<?php
/**
 * Fliptale_Plugin class.
 *
 * @package Fliptale
 */

defined( 'ABSPATH' ) || exit;

/**
 * Registers the block, the shortcode and the handler that turns pasted Fliptale links into embeds.
 */
final class Fliptale_Plugin {

	/**
	 * Hooks the plugin into WordPress.
	 */
	public static function init() {
		add_action( 'init', array( __CLASS__, 'register' ) );
	}

	/**
	 * Registers everything on `init`.
	 */
	public static function register() {
		register_block_type( FLIPTALE_PLUGIN_DIR . 'blocks/flipbook' );

		// The editor previews with the same rules as the server, custom domains included.
		wp_add_inline_script(
			generate_block_asset_handle( 'fliptale/flipbook', 'editorScript' ),
			'window.fliptaleEditor = ' . wp_json_encode(
				array(
					'customDomains' => Fliptale_Url::custom_domains(),
					'defaultHeight' => Fliptale_Embed::DEFAULT_HEIGHT,
					'minHeight'     => Fliptale_Embed::MIN_HEIGHT,
					'maxHeight'     => Fliptale_Embed::MAX_HEIGHT,
				)
			) . ';',
			'before'
		);

		add_shortcode( 'fliptale', array( __CLASS__, 'shortcode' ) );

		// A Fliptale link on its own line, or in an Embed block, becomes the book.
		wp_embed_register_handler( 'fliptale', '#^https?://(?:[a-z0-9-]+\.)?fliptale\.io/\S*$#i', array( __CLASS__, 'embed_handler' ) );
		$domains = Fliptale_Url::custom_domains();
		if ( $domains ) {
			$hosts = implode(
				'|',
				array_map(
					static function ( $domain ) {
						return preg_quote( $domain, '#' );
					},
					$domains
				)
			);
			wp_embed_register_handler( 'fliptale-custom-domains', '#^https?://(?:' . $hosts . ')(?:/\S*)?$#i', array( __CLASS__, 'embed_handler' ) );
		}
	}

	/**
	 * The [fliptale] shortcode: `[fliptale url="https://fliptale.io/b/…" height="640" title="Spring catalog"]`.
	 *
	 * @param array|string $atts Shortcode attributes: url (or id), height, title.
	 * @return string
	 */
	public static function shortcode( $atts ) {
		$atts      = shortcode_atts(
			array(
				'url'    => '',
				'id'     => '',
				'height' => Fliptale_Embed::DEFAULT_HEIGHT,
				'title'  => '',
			),
			$atts,
			'fliptale'
		);
		$embed_url = Fliptale_Url::to_embed_url( '' !== $atts['url'] ? $atts['url'] : $atts['id'] );
		if ( null === $embed_url ) {
			return '';
		}
		return wp_kses( Fliptale_Embed::html( $embed_url, $atts ), Fliptale_Embed::allowed_html() );
	}

	/**
	 * Turns a pasted Fliptale link into the embed.
	 *
	 * @param array  $matches The regex matches.
	 * @param array  $attr    Embed attributes, with WordPress' default width and height.
	 * @param string $url     The pasted link.
	 * @param array  $rawattr Only the attributes set in an [embed] shortcode.
	 * @return string|false The embed, or false to leave the link to WordPress.
	 */
	public static function embed_handler( $matches, $attr, $url, $rawattr ) {
		$embed_url = Fliptale_Url::to_embed_url( $url );
		if ( null === $embed_url ) {
			return false;
		}
		$height = isset( $rawattr['height'] ) ? $rawattr['height'] : Fliptale_Embed::DEFAULT_HEIGHT;
		return wp_kses( Fliptale_Embed::html( $embed_url, array( 'height' => $height ) ), Fliptale_Embed::allowed_html() );
	}
}