<?php
/**
 * Youtube shortcode
 *
 * Contains shortcode + some improvements over the Core Embeds syntax (see http://codex.wordpress.org/Embeds )
 *
 * Examples:
 * [youtube https://www.youtube.com/watch?v=WVbQ-oro7FQ]
 * [youtube=http://www.youtube.com/watch?v=wq0rXGLs0YM&fs=1&hl=bg_BG&autohide=1&rel=0]
 * http://www.youtube.com/watch?v=H2Ncxw1xfck&w=320&h=240&fmt=1&rel=0&showsearch=1&hd=0
 * http://www.youtube.com/v/9FhMMmqzbD8?fs=1&hl=en_US
 * https://www.youtube.com/playlist?list=PLP7HaNDU4Cifov7C2fQM8Ij6Ew_uPHEXW
 *
 * @package Jetpack
 */

/**
 * Replaces YouTube embeds with YouTube shortcodes.
 *
 * Covers the following formats:
 * 2008-07-15:
 * <object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/bZBHZT3a-FA&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/bZBHZT3a-FA&hl=en&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" width="425" height="344"></embed></object>
 * around 2008-06-06 youtube changed their old embed code to this:
 * <object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/M1D30gS7Z8U&hl=en"></param><embed src="http://www.youtube.com/v/M1D30gS7Z8U&hl=en" type="application/x-shockwave-flash" width="425" height="344"></embed></object>
 * old style was:
 * <object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/dGY28Qbj76A&rel=0"></param><param name="wmode" value="transparent"></param><embed src="http://www.youtube.com/v/dGY28Qbj76A&rel=0" type="application/x-shockwave-flash" wmode="transparent" width="425" height="344"></embed></object>
 * 12-2010:
 * <object width="640" height="385"><param name="movie" value="http://www.youtube.com/v/3H8bnKdf654?fs=1&amp;hl=en_GB"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/3H8bnKdf654?fs=1&amp;hl=en_GB" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="385"></embed></object>
 * 01-2011:
 * <iframe title="YouTube video player" class="youtube-player" type="text/html" width="640" height="390" src="http://www.youtube.com/embed/Qq9El3ki0_g" frameborder="0" allowFullScreen></iframe>
 * <iframe class="youtube-player" type="text/html" width="640" height="385" src="http://www.youtube.com/embed/VIDEO_ID" frameborder="0"></iframe>
 *
 * @param string $content HTML content.
 * @return string The content with YouTube embeds replaced with YouTube shortcodes.
 */
function youtube_embed_to_short_code( $content ) {
	if ( ! is_string( $content ) || false === strpos( $content, 'youtube.com' ) ) {
		return $content;
	}

	// older codes.
	$regexp         = '!<object(.*?)>.*?<param\s+name=[\'"]movie[\'"]\s+value=[\'"](https?:)?//www\.youtube\.com/v/([^\'"]+)[\'"].*?>.*?</object>!i';
	$regexp_ent     = htmlspecialchars( $regexp, ENT_NOQUOTES );
	$old_regexp     = '!<embed(?:\s+\w+="[^"]*")*\s+src="https?(?:\:|&#0*58;)//www\.youtube\.com/v/([^"]+)"(?:\s+\w+="[^"]*")*\s*(?:/>|>\s*</embed>)!';
	$old_regexp_ent = str_replace( '&amp;#0*58;', '&amp;#0*58;|&#0*58;', htmlspecialchars( $old_regexp, ENT_NOQUOTES ) );

	// new code.
	$ifr_regexp     = '!<iframe((?:\s+\w+="[^"]*")*?)\s+src="(https?:)?//(?:www\.)*youtube.com/embed/([^"]+)".*?</iframe>!i';
	$ifr_regexp_ent = str_replace( '&amp;#0*58;', '&amp;#0*58;|&#0*58;', htmlspecialchars( $ifr_regexp, ENT_NOQUOTES ) );

	foreach ( compact( 'regexp', 'regexp_ent', 'old_regexp', 'old_regexp_ent', 'ifr_regexp', 'ifr_regexp_ent' ) as $reg => $regexp ) {
		if ( ! preg_match_all( $regexp, $content, $matches, PREG_SET_ORDER ) ) {
			continue;
		}

		foreach ( $matches as $match ) {
			/*
			 * Hack, but '?' should only ever appear once, and
			 * it should be for the 1st field-value pair in query string,
			 * if it is present
			 * YouTube changed their embed code.
			 * Example of how it is now:
			 * <object width="640" height="385"><param name="movie" value="http://www.youtube.com/v/aP9AaD4tgBY?fs=1&amp;hl=en_US"></param><param name="allowFullScreen" value="true"></param><param name="allowscriptaccess" value="always"></param><embed src="http://www.youtube.com/v/aP9AaD4tgBY?fs=1&amp;hl=en_US" type="application/x-shockwave-flash" allowscriptaccess="always" allowfullscreen="true" width="640" height="385"></embed></object>
			 * As shown at the start of function, previous YouTube didn't '?'
			 * the 1st field-value pair.
			 */
			if ( in_array( $reg, array( 'ifr_regexp', 'ifr_regexp_ent', 'regexp', 'regexp_ent' ), true ) ) {
				$params = $match[1];

				if ( in_array( $reg, array( 'ifr_regexp_ent', 'regexp_ent' ), true ) ) {
					$params = html_entity_decode( $params );
				}

				$params = wp_kses_hair( $params, array( 'http' ) );

				$width  = isset( $params['width'] ) ? (int) $params['width']['value'] : 0;
				$height = isset( $params['height'] ) ? (int) $params['height']['value'] : 0;
				$wh     = '';

				if ( $width && $height ) {
					$wh = "&w=$width&h=$height";
				}

				$url = esc_url_raw( "https://www.youtube.com/watch?v={$match[3]}{$wh}" );
			} else {
				$match[1] = str_replace( '?', '&', $match[1] );

				$url = esc_url_raw( 'https://www.youtube.com/watch?v=' . html_entity_decode( $match[1] ) );
			}

			$content = str_replace( $match[0], "[youtube $url]", $content );

			/**
			 * Fires before the YouTube embed is transformed into a shortcode.
			 *
			 * @module shortcodes
			 *
			 * @since 1.2.0
			 *
			 * @param string youtube Shortcode name.
			 * @param string $url YouTube video URL.
			 */
			do_action( 'jetpack_embed_to_shortcode', 'youtube', $url );
		}
	}

	return $content;
}
add_filter( 'pre_kses', 'youtube_embed_to_short_code' );

/**
 * Replaces plain-text links to YouTube videos with YouTube embeds.
 *
 * @param string $content HTML content.
 *
 * @return string The content with embeds instead of URLs
 */
function youtube_link( $content ) {
	return jetpack_preg_replace_callback_outside_tags( '!(?:\n|\A)https?://(?:www\.)?(?:youtube.com/(?:v/|playlist|watch[/\#?])|youtu\.be/)[^\s]+?(?:\n|\Z)!i', 'youtube_link_callback', $content, 'youtube.com/' );
}

/**
 * Callback function for the regex that replaces YouTube URLs with
 * YouTube embeds.
 *
 * @param array $matches An array containing a YouTube URL.
 */
function youtube_link_callback( $matches ) {
	return "\n" . youtube_id( $matches[0] ) . "\n";
}

/**
 * Normalizes a YouTube URL to include a v= parameter and a query string free of encoded ampersands.
 *
 * @param string $url
 * @return string The normalized URL
 */
if ( ! function_exists( 'youtube_sanitize_url' ) ) :
	/**
	 * Clean up Youtube URL to match a single format.
	 *
	 * @param string $url Youtube URL.
	 */
	function youtube_sanitize_url( $url ) {
		$url = trim( $url, ' "' );
		$url = trim( $url );
		$url = str_replace( array( 'youtu.be/', '/v/', '#!v=', '&amp;', '&#038;', 'playlist' ), array( 'youtu.be/?v=', '/?v=', '?v=', '&', '&', 'videoseries' ), $url );

		// Replace any extra question marks with ampersands - the result of a URL like "http://www.youtube.com/v/9FhMMmqzbD8?fs=1&hl=en_US" being passed in.
		$query_string_start = strpos( $url, '?' );

		if ( false !== $query_string_start ) {
			$url = substr( $url, 0, $query_string_start + 1 ) . str_replace( '?', '&', substr( $url, $query_string_start + 1 ) );
		}

		return $url;
	}
endif;

/**
 * Converts a YouTube URL into an embedded YouTube video.
 *
 * URL can be:
 *    http://www.youtube.com/embed/videoseries?list=PL94269DA08231042B&amp;hl=en_US
 *    http://www.youtube.com/watch#!v=H2Ncxw1xfck
 *    http://www.youtube.com/watch?v=H2Ncxw1xfck
 *    http://www.youtube.com/watch?v=H2Ncxw1xfck&w=320&h=240&fmt=1&rel=0&showsearch=1&hd=0
 *    http://www.youtube.com/v/jF-kELmmvgA
 *    http://www.youtube.com/v/9FhMMmqzbD8?fs=1&hl=en_US
 *    http://youtu.be/Rrohlqeir5E
 *
 * @param string $url Youtube URL.
 */
function youtube_id( $url ) {
	$id = jetpack_get_youtube_id( $url );

	if ( ! $id ) {
		return '<!--YouTube Error: bad URL entered-->';
	}

	$url = youtube_sanitize_url( $url );
	$url = wp_parse_url( $url );

	$qargs = array();
	if ( ! empty( $url['query'] ) ) {
		wp_parse_str( $url['query'], $qargs );
	} else {
		return false;
	}

	$fargs = array();
	if ( ! empty( $url['fragment'] ) ) {
		wp_parse_str( $url['fragment'], $fargs );
	}

	$qargs = array_merge( $fargs, $qargs );

	// calculate the width and height, taking content_width into consideration.
	global $content_width;

	$input_w = ( isset( $qargs['w'] ) && intval( $qargs['w'] ) ) ? intval( $qargs['w'] ) : 0;
	$input_h = ( isset( $qargs['h'] ) && intval( $qargs['h'] ) ) ? intval( $qargs['h'] ) : 0;

	// If we have $content_width, use it.
	if ( ! empty( $content_width ) ) {
		$default_width = $content_width;
	} else {
		// Otherwise get default width from the old, now deprecated embed_size_w option.
		$default_width = get_option( 'embed_size_w' );
	}

	// If we don't know those 2 values use a hardcoded width.
	if ( empty( $default_width ) ) {
		$default_width = 640;
	}

	if ( $input_w > 0 && $input_h > 0 ) {
		$w = $input_w;
		$h = $input_h;
	} elseif ( 0 === $input_w && 0 === $input_h ) {
		if ( isset( $qargs['fmt'] ) && intval( $qargs['fmt'] ) ) {
			$w = ( ! empty( $content_width ) ? min( $content_width, 480 ) : 480 );
		} else {
			$w = ( ! empty( $content_width ) ? min( $content_width, $default_width ) : $default_width );
			$h = ceil( ( $w / 16 ) * 9 );
		}
	} elseif ( $input_w > 0 ) {
		$w = $input_w;
		$h = ceil( ( $w / 16 ) * 9 );
	} else {
		if ( isset( $qargs['fmt'] ) && intval( $qargs['fmt'] ) ) {
			$w = ( ! empty( $content_width ) ? min( $content_width, 480 ) : 480 );
		} else {
			$w = ( ! empty( $content_width ) ? min( $content_width, $default_width ) : $default_width );
			$h = $input_h;
		}
	}

	/**
	 * Filter the YouTube player width.
	 *
	 * @module shortcodes
	 *
	 * @since 1.1.0
	 *
	 * @param int $w Width of the YouTube player in pixels.
	 */
	$w = (int) apply_filters( 'youtube_width', $w );

	/**
	 * Filter the YouTube player height.
	 *
	 * @module shortcodes
	 *
	 * @since 1.1.0
	 *
	 * @param int $h Height of the YouTube player in pixels.
	 */
	$h = (int) apply_filters( 'youtube_height', $h );

	$rel    = ( isset( $qargs['rel'] ) && '0' === $qargs['rel'] ) ? 0 : 1;
	$search = ( isset( $qargs['showsearch'] ) && '1' === $qargs['showsearch'] ) ? 1 : 0;
	$info   = ( isset( $qargs['showinfo'] ) && '0' === $qargs['showinfo'] ) ? 0 : 1;
	$iv     = ( isset( $qargs['iv_load_policy'] ) && '3' === $qargs['iv_load_policy'] ) ? 3 : 1;

	$fmt = ( isset( $qargs['fmt'] ) && intval( $qargs['fmt'] ) ) ? '&fmt=' . (int) $qargs['fmt'] : '';

	if ( ! isset( $qargs['autohide'] ) || ( $qargs['autohide'] < 0 || 2 < $qargs['autohide'] ) ) {
		$autohide = '&autohide=2';
	} else {
		$autohide = '&autohide=' . absint( $qargs['autohide'] );
	}

	$start = 0;
	if ( isset( $qargs['start'] ) ) {
		$start = intval( $qargs['start'] );
	} elseif ( isset( $qargs['t'] ) ) {
		$time_pieces = preg_split( '/(?<=\D)(?=\d+)/', $qargs['t'] );

		foreach ( $time_pieces as $time_piece ) {
			$int = (int) $time_piece;
			switch ( substr( $time_piece, -1 ) ) {
				case 'h':
					$start += $int * 3600;
					break;
				case 'm':
					$start += $int * 60;
					break;
				case 's':
					$start += $int;
					break;
			}
		}
	}

	$start = $start ? '&start=' . $start : '';
	$end   = ( isset( $qargs['end'] ) && intval( $qargs['end'] ) ) ? '&end=' . (int) $qargs['end'] : '';
	$hd    = ( isset( $qargs['hd'] ) && intval( $qargs['hd'] ) ) ? '&hd=' . (int) $qargs['hd'] : '';

	$vq = ( isset( $qargs['vq'] ) && in_array( $qargs['vq'], array( 'hd720', 'hd1080' ), true ) ) ? '&vq=' . $qargs['vq'] : '';

	$cc      = ( isset( $qargs['cc_load_policy'] ) ) ? '&cc_load_policy=1' : '';
	$cc_lang = ( isset( $qargs['cc_lang_pref'] ) ) ? '&cc_lang_pref=' . preg_replace( '/[^_a-z0-9-]/i', '', $qargs['cc_lang_pref'] ) : '';

	$wmode = ( isset( $qargs['wmode'] ) && in_array( strtolower( $qargs['wmode'] ), array( 'opaque', 'window', 'transparent' ), true ) ) ? $qargs['wmode'] : 'transparent';

	$theme = ( isset( $qargs['theme'] ) && in_array( strtolower( $qargs['theme'] ), array( 'dark', 'light' ), true ) ) ? '&theme=' . $qargs['theme'] : '';

	$autoplay = '';
	/**
	 * Allow YouTube videos to start playing automatically.
	 *
	 * @module shortcodes
	 *
	 * @since 2.2.2
	 *
	 * @param bool false Enable autoplay for YouTube videos.
	 */
	if ( apply_filters( 'jetpack_youtube_allow_autoplay', false ) && isset( $qargs['autoplay'] ) ) {
		$autoplay = '&autoplay=' . (int) $qargs['autoplay'];
	}

	if (
		( isset( $url['path'] ) && '/videoseries' === $url['path'] )
		|| isset( $qargs['list'] )
	) {
		$html = "<iframe class='youtube-player' type='text/html' width='$w' height='$h' src='" . esc_url( "https://www.youtube.com/embed/videoseries?list=$id&hl=en_US" ) . "' allowfullscreen='true' style='border:0;'></iframe>";
	} else {
		$html = "<iframe class='youtube-player' type='text/html' width='$w' height='$h' src='" . esc_url( "https://www.youtube.com/embed/$id?version=3&rel=$rel&fs=1$fmt$autohide&showsearch=$search&showinfo=$info&iv_load_policy=$iv$start$end$hd&wmode=$wmode$theme$autoplay$vq{$cc}{$cc_lang}" ) . "' allowfullscreen='true' style='border:0;'></iframe>";
	}

	// Let's do some alignment wonder in a span, unless we're producing a feed.
	if ( ! is_feed() ) {
		$alignmentcss = 'text-align:center;';
		if ( isset( $qargs['align'] ) ) {
			switch ( $qargs['align'] ) {
				case 'left':
					$alignmentcss = "float:left; width:{$w}px; height:{$h}px; margin-right:10px; margin-bottom: 10px;";
					break;
				case 'right':
					$alignmentcss = "float:right; width:{$w}px; height:{$h}px; margin-left:10px; margin-bottom: 10px;";
					break;
			}
		}

		$html = sprintf(
			'<span class="embed-youtube" style="%s display: block;">%s</span>',
			esc_attr( $alignmentcss ),
			$html
		);

	}

	/**
	 * Filter the YouTube video HTML output.
	 *
	 * @module shortcodes
	 *
	 * @since 1.2.3
	 *
	 * @param string $html YouTube video HTML output.
	 */
	$html = apply_filters( 'video_embed_html', $html );

	return $html;
}

/**
 * Display the Youtube shortcode.
 *
 * @param array $atts Shortcode attributes.
 */
function youtube_shortcode( $atts ) {
	return youtube_id( ( isset( $atts[0] ) ) ? ltrim( $atts[0], '=' ) : shortcode_new_to_old_params( $atts ) );
}
add_shortcode( 'youtube', 'youtube_shortcode' );

/**
 * For bare URLs on their own line of the form
 * http://www.youtube.com/v/9FhMMmqzbD8?fs=1&hl=en_US
 *
 * @param array $matches Regex partial matches against the URL passed.
 * @param array $attr    Attributes received in embed response.
 * @param array $url     Requested URL to be embedded.
 */
function wpcom_youtube_embed_crazy_url( $matches, $attr, $url ) {
	return youtube_id( $url );
}

/**
 * Add a new handler to automatically transform custom Youtube URLs (like playlists) into embeds.
 */
function wpcom_youtube_embed_crazy_url_init() {
	wp_embed_register_handler( 'wpcom_youtube_embed_crazy_url', '#https?://(?:www\.)?(?:youtube.com/(?:v/|playlist|watch[/\#?])|youtu\.be/).*#i', 'wpcom_youtube_embed_crazy_url' );
}
add_action( 'init', 'wpcom_youtube_embed_crazy_url_init' );

/**
 * Allow oEmbeds in Jetpack's Comment form.
 *
 * @module shortcodes
 *
 * @since 2.8.0
 *
 * @param int get_option('embed_autourls') Option to automatically embed all plain text URLs.
 */
if ( ! is_admin() && apply_filters( 'jetpack_comments_allow_oembed', true ) ) {
	/*
	 * We attach wp_kses_post to comment_text in default-filters.php with priority of 10 anyway,
	 * so the iframe gets filtered out.
	 * Higher priority because we need it before auto-link and autop get to it.
	 */
	add_filter( 'comment_text', 'youtube_link', 1 );
}

/**
 * Core changes to do_shortcode (https://core.trac.wordpress.org/changeset/34747) broke "improper" shortcodes
 * with the format [shortcode=http://url.com].
 *
 * This removes the "=" from the shortcode so it can be parsed.
 *
 * @see https://github.com/Automattic/jetpack/issues/3121
 *
 * @param string $content HTML content.
 */
function jetpack_fix_youtube_shortcode_display_filter( $content ) {
	if ( strpos( $content, '[youtube=' ) !== false ) {
		$content = preg_replace( '@\[youtube=(.*?)\]@', '[youtube $1]', $content );
	}

	return $content;
}
add_filter( 'the_content', 'jetpack_fix_youtube_shortcode_display_filter', 7 );
