<?php

namespace App\Endpoint\Api\Http\Controllers;

use App\Endpoint\Api\Http\Resources\ProductSku\ProductSkuSimpleResource;
use App\Models\ProductPart;
use App\Models\ProductPartSku;
use App\Models\ProductSku;
use Illuminate\Http\Request;
use Illuminate\Pagination\Paginator;

class ProductController extends Controller
{
    /**
     * 商品列表
     *
     * @param \Illuminate\Http\Request $request
     * @return \Illuminate\Http\JsonResponse
     */
    public function index(Request $request)
    {
        return ProductSkuSimpleResource::collection(
            $request->filled('part')
                ? $this->filterProductsByPart($request)
                : $this->filterProducts($request)
        );
    }

    /**
     * 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($input)
                        ->isRelease()
                        ->whereRelation('category', 'is_show', true)
                        ->simplePaginate($this->getPerPage($request));
    }

    /**
     * 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->isRelease()->whereRelation('category', 'is_show', true);
                                    })
                                    ->where('part_id', $productPart->id)
                                    ->latest('sort')
                                    ->simplePaginate($this->getPerPage($request));

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

    /**
     * @return int
     */
    protected function getPerPage(Request $request): int
    {
        $perPage = (int) $request->input('per_page');

        if ($perPage > 0) {
            return $perPage > 50 ? 50 : $perPage;
        }

        return 20;
    }
}