VITEC-website/packages/vitec/Classes/Import/SubsolutionWorkbookImporter.php

<?php

declare(strict_types=1);

namespace Evomedien\Vitec\Import;

use PhpOffice\PhpSpreadsheet\IOFactory;
use PhpOffice\PhpSpreadsheet\Spreadsheet;
use TYPO3\CMS\Core\Database\ConnectionPool;
use TYPO3\CMS\Core\DataHandling\DataHandler;
use TYPO3\CMS\Core\Resource\Enum\DuplicationBehavior;
use TYPO3\CMS\Core\Resource\StorageRepository;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * Imports ONE customer-filled sub-solution workbook (produced by
 * vitec:generate-subsolution-workbooks) into its layout-5 page.
 *
 * DELIBERATE SIBLING of SubmarketWorkbookImporter, NOT a shared
 * implementation (decision 2026-10-05): markets and solutions evolve
 * independently, changing one must never break the other.
 *
 * Differences from the sub-market importer:
 *  - target template is layout 5 "Solution Detail" (zones hero=1, main=0,
 *    sidebar=2), NOT the slotted layout 21: the hero element goes into
 *    colPos 1, everything else into colPos 0 in a fixed order. Elements
 *    are found by CType within their column (each CType appears once,
 *    except the flip cards).
 *  - the sub-solution pages usually ALREADY EXIST as empty shells below
 *    /solutions/<area>/ - they are switched to layout 5; missing pages are
 *    created HIDDEN as with markets.
 *  - intro carries a headline (vitec_intro_headline) and no learn-more /
 *    portfolio (solution design); hero has no video teaser.
 *  - detail_page is set on tx_vitec_domain_model_solution.
 *
 * Shared lessons (same as the market importer): named ranges first, then
 * label-scan over the locked column A; content-idempotent file attach;
 * sys_file_reference needs pid + tablenames + uid_foreign.
 */
final class SubsolutionWorkbookImporter
{
    private const LAYOUT = 5;
    private const COLPOS_HERO = 1;
    private const COLPOS_MAIN = 0;
    private const CARD_ROWS = 8;
    private const STORY_ROWS = 6;
    private const PRODUCT_ROWS = 9;

    /** Story detail page; mirrors the site setting vitec.storyDetailPid. */
    private const STORY_SINGLE_PID = 26;

    /** @var string[] */
    private array $report = [];
    /** @var array<string,array<string|int,array<string,mixed>>> */
    private array $datamap = [];
    /** @var array<string,array<int,array<string,int>>> */
    private array $cmdmap = [];
    /** @var array<int,string[]> colPos => element ids (uid or NEW id) in page order */
    private array $sequence = [];
    private int $newCounter = 0;

    /**
     * @return array{file:string,group:string,subsolution:string,newPage:bool,pageUid:int,elements:int,applied:bool,report:string[]}
     * @throws \RuntimeException on fatal problems
     */
    public function importFile(string $file, bool $apply): array
    {
        $this->report = [];
        $this->datamap = [];
        $this->cmdmap = [];
        $this->sequence = [];

        $spreadsheet = IOFactory::load($file);
        $values = $this->readNamedValues($spreadsheet);
        $subsolution = trim((string)($values['meta_subsolution'] ?? ''));
        $group = trim((string)($values['meta_group'] ?? ''));
        $recordUid = (int)($values['meta_record_uid'] ?? 0);
        $spreadsheet->disconnectWorksheets();
        if ($subsolution === '' || $group === '') {
            throw new \RuntimeException('Meta sheet missing - not a generated sub-solution workbook?');
        }

        // --- resolve pages ---------------------------------------------------
        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable('pages');
        $solutionsRoot = $connection->fetchAssociative("SELECT uid FROM pages WHERE deleted = 0 AND slug = '/solutions'");
        if (!$solutionsRoot) {
            throw new \RuntimeException('Page /solutions not found.');
        }
        $mainPage = $this->childByTitle((int)$solutionsRoot['uid'], $group);
        if ($mainPage === null) {
            throw new \RuntimeException('Solution area page "' . $group . '" not found below /solutions.');
        }
        $subPage = $this->childByTitle((int)$mainPage['uid'], $subsolution);

        if ($subPage === null) {
            $pageId = $this->newId();
            $this->datamap['pages'][$pageId] = [
                'pid' => (int)$mainPage['uid'],
                'title' => $subsolution,
                'doktype' => 1,
                'layout' => self::LAYOUT,
                'hidden' => 1,
                'backend_layout' => 'vitec__' . self::LAYOUT,
            ];
            $this->report[] = 'page: CREATE (hidden, review & publish editorially)';
        } else {
            $pageId = (string)(int)$subPage['uid'];
            $updates = [];
            if ((int)$subPage['layout'] !== self::LAYOUT) {
                $updates['layout'] = self::LAYOUT;
                $updates['backend_layout'] = 'vitec__' . self::LAYOUT;
                $this->report[] = 'page: switch layout -> ' . self::LAYOUT . ' (was ' . (int)$subPage['layout'] . ')';
            }
            if ($updates !== []) {
                $this->datamap['pages'][$pageId] = $updates;
            }
        }

        // --- SEO on the page --------------------------------------------------
        $seoTitle = trim((string)($values['seo_title'] ?? ''));
        $seoDescription = trim((string)($values['seo_description'] ?? ''));
        if ($seoTitle !== '') {
            $this->datamap['pages'][$pageId]['seo_title'] = $seoTitle;
        }
        if ($seoDescription !== '') {
            $this->datamap['pages'][$pageId]['description'] = $seoDescription;
        }

        // --- hero zone (colPos 1) ---------------------------------------------
        // The blocks below are registered in PAGE ORDER ($this->sequence) and
        // their sorting is written explicitly after DataHandler ran - see
        // applySequence() for why the creation order cannot be relied on.
        $heroId = $this->slotElement($pageId, $subPage, self::COLPOS_HERO, 'vitec_markethero');
        $this->setFields('tt_content', $heroId, [
            'vitec_subline' => (string)($values['hero_subline'] ?? ''),
            'vitec_cta_label' => (string)($values['hero_cta_label'] ?? ''),
            'vitec_cta_link' => (string)($values['hero_cta_url'] ?? ''),
        ]);
        $this->attachUrlFile($heroId, 'vitec_bgimage', (string)($values['hero_bgimage_url'] ?? ''), $subsolution, $apply, $this->pidValue($pageId));

        // --- main column: intro -------------------------------------------------
        $introId = $this->slotElement($pageId, $subPage, self::COLPOS_MAIN, 'vitec_marketintro');
        $this->setFields('tt_content', $introId, [
            'vitec_intro_headline' => (string)($values['intro_headline'] ?? ''),
            'vitec_intro_text' => (string)($values['intro_text'] ?? ''),
            'vitec_show_portfolio' => 0,
        ]);
        $this->attachUrlFile($introId, 'vitec_image', (string)($values['intro_image_url'] ?? ''), $subsolution, $apply, $this->pidValue($pageId));

        // --- main column: advantages (intro-paragraph + flip cards) --------------
        $flowHeaderId = $this->slotElement($pageId, $subPage, self::COLPOS_MAIN, 'vitec_introparagraph');
        $this->setFields('tt_content', $flowHeaderId, [
            'header' => (string)($values['flow_headline'] ?? ''),
            'bodytext' => (string)($values['flow_subtext'] ?? ''),
        ]);
        $existingCards = $subPage ? $this->slotElements((int)$subPage['uid'], self::COLPOS_MAIN, 'vitec_card') : [];
        $cardIndex = 0;
        for ($i = 1; $i <= self::CARD_ROWS; $i++) {
            $title = trim((string)($values['flow_card' . $i . '_title'] ?? ''));
            $front = trim((string)($values['flow_card' . $i . '_front'] ?? ''));
            $back = trim((string)($values['flow_card' . $i . '_back'] ?? ''));
            $icon = trim((string)($values['flow_card' . $i . '_icon'] ?? ''));
            if ($title === '' && $front === '') {
                continue;
            }
            $cardId = $existingCards[$cardIndex] ?? $this->newId();
            if (!isset($existingCards[$cardIndex])) {
                $this->datamap['tt_content'][$cardId]['pid'] = $this->pidValue($pageId);
                $this->datamap['tt_content'][$cardId]['colPos'] = self::COLPOS_MAIN;
                $this->datamap['tt_content'][$cardId]['CType'] = 'vitec_card';
            }
            $this->sequence[self::COLPOS_MAIN][] = (string)$cardId;
            $this->setFields('tt_content', (string)$cardId, [
                'vitec_layout_variant' => 'flipcard',
                'header' => $title,
                'bodytext' => $front,
                'vitec_back_headline' => $title,
                'vitec_back_text' => $back,
            ]);
            if ($icon !== '') {
                $this->report[] = 'card ' . $i . ': icon "' . $icon . '" noted - icon set still pending, attach later';
            }
            $cardIndex++;
        }
        if (count($existingCards) > $cardIndex) {
            $this->report[] = 'advantages: ' . (count($existingCards) - $cardIndex) . ' existing card(s) beyond the workbook - left untouched, review editorially';
        }

        // --- main column: testimonials -------------------------------------------
        $storyUids = [];
        foreach (range(1, self::STORY_ROWS) as $i) {
            $storyTitle = trim((string)($values['testi_story_' . $i] ?? ''));
            if ($storyTitle === '') {
                continue;
            }
            $story = $this->recordByTitle('tx_vitec_domain_model_usecase', $storyTitle);
            if ($story === null) {
                $this->report[] = 'testimonial ' . $i . ': story "' . $storyTitle . '" NOT FOUND - skipped';
                continue;
            }
            if (trim((string)$story['quote']) === '') {
                $this->report[] = 'testimonial: "' . $storyTitle . '" has NO QUOTE yet - maintain on the story record';
            }
            $storyUids[] = (int)$story['uid'];
        }
        $testiId = $this->slotElement($pageId, $subPage, self::COLPOS_MAIN, 'vitec_usecaselist');
        $this->setFields('tt_content', $testiId, [
            'header' => (string)($values['testi_headline'] ?? ''),
            'pi_flexform' => $this->flex([
                'settings.layout' => 'testimonials',
                'settings.usecases' => implode(',', $storyUids),
                'settings.singlePid' => (string)self::STORY_SINGLE_PID,
                'settings.showtoolbar' => '0',
            ]),
        ]);

        // --- main column: products -------------------------------------------------
        $featuredTitle = trim((string)($values['prod_featured'] ?? ''));
        $featuredUid = 0;
        if ($featuredTitle !== '') {
            $featured = $this->recordByTitle('tx_vitec_domain_model_product', $featuredTitle);
            $featured === null
                ? $this->report[] = 'featured product "' . $featuredTitle . '" NOT FOUND'
                : $featuredUid = (int)$featured['uid'];
        }
        $featureId = $this->slotElement($pageId, $subPage, self::COLPOS_MAIN, 'vitec_productfeature');
        $this->setFields('tt_content', $featureId, [
            'pi_flexform' => $this->flex(['settings.product' => (string)$featuredUid]),
        ]);

        $productUids = [];
        foreach (range(1, self::PRODUCT_ROWS) as $i) {
            $productTitle = trim((string)($values['prod_card_' . $i] ?? ''));
            if ($productTitle === '') {
                continue;
            }
            $product = $this->recordByTitle('tx_vitec_domain_model_product', $productTitle);
            $product === null
                ? $this->report[] = 'product card ' . $i . ': "' . $productTitle . '" NOT FOUND - skipped'
                : $productUids[] = (int)$product['uid'];
        }
        $listId = $this->slotElement($pageId, $subPage, self::COLPOS_MAIN, 'vitec_productlist');
        $this->setFields('tt_content', $listId, [
            'pi_flexform' => $this->flex([
                'settings.selectedproducts' => implode(',', $productUids),
                'settings.layout' => '0',
                'settings.showtoolbar' => '0',
            ]),
        ]);

        // --- main column: insights ---------------------------------------------------
        $insightsId = $this->slotElement($pageId, $subPage, self::COLPOS_MAIN, 'vitec_marketinsights');
        $this->setFields('tt_content', $insightsId, [
            'vitec_text1' => (string)($values['insights_text1'] ?? ''),
            'vitec_text2' => (string)($values['insights_text2'] ?? ''),
            'vitec_cta_label' => (string)($values['insights_cta_label'] ?? ''),
            'vitec_cta_target' => (string)($values['insights_cta_target'] ?? ''),
            'vitec_video_person' => (string)($values['insights_video_person'] ?? ''),
            'vitec_video_role' => (string)($values['insights_video_role'] ?? ''),
            'vitec_video_title' => (string)($values['insights_video_title'] ?? ''),
            'vitec_video_url' => (string)($values['insights_video_url'] ?? ''),
        ]);
        $this->attachUrlFile($insightsId, 'vitec_video_cover', (string)($values['insights_video_cover_url'] ?? ''), $subsolution, $apply, $this->pidValue($pageId));

        // --- solution record link -----------------------------------------------------
        if ($recordUid > 0 && !str_starts_with($pageId, 'NEW')) {
            $this->datamap['tx_vitec_domain_model_solution'][$recordUid]['detail_page'] = (int)$pageId;
        } elseif ($recordUid > 0) {
            $this->datamap['tx_vitec_domain_model_solution'][$recordUid]['detail_page'] = $pageId;
        } else {
            $this->report[] = 'no solution record for this sub-solution - detail_page not set';
        }

        $isNewPage = str_starts_with($pageId, 'NEW');
        $result = [
            'file' => basename($file),
            'group' => $group,
            'subsolution' => $subsolution,
            'newPage' => $isNewPage,
            'pageUid' => $isNewPage ? 0 : (int)$pageId,
            'elements' => count($this->datamap['tt_content'] ?? []),
            'applied' => $apply,
            'report' => $this->report,
        ];

        if (!$apply) {
            return $result;
        }

        $dataHandler = GeneralUtility::makeInstance(DataHandler::class);
        $dataHandler->start($this->datamap, $this->cmdmap);
        $dataHandler->process_datamap();
        if ($this->cmdmap !== []) {
            $dataHandler->process_cmdmap();
        }
        if ($dataHandler->errorLog !== []) {
            throw new \RuntimeException('DataHandler: ' . implode(' | ', $dataHandler->errorLog));
        }
        $this->applySequence($dataHandler->substNEWwithIDs);
        if ($isNewPage && isset($dataHandler->substNEWwithIDs[$pageId])) {
            $result['pageUid'] = (int)$dataHandler->substNEWwithIDs[$pageId];
        }
        $result['report'] = $this->report;
        return $result;
    }

    // ---- helpers -------------------------------------------------------------

    /** @return array<string,mixed> name => first-cell value */
    private function readNamedValues(Spreadsheet $spreadsheet): array
    {
        $values = [];
        foreach ($spreadsheet->getNamedRanges() as $namedRange) {
            $name = $namedRange->getName();
            $sheet = $namedRange->getWorksheet();
            if ($sheet === null) {
                continue;
            }
            $range = str_replace('$', '', (string)$namedRange->getValue());
            $range = str_contains($range, '!') ? substr($range, strpos($range, '!') + 1) : $range;
            $cell = str_contains($range, ':') ? substr($range, 0, strpos($range, ':')) : $range;
            $values[$name] = $sheet->getCell($cell)->getValue();
        }
        if (isset($values['meta_subsolution'])) {
            return $values;
        }

        // Names are gone - scan by the LOCKED labels in column A instead
        // (same Excel round-trip lesson as the sub-market importer).
        $meta = $spreadsheet->getSheetByName('Meta');
        $content = $spreadsheet->getSheetByName('Content');
        if ($meta === null || $content === null) {
            return $values; // caller reports "Meta sheet missing"
        }
        $this->report[] = 'NOTE: defined names were stripped (Excel save) - reading by column-A labels instead';
        $values['meta_subsolution'] = $meta->getCell('B1')->getValue();
        $values['meta_group'] = $meta->getCell('B2')->getValue();
        $values['meta_record_uid'] = $meta->getCell('B3')->getValue();

        $section = 0;
        $inCardTable = false;
        $cardIndex = 0;
        $highestRow = min(200, (int)$content->getHighestRow());
        for ($rowNum = 1; $rowNum <= $highestRow; $rowNum++) {
            $label = mb_strtolower(trim((string)$content->getCell('A' . $rowNum)->getValue()));
            if (preg_match('/^section (\d)/', $label, $m)) {
                $section = (int)$m[1];
                $inCardTable = false;
                continue;
            }
            if ($inCardTable && $section === 3) {
                $icon = trim((string)$content->getCell('A' . $rowNum)->getValue());
                $title = trim((string)$content->getCell('B' . $rowNum)->getValue());
                $front = trim((string)$content->getCell('C' . $rowNum)->getValue());
                $back = trim((string)$content->getCell('D' . $rowNum)->getValue());
                if ($icon === '' && $title === '' && $front === '' && $back === '') {
                    continue;
                }
                $cardIndex++;
                if ($cardIndex <= self::CARD_ROWS) {
                    $values['flow_card' . $cardIndex . '_icon'] = $icon;
                    $values['flow_card' . $cardIndex . '_title'] = $title;
                    $values['flow_card' . $cardIndex . '_front'] = $front;
                    $values['flow_card' . $cardIndex . '_back'] = $back;
                }
                continue;
            }
            if ($label === '') {
                continue;
            }
            if ($section === 3 && $label === 'icon') {
                $inCardTable = true;
                continue;
            }
            $label = rtrim($label, ' *');
            $b = $content->getCell('B' . $rowNum)->getValue();
            $name = match (true) {
                $label === 'subline' => 'hero_subline',
                $label === 'cta button label' => 'hero_cta_label',
                $label === 'cta button link (url)' => 'hero_cta_url',
                $label === 'background image url' => 'hero_bgimage_url',
                $label === 'headline' && $section === 2 => 'intro_headline',
                $label === 'intro text' => 'intro_text',
                $label === 'image url (right)' => 'intro_image_url',
                $label === 'headline' && $section === 3 => 'flow_headline',
                $label === 'subtext' => 'flow_subtext',
                $label === 'headline' && $section === 4 => 'testi_headline',
                str_starts_with($label, 'case study ') => 'testi_story_' . (int)substr($label, 11),
                $label === 'featured product' => 'prod_featured',
                str_starts_with($label, 'product card ') => 'prod_card_' . (int)substr($label, 13),
                $label === 'paragraph 1' => 'insights_text1',
                $label === 'paragraph 2' => 'insights_text2',
                $label === 'cta label' => 'insights_cta_label',
                $label === 'cta target' => 'insights_cta_target',
                $label === 'video card: person' => 'insights_video_person',
                $label === 'video card: role / title' => 'insights_video_role',
                $label === 'video card: video title' => 'insights_video_title',
                $label === 'video card: video url' => 'insights_video_url',
                $label === 'video card: cover image url' => 'insights_video_cover_url',
                $label === 'seo title' => 'seo_title',
                $label === 'seo description' => 'seo_description',
                default => null,
            };
            if ($name !== null && !array_key_exists($name, $values)) {
                $values[$name] = $b;
            }
        }
        return $values;
    }

    /** @return array{uid:int,layout:int}|null */
    private function childByTitle(int $parentUid, string $title): ?array
    {
        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable('pages');
        foreach ($connection->fetchAllAssociative(
            'SELECT uid, title, layout FROM pages WHERE deleted = 0 AND pid = ? AND sys_language_uid IN (0,-1)', [$parentUid]
        ) as $row) {
            if ($this->norm((string)$row['title']) === $this->norm($title)) {
                return ['uid' => (int)$row['uid'], 'layout' => (int)$row['layout']];
            }
        }
        return null;
    }

    /** Existing element uid for a single-element slot, or a NEW id. */
    private function slotElement(string $pageId, ?array $subPage, int $colPos, string $ctype): string
    {
        if ($subPage !== null) {
            $existing = $this->slotElements((int)$subPage['uid'], $colPos, $ctype);
            if ($existing !== []) {
                $this->sequence[$colPos][] = (string)$existing[0];
                return (string)$existing[0];
            }
        }
        $id = $this->newId();
        $this->datamap['tt_content'][$id] = [
            'pid' => $this->pidValue($pageId),
            'colPos' => $colPos,
            'CType' => $ctype,
        ];
        $this->sequence[$colPos][] = $id;
        return $id;
    }

    /**
     * Writes tt_content.sorting in page order. Necessary because DataHandler
     * puts every NEW record created with a positive pid at the TOP of its
     * column - a page built in one run came out exactly reversed (found
     * 2026-10-07). `sorting` is no TCA column, so it cannot travel through
     * the datamap; a direct update is the only way. Runs on every apply, so
     * a re-import also repairs pages imported before this fix.
     *
     * @param array<string,int> $substNEWwithIDs
     */
    private function applySequence(array $substNEWwithIDs): void
    {
        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable('tt_content');
        foreach ($this->sequence as $ids) {
            $sorting = 0;
            foreach ($ids as $id) {
                $uid = str_starts_with($id, 'NEW') ? (int)($substNEWwithIDs[$id] ?? 0) : (int)$id;
                if ($uid > 0) {
                    $sorting += 256;
                    $connection->update('tt_content', ['sorting' => $sorting], ['uid' => $uid]);
                }
            }
        }
    }

    /** @return int[] uids in sorting order */
    private function slotElements(int $pageUid, int $colPos, string $ctype): array
    {
        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable('tt_content');
        return array_map('intval', $connection->fetchFirstColumn(
            'SELECT uid FROM tt_content WHERE deleted = 0 AND pid = ? AND colPos = ? AND CType = ? ORDER BY sorting',
            [$pageUid, $colPos, $ctype]
        ));
    }

    /** @param array<string,mixed> $fields */
    private function setFields(string $table, string $id, array $fields): void
    {
        foreach ($fields as $field => $value) {
            $this->datamap[$table][$id][$field] = $value;
        }
    }

    /** NEW page ids must stay strings in datamap pid references. */
    private function pidValue(string $pageId): int|string
    {
        return str_starts_with($pageId, 'NEW') ? $pageId : (int)$pageId;
    }

    /** @return array<string,mixed>|null */
    private function recordByTitle(string $table, string $title): ?array
    {
        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable($table);
        foreach ($connection->fetchAllAssociative(
            'SELECT * FROM ' . $table . ' WHERE deleted = 0', []
        ) as $row) {
            if ($this->norm((string)$row['title']) === $this->norm($title)) {
                return $row;
            }
        }
        return null;
    }

    /**
     * Download a URL into fileadmin/subsolution_import/<page>/ and attach it
     * as the element's file field. Editorial review happens in the backend;
     * a failed download is a warning. Skipped entirely in dry runs.
     */
    private function attachUrlFile(string $elementId, string $fieldName, string $url, string $subsolution, bool $apply, int|string $pid = 0): void
    {
        $url = trim($url);
        if ($url === '' || !str_starts_with($url, 'http')) {
            return;
        }
        if (!$apply) {
            $this->report[] = $fieldName . ': would download ' . $url;
            return;
        }
        try {
            $response = GeneralUtility::makeInstance(\TYPO3\CMS\Core\Http\RequestFactory::class)
                ->request($url, 'GET', ['timeout' => 20]);
            if ($response->getStatusCode() !== 200) {
                $this->report[] = $fieldName . ': DOWNLOAD FAILED (HTTP ' . $response->getStatusCode() . ' for ' . $url . ') - attach editorially';
                return;
            }
            $content = (string)$response->getBody();
            if ($content === '') {
                $this->report[] = $fieldName . ': DOWNLOAD FAILED (empty response from ' . $url . ') - attach editorially';
                return;
            }
            $storage = GeneralUtility::makeInstance(StorageRepository::class)->getDefaultStorage();
            $folderPath = 'subsolution_import/' . mb_strtolower((string)preg_replace('/[^A-Za-z0-9]+/', '-', $subsolution));
            $folder = $storage->hasFolder($folderPath) ? $storage->getFolder($folderPath) : $storage->createFolder($folderPath);
            $fileName = basename(parse_url($url, PHP_URL_PATH) ?: '') ?: ($fieldName . '.bin');
            $temp = GeneralUtility::tempnam('subsolution_');
            file_put_contents($temp, $content);
            $file = $storage->addFile($temp, $folder, $fileName, DuplicationBehavior::REPLACE);

            // Re-import idempotency BY CONTENT (lesson 2026-10-02): reuse the
            // first live reference, delete our own surplus duplicates.
            if (!str_starts_with($elementId, 'NEW')) {
                $existingRefs = $this->liveReferences((int)$elementId, $fieldName);
                if ($existingRefs !== []) {
                    $first = array_shift($existingRefs);
                    if ((int)$first['uid_local'] === $file->getUid()) {
                        $this->report[] = $fieldName . ': ' . $fileName . ' already attached - unchanged';
                    } else {
                        $this->datamap['sys_file_reference'][(int)$first['uid']] = ['uid_local' => $file->getUid()];
                        $this->report[] = $fieldName . ': ' . $fileName . ' swapped onto the existing reference';
                    }
                    foreach ($existingRefs as $surplus) {
                        $this->cmdmap['sys_file_reference'][(int)$surplus['uid']]['delete'] = 1;
                        $this->report[] = $fieldName . ': removed duplicate reference #' . $surplus['uid'];
                    }
                    return;
                }
            }

            $refId = $this->newId();
            // pid, tablenames and uid_foreign are REQUIRED - without them
            // DataHandler silently rejects the reference (lesson 2026-10-02).
            $this->datamap['sys_file_reference'][$refId] = [
                'pid' => $pid,
                'table_local' => 'sys_file',
                'uid_local' => $file->getUid(),
                'tablenames' => 'tt_content',
                'fieldname' => $fieldName,
                'uid_foreign' => str_starts_with($elementId, 'NEW') ? $elementId : (int)$elementId,
            ];
            $this->datamap['tt_content'][$elementId][$fieldName] = $refId;
            $this->report[] = $fieldName . ': downloaded ' . $fileName . ' - review editorially';
        } catch (\Throwable $e) {
            $this->report[] = $fieldName . ': DOWNLOAD FAILED (' . $e->getMessage() . ') - attach editorially';
        }
    }

    /** @return array<int,array{uid:int,uid_local:int}> live refs on one field, oldest first */
    private function liveReferences(int $elementUid, string $fieldName): array
    {
        $connection = GeneralUtility::makeInstance(ConnectionPool::class)->getConnectionForTable('sys_file_reference');
        return array_map(
            static fn(array $r): array => ['uid' => (int)$r['uid'], 'uid_local' => (int)$r['uid_local']],
            $connection->fetchAllAssociative(
                "SELECT uid, uid_local FROM sys_file_reference
                 WHERE deleted = 0 AND hidden = 0 AND tablenames = 'tt_content'
                   AND fieldname = ? AND uid_foreign = ? ORDER BY uid",
                [$fieldName, $elementUid]
            )
        );
    }

    /**
     * DataHandler flexform array for sheet sDEF.
     *
     * @param array<string,string> $settings
     * @return array<string,mixed>
     */
    private function flex(array $settings): array
    {
        $fields = [];
        foreach ($settings as $key => $value) {
            $fields[$key] = ['vDEF' => $value];
        }
        return ['data' => ['sDEF' => ['lDEF' => $fields]]];
    }

    private function newId(): string
    {
        return 'NEW' . str_pad((string)(++$this->newCounter), 6, '0', STR_PAD_LEFT) . substr(md5(uniqid('', true)), 0, 6);
    }

    private function norm(string $value): string
    {
        return (string)preg_replace('/[^a-z0-9]+/', '', str_replace('+', 'plus', mb_strtolower($value)));
    }
}