<?php

declare(strict_types=1);

/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

namespace TYPO3\CMS\ContentBlocks\Generator;

use TYPO3\CMS\ContentBlocks\Definition\FlexForm\ContainerDefinition;
use TYPO3\CMS\ContentBlocks\Definition\FlexForm\FlexFormDefinition;
use TYPO3\CMS\ContentBlocks\Definition\FlexForm\SectionDefinition;
use TYPO3\CMS\ContentBlocks\Definition\FlexForm\SheetDefinition;
use TYPO3\CMS\ContentBlocks\Definition\TcaFieldDefinition;
use TYPO3\CMS\ContentBlocks\Registry\LanguageFileRegistry;
use TYPO3\CMS\Core\Utility\GeneralUtility;

/**
 * @internal Not part of TYPO3's public API.
 */
readonly class FlexFormGenerator
{
    public function __construct(
        protected LanguageFileRegistry $languageFileRegistry,
    ) {}

    public function generate(FlexFormDefinition $flexFormDefinition): string
    {
        $sheets = [];
        foreach ($flexFormDefinition as $sheetDefinition) {
            $sheet = $this->processSheet($sheetDefinition, $flexFormDefinition);
            $root = [
                'type' => 'array',
                'el' => $sheet,
            ];
            if (!$flexFormDefinition->hasDefaultSheet()) {
                $root = $this->enrichSheetLabels($flexFormDefinition, $sheetDefinition, $root);
            }
            $sheets[$sheetDefinition->getIdentifier()] = [
                'ROOT' => $root,
            ];
        }
        $dataStructure['sheets'] = $sheets;
        $options = [
            'parentTagMap' => [
                'el' => 'field',
            ],
        ];
        $flexForm = GeneralUtility::array2xml($dataStructure, '', 0, 'T3FlexForms', 4, $options);
        return $flexForm;
    }

    protected function processSheet(SheetDefinition $sheetDefinition, FlexFormDefinition $flexFormDefinition): array
    {
        $fields = [];
        foreach ($sheetDefinition as $tcaFieldOrSection) {
            $field = match ($tcaFieldOrSection::class) {
                SectionDefinition::class => $this->processSection($tcaFieldOrSection, $flexFormDefinition),
                TcaFieldDefinition::class => $this->processTcaField($tcaFieldOrSection, $flexFormDefinition),
            };
            $identifier = match ($tcaFieldOrSection::class) {
                SectionDefinition::class => $tcaFieldOrSection->getIdentifier(),
                TcaFieldDefinition::class => $tcaFieldOrSection->identifier,
            };
            $fields[$identifier] = $field;
        }
        return $fields;
    }

    protected function processSection(SectionDefinition $sectionDefinition, FlexFormDefinition $flexFormDefinition): array
    {
        $sectionTitle = $this->resolveLabel($flexFormDefinition, $sectionDefinition);
        $result = [
            'title' => $sectionTitle,
            'type' => 'array',
            'section' => '1',
        ];
        $processedContainers = [];
        foreach ($sectionDefinition as $container) {
            $containerTitle = $this->resolveLabel($flexFormDefinition, $container);
            $containerResult = [
                'title' => $containerTitle,
                'type' => 'array',
            ];
            $processedContainerFields = [];
            foreach ($container as $containerField) {
                $processedContainerFields[$containerField->identifier] = $this->processTcaField($containerField, $flexFormDefinition);
            }
            $containerResult['el'] = $processedContainerFields;
            $processedContainers[$container->getIdentifier()] = $containerResult;
        }
        $result['el'] = $processedContainers;
        return $result;
    }

    protected function processTcaField(TcaFieldDefinition $flexFormTcaDefinition, FlexFormDefinition $flexFormDefinition): array
    {
        $name = $flexFormDefinition->getContentBlockName();
        $flexFormTca = $flexFormTcaDefinition->getTca();
        // FlexForm child fields can't be excluded.
        unset($flexFormTca['exclude']);

        $labelPath = $flexFormTcaDefinition->labelPath;
        if ($this->languageFileRegistry->isset($name, $labelPath)) {
            $flexFormTca['label'] = $labelPath;
        }
        $descriptionPath = $flexFormTcaDefinition->descriptionPath;
        if ($this->languageFileRegistry->isset($name, $descriptionPath)) {
            $flexFormTca['description'] = $descriptionPath;
        }
        $placeholderPath = $flexFormTcaDefinition->placeholderPath;
        if ($this->languageFileRegistry->isset($name, $placeholderPath)) {
            $flexFormTca['config']['placeholder'] = $placeholderPath;
        }
        $fieldType = $flexFormTcaDefinition->fieldType;
        $itemsFieldTypes = ['select', 'radio', 'check'];
        if (in_array($fieldType->getTcaType(), $itemsFieldTypes, true)) {
            $items = $flexFormTca['config']['items'] ?? [];
            foreach ($items as $index => $item) {
                if (!isset($item['labelPath'])) {
                    continue;
                }
                $labelPath = $item['labelPath'];
                unset($flexFormTca['config']['items'][$index]['labelPath']);
                if (!$this->languageFileRegistry->isset($name, $labelPath)) {
                    continue;
                }
                $flexFormTca['config']['items'][$index]['label'] = $labelPath;
            }
        }
        return $flexFormTca;
    }

    protected function enrichSheetLabels(FlexFormDefinition $flexFormDefinition, SheetDefinition $sheetDefinition, array $root): array
    {
        $root['sheetTitle'] = $this->resolveLabel($flexFormDefinition, $sheetDefinition);
        if ($this->languageFileRegistry->isset($flexFormDefinition->getContentBlockName(), $sheetDefinition->getLanguagePathDescription())) {
            $root['sheetDescription'] = $sheetDefinition->getLanguagePathDescription();
        } elseif ($sheetDefinition->hasDescription()) {
            $root['sheetDescription'] = $sheetDefinition->getDescription();
        }
        if ($this->languageFileRegistry->isset($flexFormDefinition->getContentBlockName(), $sheetDefinition->getLanguagePathLinkTitle())) {
            $root['sheetShortDescr'] = $sheetDefinition->getLanguagePathLinkTitle();
        } elseif ($sheetDefinition->hasLinkTitle()) {
            $root['sheetShortDescr'] = $sheetDefinition->getLinkTitle();
        }
        return $root;
    }

    protected function resolveLabel(FlexFormDefinition $flexFormDefinition, SheetDefinition|SectionDefinition|ContainerDefinition $definition): string
    {
        if ($this->languageFileRegistry->isset($flexFormDefinition->getContentBlockName(), $definition->getLanguagePathLabel())) {
            return $definition->getLanguagePathLabel();
        }
        if ($definition->hasLabel()) {
            return $definition->getLabel();
        }
        return $definition->getIdentifier();
    }
}