<?php
namespace App\Services\Arera;

use App\Models\AreraNaturaGiuridica;
use App\Models\AreraOperatore;
use App\Models\AreraSettoreAttivita;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Str;
use PhpOffice\PhpSpreadsheet\IOFactory;
use ZipArchive;

class AreraOperatoriImportService
{
    /**
     * @return array{rows:int, imported:int, updated:int, skipped:int, sectors:int, errors:array<int,string>, files:int}
     */
    public function importZipFromUrl(string $url): array
    {
        @set_time_limit(0);
        $url = trim($url);
        if ($url === '' || ! preg_match('/^https?:\/\//i', $url)) {
            throw new \InvalidArgumentException('URL ARERA non valido.');
        }

        $host = parse_url($url, PHP_URL_HOST);
        if (! is_string($host) || ! str_ends_with(strtolower($host), 'arera.it')) {
            throw new \InvalidArgumentException('Per sicurezza sono accettati solo URL del dominio arera.it.');
        }

        $response = Http::timeout(180)->get($url);
        if (! $response->successful()) {
            throw new \RuntimeException('Download ARERA fallito: HTTP ' . $response->status());
        }

        $bytes = $response->body();
        if (! is_string($bytes) || $bytes === '') {
            throw new \RuntimeException('Download ARERA vuoto.');
        }

        $zipPath = tempnam(sys_get_temp_dir(), 'arera_zip_');
        if (! is_string($zipPath) || $zipPath === '') {
            throw new \RuntimeException('Impossibile creare file temporaneo ZIP.');
        }

        file_put_contents($zipPath, $bytes);

        try {
            return $this->importZipFile($zipPath, basename((string) parse_url($url, PHP_URL_PATH)) ?: 'arera.zip');
        } finally {
            @unlink($zipPath);
        }
    }

    /**
     * @return array{rows:int, imported:int, updated:int, skipped:int, sectors:int, errors:array<int,string>, files:int}
     */
    public function importZipFile(string $zipPath, string $sourceFilename = ''): array
    {
        @set_time_limit(0);
        if (! class_exists(ZipArchive::class)) {
            throw new \RuntimeException('Estensione ZIP non disponibile sul server.');
        }

        $zip = new ZipArchive();
        if ($zip->open($zipPath) !== true) {
            throw new \RuntimeException('Impossibile aprire lo ZIP ARERA.');
        }

        $summary = ['rows' => 0, 'imported' => 0, 'updated' => 0, 'skipped' => 0, 'sectors' => 0, 'errors' => [], 'files' => 0];

        try {
            for ($index = 0; $index < $zip->numFiles; $index++) {
                $name  = (string) $zip->getNameIndex($index);
                $lower = strtolower($name);
                if (! str_ends_with($lower, '.xlsx') && ! str_ends_with($lower, '.xls')) {
                    continue;
                }

                $contents = $zip->getFromIndex($index);
                if (! is_string($contents) || $contents === '') {
                    $summary['errors'][] = 'File Excel vuoto nello ZIP: ' . $name;
                    continue;
                }

                $xlsxPath = tempnam(sys_get_temp_dir(), 'arera_xlsx_');
                if (! is_string($xlsxPath) || $xlsxPath === '') {
                    $summary['errors'][] = 'Impossibile creare temporaneo per ' . $name;
                    continue;
                }

                file_put_contents($xlsxPath, $contents);
                try {
                    $result               = $this->importXlsx($xlsxPath, $sourceFilename !== '' ? ($sourceFilename . '::' . basename($name)) : basename($name));
                    $summary['rows']     += $result['rows'];
                    $summary['imported'] += $result['imported'];
                    $summary['updated']  += $result['updated'];
                    $summary['skipped']  += $result['skipped'];
                    $summary['sectors']  += $result['sectors'];
                    $summary['errors']    = array_slice(array_merge($summary['errors'], $result['errors']), 0, 40);
                    $summary['files']++;
                } finally {
                    @unlink($xlsxPath);
                }
            }
        } finally {
            $zip->close();
        }

        if ($summary['files'] === 0) {
            throw new \RuntimeException('Nessun file Excel trovato nello ZIP ARERA.');
        }

        return $summary;
    }

    /**
     * @return array{rows:int, imported:int, updated:int, skipped:int, sectors:int, errors:array<int,string>}
     */
    public function importXlsx(string $path, string $sourceFilename = ''): array
    {
        @set_time_limit(0);
        $spreadsheet = IOFactory::load($path);
        $sheet       = $spreadsheet->getActiveSheet();
        $rows        = $sheet->toArray(null, true, true, true);

        if ($rows === []) {
            return ['rows' => 0, 'imported' => 0, 'updated' => 0, 'skipped' => 0, 'sectors' => 0, 'errors' => ['File vuoto']];
        }

        $headerRow = array_shift($rows) ?: [];
        $headers   = [];
        foreach ($headerRow as $column => $label) {
            $normalized = $this->normalizeHeader((string) $label);
            if ($normalized !== '') {
                $headers[$column] = $normalized;
            }
        }

        $imported  = 0;
        $updated   = 0;
        $skipped   = 0;
        $sectorIds = [];
        $errors    = [];

        foreach ($rows as $index => $row) {
            $data = [];
            foreach ($headers as $column => $key) {
                $data[$key] = trim((string) ($row[$column] ?? ''));
            }

            $societa = $this->cleanText($data['societa'] ?? $data['ragione_sociale'] ?? '');
            $piva    = $this->normalizeVat($data['partita_iva'] ?? '');
            if ($societa === '' && $piva === '') {
                $skipped++;
                continue;
            }

            if ($piva === '') {
                $errors[] = 'Riga ' . ((int) $index + 1) . ': P.IVA mancante per ' . ($societa ?: 'operatore senza nome');
                $skipped++;
                continue;
            }

            $natura   = $this->cleanText($data['natura_giuridica'] ?? '');
            $naturaId = null;
            if ($natura !== '') {
                $naturaId = (int) AreraNaturaGiuridica::query()->firstOrCreate(['nome' => $natura])->id;
            }

            $settori = $this->splitMultiValue($data['settori_attivita'] ?? '');
            if ($settori === []) {
                $sourceLower = mb_strtolower($sourceFilename);
                if (str_contains($sourceLower, 'export-gas-vend')) {
                    $settori = ['Gas vendita'];
                } elseif (str_contains($sourceLower, 'export-mercato-vend')) {
                    $settori = ['Mercato vendita'];
                }
            }
            $settoreSync = [];
            foreach ($settori as $settore) {
                $settoreModel = AreraSettoreAttivita::query()->firstOrCreate(
                    ['slug' => $this->sectorSlug($settore)],
                    ['nome' => $settore]
                );
                $settoreSync[]                      = (int) $settoreModel->id;
                $sectorIds[(int) $settoreModel->id] = true;
            }

            $sedeLegaleRaw = (string) ($data['sede_legale'] ?? '');
            if ($sedeLegaleRaw === '' && ! empty($data['indirizzo'])) {
                $comuneSedeLegale = $this->cleanText($data['comune_sede_legale'] ?? '');
                $sedeLegaleRaw    = $this->cleanText((string) $data['indirizzo'] . ($comuneSedeLegale !== '' ? (' - ' . $comuneSedeLegale) : ''));
            }

            $sedeLegale    = $this->parseAddress($sedeLegaleRaw);
            $sedeOperativa = $this->parseAddress($data['sede_operativa'] ?? '');

            $payload = [
                'societa'                  => $societa,
                'id_soggetto'              => $this->cleanText($data['id_soggetto'] ?? ''),
                'natura_giuridica_id'      => $naturaId,
                'partita_iva'              => $this->cleanText($data['partita_iva'] ?? ''),
                'partita_iva_normalizzata' => $piva,
                'gruppo_societario'        => $this->nullIfEmpty($data['gruppo_societario'] ?? ''),
                'sito_internet'            => $this->normalizeWebsite($data['sito_internet'] ?? ''),
                'sede_legale_raw'          => $this->nullIfEmpty($sedeLegaleRaw),
                'sede_legale_indirizzo'    => $sedeLegale['indirizzo'],
                'sede_legale_cap'          => $sedeLegale['cap'],
                'sede_legale_citta'        => $sedeLegale['citta'],
                'sede_legale_provincia'    => $sedeLegale['provincia'],
                'sede_operativa_raw'       => $this->nullIfEmpty($data['sede_operativa'] ?? ''),
                'sede_operativa_indirizzo' => $sedeOperativa['indirizzo'],
                'sede_operativa_cap'       => $sedeOperativa['cap'],
                'sede_operativa_citta'     => $sedeOperativa['citta'],
                'sede_operativa_provincia' => $sedeOperativa['provincia'],
                'contatti_cliente'         => $this->splitMultiValue($data['contatti_cliente'] ?? ''),
                'contatti_cliente2'        => $this->splitMultiValue($data['contatti_clienti2'] ?? ''),
                'settori_raw'              => $settori,
                'extra_search_tokens'      => array_values(array_unique(array_filter(array_merge(
                    $settori,
                    $this->splitMultiValue($data['contatti_cliente'] ?? ''),
                    $this->splitMultiValue($data['contatti_clienti2'] ?? ''),
                    [$natura, $data['gruppo_societario'] ?? '']
                )))),
                'source_filename'          => $sourceFilename !== '' ? basename($sourceFilename) : null,
                'source_imported_at'       => now(),
            ];

            $existing  = AreraOperatore::query()->where('partita_iva_normalizzata', $piva)->first();
            $operatore = AreraOperatore::query()->updateOrCreate(
                ['partita_iva_normalizzata' => $piva],
                $payload
            );
            if ($settoreSync !== []) {
                $operatore->settori()->sync($settoreSync);
            }

            $existing ? $updated++ : $imported++;
        }

        return [
            'rows'     => count($rows),
            'imported' => $imported,
            'updated'  => $updated,
            'skipped'  => $skipped,
            'sectors'  => count($sectorIds),
            'errors'   => array_slice($errors, 0, 20),
        ];
    }

    private function normalizeHeader(string $value): string
    {
        $value = Str::of($value)->lower()->ascii()->replaceMatches('/[^a-z0-9]+/', '_')->trim('_')->toString();

        return match ($value) {
            'societa', 'societa_'                    => 'societa',
            'ragione_sociale'    => 'ragione_sociale',
            'id_soggetto'        => 'id_soggetto',
            'natura_giuridica'   => 'natura_giuridica',
            'partita_iva'        => 'partita_iva',
            'gruppo_societario'  => 'gruppo_societario',
            'sito_internet'      => 'sito_internet',
            'sito_web'           => 'sito_internet',
            'sede_legale'        => 'sede_legale',
            'comune_sede_legale' => 'comune_sede_legale',
            'indirizzo'          => 'indirizzo',
            'sede_operativa'     => 'sede_operativa',
            'settori_attivita'   => 'settori_attivita',
            'contatti_cliente'   => 'contatti_cliente',
            'contatti_clienti2', 'contatti_cliente2' => 'contatti_clienti2',
            default              => $value,
        };
    }

    private function cleanText(string $value): string
    {
        return trim(preg_replace('/\s+/', ' ', $value) ?? $value);
    }

    private function nullIfEmpty(string $value): ?string
    {
        $value = $this->cleanText($value);

        return $value !== '' ? $value : null;
    }

    private function normalizeVat(string $value): string
    {
        return preg_replace('/\D+/', '', $value) ?? '';
    }

    /** @return list<string> */
    private function splitMultiValue(string $value): array
    {
        return array_values(array_unique(array_filter(array_map(
            fn(string $part): string => $this->cleanText($part),
            preg_split('/;|\R/', $value) ?: []
        ))));
    }

    private function normalizeWebsite(string $value): ?string
    {
        $value = $this->cleanText($value);
        if ($value === '') {
            return null;
        }

        return preg_match('/^https?:\/\//i', $value) ? $value : 'https://' . $value;
    }

    private function sectorSlug(string $value): string
    {
        $base = Str::slug($value);
        if ($base === '') {
            $base = 'settore';
        }

        $hash   = substr(sha1($value), 0, 10);
        $prefix = Str::limit($base, 175, '');

        return $prefix . '-' . $hash;
    }

    /** @return array{indirizzo:?string, cap:?string, citta:?string, provincia:?string} */
    private function parseAddress(string $value): array
    {
        $value = $this->cleanText($value);
        $out   = ['indirizzo' => null, 'cap' => null, 'citta' => null, 'provincia' => null];
        if ($value === '') {
            return $out;
        }

        $parts            = array_map('trim', explode(' - ', $value, 2));
        $out['indirizzo'] = $parts[0] !== '' ? $parts[0] : null;
        $tail             = $parts[1] ?? '';

        if ($tail !== '' && preg_match('/^(\d{5})\s+(.+?)(?:\s+\(([^)]+)\))?$/u', $tail, $matches)) {
            $out['cap']       = $matches[1];
            $out['citta']     = trim($matches[2]);
            $out['provincia'] = isset($matches[3]) ? trim($matches[3]) : null;
        }

        return $out;
    }
}