseif ($item->current_stock > 0 && $item->turnover_days > 60) {
+                 $item->status = 'slow'; // 週轉慢
+                 $item->status_label = '週轉慢';
+            } elseif ($item->current_stock == 0) {
+                 $item->status = 'out_of_stock';
+                 $item->status_label = '缺貨';
+            } else {
+                $item->status = 'normal';
+                $item->status_label = '正常';
+            }
+            
+            return $item;
+        });
+    }
+
+    public function getKPIs(array $filters)
+    {
+         // Calculates aggregate KPIs
+         $warehouseId = $filters['warehouse_id'] ?? null;
+         $categoryId = $filters['category_id'] ?? null;
+         
+         // Helper to build base inv query
+         $buildInvQuery = function() use ($warehouseId, $categoryId) {
+             $q = DB::table('inventories')
+                 ->join('products', 'inventories.product_id', '=', 'products.id')
+                 ->where('inventories.quantity', '>', 0);
+             if ($warehouseId) $q->where('inventories.warehouse_id', $warehouseId);
+             if ($categoryId) $q->where('products.category_id', $categoryId);
+             return $q;
+         };
+         
+         // 1. Total Inventory Value (Cost)
+         $totalValue = (clone $buildInvQuery())
+             ->sum(DB::raw('inventories.quantity * COALESCE(products.cost_price, 0)'));
+             
+         // 2. Dead Stock Value (No sale in 90 days)
+         // Need last sale date for each product-location or just product? 
+         // Assuming dead stock is product-level logic for simplicity.
+         
+         $ninetyDaysAgo = Carbon::now()->subDays(90);
+         
+         // Get IDs of products sold in last 90 days
+         $soldProductIds = InventoryTransaction::query()
+             ->where('type', '出庫')
+             ->where('actual_time', '>=', $ninetyDaysAgo)
+             ->distinct()
+             ->pluck('inventory_id') // Wait, transaction links to inventory, inventory links to product.
+             // We need product_id.
+             ->map(function($id) {
+                 return DB::table('inventories')->where('id', $id)->value('product_id');
+             })
+             ->filter()
+             ->unique()
+             ->toArray();
+             // Optimization: Use join in subquery
+         
+         $soldProductIdsQuery = DB::table('inventory_transactions')
+             ->join('inventories', 'inventory_transactions.inventory_id', '=', 'inventories.id')
+             ->where('inventory_transactions.type', '出庫')
+             ->where('inventory_transactions.actual_time', '>=', $ninetyDaysAgo)
+             ->select('inventories.product_id')
+             ->distinct();
+             
+         $deadStockQuery = (clone $buildInvQuery())
+             ->whereNotIn('products.id', $soldProductIdsQuery);
+             
+         $deadStockValue = $deadStockQuery->sum(DB::raw('inventories.quantity * COALESCE(products.cost_price, 0)'));
+         $deadStockCount = $deadStockQuery->count('products.id'); // Count of inventory records (batches) or products? 
+         // Let's count distinct products
+         $deadStockProductCount = $deadStockQuery->distinct('products.id')->count('products.id');
+
+         // 3. Average Turnover Days (Company wide)
+         // Formula: (Avg Inventory / COGS) * 365 ?
+         // Simplified: (Total Stock / Total Sales 30d) * 30
+         
+         $totalStock = (clone $buildInvQuery())->sum('inventories.quantity');
+         
+         $totalSales30d = DB::table('inventory_transactions')
+             ->join('inventories', 'inventory_transactions.inventory_id', '=', 'inventories.id')
+             ->join('products', 'inventories.product_id', '=', 'products.id')
+             ->where('inventory_transactions.type', '出庫')
+             ->where('inventory_transactions.actual_time', '>=', Carbon::now()->subDays(30))
+             ->when($warehouseId, fn($q) => $q->where('inventories.warehouse_id', $warehouseId))
+             ->when($categoryId, fn($q) => $q->where('products.category_id', $categoryId))
+             ->sum(DB::raw('ABS(inventory_transactions.quantity)'));
+             
+         $avgTurnoverDays = $totalSales30d > 0 ? ($totalStock * 30) / $totalSales30d : 0;
+
+         return [
+             'total_stock_value' => $totalValue,
+             'dead_stock_value' => $deadStockValue,
+             'dead_stock_count' => $deadStockProductCount,
+             'avg_turnover_days' => round($avgTurnoverDays, 1),
+         ];
+    }
+}