<?php

namespace App\Services\FattureElettroniche;

use App\Models\FeXsdCode;
use App\Models\FeXsdCodeDomain;
use App\Models\FeXsdVersion;
use App\Models\User;
use DOMDocument;
use DOMXPath;
use Illuminate\Support\Arr;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Storage;

class FeXsdCodesImporter
{
    /**
     * Importa tutte le enumerazioni (simpleType/restriction/enumeration) da un file XSD.
     *
     * @return array{version: FeXsdVersion, summary: array<string,mixed>}
     */
    public function importFromUploadedXsd(
        string $tempPath,
        ?string $versionLabel,
        ?string $note,
        ?User $createdBy
    ): array {
        $content = Storage::disk('local')->get($tempPath);
        $sha256 = hash('sha256', $content);

        $existing = FeXsdVersion::query()->where('sha256', $sha256)->first();
        if ($existing) {
            // File già importato: pulisco il temporaneo e ritorno la versione esistente.
            try {
                Storage::disk('local')->delete($tempPath);
            } catch (\Throwable) {
                // ignore
            }

            return [
                'version' => $existing,
                'summary' => [
                    'already_imported' => true,
                    'sha256' => $sha256,
                ],
            ];
        }

        $originalFilename = basename($tempPath);
        $finalPath = 'fe/xsd/' . $sha256 . '.xsd';

        return DB::transaction(function () use ($content, $sha256, $tempPath, $finalPath, $originalFilename, $versionLabel, $note, $createdBy): array {
            // Sposto/normalizzo il path del file appena possibile (se fallisce, andiamo avanti).
            try {
                if (!Storage::disk('local')->exists($finalPath)) {
                    Storage::disk('local')->move($tempPath, $finalPath);
                } else {
                    Storage::disk('local')->delete($tempPath);
                }
            } catch (\Throwable) {
                // ignore
            }

            $parsed = $this->parseXsdEnumerations($content);

            $version = FeXsdVersion::query()->create([
                'version_label' => $versionLabel ? trim($versionLabel) : null,
                'original_filename' => $originalFilename,
                'stored_path' => $finalPath,
                'sha256' => $sha256,
                'created_by_user_id' => $createdBy?->id,
                'imported_at' => now(),
                'note' => $note ? trim($note) : null,
                'meta' => [
                    'domains' => count($parsed['domains']),
                    'codes' => $parsed['codes_count'],
                ],
            ]);

            foreach ($parsed['domains'] as $domain) {
                $domainRow = FeXsdCodeDomain::query()->create([
                    'version_id' => $version->id,
                    'type_name' => (string) $domain['type_name'],
                    'base_type' => Arr::get($domain, 'base_type'),
                    'documentation' => Arr::get($domain, 'documentation'),
                    'codes_count' => count($domain['codes'] ?? []),
                ]);

                $i = 0;
                foreach (($domain['codes'] ?? []) as $codeRow) {
                    $i++;
                    FeXsdCode::query()->create([
                        'domain_id' => $domainRow->id,
                        'code' => (string) ($codeRow['code'] ?? ''),
                        'label' => Arr::get($codeRow, 'label'),
                        'documentation' => Arr::get($codeRow, 'documentation'),
                        'sort_order' => $i,
                    ]);
                }
            }

            return [
                'version' => $version,
                'summary' => [
                    'already_imported' => false,
                    'sha256' => $sha256,
                    'domains' => count($parsed['domains']),
                    'codes' => $parsed['codes_count'],
                ],
            ];
        });
    }

    /**
     * @return array{domains: array<int,array{type_name:string,base_type:?string,documentation:?string,codes:array<int,array{code:string,label:?string,documentation:?string}>}>, codes_count:int}
     */
    private function parseXsdEnumerations(string $content): array
    {
        $doc = new DOMDocument();
        $doc->preserveWhiteSpace = false;
        $doc->formatOutput = false;

        $ok = @$doc->loadXML($content, LIBXML_NONET | LIBXML_NOERROR | LIBXML_NOWARNING);
        if (!$ok) {
            throw new \RuntimeException('XSD non valido o non leggibile.');
        }

        $xpath = new DOMXPath($doc);

        // Trova simpleType con name e con almeno una enumeration.
        $simpleTypes = $xpath->query("//*[local-name()='simpleType'][@name][.//*[local-name()='enumeration']]");

        $domains = [];
        $codesCount = 0;

        if ($simpleTypes) {
            foreach ($simpleTypes as $simpleTypeNode) {
                $typeName = (string) $simpleTypeNode->attributes?->getNamedItem('name')?->nodeValue;
                $typeName = trim($typeName);
                if ($typeName === '') {
                    continue;
                }

                // baseType dal restriction base="..."
                $baseTypeNode = $xpath->query(".//*[local-name()='restriction'][@base]", $simpleTypeNode)?->item(0);
                $baseType = $baseTypeNode?->attributes?->getNamedItem('base')?->nodeValue;
                $baseType = is_string($baseType) ? trim($baseType) : null;

                $docTextNode = $xpath->query(".//*[local-name()='annotation']/*[local-name()='documentation']", $simpleTypeNode)?->item(0);
                $documentation = $docTextNode ? trim((string) $docTextNode->textContent) : null;
                $documentation = $documentation !== '' ? $documentation : null;

                $enumNodes = $xpath->query(".//*[local-name()='restriction']/*[local-name()='enumeration'][@value]", $simpleTypeNode);
                if (!$enumNodes || $enumNodes->length === 0) {
                    continue;
                }

                $codes = [];
                foreach ($enumNodes as $enumNode) {
                    $value = (string) $enumNode->attributes?->getNamedItem('value')?->nodeValue;
                    $value = trim($value);
                    if ($value === '') {
                        continue;
                    }

                    $enumDocNode = $xpath->query(".//*[local-name()='annotation']/*[local-name()='documentation']", $enumNode)?->item(0);
                    $enumDoc = $enumDocNode ? trim((string) $enumDocNode->textContent) : null;
                    $enumDoc = $enumDoc !== '' ? $enumDoc : null;

                    $codes[] = [
                        'code' => $value,
                        'label' => null,
                        'documentation' => $enumDoc,
                    ];

                    $codesCount++;
                }

                $domains[] = [
                    'type_name' => $typeName,
                    'base_type' => $baseType,
                    'documentation' => $documentation,
                    'codes' => $codes,
                ];
            }
        }

        // Ordina stabilmente per nome per evitare fluttuazioni tra import.
        usort($domains, fn(array $a, array $b) => strcmp((string) $a['type_name'], (string) $b['type_name']));

        return [
            'domains' => $domains,
            'codes_count' => $codesCount,
        ];
    }
}