<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\Translation\Loader;

use Symfony\Component\Config\Resource\FileResource;
use Symfony\Component\Config\Util\Exception\InvalidXmlException;
use Symfony\Component\Config\Util\Exception\XmlParsingException;
use Symfony\Component\Config\Util\XmlUtils;
use Symfony\Component\Translation\Exception\InvalidResourceException;
use Symfony\Component\Translation\Exception\NotFoundResourceException;
use Symfony\Component\Translation\Exception\RuntimeException;
use Symfony\Component\Translation\MessageCatalogue;
use Symfony\Component\Translation\MessageCatalogueInterface;
use Symfony\Component\Translation\Util\XliffUtils;

/**
 * XliffFileLoader loads translations from XLIFF files.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 */
class XliffFileLoader implements LoaderInterface
{
    public function load(mixed $resource, string $locale, string $domain = 'messages'): MessageCatalogue
    {
        if (!class_exists(XmlUtils::class)) {
            throw new RuntimeException('Loading translations from the Xliff format requires the Symfony Config component.');
        }

        if (!$this->isXmlString($resource)) {
            if (!stream_is_local($resource)) {
                throw new InvalidResourceException(\sprintf('This is not a local file "%s".', $resource));
            }

            if (!file_exists($resource)) {
                throw new NotFoundResourceException(\sprintf('File "%s" not found.', $resource));
            }

            if (!is_file($resource)) {
                throw new InvalidResourceException(\sprintf('This is neither a file nor an XLIFF string "%s".', $resource));
            }
        }

        try {
            if ($this->isXmlString($resource)) {
                $dom = XmlUtils::parse($resource);
            } else {
                $dom = XmlUtils::loadFile($resource);
            }
        } catch (\InvalidArgumentException|XmlParsingException|InvalidXmlException $e) {
            throw new InvalidResourceException(\sprintf('Unable to load "%s": ', $resource).$e->getMessage(), $e->getCode(), $e);
        }

        if ($errors = XliffUtils::validateSchema($dom)) {
            throw new InvalidResourceException(\sprintf('Invalid resource provided: "%s"; Errors: ', $resource).XliffUtils::getErrorsAsString($errors));
        }

        $catalogue = new MessageCatalogue($locale);
        $this->extract($dom, $catalogue, $domain);

        if (is_file($resource) && class_exists(FileResource::class)) {
            $catalogue->addResource(new FileResource($resource));
        }

        return $catalogue;
    }

    private function extract(\DOMDocument $dom, MessageCatalogue $catalogue, string $domain): void
    {
        $xliffVersion = XliffUtils::getVersionNumber($dom);

        if ('1.2' === $xliffVersion) {
            $this->extractXliff1($dom, $catalogue, $domain);
        }

        if (\in_array($xliffVersion, ['2.0', '2.1', '2.2'], true)) {
            $this->extractXliff2($dom, $catalogue, $domain);
        }
    }

    /**
     * Extract messages and metadata from DOMDocument into a MessageCatalogue.
     */
    private function extractXliff1(\DOMDocument $dom, MessageCatalogue $catalogue, string $domain): void
    {
        $xml = simplexml_import_dom($dom);
        $encoding = $dom->encoding ? strtoupper($dom->encoding) : null;

        $namespace = 'urn:oasis:names:tc:xliff:document:1.2';
        $xml->registerXPathNamespace('xliff', $namespace);

        foreach ($xml->xpath('//xliff:file') as $file) {
            $fileAttributes = $file->attributes();

            $file->registerXPathNamespace('xliff', $namespace);

            foreach ($file->xpath('.//xliff:prop') as $prop) {
                $catalogue->setCatalogueMetadata($prop->attributes()['prop-type'], (string) $prop, $domain);
            }

            foreach ($file->xpath('.//xliff:trans-unit') as $translation) {
                $attributes = $translation->attributes();

                if (!(isset($attributes['resname']) || isset($translation->source))) {
                    continue;
                }

                $source = (string) (isset($attributes['resname']) && $attributes['resname'] ? $attributes['resname'] : $translation->source);

                if (isset($translation->target)
                    && 'needs-translation' === (string) $translation->target->attributes()['state']
                    && \in_array((string) $translation->target, [$source, (string) $translation->source], true)
                ) {
                    continue;
                }

                // If the xlf file has another encoding specified, try to convert it because
                // simple_xml will always return utf-8 encoded values
                $target = $this->utf8ToCharset((string) ($translation->target ?? $translation->source), $encoding);

                $catalogue->set($source, $target, $domain);

                $metadata = [
                    'source' => (string) $translation->source,
                    'file' => [
                        'original' => (string) $fileAttributes['original'],
                    ],
                ];
                if ($notes = $this->parseNotesMetadata($translation->note, $encoding)) {
                    $metadata['notes'] = $notes;
                }

                if (isset($translation->target) && $translation->target->attributes()) {
                    $metadata['target-attributes'] = [];
                    foreach ($translation->target->attributes() as $key => $value) {
                        $metadata['target-attributes'][$key] = (string) $value;
                    }
                }

                if (isset($attributes['id'])) {
                    $metadata['id'] = (string) $attributes['id'];
                }

                $catalogue->setMetadata($source, $metadata, $domain);
            }
        }
    }

    private function extractXliff2(\DOMDocument $dom, MessageCatalogue $catalogue, string $domain): void
    {
        $xml = simplexml_import_dom($dom);
        $encoding = $dom->encoding ? strtoupper($dom->encoding) : null;

        $xml->registerXPathNamespace('mda', 'urn:oasis:names:tc:xliff:metadata:2.0');

        foreach ($xml->xpath('//mda:meta') as $meta) {
            $catalogue->setCatalogueMetadata($meta->attributes()['type'] ?? '', (string) $meta, $domain);
        }

        $xml->registerXPathNamespace('xliff', 'urn:oasis:names:tc:xliff:document:2.0');

        foreach ($xml->xpath('//xliff:unit') as $unit) {
            if (null !== $pgsSwitch = $unit->attributes('urn:oasis:names:tc:xliff:pgs:1.0')['switch'] ?? null) {
                $this->extractXliff2PgsUnit($unit, $catalogue, $domain, (string) $pgsSwitch, $encoding);
                continue;
            }

            foreach ($unit->segment as $segment) {
                $attributes = $unit->attributes();
                $source = $attributes['name'] ?? $segment->source;

                // If the xlf file has another encoding specified, try to convert it because
                // simple_xml will always return utf-8 encoded values
                $target = $this->utf8ToCharset((string) ($segment->target ?? $segment->source), $encoding);

                $catalogue->set((string) $source, $target, $domain);

                $metadata = [];
                if ($segment->attributes()) {
                    $metadata['segment-attributes'] = [];
                    foreach ($segment->attributes() as $key => $value) {
                        $metadata['segment-attributes'][$key] = (string) $value;
                    }
                }

                if (isset($segment->target) && $segment->target->attributes()) {
                    $metadata['target-attributes'] = [];
                    foreach ($segment->target->attributes() as $key => $value) {
                        $metadata['target-attributes'][$key] = (string) $value;
                    }
                }

                if (isset($unit->notes)) {
                    $metadata['notes'] = [];
                    foreach ($unit->notes->note as $noteNode) {
                        $note = [];
                        foreach ($noteNode->attributes() as $key => $value) {
                            $note[$key] = (string) $value;
                        }
                        $note['content'] = (string) $noteNode;
                        $metadata['notes'][] = $note;
                    }
                }

                $catalogue->setMetadata((string) $source, $metadata, $domain);
            }
        }
    }

    private function extractXliff2PgsUnit(\SimpleXMLElement $unit, MessageCatalogue $catalogue, string $domain, string $pgsSwitch, ?string $encoding): void
    {
        $switches = $this->parsePgsSwitch($pgsSwitch);
        $attributes = $unit->attributes();
        $source = (string) ($attributes['name'] ?? $attributes['id']);

        $cases = [];
        foreach ($unit->segment as $segment) {
            if (null === $pgsCase = $segment->attributes('urn:oasis:names:tc:xliff:pgs:1.0')['case'] ?? null) {
                continue;
            }

            $cases[(string) $pgsCase] = $this->extractPgsSegmentText($segment->target ?? $segment->source, $switches);
        }

        $intlDomain = $domain.MessageCatalogueInterface::INTL_DOMAIN_SUFFIX;
        $catalogue->set($source, $this->utf8ToCharset($this->buildIcuMessage($switches, $cases), $encoding), $intlDomain);

        $metadata = ['pgs-switch' => $pgsSwitch];
        if (isset($unit->notes)) {
            $metadata['notes'] = [];
            foreach ($unit->notes->note as $noteNode) {
                $note = array_map('strval', $noteNode->attributes() ?? []);

                $note['content'] = (string) $noteNode;
                $metadata['notes'][] = $note;
            }
        }

        $catalogue->setMetadata($source, $metadata, $intlDomain);
    }

    private function parsePgsSwitch(string $pgsSwitch): array
    {
        $trimmed = trim($pgsSwitch);
        if ('' === $trimmed) {
            throw new InvalidResourceException('The pgs:switch attribute must not be empty.');
        }

        $switches = [];
        foreach (preg_split('/\s+/', $trimmed) as $item) {
            $parts = explode(':', $item, 2);
            if (2 !== \count($parts) || '' === $parts[0] || '' === $parts[1]) {
                throw new InvalidResourceException(\sprintf('The pgs:switch token "%s" must use the "type:variable" form.', $item));
            }
            $switches[] = ['type' => $parts[0], 'variable' => $parts[1]];
        }

        return $switches;
    }

    private function extractPgsSegmentText(\SimpleXMLElement $element, array $switches): string
    {
        $pluralVariables = [];
        foreach ($switches as $switch) {
            if ('plural' === $switch['type'] || 'ordinal' === $switch['type']) {
                $pluralVariables[$switch['variable']] = true;
            }
        }

        return $this->collectPgsText(dom_import_simplexml($element), $pluralVariables);
    }

    private function collectPgsText(\DOMNode $node, array $pluralVariables): string
    {
        $text = '';
        foreach ($node->childNodes as $child) {
            if (\XML_TEXT_NODE === $child->nodeType || \XML_CDATA_SECTION_NODE === $child->nodeType) {
                $text .= $child->textContent;
                continue;
            }

            if (\XML_ELEMENT_NODE !== $child->nodeType) {
                continue;
            }

            if ('ph' === $child->localName) {
                $disp = $child->getAttribute('disp');
                if ('' !== $disp && isset($pluralVariables[$disp])) {
                    $text .= '#';
                } elseif ('' !== $disp) {
                    $text .= '{'.$disp.'}';
                }
                continue;
            }

            if (\in_array($child->localName, ['pc', 'mrk'], true)) {
                $text .= $this->collectPgsText($child, $pluralVariables);
                continue;
            }

            if ('cp' === $child->localName) {
                $hex = $child->getAttribute('hex');
                if ('' !== $hex && ctype_xdigit($hex)) {
                    $codepoint = hexdec($hex);
                    if ($codepoint <= 0x10FFFF && ($codepoint < 0xD800 || $codepoint > 0xDFFF)) {
                        $text .= mb_chr($codepoint, 'UTF-8');
                    }
                }
                continue;
            }

            if (\in_array($child->localName, ['sc', 'ec', 'sm', 'em'], true)) {
                continue;
            }

            $text .= $this->collectPgsText($child, $pluralVariables);
        }

        return $text;
    }

    private function buildIcuMessage(array $switches, array $cases): string
    {
        if (1 === \count($switches)) {
            $switch = $switches[0];
            $icuType = $this->getIcuType($switch['type']);

            $icuCases = [];
            foreach ($cases as $caseValue => $text) {
                $icuCases[] = $this->formatIcuCase($caseValue, $switch['type']).' {'.$text.'}';
            }

            return '{'.$switch['variable'].', '.$icuType.', '.implode(' ', $icuCases).'}';
        }

        $outerSwitch = $switches[0];
        $innerSwitches = \array_slice($switches, 1);
        $icuType = $this->getIcuType($outerSwitch['type']);

        $grouped = [];
        foreach ($cases as $caseKey => $text) {
            $caseParts = explode(' ', $caseKey, 2);
            $grouped[$caseParts[0]][$caseParts[1] ?? 'other'] = $text;
        }

        $icuCases = [];
        foreach ($grouped as $caseValue => $innerCases) {
            $icuCases[] = $this->formatIcuCase($caseValue, $outerSwitch['type']).' {'.$this->buildIcuMessage($innerSwitches, $innerCases).'}';
        }

        return '{'.$outerSwitch['variable'].', '.$icuType.', '.implode(' ', $icuCases).'}';
    }

    private function getIcuType(string $pgsType): string
    {
        return match ($pgsType) {
            'plural' => 'plural',
            'ordinal' => 'selectordinal',
            default => 'select',
        };
    }

    private function formatIcuCase(int|string $caseValue, string $switchType): string
    {
        return (\in_array($switchType, ['plural', 'ordinal'], true) && is_numeric($caseValue) ? '=' : '').$caseValue;
    }

    /**
     * Convert a UTF8 string to the specified encoding.
     */
    private function utf8ToCharset(string $content, ?string $encoding = null): string
    {
        if ('UTF-8' !== $encoding && $encoding) {
            return mb_convert_encoding($content, $encoding, 'UTF-8');
        }

        return $content;
    }

    private function parseNotesMetadata(?\SimpleXMLElement $noteElement = null, ?string $encoding = null): array
    {
        $notes = [];

        if (null === $noteElement) {
            return $notes;
        }

        /** @var \SimpleXMLElement $xmlNote */
        foreach ($noteElement as $xmlNote) {
            $noteAttributes = $xmlNote->attributes();
            $note = ['content' => $this->utf8ToCharset((string) $xmlNote, $encoding)];
            if (isset($noteAttributes['priority'])) {
                $note['priority'] = (int) $noteAttributes['priority'];
            }

            if (isset($noteAttributes['from'])) {
                $note['from'] = (string) $noteAttributes['from'];
            }

            $notes[] = $note;
        }

        return $notes;
    }

    private function isXmlString(string $resource): bool
    {
        return str_starts_with($resource, '<?xml');
    }
}