<?php



add_action('wp_head','seo_head_meta',0);

// 将关键词和描述输出在wp_head区域

function seo_head_meta(){

    seo_head_meta_keywords();

    seo_head_meta_description();

}

// 网页关键字描述

function seo_head_meta_keywords(){

    if(is_paged()) // 为了避免翻页带来的问题，把翻页以后的给屏蔽掉

    {

        return;

    }



    $keywords = '';

	$blog_name = get_bloginfo('name');

	$blog_description = get_bloginfo('description');



    if(is_home() || is_front_page())

    {

        $keywords = seo_get('site_keywords');

	    if($keywords)

	    {

		    $partten = array(

			    '{blog_name}',

			    '{blog_description}'

		    );

		    $res = array(

			    $blog_name,

			    $blog_description

		    );

		    $keywords = str_replace($partten,$res,$keywords);

	    }

    }

    elseif(is_category())

    {

	    global $cat;

	    $cat_name = single_cat_title('',false);

	    $cat_parents = seo_get_category_parents($cat);

	    $keywords = seo_get_term_meta($cat,'seo_keywords');

	    if($keywords) {

		    $partten = array(

			    '{blog_name}',

			    '{blog_description}',

			    '{title}',

			    '{parents}'

		    );

		    $res = array(

			    $blog_name,

			    $blog_description,

			    $cat_name,

			    $cat_parents

		    );

		    $keywords = str_replace($partten,$res,$keywords);

	    }

    }

    elseif(is_tag())

    {

        global $wp_query;

        $tag_id = $wp_query->queried_object->term_id;

	    $tag_name = $wp_query->queried_object->name;

        $keywords = seo_get_term_meta($tag_id,'seo_keywords');

	    if($keywords) {

		    $partten = array(

			    '{blog_name}',

			    '{blog_description}',

			    '{title}'

		    );

		    $res = array(

			    $blog_name,

			    $blog_description,

			    $tag_name

		    );

		    $keywords = str_replace($partten,$res,$keywords);

	    }

    }

    elseif(is_single())

    {

        global $post;

	    $post_id = $post->ID;

	    $post_title = trim($post->post_title);

	    $post_time = $post->post_date;

        $post_cats = strip_tags(get_the_category_list( ',', 'multiple', $post_id ));

        $post_tags = strip_tags(get_the_tag_list('',',',''));

        $post_meta = seo_get_post_meta($post_id, '_seo_keywords');

        $keywords = $post_meta ? $post_meta : $post_tags.($post_tags ? ',' : '').$post_cats;

	    if($keywords) {

		    $partten = array(

			    '{blog_name}',

			    '{blog_description}',

			    '{title}',

			    '{time}',

			    '{categories}',

			    '{tags}'

		    );

		    $res = array(

			    $blog_name,

			    $blog_description,

			    $post_title,

			    $post_time,

			    $post_cats,

			    $post_tags

		    );

		    $keywords = str_replace($partten,$res,$keywords);

	    }

    }

    elseif(is_singular())

    {

        global $post;

	    $post_title = trim($post->post_title);

        $keywords = seo_get_post_meta($post->ID, '_seo_keywords');

	    if($keywords) {

		    $partten = array(

			    '{blog_name}',

			    '{blog_description}',

			    '{title}'

		    );

		    $res = array(

			    $blog_name,

			    $blog_description,

			    $post_title

		    );

		    $keywords = str_replace($partten,$res,$keywords);

	    }

    }



    $keywords = seo_clear_code($keywords);

    $keywords = strip_tags($keywords);

    $keywords = trim($keywords);



    if($keywords)

    {

        echo '<meta name="keywords" content="'.$keywords.'" />'."\n";

    }

}

// 网页描述

function seo_head_meta_description(){

    if(is_paged())

    {

        return;

    }



    $description = '';

	$blog_name = get_bloginfo('name');

	$blog_description = get_bloginfo('description');



    if(is_home() || is_front_page())

    {

        $description = seo_get('site_description');

	    if($description)

	    {

		    $partten = array(

			    '{blog_name}',

			    '{blog_description}'

		    );

		    $res = array(

			    $blog_name,

			    $blog_description

		    );

		    $description = str_replace($partten,$res,$description);

	    }

    }

    elseif(is_category())

    {

		global $cat;

		$description = seo_get_term_meta($cat,'seo_description');

		if (!$description || trim($description) == '') {

			$description = category_description();

		}

    }

    elseif(is_tag())

    {

		global $wp_query;

		$tag_id = $wp_query->queried_object->term_id;

		$description = seo_get_term_meta($tag_id,'seo_description');

		if (!$description || trim($description) == '') {

			$description = tag_description();

		}

    }

    elseif(is_single())

    {

        global $post;

        $post_id = $post->ID;

        $post_meta = seo_get_post_meta($post_id, '_seo_description');

        $post_excpert = $post->post_excerpt;

        $post_content = seo_strimwidth(strip_tags($post->post_content),0,300,'...');



        $description = $post_meta ? $post_meta : ($post_excpert ? $post_excpert : $post_content);

    }

    elseif(is_singular()){

        global $post;

        $description = seo_get_post_meta($post->ID, '_seo_description');

    }



    $description = seo_clear_code($description);

    $description = strip_tags($description);

    $description = trim($description);



    if($description)

    {

        echo '<meta name="description" content="'.$description.'" />'."\n";

    }

}