<?php

namespace App\Services;

use App\Models\Bundle;
use App\Models\BundleItem;
use App\Models\BundlePrice;
use Illuminate\Support\Facades\DB;

class BundleService
{
    /**
     * Crear un nuevo kit/bundle con sus componentes y precio
     */
    public function createBundle(array $data): Bundle
    {
        return DB::transaction(function () use ($data) {
            // 1. Crear el bundle principal
            $bundle = Bundle::create([
                'name' => $data['name'],
                'sku' => $data['sku'],
                'barcode' => $data['barcode'] ?? null,
            ]);

            // 2. Agregar componentes al kit
            foreach ($data['items'] as $item) {
                BundleItem::create([
                    'bundle_id' => $bundle->id,
                    'inventory_id' => $item['inventory_id'],
                    'quantity' => $item['quantity'],
                ]);
            }

            // 3. Calcular costos y crear precio
            $bundle->load('items.inventory.price');

            $totalCost = 0;
            $totalRetailPrice = 0;

            foreach ($bundle->items as $item) {
                $totalCost += ($item->inventory->price->cost ?? 0) * $item->quantity;
                $totalRetailPrice += ($item->inventory->price->retail_price ?? 0) * $item->quantity;
            }

            // Permitir override de precio (para promociones)
            $finalRetailPrice = $data['retail_price'] ?? $totalRetailPrice;
            $tax = $data['tax'] ?? 16.00;

            BundlePrice::create([
                'bundle_id' => $bundle->id,
                'cost' => $totalCost,
                'retail_price' => $finalRetailPrice,
                'tax' => $tax,
            ]);

            return $bundle->fresh(['items.inventory.price', 'price']);
        });
    }

    /**
     * Actualizar un kit existente
     */
    public function updateBundle(Bundle $bundle, array $data): Bundle
    {
        return DB::transaction(function () use ($bundle, $data) {
            // 1. Actualizar datos básicos del bundle
            $bundle->update([
                'name' => $data['name'] ?? $bundle->name,
                'sku' => $data['sku'] ?? $bundle->sku,
                'barcode' => $data['barcode'] ?? $bundle->barcode,
            ]);

            // 2. Actualizar componentes si se proporcionan
            if (isset($data['items'])) {
                // Eliminar componentes actuales
                $bundle->items()->delete();

                // Crear nuevos componentes
                foreach ($data['items'] as $item) {
                    BundleItem::create([
                        'bundle_id' => $bundle->id,
                        'inventory_id' => $item['inventory_id'],
                        'quantity' => $item['quantity'],
                    ]);
                }
            }

            // 3. Recalcular o actualizar precio
            if (isset($data['recalculate_price']) && $data['recalculate_price']) {
                // Recalcular precio basado en componentes actuales
                $bundle->load('items.inventory.price');

                $totalCost = 0;
                $totalRetailPrice = 0;

                foreach ($bundle->items as $item) {
                    $totalCost += ($item->inventory->price->cost ?? 0) * $item->quantity;
                    $totalRetailPrice += ($item->inventory->price->retail_price ?? 0) * $item->quantity;
                }

                $finalRetailPrice = $data['retail_price'] ?? $totalRetailPrice;
                $tax = $data['tax'] ?? 16.00;

                $bundle->price->update([
                    'cost' => $totalCost,
                    'retail_price' => $finalRetailPrice,
                    'tax' => $tax,
                ]);
            } elseif (isset($data['retail_price'])) {
                // Solo actualizar precio sin recalcular componentes
                $bundle->price->update([
                    'retail_price' => $data['retail_price'],
                    'tax' => $data['tax'] ?? 16.00,
                ]);
            }

            return $bundle->fresh(['items.inventory.price', 'price']);
        });
    }

    /**
     * Validar disponibilidad de stock del kit
     */
    public function validateBundleAvailability(Bundle $bundle, int $quantity, ?int $warehouseId = null): void
    {
        if (!$bundle->hasStock($quantity, $warehouseId)) {
            $availableStock = $warehouseId
                ? $bundle->stockInWarehouse($warehouseId)
                : $bundle->available_stock;

            throw new \Exception(
                "Stock insuficiente del kit '{$bundle->name}'. " .
                "Disponibles: {$availableStock}, Requeridos: {$quantity}"
            );
        }
    }

    /**
     * Obtener precio total de componentes (sin promoción)
     */
    public function getComponentsValue(Bundle $bundle): float
    {
        $total = 0;

        foreach ($bundle->items as $item) {
            $componentPrice = $item->inventory->price->retail_price ?? 0;
            $total += $componentPrice * $item->quantity;
        }

        return round($total, 2);
    }

    /**
     * Eliminar (soft delete) un bundle
     */
    public function deleteBundle(Bundle $bundle): bool
    {
        return $bundle->delete();
    }

    /**
     * Restaurar un bundle eliminado
     */
    public function restoreBundle(int $bundleId): ?Bundle
    {
        $bundle = Bundle::withTrashed()->find($bundleId);

        if ($bundle && $bundle->trashed()) {
            $bundle->restore();
            return $bundle->fresh(['items.inventory.price', 'price']);
        }

        return null;
    }
}