<?php

namespace App\Services\Hosting\Provisioning;

use App\Exceptions\Hosting\ProvisioningException;
use App\Models\Customer;
use App\Models\VmidReservation;
use Illuminate\Support\Facades\DB;

class VmidReservationService
{
    public function reserveForCustomer(Customer $customer): int
    {
        return DB::transaction(function () use ($customer) {
            $vmid = $this->findNextAvailableVmid();

            VmidReservation::query()->create([
                'vmid' => $vmid,
                'customer_id' => $customer->id,
                'status' => 'reserved',
            ]);

            return $vmid;
        });
    }

    public function activate(int $vmid, Customer $customer): void
    {
        VmidReservation::query()
            ->where('vmid', $vmid)
            ->where('customer_id', $customer->id)
            ->update([
                'status' => 'active',
                'release_at' => null,
            ]);
    }

    public function scheduleRelease(int $vmid, ?Customer $customer = null): void
    {
        $hours = (int) config('hosting.vmid.release_after_hours', 48);

        $query = VmidReservation::query()->where('vmid', $vmid);

        if ($customer) {
            $query->where('customer_id', $customer->id);
        }

        $query->update([
            'status' => 'pending_release',
            'release_at' => now()->addHours($hours),
        ]);
    }

    public function releaseDue(): int
    {
        $count = 0;

        $due = VmidReservation::query()
            ->where('status', 'pending_release')
            ->where('release_at', '<=', now())
            ->get();

        foreach ($due as $reservation) {
            $reservation->update([
                'status' => 'released',
                'released_at' => now(),
            ]);
            $count++;
        }

        return $count;
    }

    public function isVmidBlocked(int $vmid): bool
    {
        return VmidReservation::query()
            ->where('vmid', $vmid)
            ->whereIn('status', ['reserved', 'active', 'pending_release'])
            ->exists();
    }

    private function findNextAvailableVmid(): int
    {
        $start = (int) config('hosting.vmid.range_start', 2000);
        $end = (int) config('hosting.vmid.range_end', 2999);

        $blocked = VmidReservation::query()
            ->whereIn('status', ['reserved', 'active', 'pending_release'])
            ->pluck('vmid')
            ->flip()
            ->all();

        for ($vmid = $start; $vmid <= $end; $vmid++) {
            if (! isset($blocked[$vmid])) {
                return $vmid;
            }
        }

        throw new ProvisioningException(
            "No free VMID in range {$start}-{$end}.",
            step: 'reserving_vmid',
        );
    }
}