<?php

namespace App\Endpoint\Api\Http\Controllers\Product;

use App\Endpoint\Api\Http\Controllers\Controller;
use App\Endpoint\Api\Http\Resources\ProductSku\ProduckSkuResource;
use App\Endpoint\Api\Http\Resources\ProductSku\ProductSkuSimpleResource;
use App\Helpers\Paginator as PaginatorHelper;
use App\Models\ProductPart;
use App\Models\ProductPartSku;
use App\Models\ProductSku;
use App\Models\ProductSpu;
use Illuminate\Http\Request;
use Illuminate\Pagination\Paginator;

class ProductController extends Controller
{
    /**
     * 筛选商品
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Http\JsonResponse
     */
    public function index(Request $request)
    {
        $skus = $request->filled('part')
                    ? $this->filterProductsByPart($request)
                    : $this->filterProducts($request);

        return ProductSkuSimpleResource::collection($skus);
    }

    /**
     * 商品详情
     *
     * @param int $id
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Http\JsonResponse
     */
    public function show($id, Request $request)
    {
        $sku = ProductSku::findOrFail($id);

        if (! $sku->isOnline()) {
            return response()->json([
                'spu_specs' => [],
                'sku' => array_merge(ProduckSkuResource::make($sku)->resolve(), [
                    'status' => ProductSku::STATUS_OFFLINE,
                ]),
            ]);
        }

        $spu = ProductSpu::with('specs')->findOrFail($sku->spu_id);

        // 如果商品已失效
        if (! $spu->isValidProductSku($sku)) {
            return response()->json([
                'spu_specs' => [],
                'sku' => array_merge(ProduckSkuResource::make($sku)->resolve(), [
                    'status' => ProductSku::STATUS_INVALID,
                ]),
            ]);
        }

        // 主商品的规格
        $spuSpecs = [];

        if (count($original = (array) $sku->specs) > 0) {
            $skus = $spu->skus()->online()->get(['id', 'specs', 'stock', 'release_at']);

            $mapSkus = $skus->mapWithKeys(function ($item) {
                $key = implode('_', $item->specs) ?: $item->id;

                return [$key => $item];
            });

            foreach ($spu->specs as $spec) {
                $spuSpecItems = [];

                foreach ($spec->items as $value) {
                    // 根据当前 SKU 的规格，组装可能出现的其它规格组合
                    $jSpecs = $original;
                    $jSpecs[$spec->id] = $value;

                    $key = implode('_', $jSpecs);
                    $mapSku = $mapSkus->get($key);

                    $spuSpecItems[] = [
                        'name' => $value,
                        'selected' => $sku->is($mapSku),
                        'sku_id' => (int) $mapSku?->id,
                        'sku_stock' => (int) $mapSku?->saleable_stock,
                    ];
                }

                $spuSpecs[] = [
                    'name' => $spec->name,
                    'items' => $spuSpecItems,
                ];
            }
        }

        return response()->json([
            'spu_specs' => $spuSpecs,
            'sku' => array_merge(ProduckSkuResource::make($sku)->resolve(), [
                'status' => ProductSku::STATUS_ONLINE,
            ]),
        ]);
    }

    /**
     * 过滤商品
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Pagination\Paginator
     */
    protected function filterProducts(Request $request): Paginator
    {
        $input = $request->input();

        if ($request->isNotFilled('sort')) {
            $input['sort'] = '-id';
        }

        return ProductSku::select(['id', 'name', 'cover', 'sell_price', 'vip_price', 'sales'])
                        ->filter($input)
                        ->online()
                        ->whereRelation('category', 'is_show', true)
                        ->simplePaginate(PaginatorHelper::resolvePerPage('per_page', 20, 50));
    }

    /**
     * 按分区过滤商品
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Pagination\Paginator
     */
    protected function filterProductsByPart(Request $request): Paginator
    {
        $productPart = ProductPart::where('key', $request->input('part'))->first();

        if ($productPart === null) {
            return new Paginator([], $this->getPerPage($request), Paginator::resolveCurrentPage());
        }

        $paginator = ProductPartSku::with('sku:id,name,cover,sell_price,vip_price,sales')
                                    ->whereHas('sku', function ($query) {
                                        $query->online()->whereRelation('category', 'is_show', true);
                                    })
                                    ->where('part_id', $productPart->id)
                                    ->latest('sort')
                                    ->simplePaginate(PaginatorHelper::resolvePerPage('per_page', 20, 50));

        return $paginator->through(function ($item) {
            return $item->sku;
        });
    }
}