<?php namespace App\Http\Controllers\App;

use App\Models\Inventory;
use App\Http\Controllers\Controller;
use App\Http\Requests\App\InventoryStoreRequest;
use App\Http\Requests\App\InventoryUpdateRequest;
use App\Http\Requests\App\InventoryImportRequest;
use App\Services\ProductService;
use App\Imports\ProductsImport;
use Illuminate\Http\Request;
use Illuminate\Support\Facades\DB;
use Notsoweb\ApiResponse\Enums\ApiResponse;
use Maatwebsite\Excel\Facades\Excel;
use Maatwebsite\Excel\Validators\ValidationException;
use Maatwebsite\Excel\Concerns\FromArray;
use Maatwebsite\Excel\Concerns\WithHeadings;
use Maatwebsite\Excel\Concerns\Exportable;

class InventoryController extends Controller
{
    public function __construct(
        protected ProductService $productService
    ) {}

    public function index(Request $request)
    {
        $products = Inventory::with(['category', 'price', 'unitOfMeasure'])->withCount('serials')
        ->where('is_active', true);


        // Filtro por búsqueda de texto (nombre, SKU, código de barras)
        if ($request->has('q') && $request->q) {
            $products->where(function($query) use ($request) {
                $query->where('name', 'like', "%{$request->q}%")
                    ->orWhere('sku', 'like', "%{$request->q}%")
                    ->orWhere('barcode', $request->q);
            });
        }

        // Filtro por categoría (independiente de la búsqueda de texto)
        if ($request->has('category_id') && $request->category_id) {
            $products->where('category_id', $request->category_id);
        }

        // Calcular el valor total del inventario
        $totalInventoryValue = DB::table('inventory_warehouse')
            ->join('prices', 'inventory_warehouse.inventory_id', '=', 'prices.inventory_id')
            ->join('inventories', 'inventory_warehouse.inventory_id', '=', 'inventories.id')
            ->where('inventories.is_active', true)
            ->sum(DB::raw('inventory_warehouse.stock * prices.cost'));

        $products = $products->orderBy('name')
                ->paginate(config('app.pagination'));

        return ApiResponse::OK->response([
            'products' => $products,
            'total_inventory_value' => round($totalInventoryValue, 2)
        ]);
    }

    public function show(Inventory $inventario)
    {
        return ApiResponse::OK->response([
            'model' => $inventario->load(['category', 'price', 'unitOfMeasure'])->loadCount('serials')
        ]);
    }

    public function store(InventoryStoreRequest $request)
    {
        $product = $this->productService->createProduct($request->validated());

        return ApiResponse::OK->response([
            'model' => $product
        ]);
    }

    public function update(InventoryUpdateRequest $request, Inventory $inventario)
    {
        $product = $this->productService->updateProduct($inventario, $request->validated());

        return ApiResponse::OK->response([
            'model' => $product
        ]);
    }

    public function destroy(Inventory $inventario)
    {
        $inventario->delete();

        return ApiResponse::OK->response();
    }

    /**
     * Obtener productos disponibles en un almacén específico
     */
    public function getProductsByWarehouse(Request $request, int $warehouseId)
    {
        $query = Inventory::query()
            ->with(['category', 'price', 'unitOfMeasure'])
            ->where('is_active', true)
            ->whereHas('warehouses', function ($q) use ($warehouseId) {
                $q->where('warehouse_id', $warehouseId)
                  ->where('stock', '>', 0);
            });

        // Filtro por búsqueda de texto
        if ($request->has('q') && $request->q) {
            $query->where(function($q) use ($request) {
                $q->where('name', 'like', "%{$request->q}%")
                  ->orWhere('sku', 'like', "%{$request->q}%")
                  ->orWhere('barcode', $request->q);
            });
        }

        // Filtro por categoría
        if ($request->has('category_id') && $request->category_id) {
            $query->where('category_id', $request->category_id);
        }

        $products = $query->orderBy('name')->get();

        // Agregar el stock específico de este almacén a cada producto
        $products->each(function ($product) use ($warehouseId) {
            $warehouseStock = $product->warehouses()
                ->where('warehouse_id', $warehouseId)
                ->first();

            $product->warehouse_stock = $warehouseStock ? $warehouseStock->pivot->stock : 0;
        });

        return ApiResponse::OK->response([
            'products' => $products,
            'warehouse_id' => $warehouseId,
        ]);
    }

    /**
     * Importar productos desde Excel
     */
    public function import(InventoryImportRequest $request)
    {
        try {
            $import = new ProductsImport();

            Excel::import($import, $request->file('file'));

            $stats = $import->getStats();

            return ApiResponse::OK->response([
                'message' => 'Importación completada exitosamente.',
                'imported' => $stats['imported'],
                'updated' => $stats['updated'],
                'skipped' => $stats['skipped'],
                'errors' => $stats['errors'],
            ]);
        } catch (ValidationException $e) {
            $failures = $e->failures();
            $errors = [];

            foreach ($failures as $failure) {
                $errors[] = [
                    'row' => $failure->row(),
                    'attribute' => $failure->attribute(),
                    'errors' => $failure->errors(),
                    'values' => $failure->values(),
                ];
            }

            return ApiResponse::BAD_REQUEST->response([
                'message' => 'Error de validación en el archivo.',
                'errors' => $errors,
            ]);
        } catch (\Exception $e) {
            return ApiResponse::INTERNAL_ERROR->response([
                'message' => 'Error al importar productos: ' . $e->getMessage(),
            ]);
        }
    }

    /**
     * Descargar plantilla de Excel para importación
     */
    public function downloadTemplate()
    {
        $headers = [
            'nombre',
            'sku',
            'codigo_barras',
            'categoria',
            'precio_venta',
            'impuesto'
        ];

        $exampleData = [
            [
                'nombre' => 'Samsung Galaxy A55',
                'sku' => 'SAM-A55-BLK',
                'codigo_barras' => '7502276853456',
                'categoria' => 'Electrónica',
                'precio_venta' => 7500.00,
                'impuesto' => 16
            ],
            [
                'nombre' => 'Coca Cola 600ml',
                'sku' => 'COCA-600',
                'codigo_barras' => '750227686666',
                'categoria' => 'Bebidas',
                'precio_venta' => 18.00,
                'impuesto' => 8
            ],
            [
                'nombre' => 'Laptop HP Pavilion 15',
                'sku' => 'HP-LAP-15',
                'codigo_barras' => '7502276854443',
                'categoria' => 'Computadoras',
                'precio_venta' => 12000.00,
                'impuesto' => 16
            ],
        ];

        return Excel::download(
            new class($headers, $exampleData) implements FromArray, WithHeadings {
                use Exportable;

                public function __construct(private array $headers, private array $data) {}

                public function array(): array
                {
                    return $this->data;
                }

                public function headings(): array
                {
                    return $this->headers;
                }
            },
            'plantilla_productos.xlsx'
        );
    }

}