<?php

namespace App\Form;

use App\Gui\Units;
use App\Model\Connection;
use App\Model\Session;
use App\Xapi\Xva;
use JumPHP\Gui\Button;
use JumPHP\Gui\ComboBox;
use JumPHP\Gui\Form;
use JumPHP\Gui\Label;
use JumPHP\Gui\TextBox;
use JumPHP\Kernel\Platform;
use JumPHP\Native\FilePicker;
use JumPHP\Native\Native;

/**
 * File > Import…: an XVA file (typed, or chosen with the system's Open dialog: a desktop app, or the browser's, which hands the file
 * to the page), the server it will belong to and the storage of its disks. What the file holds (its ova.xml: the VM's name, its
 * disks) shows before it is sent. Closes with ['xva' => ['op' => 'import', ...]], src/Feature/Xva/XvaTransfers streams it.
 *
 * @property Label $where
 * @property TextBox $path
 * @property Button $browse
 * @property Label $info
 * @property ComboBox $home
 * @property ComboBox $sr
 * @property Label $error
 * @property Button $import
 * @property Button $cancel
 */
final class ImportForm extends Form
{
    private array $params = [];
    /** @var array<string, mixed>|null what ova.xml says of the file chosen */
    private ?array $vm = null;

    public function __construct(private 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);
    }

    /** @return array<string, mixed> */
    public static function paramsFor(Connection $c, ?string $host = null): array
    {
        $cache = $c->cache;
        $hosts = [['ref' => '', 'name' => "Don't assign a home server"]];
        foreach ($cache->hosts() as $ref => $h) {
            $hosts[] = ['ref' => (string)$ref, 'name' => (string)$h['name_label']];
        }
        $default = (string)$cache->field((string)$cache->poolRef(), 'default_SR', '');
        $srs = [];
        foreach ($cache->srs() as $ref => $sr) {
            if (($sr['content_type'] ?? '') !== 'iso') {
                $srs[] = ['ref' => (string)$ref, 'name' => $cache->name((string)$ref) . ' (' . Units::bytes((float)$sr['physical_size'] - (float)$sr['physical_utilisation']) . ' free)'];
            }
        }
        usort($srs, fn ($a, $b) => ($b['ref'] === $default) <=> ($a['ref'] === $default));
        return ['server' => $c->name(), 'pool' => (string)($cache->poolRef() ?? ''), 'hosts' => $hosts, 'srs' => $srs, 'host' => $host];
    }

    protected function loaded(array $params = []): void
    {
        $this->params = $params;
        $this->vm = null;
        $this->where->text = "Into '" . ($params['server'] ?? '') . "'";
        $this->path->text = (string)($params['file'] ?? '');
        $this->home->items = array_column($params['hosts'] ?? [], 'name');
        $at = array_search($params['host'] ?? null, array_column($params['hosts'] ?? [], 'ref'), true);
        $this->home->selected = $at === false ? 0 : (int)$at;
        $this->sr->items = array_column($params['srs'] ?? [], 'name');
        $this->sr->selected = 0;
        $this->browse->enabled = Native::supports('open');
        $this->error->text = '';
        $this->info->text = Native::supports('open') ? '' : 'Type the path of the file' . (Platform::isWasm() ? '.' : ' (no file chooser in this window).');
        $this->onFileChange($this->path, $this->path->text);
        $this->setFocus($this->path);
    }

    public function onBrowseClick(Button $sender): void
    {
        if (!Native::supports('open')) {
            return;
        }
        FilePicker::open(['title' => 'Import an XVA file', 'filters' => ['XVA files' => ['xva'], 'All files' => ['*']]])->then(function (mixed $file): void {
            if (is_string($file)) {
                $this->path->text = $file;
                $this->onFileChange($this->path, $file);
            }
        }, fn (\Throwable $e) => $this->error->text = $e->getMessage());
    }

    public function onFileChange(TextBox $sender, string $text): void
    {
        $this->vm = null;
        $file = trim($text);
        if ($file === '' || !is_file($file)) {
            if ($file !== '') {
                $this->info->text = 'No such file.';
            }
            return;
        }
        $this->vm = Xva::readHeader(Xva::headOf($file));
        $size = (float)@filesize($file);
        if ($this->vm === null) {
            $this->info->text = Units::bytes($size) . ' — this is not an XVA file (no ova.xml at its start).';
            return;
        }
        $disks = array_map(fn (array $d) => $d[0] . ' (' . Units::bytes($d[1]) . ')', $this->vm['disks']);
        $this->info->text = "VM '" . $this->vm['name_label'] . "': " . (int)$this->vm['VCPUs_max'] . ' vCPUs, ' . Units::bytes((float)$this->vm['memory_static_max'])
            . ' of memory' . ($disks !== [] ? ', disks ' . implode(', ', $disks) : '') . ' · file ' . Units::bytes($size);
    }

    public function onImportClick(mixed $sender = null): void
    {
        $file = trim($this->path->text);
        $this->onFileChange($this->path, $file);
        if ($file === '' || !is_file($file)) {
            $this->error->text = 'Choose the XVA file to import.';
            return;
        }
        if ($this->vm === null) {
            $this->error->text = 'This file is not an XVA export.';
            return;
        }
        $sr = $this->params['srs'][(int)$this->sr->selected]['ref'] ?? null;
        if ($sr === null) {
            $this->error->text = 'There is no storage repository to put the disks on.';
            return;
        }
        $host = $this->params['hosts'][(int)$this->home->selected]['ref'] ?? '';
        $this->close(['xva' => ['op' => 'import', 'file' => $file, 'sr' => $sr, 'host' => $host, 'label' => (string)$this->vm['name_label']]]);
    }

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