<?php
/**
 * Copyright 2019 Adobe
 * All Rights Reserved.
 */
declare(strict_types=1);

namespace Magento\CatalogCustomerGraphQl\Model\Resolver;

use Magento\Catalog\Model\Product;
use Magento\CatalogCustomerGraphQl\Model\Resolver\Customer\GetCustomerGroup;
use Magento\CatalogCustomerGraphQl\Model\Resolver\Product\Price\Tiers;
use Magento\CatalogCustomerGraphQl\Model\Resolver\Product\Price\TiersFactory;
use Magento\Framework\Exception\LocalizedException;
use Magento\Framework\GraphQl\Schema\Type\ResolveInfo;
use Magento\Framework\GraphQl\Config\Element\Field;
use Magento\Framework\GraphQl\Query\ResolverInterface;
use Magento\Framework\GraphQl\Query\Resolver\ValueFactory;
use Magento\Framework\ObjectManager\ResetAfterRequestInterface;

/**
 * @inheritdoc
 */
class TierPrices implements ResolverInterface, ResetAfterRequestInterface
{
    /**
     * @var ValueFactory
     */
    private $valueFactory;

    /**
     * @var int
     */
    private $customerGroupId = null;

    /**
     * @var Tiers
     */
    private $tiers;

    /**
     * @var TiersFactory
     */
    private $tiersFactory;

    /**
     * @var GetCustomerGroup
     */
    private $getCustomerGroup;

    /**
     * @param ValueFactory $valueFactory
     * @param TiersFactory $tiersFactory
     * @param GetCustomerGroup $getCustomerGroup
     */
    public function __construct(
        ValueFactory $valueFactory,
        TiersFactory $tiersFactory,
        GetCustomerGroup $getCustomerGroup
    ) {
        $this->valueFactory = $valueFactory;
        $this->tiersFactory = $tiersFactory;
        $this->getCustomerGroup = $getCustomerGroup;
    }

    /**
     * @inheritdoc
     */
    public function resolve(
        Field $field,
        $context,
        ResolveInfo $info,
        ?array $value = null,
        ?array $args = null
    ) {
        if (!isset($value['model'])) {
            throw new LocalizedException(__('"model" value should be specified'));
        }

        if (null === $this->customerGroupId) {
            $this->customerGroupId = $this->getCustomerGroup->execute($context->getUserId());
            $this->tiers = $this->tiersFactory->create(['customerGroupId' => $this->customerGroupId]);
        }

        /** @var Product $product */
        $product = $value['model'];
        $productId = (int)$product->getId();
        $this->tiers->addProductFilter($productId);

        return $this->valueFactory->create(
            function () use ($productId) {
                $tierPrices = $this->tiers->getProductTierPrices($productId);

                return $tierPrices ?? [];
            }
        );
    }

    /**
     * @inheritDoc
     */
    public function _resetState(): void
    {
        $this->customerGroupId = null;
        $this->tiers = null;
    }
}