<?php

namespace App\View;

use App\Service\Art;
use App\Sim\Autoplay;
use App\Sim\LevelBuilder;
use App\Sim\Levels;
use App\Sim\Lumi;
use App\Sim\World;
use JumPHP\Kernel\Engine;
use JumPHP\Renderer\Renderer;

/** Levels that play themselves, one after the other, without sound: the living background of the menus. */
final class DemoRunner
{
    private World $world;
    private ?WorldView $view = null;
    private Autoplay $auto;
    private float $acc = 0;
    private float $camX = 0;
    private float $end = 0;

    public function __construct(private Engine $engine, private Art $art, private int $level = 0)
    {
        $this->start($level);
    }

    private function start(int $level): void
    {
        $this->level = $level % Levels::count();
        $def = Levels::get($this->level);
        $this->world = LevelBuilder::build($def);
        $this->view?->release();
        $this->view = new WorldView($this->engine, $this->art, $this->world, $def['theme']);
        $this->auto = new Autoplay($this->world, $def['solution']);
        $this->camX = max(0, $this->world->hatch[0] - 240);
        $this->acc = 0;
        $this->end = 0;
    }

    public function update(float $dt): void
    {
        $this->acc = min(0.3, $this->acc + $dt * 1.5);
        while ($this->acc >= 1 / World::TICKS_PER_SECOND) {
            $this->acc -= 1 / World::TICKS_PER_SECOND;
            if (!$this->world->isOver()) {
                $this->world->step();
                $this->auto->step();
            }
        }
        $this->view->consume(false);
        $this->view->update($dt);
        $lead = null;
        foreach ($this->world->lumis as $l) {
            if ($l->alive && !$l->is(Lumi::STOP) && ($lead === null || $l->x > $lead->x)) {
                $lead = $l;
            }
        }
        $target = max(0, min($this->world->terrain->width - WorldView::VIEW_W, ($lead->x ?? $this->world->hatch[0]) - 240));
        $this->camX += ($target - $this->camX) * min(1, $dt * 2);
        if ($this->world->isOver() && ($this->end += $dt) > 1.5) {
            $this->start($this->level + 1);
        }
    }

    public function render(Renderer $r): void
    {
        $this->view->render($r, $this->camX);
    }

    public function release(): void
    {
        $this->view?->release();
        $this->view = null;
    }
}