wp-youtube-live.php

<?php
/**
 * Plugin Name: YouTube Live
 * Plugin URI: https://github.com/macbookandrew/wp-youtube-live
 * Description: Displays the current YouTube live video from a specified channel
 * Version: 1.10.0
 * Author: Andrew Minion
 * Author URI: https://andrewrminion.com/
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

define( 'WP_YOUTUBE_LIVE_VERSION', '1.10.0' );

/**
 * Include admin.
 */
require 'inc/admin.php';

/**
 * Enqueue frontend scripts
 */
function youtube_live_scripts() {
	wp_register_script( 'wp-youtube-live', plugin_dir_url( __FILE__ ) . 'js/wp-youtube-live.min.js', array( 'jquery' ), WP_YOUTUBE_LIVE_VERSION, true );
	wp_register_style( 'wp-youtube-live', plugin_dir_url( __FILE__ ) . 'css/wp-youtube-live.css', array(), WP_YOUTUBE_LIVE_VERSION );
	wp_register_script( 'youtube-iframe-api', 'https://www.youtube.com/iframe_api', array(), null, true ); // phpcs:ignore WordPress.WP.EnqueuedResourceParameters.MissingVersion -- because it’s a third-party script that we can’t version.
}
add_action( 'wp_enqueue_scripts', 'youtube_live_scripts' );

/**
 * Create shortcode
 *
 * @param  array $atts shortcode parameters.
 * @return string HTML shortcode output
 */
function output_youtube_live( $atts ) {
	// enqueue assets.
	wp_enqueue_script( 'wp-youtube-live' );
	wp_enqueue_style( 'wp-youtube-live' );
	wp_enqueue_script( 'youtube-iframe-api' );

	// get plugin settings.
	$settings = get_option( 'youtube_live_settings' );

	// get shortcode attributes.
	$shortcode_attributes = shortcode_atts(
		array(
			'width'             => $settings['default_width'],
			'height'            => $settings['default_height'],
			'autoplay'          => $settings['autoplay'],
			'show_related'      => $settings['show_related'],
			'js_only'           => false,
			'ajaxUrl'           => admin_url( 'admin-ajax.php' ),
			'auto_refresh'      => $settings['auto_refresh'],
			'fallback_behavior' => $settings['fallback_behavior'],
			'fallback_message'  => ( array_key_exists( 'no_stream_message', $settings ) ? $settings['no_stream_message'] : $settings['fallback_message'] ),
			'no_stream_message' => null,
			'fallback_playlist' => $settings['fallback_playlist'],
			'fallback_video'    => $settings['fallback_video'],
			'refreshInterval'   => apply_filters( 'wp_youtube_live_transient_timeout', '30' ),
		),
		$atts
	);

	// handle legacy parameter.
	if ( isset( $shortcode_attributes['no_stream_message'] ) ) {
		$shortcode_attributes['fallback_message'] = esc_attr( $shortcode_attributes['no_stream_message'] );
		unset( $shortcode_attributes['no_stream_message'] );
	}

	wp_add_inline_script( 'wp-youtube-live', 'var wpYouTubeLiveSettings = ' . wp_json_encode( $shortcode_attributes ), 'before' );

	return get_youtube_live_content( $shortcode_attributes );
}
add_shortcode( 'youtube_live', 'output_youtube_live' );

/**
 * Add ajax handlers
 */
add_action( 'wp_ajax_load_youtube_live', 'get_youtube_live_content' );
add_action( 'wp_ajax_nopriv_load_youtube_live', 'get_youtube_live_content' );

/**
 * Output YouTube Live content
 *
 * @param  array $request_options array of settings.
 * @return string JSON or HTML content
 */
function get_youtube_live_content( $request_options ) {
	// fix undefined errors in ajax context.
	if ( ! is_array( $request_options ) ) {
		$request_options = array();
	}

	// load embed class.
	require_once 'inc/EmbedYoutubeLiveStreaming.php';

	// get saved options.
	$youtube_options = get_option( 'youtube_live_settings' );

	// merge request and saved options.
	$request_options = wp_parse_args( $request_options, $youtube_options );

	// set up player.
	// phpcs:disable WordPress.Security.NonceVerification.Missing -- because we have to allow unauthenticated users the ability to check for live videos, as well as handle statically-cached markup that might contain a stale nonce.
	$youtube_live                     = new EmbedYoutubeLiveStreaming( esc_attr( $youtube_options['youtube_live_channel_id'] ), esc_attr( $youtube_options['youtube_live_api_key'] ) );
	$youtube_live->subdomain          = $youtube_options['subdomain']
		? esc_attr( $youtube_options['subdomain'] )
		: 'www';
	$youtube_live->embed_width        = wp_youtube_live_is_ajax() && array_key_exists( 'width', $_POST )
		? sanitize_key( wp_unslash( $_POST['width'] ) )
		: sanitize_key( $request_options['width'] );
	$youtube_live->embed_height       = wp_youtube_live_is_ajax() && array_key_exists( 'height', $_POST )
		? sanitize_key( wp_unslash( $_POST['height'] ) )
		: sanitize_key( $request_options['height'] );
	$youtube_live->embed_autoplay     = wp_youtube_live_is_ajax() && array_key_exists( 'autoplay', $_POST )
		? sanitize_key( wp_unslash( $_POST['autoplay'] ) )
		: sanitize_key( $request_options['autoplay'] );
	$youtube_live->show_related       = wp_youtube_live_is_ajax() && array_key_exists( 'show_related', $_POST )
		? sanitize_key( wp_unslash( $_POST['show_related'] ) )
		: sanitize_key( $request_options['show_related'] );
	$youtube_live->completed_video_id = wp_youtube_live_is_ajax() && array_key_exists( 'completedVideoID', $_POST )
		? sanitize_key( wp_unslash( $_POST['completedVideoID'] ) )
		: '';
	// phpcs:enable WordPress.Security.NonceVerification.Missing

	if ( strlen( $youtube_live->completed_video_id ) > 0 ) {
		$youtube_live->isLive( true );
	}

	// start output.
	$json_data = array(
		'error' => null,
	);
	ob_start();
	if ( 'no_message' !== $youtube_options['fallback_behavior'] ) {
		echo '<div class="wp-youtube-live ' . ( $youtube_live->isLive ? 'live' : 'dead' ) . '">';
	}

	if ( $youtube_live->isLive ) {
		if ( ( array_key_exists( 'js_only', $request_options ) && 'true' !== $request_options['js_only'] ) || ( array_key_exists( 'js_only', $request_options ) && 'true' === $request_options['js_only'] && wp_youtube_live_is_ajax() ) ) {
			$is_live = true;
			// TODO: load a placeholder or nothing on initial page load?
			echo $youtube_live->embedCode(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in the method.

			/**
			 * Control visibility of the YouTube terms of service and Google Privacy Policy.
			 *
			 * @param boolean $display Whether the terms of service should display or not.
			 *
			 * @return boolean
			 */
			if ( apply_filters( 'wp_youtube_live_display_youtube_tos', true ) ) {
				echo '<p class="wp-youtube-live-terms" style="font-size: small; margin-top: 4px; margin-bottom: 8px;">See <a target="_blank" href="https://www.youtube.com/t/terms">YouTube Terms of Service</a> and <a target="blank" href="https://policies.google.com/privacy">Google Privacy Policy</a>.</p>';
			}
		}
	} else {
		$is_live = false;
		add_filter( 'oembed_result', 'wp_ytl_set_oembed_id' );
		add_filter( 'embed_defaults', 'wp_ytl_set_embed_size' );

		// set player parameters for playlist and video fallbacks.
		$player_args = array(
			'autoplay' => ( 'true' === $youtube_live->embed_autoplay ? '1' : '0' ),
			'rel'      => ( 'true' === $youtube_live->show_related ? '1' : '0' ),
		);

		if ( 'upcoming' === $request_options['fallback_behavior'] ) {
			$youtube_live->getVideoInfo( 'live', 'upcoming' );
			echo $youtube_live->embedCode(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in the method.
		} elseif ( 'completed' === $request_options['fallback_behavior'] ) {
			$youtube_live->getVideoInfo( 'live', 'completed' );
			echo $youtube_live->embedCode(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in the method.
		} elseif ( 'channel' === $request_options['fallback_behavior'] ) {
			$youtube_live->getVideoInfo( 'channel' );
			echo $youtube_live->embedCode(); // phpcs:ignore WordPress.Security.EscapeOutput.OutputNotEscaped -- escaped in the method.
		} elseif ( 'playlist' === $request_options['fallback_behavior'] ) {
			add_filter( 'oembed_result', 'wp_ytl_add_player_attributes_result', 10, 3 );
			echo wp_kses_post( wp_oembed_get( esc_attr( $youtube_options['fallback_playlist'] ), $player_args ) );
		} elseif ( 'video' === $request_options['fallback_behavior'] && isset( $youtube_options['fallback_video'] ) ) {
			add_filter( 'oembed_result', 'wp_ytl_add_player_attributes_result', 10, 3 );
			echo wp_kses_post( wp_oembed_get( esc_attr( $youtube_options['fallback_video'] ), $player_args ) );
		} elseif ( 'message' === $request_options['fallback_behavior'] && 'no_message' !== $request_options['fallback_message'] ) {
			echo wp_kses_post( apply_filters( 'wp_youtube_live_no_stream_available', $request_options['fallback_message'] ) );
		}
	}

	/**
	 * Filters the capability required to see debug output.
	 *
	 * @since 1.10.0
	 *
	 * @var string $capability The capability required.
	 *
	 * @return string
	 */
	$capability = apply_filters( 'wp_youtube_live_debug_user_capability', 'manage_options' );

	// debugging.
	if ( 'true' === $youtube_options['debugging'] && is_user_logged_in() && current_user_can( $capability ) ) {
		if ( $youtube_live->getErrorMessage() ) {
			$error_message = '<p><strong>WP YouTube Live error:</strong></p>
			<ul>';
			foreach ( $youtube_live->getAllErrors() as $error ) {
				$error_message .= '<li><strong>Domain:</strong> ' . esc_url( $error['domain'] ) . '</li>
				<li><strong>Reason:</strong> ' . esc_attr( $error['reason'] ) . '</li>
				<li><strong>Message:</strong> ' . esc_attr( $error['message'] ) . '</li>
				<li><strong>Extended help:</strong> ' . wp_kses_post( $error['extendedHelp'] ) . '</li>';
			}
			if ( 'video' === $youtube_options['fallback_behavior'] && empty( $youtube_options['fallback_video'] ) ) {
				$error_message .= '<li>Please double-check that you have set a fallback video.</li>';
			}
			$error_message     .= '</ul>';
			$json_data['error'] = $error_message;
		}

		$debugging_code = var_export( $youtube_live, true ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_var_export -- because this is only available for admins if they enable the debug option.
		echo '<!-- YouTube Live debugging: ' . PHP_EOL . wp_kses_post( $debugging_code ) . PHP_EOL . ' -->';
		$json_data['error'] .= $debugging_code;
	}

	if ( 'no_message' !== $youtube_options['fallback_behavior'] ) {
		echo '<span class="wp-youtube-live-error" style="display: none;">' . wp_kses_post( $error_message ) . '</span>
        </div>';
	}

	// return the content.
	if ( wp_youtube_live_is_ajax() ) {
		if ( isset( $_POST['requestType'] ) && sanitize_key( wp_unslash( $_POST['requestType'] ) ) !== 'refresh' || $is_live ) { // phpcs:ignore WordPress.Security.NonceVerification.Missing -- because we have to allow unauthenticated users the ability to check for live videos, as well as handle statically-cached markup that might contain a stale nonce.
			$json_data['content'] = ob_get_clean();
		} else {
			ob_clean();
		}
		$json_data['live'] = ( $youtube_live->isLive ? true : false );
		if ( property_exists( $youtube_live->objectResponse, 'fromTransientCache' ) ) {
			$json_data['fromTransientCache'] = $youtube_live->objectResponse->fromTransientCache;
		}
		echo wp_json_encode( $json_data, JSON_FORCE_OBJECT );
		wp_die();
	} else {
		return ob_get_clean();
	}
}

/**
 * Add id to oembedded iframe
 *
 * @param  string $html HTML oembed output.
 * @return string HTML oembed output
 */
function wp_ytl_set_oembed_id( $html ) {
	$html = str_replace( '<iframe', '<iframe id="wpYouTubeLive"', $html );

	return $html;
}

/**
 * Set default oembed size for video/playlist fallback behavior
 *
 * @param  array $size Default oembed sizes.
 *
 * @return array Modified oembed size
 */
function wp_ytl_set_embed_size( $size ) {
	$request_options = get_option( 'youtube_live_settings' );

	// phpcs:disable WordPress.Security.NonceVerification.Missing -- because we have to allow unauthenticated users the ability to check for live videos, as well as handle statically-cached markup that might contain a stale nonce.
	$size['width']  = ( wp_youtube_live_is_ajax() && array_key_exists( 'width', $_POST )
		? sanitize_key( wp_unslash( $_POST['width'] ) )
		: $request_options['default_width'] );
	$size['height'] = ( wp_youtube_live_is_ajax() && array_key_exists( 'height', $_POST )
		? sanitize_key( wp_unslash( $_POST['height'] ) )
		: $request_options['default_height'] );
	// phpcs:enable WordPress.Security.NonceVerification.Missing

	return $size;
}

add_action( 'wp_ajax_youtube_live_flush_cache', 'wp_ytl_flush_cache' );
/**
 * Flush transient cache.
 */
function wp_ytl_flush_cache() {
	if ( ! current_user_can( 'manage_options' ) ) {
		wp_send_json_error( array( 'error' => 'Access denied.' ), 403 );
		wp_die();
	}

	if ( delete_transient( 'wp-youtube-live-api-response' ) ) {
		wp_send_json_success( array( 'message' => 'Cleared cache.' ), 200 );
		wp_die();
	}

	wp_send_json_error( array( 'error' => 'Couldn’t clear cache.' ), 500 );
	wp_die();
}

/**
 * Check plugin and database version numbers
 */
function wp_ytl_check_version() {
	if ( WP_YOUTUBE_LIVE_VERSION !== get_option( 'youtube_live_version' ) ) {
		wp_ytl_plugin_activation();
	}
}
add_action( 'plugins_loaded', 'wp_ytl_check_version' );

/**
 * Handle database upgrades on activation/upgrade
 */
function wp_ytl_plugin_activation() {
	$request_options = get_option( 'youtube_live_settings', array() );

	// removed in v1.7.0.
	if ( array_key_exists( 'show_channel_if_dead', $request_options ) && 'true' === $request_options['show_channel_if_dead'] ) {
		$request_options['fallback_behavior'] = 'channel';
	}
	unset( $request_options['show_channel_if_dead'] );

	// updated in v1.7.0.
	if ( array_key_exists( 'fallback_video', $request_options ) && isset( $request_options['fallback_video'] ) ) {
		$request_options['fallback_behavior'] = 'video';
	}

	// added in v1.7.0.
	if ( ! array_key_exists( 'autoplay', $request_options ) ) {
		$request_options['autoplay'] = true;
	}

	// added in v1.7.0.
	if ( ! array_key_exists( 'show_related', $request_options ) ) {
		$request_options['show_related'] = false;
	}

	update_option( 'youtube_live_settings', $request_options );
	update_option( 'youtube_live_version', WP_YOUTUBE_LIVE_VERSION );
}
register_activation_hook( __FILE__, 'wp_ytl_plugin_activation' );

/**
 * Add autoplay and related parameters to oembedded videos
 *
 * @param  string $data2html HTML embed code.
 * @param  string $url       URL to be embedded.
 * @param  array  $args      extra arguments passed to wp_oembed_get function.
 * @return string HTML embed code
 */
function wp_ytl_add_player_attributes_result( $data2html, $url, $args ) {
	$player_settings = '';
	foreach ( $args as $key => $value ) {
		if ( is_null( $value ) ) {
			$value = 1;
		}
		$player_settings .= '&' . $key . '=' . $value;
	}

	$data2html = str_replace( '?feature=oembed', '?feature=oembed' . $player_settings, $data2html );

	return $data2html;
}

/**
 * Determine whether the current request is our ajax request.
 *
 * @since 1.8.0
 *
 * @return bool
 */
function wp_youtube_live_is_ajax() {
	return isset( $_POST['isAjax'] ) && (bool) sanitize_key( wp_unslash( $_POST['isAjax'] ) ); // phpcs:ignore WordPress.Security.NonceVerification.Missing -- because we have to allow unauthenticated users the ability to check for live videos, as well as handle statically-cached markup that might contain a stale nonce.
}

// TODO: add a notice about resaving settings on plugin activation
// FUTURE: add support for modestbranding URL paramater (hides YouTube logo)