<?php
/**
 * Preview of the buy box for the product form, drawn with the site's own theme styles.
 *
 * @package PAYGRAB
 */

defined( 'ABSPATH' ) || exit;

/**
 * The page loaded in the product form's preview frame.
 */
class Paygrab_Preview {

	/** Query argument that asks for the preview page. */
	const ARG = 'paygrab_preview';

	/**
	 * Hooks.
	 *
	 * @return void
	 */
	public static function init() {
		add_action( 'template_redirect', array( __CLASS__, 'maybe_render' ), 0 );
	}

	/**
	 * Draw the preview page when asked by someone who can manage products.
	 *
	 * @return void
	 */
	public static function maybe_render() {
		// phpcs:disable WordPress.Security.NonceVerification.Recommended -- the nonce is checked right below.
		if ( empty( $_GET[ self::ARG ] ) ) {
			return;
		}
		$nonce = isset( $_GET['_wpnonce'] ) ? sanitize_text_field( wp_unslash( $_GET['_wpnonce'] ) ) : '';
		if ( ! wp_verify_nonce( $nonce, self::ARG ) || ! current_user_can( 'manage_options' ) ) {
			status_header( 403 );
			nocache_headers();
			exit;
		}
		$values = isset( $_GET['v'] ) ? json_decode( wp_unslash( (string) $_GET['v'] ), true ) : array(); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized -- every value is sanitized in values().
		// phpcs:enable
		$preview = self::values( is_array( $values ) ? $values : array() );
		// The settings screen previews a look and a key colour that are not saved yet.
		$look = is_array( $values ) ? $values : array();
		foreach ( array( 'style', 'mode', 'color' ) as $key ) {
			if ( isset( $look[ $key ] ) && is_string( $look[ $key ] ) ) {
				Paygrab_Styles::$preview[ $key ] = sanitize_key( 'color' === $key ? ltrim( $look[ $key ], '#' ) : $look[ $key ] );
			}
		}
		if ( isset( Paygrab_Styles::$preview['color'] ) ) {
			Paygrab_Styles::$preview['color'] = '#' . Paygrab_Styles::$preview['color'];
		}

		nocache_headers();
		show_admin_bar( false );
		add_filter( 'wp_robots', 'wp_robots_no_robots' );
		add_action( 'wp_enqueue_scripts', array( __CLASS__, 'theme_assets' ), 999 );
		Paygrab_Frontend::enqueue();
		$html = Paygrab_Product::buy_box( $preview['id'], array( 'preview' => $preview ) );
		echo paygrab_get_template( 'preview-page', array( 'html' => $html ) ); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- a full page built from escaped templates.
		exit;
	}

	/**
	 * What the theme loads in header.php, which the preview page does not use.
	 * TCD themes enqueue their style.css and jQuery there; without them the preview
	 * would be drawn without the theme's styles, and theme scripts stop on "jQuery is not defined".
	 *
	 * @return void
	 */
	public static function theme_assets() {
		wp_enqueue_script( 'jquery' );
		$sheet = strtok( get_stylesheet_uri(), '?' );
		foreach ( wp_styles()->queue as $handle ) {
			$src = wp_styles()->registered[ $handle ]->src ?? '';
			if ( is_string( $src ) && '' !== $src && strtok( $src, '?' ) === $sheet ) {
				return;
			}
		}
		wp_enqueue_style( 'paygrab-preview-theme', $sheet, array(), (string) wp_get_theme()->get( 'Version' ) );
	}

	/**
	 * Clean the values sent by the form.
	 *
	 * @param array $v Raw values.
	 * @return array Preview arguments for Paygrab_Product::buy_box().
	 */
	private static function values( array $v ) {
		$id   = isset( $v['id'] ) ? absint( $v['id'] ) : 0;
		$id   = $id && Paygrab_Product::TYPE === get_post_type( $id ) ? $id : 0;
		$file = $id ? Paygrab_Product::data( $id )['file'] : null;
		if ( ! empty( $v['file'] ) && is_array( $v['file'] ) ) {
			$file = array(
				'name' => sanitize_file_name( (string) ( $v['file']['name'] ?? 'file.zip' ) ),
				'size' => absint( $v['file']['size'] ?? 0 ),
				'path' => '',
			);
		} elseif ( array_key_exists( 'file', $v ) && null === $v['file'] ) {
			$file = null;
		}
		return array(
			'id'      => $id,
			'title'   => sanitize_text_field( (string) ( $v['title'] ?? '' ) ),
			'excerpt' => Paygrab_Product::clean_excerpt( (string) ( $v['excerpt'] ?? '' ) ),
			'state'   => sanitize_key( (string) ( $v['state'] ?? 'buy' ) ),
			'data'    => array(
				'price'   => min( 10000000, absint( $v['price'] ?? 0 ) ),
				'limit'   => min( 1000, absint( $v['limit'] ?? 0 ) ),
				'days'    => min( 3650, absint( $v['days'] ?? 0 ) ),
				'on_sale' => ! empty( $v['onSale'] ),
				'file'    => $file,
				// An image chosen in the form, or 'sample' for the design settings.
				'image'   => isset( $v['image'] ) && 'sample' === $v['image'] ? 'sample' : ( isset( $v['image'] ) && wp_attachment_is_image( absint( $v['image'] ) ) ? absint( $v['image'] ) : 0 ),
			),
		);
	}
}