<?php

namespace App\Models;

use App\Models\Concerns\HasUuid;
use App\Provisioning\Contracts\ProvisioningSubject;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\HasMany;
use Illuminate\Database\Eloquent\Relations\MorphMany;

class Host extends Model implements ProvisioningSubject
{
    /** @use HasFactory<\Database\Factories\HostFactory> */
    use HasFactory, HasUuid;

    protected $fillable = [
        'name', 'datacenter', 'cluster', 'public_ip', 'wg_ip', 'wg_pubkey',
        'ssh_host_key', 'api_token_ref', 'total_gb', 'total_ram_mb', 'cpu_cores',
        'cpu_weight', 'reserve_pct', 'pve_version', 'status', 'last_seen_at',
    ];

    protected $hidden = ['api_token_ref'];

    protected function casts(): array
    {
        return [
            'api_token_ref' => 'encrypted',
            'last_seen_at' => 'datetime',
            'total_gb' => 'integer',
            'total_ram_mb' => 'integer',
            'cpu_cores' => 'integer',
            'cpu_weight' => 'integer',
            'reserve_pct' => 'integer',
        ];
    }

    /** Placement runs (polymorphic subject). */
    public function runs(): MorphMany
    {
        return $this->morphMany(ProvisioningRun::class, 'subject');
    }

    /** Runner hook: a failed onboarding run moves the host to the error status. */
    public function onProvisioningFailed(): void
    {
        $this->update(['status' => 'error']);
    }

    public function instances(): HasMany
    {
        return $this->hasMany(Instance::class);
    }

    /** Free committable storage: total minus reserve. */
    public function freeGb(): int
    {
        if ($this->total_gb === null) {
            return 0;
        }

        return (int) floor($this->total_gb * (100 - $this->reserve_pct) / 100);
    }

    /** Storage already committed to non-failed instances. */
    public function committedGb(): int
    {
        return (int) $this->instances()->where('status', '!=', 'failed')->sum('quota_gb');
    }

    /** Storage still available for new instances. */
    public function availableGb(): int
    {
        return max(0, $this->freeGb() - $this->committedGb());
    }

    /**
     * Placement (spec §1): first active host in the datacenter with enough free
     * committable storage. Cluster is ignored in v1.0.
     */
    public static function placeableIn(string $datacenter, int $quotaGb): ?self
    {
        return self::query()
            ->where('datacenter', $datacenter)
            ->where('status', 'active')
            ->orderBy('name')
            ->get()
            ->first(fn (self $host) => $host->availableGb() >= $quotaGb);
    }
}