<meta name="twitter:site" content="@cyokodog" />
<meta name="twitter:card" content="summary" />

<?php
class WpOGP {
 
    private $defaults = array(
        'fb:admins' => '',
        'twitter:card' => 'summary',    // 【Twitter カード用に追加】
        'twitter:site' => '',           // 【Twitter カード用に追加】
        'og:locale' => 'ja_JP',
        'og:site_name' => '',
        'og:image' => '',
        'og:type' => 'blog',
        'og:description' => '',
        'og:title' => '',
        'og:url' => '',
        'defaultImage' => '',
        'descriptionSize' => 100
    );
 
    private $params;
 
    function extend($a, $b) {
        $r = array();
        foreach($a as $k=>$v) {
            $r[$k] = $v;
        }
        foreach($b as $k=>$v) {
            $r[$k] = $v;
        }
        return $r;
    }
 
    function __construct($args) {
        global $post;
        $args = $this->extend($this->defaults, $args);
        //サイト情報を設定
        $args['og:site_name'] = get_bloginfo('name');
        $args['og:description'] = get_bloginfo('description');
        $args['og:title'] = get_bloginfo('name');
        $args['og:url'] = get_bloginfo('url');
        //個別ページの場合、個別の記事情報を設定
        if (is_singular()){
            $args['og:description'] = mb_substr(
                strip_tags($post->post_excerpt ? $post->post_excerpt : $post->post_content),
                0,
                $args['descriptionSize']
            );
            $args['og:title'] = $post->post_title;
            $args['og:url'] = get_permalink($post->ID);
        }
        //表示画像をカスタムフィールド、アイキャッチ、本文画像の優先順位で決定
        $args['og:image'] = $args['defaultImage'];
        if (is_singular()){
            $eyecatch = post_custom('eyecatch');
            if($eyecatch != ''){
                $args['og:image'] = $eyecatch;
            }
            else
            if (has_post_thumbnail()){
                $image = wp_get_attachment_image_src(
                    get_post_thumbnail_id(),
                    'full'
                );
                $args['og:image'] = $image[0];
            }
            else
            if ( preg_match( '/<img.*?src=(["\'])(.+?)\1.*?>/i',
                    $post->post_content, $matchText ) && !is_archive()) {
                $args['og:image'] = $matchText[2];
            }
        }
        //ピカサの画像の場合は画像サイズを800pxに設定
        if(preg_match( '/\.googleusercontent\./i', $args['og:image'])){
            $args['og:image'] = str_replace('/s144/', '/s800/', $args['og:image']);
            $args['og:image'] = str_replace('/s288/', '/s800/', $args['og:image']);
        }
        $this->params = $args;
    }
 
    function getMeta($args=array()){
        global $post;
        $args = $this->extend($this->params, $args);
        $args['og:site_name'] = esc_attr($args['og:site_name']);
        $args['og:description'] = esc_attr($args['og:description']);
        $args['og:title'] = esc_attr($args['og:title']);
        $args['og:url'] = esc_url($args['og:url']);
        $args['og:image'] = esc_url($args['og:image']);
        //マークアップを返す
        ob_start();
        foreach($args as $key => $value){
            if(strpos($key, ':') && $value != ''){
                printf('<meta name="%1$s" content="%2$s" />'."\n", $key, $value);
            }
        }
        return ob_get_clean();
    }
}
?>

function WpOGP_put_meta(){
    if (!is_admin()) {
        require_once('WpOGP.php');
        $ogp = new WpOGP(array(
            'fb:admins' => '100001731701651',
            'twitter:site' => '@cyokodog',  // 【Twitter カード用に追加】
            'defaultImage' => 'http://lh4.googleusercontent.com/JXurra1m9PY/s400/IMG_1977.png'
        ));
        echo $ogp->getMeta();
    }
}
add_action('wp_head', 'WpOGP_put_meta');