Social sharing with Pinterest thumbnail

functions.php

// Social sharing

function social_sharing_buttons($content) {
	global $post;
	if(is_singular() || is_home()){

		// Get current page URL
		$crunchifyURL = urlencode(get_permalink());

		// Get current page title
		$crunchifyTitle = str_replace( ' ', '%20', get_the_title());

		// Get Post Thumbnail for pinterest
		$crunchifyThumbnail = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), 'full' );

		// Sharing URL
		$facebookURL = 'https://www.facebook.com/sharer/sharer.php?u='.$crunchifyURL;
		$googleURL = 'https://plus.google.com/share?url='.$crunchifyURL;

		// Pinterest
		$pinterestURL = 'https://pinterest.com/pin/create/button/?url='.$crunchifyURL.'&media='.$crunchifyThumbnail[0].'&description='.$crunchifyTitle;

		// Add sharing button at the end of page/page content
		$content .= '<!-- Social sharing -->';
		$content .= '<div class="social-block">';
		$content .= '<a class="share-facebook" href="'.$facebookURL.'" target="_blank">Facebook</a>';
		$content .= '<a class="share-pinterest" href="'.$pinterestURL.'" data-pin-custom="true" target="_blank">Pin It</a>';
		$content .= '</div>';

		return $content;
	}else{
		// if not a post/page then don't include sharing button
		return $content;
	}
};
add_filter( 'the_content', 'social_sharing_buttons');