Helper functions for product import in Magento 2 to create swatch attribute options

swatch_attribute_options.php

<?php

    /**
     * @param $attributeCode
     * @param $newOptionValues
     * @internal param $attributeData
     */
    public function addSwatchValuesToSwatchAttribute($attributeCode, $newOptionValues)
    {
        $this->eavConfig->clear();
        $attribute = $this->eavConfig->getAttribute(\Magento\Catalog\Model\Product::ENTITY, $attributeCode);
        /** @var \Magento\Catalog\Model\ResourceModel\Eav\Attribute $attribute */
        if (!$attribute) {
            return;
        }
        $attributeData = [];
        $attributeData['option'] = $this->addExistingOptions($attribute);

        $existingColors = array_values($attributeData['option']);

        foreach ($newOptionValues as $key => $value) {
            if (is_numeric($key)) {
                $colorLabel = $value;
                $colorValue = '#fff'; // Default is white when no hex value is given
            } else {
                $colorLabel = $key;
                // If multiple colors are set, we need image swatches
                // For now, we just use the first color
                $value = explode('/', $value);
                $colorValue = $value[0];
            }
            if (in_array($colorLabel, $existingColors)) continue;
            $newOptionId = $this->insertSwatchOption($attribute, $colorLabel);
            $this->colorMap[$colorLabel] = $colorValue;
            $attributeData['option'][$newOptionId] = $colorLabel;
        }
        $this->eavConfig->clear();

        $attributeData['frontend_input'] = 'select';
        $attributeData['swatch_input_type'] = 'visual';
        $attributeData['update_product_preview_image'] = 1;
        $attributeData['use_product_image_for_swatch'] = 0;
        $attributeData['optionvisual'] = $this->getOptionSwatch($attributeData);
        $attributeData['defaultvisual'] = $this->getOptionDefaultVisual($attributeData);
        $attributeData['swatchvisual'] = $this->getOptionSwatchVisual($attributeData);
        $attribute->addData($attributeData);
        $attribute->save();
    }

    /**
     * @param array $attributeData
     * @return array
     */
    protected function getOptionSwatch(array $attributeData)
    {
        $optionSwatch = ['order' => [], 'value' => [], 'delete' => []];
        $i = 0;
        foreach ($attributeData['option'] as $optionKey => $optionValue) {
            $optionSwatch['delete'][$optionKey] = '';
            $optionSwatch['order'][$optionKey] = (string)$i++;
            $optionSwatch['value'][$optionKey] = [$optionValue, ''];
        }
        return $optionSwatch;
    }

    /**
     * @param array $attributeData
     * @return array
     */
    private function getOptionSwatchVisual(array $attributeData)
    {
        $optionSwatch = ['value' => []];
        foreach ($attributeData['option'] as $optionKey => $optionValue) {
            if (substr($optionValue, 0, 1) == '#' && strlen($optionValue) == 7) {
                $optionSwatch['value'][$optionKey] = $optionValue;
            } else if (isset($this->colorMap[$optionValue])) {
                $optionSwatch['value'][$optionKey] = $this->colorMap[$optionValue];
            } else {
                /* Fetch swatch value from current swatch option */
                $swatches = $this->swatchHelper->getSwatchesByOptionsId([$optionKey]);
                if (isset($swatches[$optionKey])) {
                    $swatch = $swatches[$optionKey];
                }
                if (isset($swatch) && isset($swatch['value']) && !empty($swatch['value'])) {
                    $optionSwatch['value'][$optionKey] = $swatch['value'];
                } else {
                    $optionSwatch['value'][$optionKey] = $this->colorMap['White'];
                }
            }
        }
        return $optionSwatch;
    }

    /**
     * @param array $attributeData
     * @return array
     */
    private function getOptionDefaultVisual(array $attributeData)
    {
        $optionSwatch = $this->getOptionSwatchVisual($attributeData);
        if (isset(array_keys($optionSwatch['value'])[0]))
            return [array_keys($optionSwatch['value'])[0]];
        else
            return [''];
    }