<?php

namespace App\Console\Commands;

use Illuminate\Console\Command;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\File;

class NetgesconRestoreRecordCommand extends Command
{
    protected $signature = 'netgescon:restore-record
        {table : Tabella da ripristinare}
        {pk : Valore chiave primaria (default id)}
        {--snapshot-id= : Snapshot specifico (default ultimo)}
        {--pk-column=id : Nome colonna PK}
        {--apply : Esegue il ripristino (altrimenti solo preview)}';

    protected $description = 'Ripristina una singola scrittura da snapshot differenziale pre-update.';

    public function handle(): int
    {
        $table = trim((string) $this->argument('table'));
        $pk = trim((string) $this->argument('pk'));
        $pkColumn = trim((string) $this->option('pk-column')) ?: 'id';

        if ($table === '' || $pk === '') {
            $this->error('Parametri table/pk obbligatori.');
            return self::FAILURE;
        }

        $snapshotDir = $this->resolveSnapshotDir();
        if ($snapshotDir === null) {
            $this->error('Snapshot non trovato.');
            return self::FAILURE;
        }

        $file = $snapshotDir . '/db/' . $table . '.ndjson';
        if (! is_file($file)) {
            $this->error('Export tabella non trovato nello snapshot: ' . $file);
            return self::FAILURE;
        }

        $record = $this->findRecordByPk($file, $pk);
        if (! is_array($record)) {
            $this->error('Record non trovato nello snapshot per PK=' . $pk);
            return self::FAILURE;
        }

        $this->line('Snapshot: ' . $snapshotDir);
        $this->line('Tabella: ' . $table . ' · PK: ' . $pkColumn . '=' . $pk);
        $this->line('Hash: ' . (string) ($record['hash'] ?? '-'));

        $data = is_array($record['data'] ?? null) ? (array) $record['data'] : [];
        if (! array_key_exists($pkColumn, $data)) {
            $data[$pkColumn] = $pk;
        }

        if (! (bool) $this->option('apply')) {
            $this->warn('Preview mode: nessuna scrittura eseguita. Usa --apply per ripristinare.');
            $this->line(json_encode($data, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES));
            return self::SUCCESS;
        }

        if (! DB::getSchemaBuilder()->hasTable($table)) {
            $this->error('Tabella non esistente su DB corrente: ' . $table);
            return self::FAILURE;
        }

        DB::table($table)->updateOrInsert(
            [$pkColumn => $data[$pkColumn]],
            $data
        );

        $this->info('Record ripristinato con successo.');
        return self::SUCCESS;
    }

    private function resolveSnapshotDir(): ?string
    {
        $snapshotId = trim((string) $this->option('snapshot-id'));
        $root = storage_path('app/update-backups/snapshots');

        if ($snapshotId !== '') {
            $dir = $root . '/' . $snapshotId;
            return is_dir($dir) ? $dir : null;
        }

        $latest = storage_path('app/update-backups/latest-manifest.json');
        if (is_file($latest)) {
            $decoded = json_decode((string) @file_get_contents($latest), true);
            if (is_array($decoded) && isset($decoded['snapshot_dir']) && is_string($decoded['snapshot_dir']) && is_dir($decoded['snapshot_dir'])) {
                return $decoded['snapshot_dir'];
            }
        }

        if (! is_dir($root)) {
            return null;
        }

        $dirs = array_values(array_filter(scandir($root) ?: [], function (string $name) use ($root): bool {
            return $name !== '.' && $name !== '..' && is_dir($root . '/' . $name);
        }));

        rsort($dirs, SORT_NATURAL);
        if ($dirs === []) {
            return null;
        }

        return $root . '/' . $dirs[0];
    }

    /** @return array<string,mixed>|null */
    private function findRecordByPk(string $file, string $pk): ?array
    {
        $handle = fopen($file, 'rb');
        if (! is_resource($handle)) {
            return null;
        }

        try {
            while (($line = fgets($handle)) !== false) {
                $decoded = json_decode((string) $line, true);
                if (! is_array($decoded)) {
                    continue;
                }

                $candidate = (string) ($decoded['pk'] ?? '');
                if ($candidate === $pk) {
                    return $decoded;
                }
            }
        } finally {
            fclose($handle);
        }

        return null;
    }
}