<?php

namespace App\Services\Hosting;

use App\Models\HostingAccount;
use App\Models\HostingNode;
use Illuminate\Support\Collection;

class HostingNodePoolService
{
    public function poolRoot(HostingNode $node): HostingNode
    {
        return $node->isExtension() && $node->primary
            ? $node->primary
            : $node;
    }

    /**
     * @return Collection<int, HostingNode>
     */
    public function poolMembers(HostingNode $node): Collection
    {
        $root = $this->poolRoot($node);

        return HostingNode::query()
            ->where(function ($query) use ($root) {
                $query->where('id', $root->id)
                    ->orWhere('primary_hosting_node_id', $root->id);
            })
            ->where('type', HostingNode::TYPE_SHARED)
            ->whereNotIn('status', [HostingNode::STATUS_DECOMMISSIONED])
            ->orderBy('role')
            ->get();
    }

    public function poolDiskGb(HostingNode $node): int
    {
        return (int) $this->poolMembers($node)->sum('disk_gb');
    }

    public function poolLogicalCapacityGb(HostingNode $node): float
    {
        return round($this->poolMembers($node)->sum(fn (HostingNode $m) => $m->logicalCapacityGb()), 2);
    }

    public function poolAllocatedDiskGb(HostingNode $node): int
    {
        $memberIds = $this->poolMembers($node)->pluck('id');

        return (int) HostingAccount::query()
            ->whereIn('hosting_node_id', $memberIds)
            ->where('type', HostingAccount::TYPE_SHARED)
            ->sum('allocated_disk_gb');
    }

    public function poolUsedDiskGb(HostingNode $node): int
    {
        $memberIds = $this->poolMembers($node)->pluck('id');

        $bytes = (int) HostingAccount::query()
            ->whereIn('hosting_node_id', $memberIds)
            ->where('type', HostingAccount::TYPE_SHARED)
            ->sum('disk_used_bytes');

        return (int) ceil($bytes / 1073741824);
    }

    /**
     * Member node with the most room for a new shared account.
     */
    public function findProvisioningMember(HostingNode $poolRoot, int $requestedDiskGb = 0, ?string $segment = null): ?HostingNode
    {
        $members = $this->poolMembers($poolRoot)
            ->filter(fn (HostingNode $n) => $n->canProvision($requestedDiskGb, $segment));

        if ($members->isEmpty()) {
            return null;
        }

        return $members->sortBy(fn (HostingNode $n) => sprintf(
            '%012.2f-%012d',
            (float) $n->current_load_percent,
            $n->used_disk_gb,
        ))->first();
    }
}