<?php

namespace App\Console\Commands;

use App\Models\Metric;
use Illuminate\Console\Command;
use Illuminate\Support\Facades\Redis;

/** Samples MQTT throughput (since the last sample) + host CPU load and memory. */
class MetricsSampleCommand extends Command
{
    protected $signature = 'metrics:sample';

    protected $description = 'Sample MQTT + host metrics for the charts.';

    public function handle(): int
    {
        $messages = 0;
        try {
            $messages = (int) (Redis::connection()->getset('metrics:mqtt:count', 0) ?? 0);
        } catch (\Throwable) {
            // counter unavailable — record 0
        }

        Metric::create([
            'sampled_at' => now(),
            'mqtt_messages' => $messages,
            'cpu_load' => $this->cpuLoad(),
            'mem_used_pct' => $this->memUsedPct(),
        ]);

        Metric::where('sampled_at', '<', now()->subDay())->delete();

        return self::SUCCESS;
    }

    private function cpuLoad(): ?float
    {
        $raw = @file_get_contents('/proc/loadavg');

        return $raw ? (float) explode(' ', $raw)[0] : null;
    }

    private function memUsedPct(): ?int
    {
        $raw = @file_get_contents('/proc/meminfo');
        if (! $raw) {
            return null;
        }

        preg_match('/MemTotal:\s+(\d+)/', $raw, $total);
        preg_match('/MemAvailable:\s+(\d+)/', $raw, $available);

        if (empty($total[1]) || ! isset($available[1])) {
            return null;
        }

        return (int) round((((int) $total[1] - (int) $available[1]) / (int) $total[1]) * 100);
    }
}