<?php

/**

 * SVG icons related functions and filters

 *

 * @package WordPress

 * @subpackage Twenty_Seventeen

 * @since 1.0

 */

/**

 * Add SVG definitions to the footer.

 */

function twentyseventeen_include_svg_icons() {

	// Define SVG sprite file.

	$svg_icons = get_parent_theme_file_path( '/assets/images/svg-icons.svg' );

	// If it exists, include it.

	if ( file_exists( $svg_icons ) ) {

		require_once( $svg_icons );

	}

}

add_action( 'wp_footer', 'twentyseventeen_include_svg_icons', 9999 );

/**

 * Return SVG markup.

 *

 * @param array $args {

 *     Parameters needed to display an SVG.

 *

 *     @type string $icon  Required SVG icon filename.

 *     @type string $title Optional SVG title.

 *     @type string $desc  Optional SVG description.

 * }

 * @return string SVG markup.

 */

function twentyseventeen_get_svg( $args = array() ) {

	// Make sure $args are an array.

	if ( empty( $args ) ) {

		return __( 'Please define default parameters in the form of an array.', 'twentyseventeen' );

	}

	// Define an icon.

	if ( false === array_key_exists( 'icon', $args ) ) {

		return __( 'Please define an SVG icon filename.', 'twentyseventeen' );

	}

	// Set defaults.

	$defaults = array(

		'icon'        => '',

		'title'       => '',

		'desc'        => '',

		'fallback'    => false,

	);

	// Parse args.

	$args = wp_parse_args( $args, $defaults );

	// Set aria hidden.

	$aria_hidden = ' aria-hidden="true"';

	// Set ARIA.

	$aria_labelledby = '';

	/*

	 * Twenty Seventeen doesn't use the SVG title or description attributes; non-decorative icons are described with .screen-reader-text.

	 *

	 * However, child themes can use the title and description to add information to non-decorative SVG icons to improve accessibility.

	 *

	 * Example 1 with title: <?php echo twentyseventeen_get_svg( array( 'icon' => 'arrow-right', 'title' => __( 'This is the title', 'textdomain' ) ) ); ?>

	 *

	 * Example 2 with title and description: <?php echo twentyseventeen_get_svg( array( 'icon' => 'arrow-right', 'title' => __( 'This is the title', 'textdomain' ), 'desc' => __( 'This is the description', 'textdomain' ) ) ); ?>

	 *

	 * See https://www.paciellogroup.com/blog/2013/12/using-aria-enhance-svg-accessibility/.

	 */

	if ( $args['title'] ) {

		$aria_hidden     = '';

		$unique_id       = uniqid();

		$aria_labelledby = ' aria-labelledby="title-' . $unique_id . '"';

		if ( $args['desc'] ) {

			$aria_labelledby = ' aria-labelledby="title-' . $unique_id . ' desc-' . $unique_id . '"';

		}

	}

	// Begin SVG markup.

	$svg = '<svg class="icon icon-' . esc_attr( $args['icon'] ) . '"' . $aria_hidden . $aria_labelledby . ' role="img">';

	// Display the title.

	if ( $args['title'] ) {

		$svg .= '<title id="title-' . $unique_id . '">' . esc_html( $args['title'] ) . '</title>';

		// Display the desc only if the title is already set.

		if ( $args['desc'] ) {

			$svg .= '<desc id="desc-' . $unique_id . '">' . esc_html( $args['desc'] ) . '</desc>';

		}

	}

	/*

	 * Display the icon.

	 *

	 * The whitespace around `<use>` is intentional - it is a work around to a keyboard navigation bug in Safari 10.

	 *

	 * See https://core.trac.wordpress.org/ticket/38387.

	 */

	$svg .= ' <use href="#icon-' . esc_html( $args['icon'] ) . '" xlink:href="#icon-' . esc_html( $args['icon'] ) . '"></use> ';

	// Add some markup to use as a fallback for browsers that do not support SVGs.

	if ( $args['fallback'] ) {

		$svg .= '<span class="svg-fallback icon-' . esc_attr( $args['icon'] ) . '"></span>';

	}

	$svg .= '</svg>';

	return $svg;

}

/**

 * Display SVG icons in social links menu.

 *

 * @param  string  $item_output The menu item output.

 * @param  WP_Post $item        Menu item object.

 * @param  int     $depth       Depth of the menu.

 * @param  array   $args        wp_nav_menu() arguments.

 * @return string  $item_output The menu item output with social icon.

 */

function twentyseventeen_nav_menu_social_icons( $item_output, $item, $depth, $args ) {

	// Get supported social icons.

	$social_icons = twentyseventeen_social_links_icons();

	// Change SVG icon inside social links menu if there is supported URL.

	if ( 'social' === $args->theme_location ) {

		foreach ( $social_icons as $attr => $value ) {

			if ( false !== strpos( $item_output, $attr ) ) {

				$item_output = str_replace( $args->link_after, '</span>' . twentyseventeen_get_svg( array( 'icon' => esc_attr( $value ) ) ), $item_output );

			}

		}

	}

	return $item_output;

}

add_filter( 'walker_nav_menu_start_el', 'twentyseventeen_nav_menu_social_icons', 10, 4 );

/**

 * Add dropdown icon if menu item has children.

 *

 * @param  string  $title The menu item's title.

 * @param  WP_Post $item  The current menu item.

 * @param  array   $args  An array of wp_nav_menu() arguments.

 * @param  int     $depth Depth of menu item. Used for padding.

 * @return string  $title The menu item's title with dropdown icon.

 */

function twentyseventeen_dropdown_icon_to_menu_link( $title, $item, $args, $depth ) {

	if ( 'top' === $args->theme_location ) {

		foreach ( $item->classes as $value ) {

			if ( 'menu-item-has-children' === $value || 'page_item_has_children' === $value ) {

				$title = $title . twentyseventeen_get_svg( array( 'icon' => 'angle-down' ) );

			}

		}

	}

	return $title;

}

add_filter( 'nav_menu_item_title', 'twentyseventeen_dropdown_icon_to_menu_link', 10, 4 );

/**

 * Returns an array of supported social links (URL and icon name).

 *

 * @return array $social_links_icons

 */

function twentyseventeen_social_links_icons() {

	// Supported social links icons.

	$social_links_icons = array(

		'behance.net'     => 'behance',

		'codepen.io'      => 'codepen',

		'deviantart.com'  => 'deviantart',

		'digg.com'        => 'digg',

		'docker.com'      => 'dockerhub',

		'dribbble.com'    => 'dribbble',

		'dropbox.com'     => 'dropbox',

		'facebook.com'    => 'facebook',

		'flickr.com'      => 'flickr',

		'foursquare.com'  => 'foursquare',

		'plus.google.com' => 'google-plus',

		'github.com'      => 'github',

		'instagram.com'   => 'instagram',

		'linkedin.com'    => 'linkedin',

		'mailto:'         => 'envelope-o',

		'medium.com'      => 'medium',

		'pinterest.com'   => 'pinterest-p',

		'pscp.tv'         => 'periscope',

		'getpocket.com'   => 'get-pocket',

		'reddit.com'      => 'reddit-alien',

		'skype.com'       => 'skype',

		'skype:'          => 'skype',

		'slideshare.net'  => 'slideshare',

		'snapchat.com'    => 'snapchat-ghost',

		'soundcloud.com'  => 'soundcloud',

		'spotify.com'     => 'spotify',

		'stumbleupon.com' => 'stumbleupon',

		'tumblr.com'      => 'tumblr',

		'twitch.tv'       => 'twitch',

		'twitter.com'     => 'twitter',

		'vimeo.com'       => 'vimeo',

		'vine.co'         => 'vine',

		'vk.com'          => 'vk',

		'wordpress.org'   => 'wordpress',

		'wordpress.com'   => 'wordpress',

		'yelp.com'        => 'yelp',

		'youtube.com'     => 'youtube',

	);

	/**

	 * Filter Twenty Seventeen social links icons.

	 *

	 * @since Twenty Seventeen 1.0

	 *

	 * @param array $social_links_icons Array of social links icons.

	 */

	return apply_filters( 'twentyseventeen_social_links_icons', $social_links_icons );

}