<?php

namespace App\Form;

use App\Feature\Storage\Actions;
use App\Feature\Storage\Menus;
use App\Gui\Units;
use App\Model\Connection;
use JumPHP\Gui\Button;
use JumPHP\Gui\Form;
use JumPHP\Gui\Label;
use JumPHP\Gui\ListBox;

/**
 * Move a virtual disk to another SR (Feature\Storage\Actions::moveDisk): its VM running -> VDI.pool_migrate (storage live
 * migration); halted (or no VM) -> VDI.copy, the VBDs made again on the copy, the original destroyed. The SRs offered: attached,
 * not ISO, not its own, with room for it. Closes with ['moveDisk' => [vdi, sr]].
 *
 * @property Label $heading
 * @property Label $where
 * @property ListBox $sr
 * @property Label $how
 * @property Label $error
 * @property Button $move
 * @property Button $cancel
 */
final class MoveDiskForm extends Form
{
    public function __construct(private \App\Model\Session $session)
    {
        parent::__construct();
    }

    /** XAPI's answers, events and the console go on while this dialog is open. */
    protected function tick(float $dt): void
    {
        $this->session->tick($dt);
    }

    private array $params = [];

    /** @return array<string, mixed> */
    public static function paramsFor(Connection $c, string $vdi): array
    {
        $cache = $c->cache;
        $r = $cache->get($vdi) ?? [];
        $size = (float)($r['virtual_size'] ?? 0);
        $vm = Actions::vmOfDisk($c, $vdi);
        $srs = [];
        foreach ($cache->srs() as $ref => $sr) {
            $free = (float)$sr['physical_size'] - (float)$sr['physical_utilisation'];
            if ($ref === ($r['SR'] ?? '') || ($sr['content_type'] ?? '') === 'iso' || !Menus::managed($cache, $ref) || Menus::attached($cache, $ref) === 0 || $free < $size) {
                continue;
            }
            $srs[] = ['ref' => $ref, 'name' => $cache->name($ref) . ' (' . Units::bytes($free) . ' free)'];
        }
        $state = $vm === null ? '' : (string)$cache->field($vm, 'power_state', '');
        return ['vdi' => $vdi, 'name' => (string)($r['name_label'] ?? ''), 'size' => $size, 'from' => $cache->name((string)($r['SR'] ?? '')), 'srs' => $srs,
            'vm' => $vm === null ? '' : $cache->name($vm), 'state' => $state, 'live' => Actions::isLive($c, $vdi)];
    }

    protected function loaded(array $params = []): void
    {
        $this->params = $params;
        $this->heading->text = "Move '" . ($params['name'] ?? '') . "'";
        $this->where->text = Units::bytes((float)($params['size'] ?? 0)) . " on '" . ($params['from'] ?? '') . "'" . (($params['vm'] ?? '') !== '' ? " · VM '{$params['vm']}'" : '');
        $this->sr->items = array_column($params['srs'] ?? [], 'name');
        $this->sr->selected = ($params['srs'] ?? []) === [] ? -1 : 0;
        $this->how->text = !empty($params['live'])
            ? 'The VM is running: the disk moves while it works (storage live migration).'
            : 'The disk is copied to the new storage repository, the VM is given the copy, then the original is deleted.';
        $this->error->text = ($params['srs'] ?? []) === [] ? 'No other storage repository has room for this disk.' : '';
        if (in_array($params['state'] ?? '', ['Suspended', 'Paused'], true)) {
            $this->error->text = 'The VM is ' . strtolower((string)$params['state']) . ': start it or shut it down first.';
        }
        $this->move->enabled = $this->error->text === '';
    }

    public function onMoveClick(mixed $sender = null): void
    {
        $sr = $this->params['srs'][(int)$this->sr->selected] ?? null;
        if ($sr === null || !$this->move->enabled) {
            $this->error->text = $this->error->text ?: 'Choose a storage repository.';
            return;
        }
        $this->close(['moveDisk' => ['vdi' => $this->params['vdi'] ?? '', 'sr' => $sr['ref']]]);
    }

    public function onCancelClick(Button $sender): void
    {
        $this->close();
    }
}