<?php

namespace App\Services\Deployment;

use App\Models\Node;
use Webmozart\Assert\Assert;
use Illuminate\Support\Collection;

class FindViableNodesService
{
    protected ?int $disk = null;
    protected ?int $memory = null;

    /**
     * Set the amount of disk that will be used by the server being created. Nodes will be
     * filtered out if they do not have enough available free disk space for this server
     * to be placed on.
     */
    public function setDisk(int $disk): self
    {
        $this->disk = $disk;

        return $this;
    }

    /**
     * Set the amount of memory that this server will be using. As with disk space, nodes that
     * do not have enough free memory will be filtered out.
     */
    public function setMemory(int $memory): self
    {
        $this->memory = $memory;

        return $this;
    }

    /**
     * Returns a collection of nodes that meet the provided requirements and can then
     * be passed to the AllocationSelectionService to return a single allocation.
     *
     * This functionality is used for automatic deployments of servers and will
     * attempt to find all nodes in the defined locations that meet the disk and
     * memory availability requirements. Any nodes not meeting those requirements
     * are tossed out, as are any nodes marked as non-public, meaning automatic
     * deployments should not be done against them.
     */
    public function handle(int $disk = null, int $memory = null, int $cpu = null): Collection
    {
        Assert::integer($this->disk, 'Disk space must be an int, got %s');
        Assert::integer($this->memory, 'Memory usage must be an int, got %s');

        $query = Node::query()->select('nodes.*')
            ->selectRaw('IFNULL(SUM(servers.memory), 0) as sum_memory')
            ->selectRaw('IFNULL(SUM(servers.disk), 0) as sum_disk')
            ->leftJoin('servers', 'servers.node_id', '=', 'nodes.id')
            ->where('nodes.public', 1);

        $results = $query->groupBy('nodes.id')
            ->havingRaw('(IFNULL(SUM(servers.memory), 0) + ?) <= (nodes.memory * (1 + (nodes.memory_overallocate / 100)))', [$this->memory])
            ->havingRaw('(IFNULL(SUM(servers.disk), 0) + ?) <= (nodes.disk * (1 + (nodes.disk_overallocate / 100)))', [$this->disk]);

        return $results->get();
    }
}