<?php

declare(strict_types=1);

namespace App\Console\Commands;

use Illuminate\Console\Command;
use Illuminate\Support\Facades\Log;
use Predis\Client as PredisClient;

class RedisCleanupLegacyPrefixCommand extends Command
{
    protected $signature = 'skinbase:redis-cleanup-legacy-prefix
                            {--dry-run : SCAN and report only}
                            {--execute : UNLINK matching obsolete keys}
                            {--max-keys=500 : Cap keys this run}';

    protected $description = 'UNLINK obsolete skinbasenova-database-* and skinbasenova_horizon:* keys only';

    private const LEGACY_PREFIXES = [
        'skinbasenova-database-',
        'skinbasenova_horizon:',
    ];

    private const PROTECTED_PREFIXES = [
        'skinbase-database-',
        'skinbase_horizon:',
    ];

    public function handle(): int
    {
        $dryRun = (bool) $this->option('dry-run');
        $execute = (bool) $this->option('execute');
        if ($dryRun === $execute) {
            $this->error('Pass exactly one of --dry-run or --execute.');

            return self::FAILURE;
        }

        $maxKeys = max(1, (int) $this->option('max-keys'));
        $currentPrefix = (string) config('database.redis.options.prefix');
        $horizonPrefix = (string) config('horizon.prefix');

        $this->info(sprintf(
            '[redis-cleanup-legacy-prefix] current_prefix=%s horizon_prefix=%s max_keys=%d %s',
            $currentPrefix,
            $horizonPrefix,
            $maxKeys,
            $dryRun ? 'dry-run' : 'execute'
        ));

        if (in_array($currentPrefix, self::LEGACY_PREFIXES, true) || in_array($horizonPrefix, self::LEGACY_PREFIXES, true)) {
            $this->error('Current process still uses a legacy prefix. Aborting.');

            return self::FAILURE;
        }

        $client = $this->unprefixedClient();
        $found = [];
        $cursor = '0';
        do {
            [$cursor, $keys] = $client->scan($cursor, ['COUNT' => 200, 'MATCH' => '*']);
            foreach ($keys as $key) {
                $key = (string) $key;
                if ($this->isProtected($key)) {
                    continue;
                }
                if (! $this->isLegacy($key)) {
                    continue;
                }
                $found[] = $key;
                if (count($found) >= $maxKeys) {
                    $cursor = '0';
                    break;
                }
            }
        } while ($cursor !== '0' && $cursor !== 0);

        $this->info('matched='.count($found));
        foreach (array_slice($found, 0, 20) as $key) {
            $this->line('key='.$key);
        }
        if (count($found) > 20) {
            $this->line('... truncated listing');
        }

        $unlinked = 0;
        if (! $dryRun && $found !== []) {
            foreach (array_chunk($found, 50) as $chunk) {
                $unlinked += (int) $client->unlink(...$chunk);
            }
        }

        $this->info('unlinked='.$unlinked);

        Log::info('[redis-cleanup-legacy-prefix] completed', [
            'matched' => count($found),
            'unlinked' => $unlinked,
            'dry_run' => $dryRun,
        ]);

        return self::SUCCESS;
    }

    private function isLegacy(string $key): bool
    {
        foreach (self::LEGACY_PREFIXES as $prefix) {
            if (str_starts_with($key, $prefix)) {
                return true;
            }
        }

        return false;
    }

    private function isProtected(string $key): bool
    {
        foreach (self::PROTECTED_PREFIXES as $prefix) {
            if (str_starts_with($key, $prefix)) {
                return true;
            }
        }

        return false;
    }

    private function unprefixedClient(): PredisClient
    {
        $redis = config('database.redis.default', []);

        return new PredisClient([
            'scheme' => 'tcp',
            'host' => $redis['host'] ?? '127.0.0.1',
            'port' => (int) ($redis['port'] ?? 6379),
            'password' => $redis['password'] ?? null,
            'database' => (int) ($redis['database'] ?? 0),
        ]);
    }
}