<?php
namespace PackageModuleSetup;
use MagentoFrameworkSetupUpgradeDataInterface;
use MagentoFrameworkSetupModuleContextInterface;
use MagentoFrameworkSetupModuleDataSetupInterface;

class UpgradeData implements UpgradeDataInterface
{
    const PRODUCT_GROUP = 'Product Details';

    /** @var MagentoFrameworkAppState */
    protected $state;

    /** @var MagentoCatalogModelProductAttributeRepository $attributeRepository */
    protected $attributeRepository;

    /** @var MagentoFrameworkFilesystem  */
    protected $filesystem;

    /** @var MagentoSwatchesHelperMedia */
    protected $swatchHelper;

    /** @var MagentoCatalogModelProductMediaConfig */
    protected $productMediaConfig;

    /** @var MagentoFrameworkFilesystemDriverFile */
    protected $driverFile;

    /** @var MagentoEavSetupEavSetupFactory */
    protected $eavSetupFactory;

    public function __construct(
        MagentoEavSetupEavSetupFactory $eavSetupFactory,
        MagentoFrameworkAppState $state,
        MagentoCatalogModelProductAttributeRepository $attributeRepository,
        MagentoFrameworkFilesystem $filesystem,
        MagentoSwatchesHelperMedia $swatchHelper,
        MagentoCatalogModelProductMediaConfig $productMediaConfig,
        MagentoFrameworkFilesystemDriverFile $driverFile
    ) {
        $this->eavSetupFactory = $eavSetupFactory;
        $this->state = $state;
        $this->attributeRepository = $attributeRepository;
        $this->filesystem = $filesystem;
        $this->swatchHelper = $swatchHelper;
        $this->productMediaConfig = $productMediaConfig;
        $this->driverFile = $driverFile;
    }

    /**
     * {@inheritdoc}
     */
    public function upgrade(ModuleDataSetupInterface $setup, ModuleContextInterface $context)
    {
        $setup->startSetup();

        if (version_compare($context->getVersion(), '1.0.0', '<')) {
            $attributesData = [
               // to add in step 2
            ];

            $attributesOptionsData = [
                // to add in step 2
            ];

            $this->addProductAttributes($attributesData, $attributesOptionsData, $setup);
        }

        $setup->endSetup();
    }

    /**
     * Add product attributes.
     *
     * @param $attributesData
     * @param $attributesOptionsData
     * @param ModuleDataSetupInterface $setup
     *
     * @throws Exception
     */
    public function addProductAttributes($attributesData, $attributesOptionsData, ModuleDataSetupInterface $setup)
    {
        // to implement in step 3
    }
}

$attributesData = [
    'fit' => [
        'type' => 'int',
        'label' => 'Fit',
        'input' => 'select',
        'backend' => 'MagentoEavModelEntityAttributeBackendArrayBackend',
        'source' => 'MagentoEavModelEntityAttributeSourceTable',
        'required' => false,
        'global' => MagentoEavModelEntityAttributeScopedAttributeInterface::SCOPE_GLOBAL,
        'group' => self::PRODUCT_GROUP,
        'used_in_product_listing' => true,
        'visible_on_front' => true,
        'user_defined' => true,
        'filterable' => 2,
        'filterable_in_search' => true,
        'used_for_promo_rules' => true,
        'is_html_allowed_on_front' => true,
        'used_for_sort_by' => true,
    ],
];
$attributesOptionsData = [
    'fit' => [
        MagentoSwatchesModelSwatch::SWATCH_INPUT_TYPE_KEY => MagentoSwatchesModelSwatch::SWATCH_INPUT_TYPE_VISUAL,
        'optionvisual' => [
            'value'     => [
                'option_0' => [
                    0 => 'FITTED'
                ],
                'option_1' => [
                    0 => 'RELAXED'
                ],
                'option_2' => [
                    0 => 'REGULAR'
                ],
            ],
        ],
        'swatchvisual' => [
            'value'     => [
                'option_0' => 'Fitted.png',
                'option_1' => 'Relaxed.png',
                'option_2' => 'Regular.png',
            ],
        ],
    ]
];

/**
 * Add product attributes.
 *
 * @param $attributesData
 * @param $attributesOptionsData
 * @param ModuleDataSetupInterface $setup
 *
 * @throws Exception
 */
public function addProductAttributes($attributesData, $attributesOptionsData, ModuleDataSetupInterface $setup)
{
    try {
        // Make sure we don't get error "Area code is not set".
        $this->state->setAreaCode('admin');
    } catch (Exception $ignored) {}
    try {
        /** @var MagentoEavSetupEavSetup $eavSetup */
        $eavSetup = $this->eavSetupFactory->create(['setup' => $setup]);

        // Add attributes.
        foreach ($attributesData as $code => $attributeData) {
            $eavSetup->addAttribute(MagentoCatalogModelProduct::ENTITY, $code, $attributeData);
        }

        // Add order if it doesn't exist. This is an important step to make sure everything will be created correctly.
        foreach ($attributesOptionsData as &$attributeOptionsData) {
            $order = 0;
            $swatchVisualFiles = isset($attributeOptionsData['optionvisual']['value'])
                ? $attributeOptionsData['optionvisual']['value']
                : [];
            foreach ($swatchVisualFiles as $index => $swatchVisualFile) {
                if (!isset($attributeOptionsData['optionvisual']['order'][$index])) {
                    $attributeOptionsData['optionvisual']['order'][$index] = ++$order;
                }
            }
        }

        // Prepare visual swatches files.
        $mediaDirectory = $this->filesystem->getDirectoryRead(MagentoFrameworkAppFilesystemDirectoryList::MEDIA);
        $tmpMediaPath = $this->productMediaConfig->getBaseTmpMediaPath();
        $fullTmpMediaPath = $mediaDirectory->getAbsolutePath($tmpMediaPath);
        $this->driverFile->createDirectory($fullTmpMediaPath);
        foreach ($attributesOptionsData as &$attributeOptionsData) {
            $swatchVisualFiles = isset($attributeOptionsData['swatchvisual']['value'])
                ? $attributeOptionsData['swatchvisual']['value']
                : [];
            foreach ($swatchVisualFiles as $index => $swatchVisualFile) {
                $this->driverFile->copy(
                    __DIR__ . DIRECTORY_SEPARATOR . 'images' . DIRECTORY_SEPARATOR . $swatchVisualFile,
                    $fullTmpMediaPath . DIRECTORY_SEPARATOR . $swatchVisualFile
                );
                $newFile = $this->swatchHelper->moveImageFromTmp($swatchVisualFile);
                if (substr($newFile, 0, 1) == '.') {
                    $newFile = substr($newFile, 1); // Fix generating swatch variations for files beginning with ".".
                }
                $this->swatchHelper->generateSwatchVariations($newFile);
                $attributeOptionsData['swatchvisual']['value'][$index] = $newFile;
            }
        }

        // Add attribute options.
        foreach ($attributesOptionsData as $code => $attributeOptionsData) {
            /* @var MagentoCatalogModelResourceModelEavAttribute $attribute */
            $attribute = $this->attributeRepository->get($code);
            $attribute->addData($attributeOptionsData);
            $attribute->save();
        }
    } catch (Exception $ex) {
        throw new Exception(__('There was an error adding product attributes.'), 0, $ex);
    }
}