<?php

namespace App\Services;

use App\Models\Inventory;
use App\Models\SaleDetail;
use Illuminate\Support\Facades\DB;

class ReportService
{
    /**
     * Obtener el producto más vendido
     *
     * @param string|null $fromDate Fecha inicial (formato: Y-m-d)
     * @param string|null $toDate Fecha final (formato: Y-m-d)
     * @return array|null Retorna el producto más vendido o null si no hay ventas
     */
    public function getTopSellingProduct(?string $fromDate = null, ?string $toDate = null): ?array
    {
        $query = SaleDetail::query()
            ->selectRaw('
                inventories.id,
                inventories.name,
                inventories.sku,
                categories.name as category_name,
                SUM(sale_details.quantity) as total_quantity_sold,
                SUM(sale_details.subtotal) as total_revenue,
                COUNT(DISTINCT sale_details.sale_id) as times_sold,
                MAX(sales.created_at) as last_sale_date,
                inventories.created_at as added_date
            ')
            ->join('inventories', 'sale_details.inventory_id', '=', 'inventories.id')
            ->join('categories', 'inventories.category_id', '=', 'categories.id')
            ->join('sales', 'sale_details.sale_id', '=', 'sales.id')
            ->where('sales.status', 'completed')
            ->whereNull('sales.deleted_at');

        // Aplicar filtro de fechas si se proporcionan ambas
        if ($fromDate && $toDate) {
            $query->whereBetween(DB::raw('DATE(sales.created_at)'), [$fromDate, $toDate]);
        }

        $result = $query
            ->groupBy('inventories.id', 'inventories.name', 'inventories.sku',
                      'categories.name', 'inventories.created_at')
            ->orderByDesc('total_quantity_sold')
            ->first();

        return $result ? $result->toArray() : null;
    }

    /**
     * Obtener productos sin movimiento
     *
     * @param int $daysThreshold Días mínimos sin movimiento (default: 30)
     * @param bool $includeStockValue Incluir valor del inventario (default: true)
     * @return array Lista de productos sin ventas
     */
    public function getProductsWithoutMovement(int $daysThreshold = 30, bool $includeStockValue = true): array
    {
        // Obtener IDs de productos que SÍ tienen ventas
        $inventoriesWithSales = SaleDetail::query()
            ->join('sales', 'sale_details.sale_id', '=', 'sales.id')
            ->where('sales.status', 'completed')
            ->whereNull('sales.deleted_at')
            ->distinct()
            ->pluck('sale_details.inventory_id')
            ->toArray();

        // Construir query para productos SIN ventas
        $query = Inventory::query()
            ->selectRaw('
                inventories.id,
                inventories.name,
                inventories.sku,
                inventories.stock,
                categories.name as category_name,
                inventories.created_at as date_added,
                DATEDIFF(NOW(), inventories.created_at) as days_without_movement,
                prices.retail_price
            ');

        // Agregar valor del inventario si se solicita
        if ($includeStockValue) {
            $query->addSelect(
                DB::raw('(inventories.stock * COALESCE(prices.cost, 0)) as inventory_value')
            );
        }

        return $query
            ->leftJoin('categories', 'inventories.category_id', '=', 'categories.id')
            ->leftJoin('prices', 'inventories.id', '=', 'prices.inventory_id')
            ->where('inventories.is_active', true)
            ->whereNull('inventories.deleted_at')
            ->whereNotIn('inventories.id', $inventoriesWithSales)
            ->havingRaw('DATEDIFF(NOW(), inventories.created_at) >= ?', [$daysThreshold])
            ->orderBy('inventories.created_at')
            ->get()
            ->toArray();
    }
}