<?php

namespace App\Scene;

use App\Net\Rtc;
use App\Ui\Look;
use JumPHP\Kernel\Platform;
use JumPHP\Native\Shell;
use JumPHP\Net\LobbyScene;
use JumPHP\Renderer\Renderer;
use JumPHP\Scene\AbstractScene;
use JumPHP\Util\Lang;
use JumPHP\WebRtc\WebRtc;

/** The main menu: the two demos, online play, the language, the tutorial and the documentation. Keys, mouse or touch. */
final class TitleScene extends AbstractScene
{
    private const DOCS = 'https://jumphp.net/extensions/jumphp/webrtc/';
    private const BW = 190;
    private const BH = 13;
    private const TOP = 50;
    private const GAP = 15;

    private int $selected = 0;
    private string $backend = '';
    private string $message = '';
    private float $time = 0;

    public function __construct(private WebRtc $webrtc)
    {
    }

    public function enter(array $params = []): void
    {
        Look::apply($this->engine, $params);
        $this->selected = 0;
        $this->time = 0;
        $this->message = (string)($params['message'] ?? '');
        $this->backend = Rtc::prepare($this->webrtc);
    }

    /** @return list<array{0: string, 1: callable, 2?: callable}> [text, on press, on left / right] */
    private function items(): array
    {
        $items = [
            [Lang::t('Two peers on this screen'), fn () => $this->scenes()->switchTo(LinkScene::class)],
            [Lang::t('Play online (2 players)'), fn () => $this->online()],
            [Lang::t('Practice against a bot'), fn () => $this->scenes()->switchTo(DuelScene::class, ['mode' => 'bot'])],
            ['< ' . Lang::t('Language: {name}', ['name' => Look::LANGUAGES[$this->engine->lang->getLang()] ?? 'English']) . ' >',
                fn () => Look::cycle($this->engine, 1), fn (int $dir) => Look::cycle($this->engine, $dir)],
            [Lang::t('Tutorial') . '  ·  ' . Lang::t('Documentation'), fn () => $this->open(self::DOCS . 'tutoriel')],
        ];
        if (Platform::isDesktop()) {
            $items[] = [Lang::t('Quit'), fn () => $this->engine->quit()];
        }
        return $items;
    }

    private function online(): void
    {
        if (!Rtc::real($this->webrtc)) {
            $this->message = 'Online play needs real WebRTC: a browser, or GStreamer on Linux.';
            return;
        }
        $this->scenes()->switchTo(LobbyScene::class, ['next' => DuelScene::class, 'nextParams' => ['mode' => 'online'],
            'back' => self::class, 'players' => 2]);
    }

    private function open(string $url): void
    {
        Platform::isWasm() ? $this->engine->bridge->send('open', ['url' => $url]) : Shell::openUrl($url);
    }

    public function update(float $dt): void
    {
        $this->time += $dt;
        $items = $this->items();
        $n = count($items);
        $a = $this->actions();
        if ($a->isPressed('up')) {
            $this->selected = ($this->selected + $n - 1) % $n;
        }
        if ($a->isPressed('down')) {
            $this->selected = ($this->selected + 1) % $n;
        }
        $x = ($this->width() - self::BW) / 2;
        foreach ($items as $i => $item) {
            $y = self::TOP + $i * self::GAP;
            if (Look::hover($this->engine, $x, $y, self::BW, self::BH) && $this->engine->input->getMouse()->isPressed(1)) {
                $this->selected = $i;
                $item[1]();
                return;
            }
        }
        $item = $items[$this->selected] ?? null;
        if ($item === null) {
            return;
        }
        if ($a->isPressed('confirm') || $a->isPressed('send')) {
            $item[1]();
        } elseif (isset($item[2]) && ($a->isPressed('left') || $a->isPressed('right'))) {
            $item[2]($a->isPressed('left') ? -1 : 1);
        }
    }

    public function render(Renderer $r): void
    {
        $r->clear(Look::BG);
        $w = $this->width();
        // two peers and the packets between them
        for ($i = 0; $i < 4; $i++) {
            $t = fmod($this->time * 0.6 + $i / 4, 1.0);
            $r->fillCircle(40 + $t * ($w - 80), 18, 1.5, $i % 2 ? Look::OTHER : Look::ME);
        }
        $r->fillRect(28, 12, 12, 12, Look::ME);
        $r->fillRect($w - 40, 12, 12, 12, Look::OTHER);
        $font = $this->font();
        $font->draw($r, 'WebRTC', $w / 2, 8, 2, [255, 255, 255], 'center');
        $font->draw($r, Lang::t('Peer to peer from PHP, in your browser'), $w / 2, 32, 1, Look::MUTED, 'center');
        $x = ($w - self::BW) / 2;
        foreach ($this->items() as $i => $item) {
            $y = self::TOP + $i * self::GAP;
            Look::button($r, $this->engine, $x, $y, self::BW, self::BH, $item[0], $i === $this->selected);
        }
        $bottom = $this->height() - 12;
        if ($this->message !== '') {
            $font->draw($r, Lang::t($this->message), $w / 2, $bottom - 11, 1, [255, 120, 120], 'center');
        }
        $font->draw($r, Lang::t('WebRTC here: {what}', ['what' => Lang::t(Rtc::describe($this->backend))]), $w / 2, $bottom, 1, Look::MUTED, 'center');
    }
}