<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;
use Illuminate\Support\Carbon;
use Illuminate\Support\Collection;

/**
 * A day in the life of one instance: how full it was, and what it moved.
 *
 * Read by the customer panel to draw the storage ring and the transfer trend.
 * Written by CollectInstanceTraffic, which already visits every active
 * instance — a second scheduler entry hitting the same Proxmox API would only
 * double the load and the failure modes.
 */
class InstanceMetric extends Model
{
    protected $fillable = ['instance_id', 'day', 'disk_used_bytes', 'disk_total_bytes', 'rx_bytes', 'tx_bytes'];

    protected function casts(): array
    {
        return [
            'day' => 'date',
            'disk_used_bytes' => 'integer',
            'disk_total_bytes' => 'integer',
            'rx_bytes' => 'integer',
            'tx_bytes' => 'integer',
        ];
    }

    public function instance(): BelongsTo
    {
        return $this->belongsTo(Instance::class);
    }

    /**
     * The last $days days, oldest first, with gaps left as gaps.
     *
     * A missing day is not a zero. Filling it would draw a cliff into the chart
     * on every day the sampler could not reach the host, and the customer would
     * read an outage that never happened.
     *
     * @return Collection<int, self>
     */
    public static function series(Instance $instance, int $days = 14): Collection
    {
        return self::query()
            ->where('instance_id', $instance->id)
            ->where('day', '>=', Carbon::today()->subDays($days - 1))
            ->orderBy('day')
            ->get();
    }

    /** The most recent day that carries a disk reading, or null. */
    public static function latestDisk(Instance $instance): ?self
    {
        return self::query()
            ->where('instance_id', $instance->id)
            ->whereNotNull('disk_used_bytes')
            ->orderByDesc('day')
            ->first();
    }
}