<?php

namespace EP\EpTheme\Form;

use TYPO3\CMS\Core\Log\LogManager;
use TYPO3\CMS\Core\Utility\GeneralUtility;
use TYPO3\CMS\Extbase\Domain\Model\FileReference;
use TYPO3\CMS\Form\Domain\Finishers\AbstractFinisher;

abstract class AbstractMappedFinisher extends AbstractFinisher
{
    /**
     * Resolves the 'mapping' option into remote name => local form element identifier.
     */
    protected function parseMapping(): array
    {
        $mappings = [];
        $mappingOption = (string)$this->parseOption('mapping');

        foreach (GeneralUtility::trimExplode(',', $mappingOption, true) as $mapping) {
            $parts = GeneralUtility::trimExplode(':', $mapping, true, 2);
            if (2 !== count($parts)) {
                continue;
            }

            [$remote, $local] = $parts;
            if ('' === $remote || '' === $local) {
                continue;
            }

            $mappings[$remote] = $local;
        }

        return $mappings;
    }

    /**
     * The mapped values, keyed by the remote name the receiving side expects. Values pass through
     * normalizeValue() just like the labeled ones do, so a date element arrives as a Y-m-d string
     * instead of a serialized DateTime. A value that does not survive normalization keeps its key:
     * the remote names make up the request shape and dropping one would change it.
     */
    protected function buildPayload(): array
    {
        $values = [];
        $formValues = $this->finisherContext->getFormValues();

        foreach ($this->parseMapping() as $remote => $local) {
            if (false === array_key_exists($local, $formValues)) {
                continue;
            }

            $values[$remote] = $this->normalizeValue($formValues[$local], $local);
        }

        return $values;
    }

    /**
     * Every submitted value that the mapping does not already cover, keyed by the element label
     * as the editor sees it in the form editor. Forms built in the backend use generated
     * identifiers (text-1, singleselect-2, ...) that carry no meaning and cannot be renamed
     * without breaking existing finisher options, so the label is the only stable description
     * of what was asked.
     *
     * The label is taken from the form definition, not through TranslationService: a translated
     * label would change the payload keys with the site language, and these keys are stored.
     */
    protected function buildLabeledValues(): array
    {
        $formValues = $this->finisherContext->getFormValues();
        $skip = array_merge(
            array_values($this->parseMapping()),
            GeneralUtility::trimExplode(',', (string)$this->parseOption('exclude'), true)
        );

        // Keyed by identifier in form order, and contains only real form elements - iterating
        // this instead of the form values keeps the collection in the order of the form and
        // leaves out anything that is not an element the visitor filled in.
        $elements = $this->finisherContext->getFormRuntime()->getFormDefinition()->getElements();

        $collected = [];
        foreach ($elements as $identifier => $element) {
            if (true === in_array($identifier, $skip, true) || false === array_key_exists($identifier, $formValues)) {
                continue;
            }

            $value = $this->normalizeValue($formValues[$identifier], $identifier);
            if (null === $value || '' === $value || [] === $value) {
                continue;
            }

            $label = trim($element->getLabel());
            if ('' === $label) {
                $label = $identifier;
            }
            if (true === array_key_exists($label, $collected)) {
                $label .= ' (' . $identifier . ')';
            }

            $collected[$label] = $value;
        }

        return $collected;
    }

    /**
     * @param mixed $value
     *
     * @return mixed null when the value has no JSON representation
     */
    protected function normalizeValue($value, string $identifier)
    {
        if (true === is_array($value)) {
            $normalized = [];
            foreach ($value as $item) {
                $item = $this->normalizeValue($item, $identifier);
                if (null !== $item && '' !== $item) {
                    $normalized[] = $item;
                }
            }

            return $normalized;
        }

        if ($value instanceof \DateTimeInterface) {
            return $value->format('Y-m-d');
        }

        if ($value instanceof FileReference) {
            $resource = $value->getOriginalResource();

            return null !== $resource ? $resource->getName() : null;
        }

        if (true === is_object($value)) {
            $this->logWarning('Form value skipped while collecting labeled values: unsupported type.', [
                'element' => $identifier,
                'class' => get_class($value),
            ]);

            return null;
        }

        return $value;
    }

    protected function logWarning(string $message, array $context = []): void
    {
        GeneralUtility::makeInstance(LogManager::class)
            ->getLogger(static::class)
            ->warning($message, array_merge([
                'finisher' => static::class,
            ], $context));
    }
}