<?php

namespace App\Console\Commands;

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

/**
 * Prune old hourly metric snapshots in bounded batches.
 *
 * Usage:
 *   php artisan nova:prune-metric-snapshots
 *   php artisan nova:prune-metric-snapshots --keep-days=30 --chunk=5000 --dry-run
 */
class PruneMetricSnapshotsCommand extends Command
{
    protected $signature = 'nova:prune-metric-snapshots
                            {--keep-days= : Keep snapshots for this many days (default: config metrics.hourly_snapshot_retention_days)}
                            {--chunk= : Rows to delete per batch (default: config metrics.hourly_snapshot_prune_chunk)}
                            {--sleep-ms= : Pause between batches in milliseconds}
                            {--max-batches=0 : Stop after N batches (0 = until done)}
                            {--dry-run : Count rows that would be deleted without deleting}';

    protected $description = 'Delete old hourly metric snapshots beyond the retention window (batched)';

    public function handle(): int
    {
        $keepDays = $this->resolveKeepDays();
        $chunk = $this->resolvePositiveInt('chunk', (int) config('metrics.hourly_snapshot_prune_chunk', 5000), 1);
        $sleepMs = $this->resolveNonNegativeInt('sleep-ms', (int) config('metrics.hourly_snapshot_prune_sleep_ms', 50));
        $maxBatches = max(0, (int) $this->option('max-batches'));
        $dryRun = (bool) $this->option('dry-run');
        $cutoff = now()->subDays($keepDays);

        if ($keepDays < 1) {
            $this->error('keep-days must be >= 1.');

            return self::FAILURE;
        }

        $eligible = (int) DB::table('artwork_metric_snapshots_hourly')
            ->where('bucket_hour', '<', $cutoff)
            ->count();

        $this->info(sprintf(
            '[nova:prune-metric-snapshots] cutoff=%s keep_days=%d eligible=%d chunk=%d sleep_ms=%d max_batches=%s%s',
            $cutoff->toDateTimeString(),
            $keepDays,
            $eligible,
            $chunk,
            $sleepMs,
            $maxBatches === 0 ? 'unlimited' : (string) $maxBatches,
            $dryRun ? ' (dry-run)' : ''
        ));

        if ($dryRun) {
            Log::info('[nova:prune-metric-snapshots] dry-run', [
                'eligible' => $eligible,
                'keep_days' => $keepDays,
                'cutoff' => $cutoff->toDateTimeString(),
            ]);

            return self::SUCCESS;
        }

        $deleted = 0;
        $batches = 0;

        while (true) {
            if ($maxBatches > 0 && $batches >= $maxBatches) {
                $this->warn("Stopped after max-batches={$maxBatches}.");
                break;
            }

            $ids = DB::table('artwork_metric_snapshots_hourly')
                ->where('bucket_hour', '<', $cutoff)
                ->orderBy('id')
                ->limit($chunk)
                ->pluck('id');

            if ($ids->isEmpty()) {
                break;
            }

            $batchDeleted = DB::table('artwork_metric_snapshots_hourly')
                ->whereIn('id', $ids->all())
                ->delete();

            $deleted += $batchDeleted;
            $batches++;

            Log::info('[nova:prune-metric-snapshots] batch', [
                'batch' => $batches,
                'deleted' => $batchDeleted,
                'deleted_total' => $deleted,
            ]);

            if ($sleepMs > 0) {
                usleep($sleepMs * 1000);
            }
        }

        $this->info("Pruned {$deleted} snapshot rows older than {$keepDays} days in {$batches} batch(es).");

        Log::info('[nova:prune-metric-snapshots] completed', [
            'deleted' => $deleted,
            'batches' => $batches,
            'keep_days' => $keepDays,
            'cutoff' => $cutoff->toDateTimeString(),
            'eligible_at_start' => $eligible,
        ]);

        return self::SUCCESS;
    }

    private function resolveKeepDays(): int
    {
        $option = $this->option('keep-days');

        if ($option === null || $option === '') {
            return (int) config('metrics.hourly_snapshot_retention_days', 30);
        }

        return (int) $option;
    }

    private function resolvePositiveInt(string $option, int $default, int $minimum): int
    {
        $raw = $this->option($option);
        $value = ($raw === null || $raw === '') ? $default : (int) $raw;

        return max($minimum, $value);
    }

    private function resolveNonNegativeInt(string $option, int $default): int
    {
        $raw = $this->option($option);
        $value = ($raw === null || $raw === '') ? $default : (int) $raw;

        return max(0, $value);
    }
}