<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\UX\TwigComponent\Event;

use Symfony\Contracts\EventDispatcher\Event;
use Symfony\UX\TwigComponent\ComponentMetadata;
use Symfony\UX\TwigComponent\MountedComponent;

/**
 * @author Kevin Bond <kevinbond@gmail.com>
 */
final class PreRenderEvent extends Event
{
    /** @internal */
    public const EMBEDDED = '__embedded';

    /**
     * Only relevant when rendering a specific embedded component.
     * This is the "component template" that the embedded component
     * should extend.
     */
    private string $parentTemplateForEmbedded;
    private string $template;
    private ?int $templateIndex = null;

    /**
     * @internal
     */
    public function __construct(
        private MountedComponent $mounted,
        private ComponentMetadata $metadata,
        private array $variables,
    ) {
        $this->template = $this->metadata->getTemplate();

        if ($method = $this->metadata->getTemplateFromMethod()) {
            $component = $this->mounted->getComponent();

            if (!\is_callable($callback = [$component, $method])) {
                throw new \LogicException(\sprintf('The template method "%s" does not exist or is not callable on component "%s".', $method, get_debug_type($component)));
            }

            $this->template = $callback();

            if (!\is_string($this->template)) {
                throw new \LogicException(\sprintf('The template method "%s" must return a string on component "%s".', $method, get_debug_type($component)));
            }
        }

        $this->parentTemplateForEmbedded = $this->template;
    }

    public function isEmbedded(): bool
    {
        return $this->variables[self::EMBEDDED] ?? false;
    }

    /**
     * @return string The twig template used for the component
     */
    public function getTemplate(): string
    {
        return $this->template;
    }

    /**
     * Change the twig template used.
     */
    public function setTemplate(string $template, ?int $index = null): self
    {
        $this->template = $template;
        $this->templateIndex = $index;
        // only if we are *not* targeting an embedded component, change the parent template
        if (null === $index) {
            $this->parentTemplateForEmbedded = $template;
        }

        return $this;
    }

    /**
     * @return string The twig template index used for the component, in case it's an embedded template
     */
    public function getTemplateIndex(): ?int
    {
        return $this->templateIndex;
    }

    public function getParentTemplateForEmbedded(): string
    {
        return $this->parentTemplateForEmbedded;
    }

    public function getComponent(): object
    {
        return $this->mounted->getComponent();
    }

    /**
     * @return array the variables that will be available in the component's template
     */
    public function getVariables(): array
    {
        return $this->variables;
    }

    /**
     * Change the twig variables used.
     */
    public function setVariables(array $variables): self
    {
        $this->variables = $variables;

        return $this;
    }

    public function getMetadata(): ComponentMetadata
    {
        return $this->metadata;
    }

    /**
     * @internal
     */
    public function getMountedComponent(): MountedComponent
    {
        return $this->mounted;
    }
}