WordPress redirect。

.php

<?php
function vasimpleredirect_redirect() {
	global $post, $pagenow;

	if ( is_admin() || is_user_logged_in() || 'wp-login.php' === $pagenow ) {
		return;
	}

	$front_id      = get_option( 'page_on_front' );
	$posts_id      = get_option( 'page_for_posts' );
	$redirect_url  = untrailingslashit( 'https://www.visualive.jp' );
	$redirect_path = untrailingslashit( '/blog/archives' );
	$redirect_name = '%post_id%';

	if ( is_front_page() && ! is_home() ) {
		$post_id = $front_id;
	} elseif ( is_home() && ! is_front_page() ) {
		$post_id = $posts_id;
	} elseif ( false !== get_the_ID() ) {
		$post_id = get_the_ID();
	} else {
		$post_id = $post->ID;
	}

	$_post    = get_post( $post_id );
	$redirect = trailingslashit( $redirect_url ) . trailingslashit( $redirect_path ) . trailingslashit( $redirect_name );
	$redirect = str_replace( '%post_id%', $_post->ID, $redirect );
	$redirect = str_replace( '%post_name%', $_post->post_name, $redirect );

	if ( ( is_front_page() && ! is_home() ) || ( is_front_page() && is_home() ) ) {
		wp_redirect( trailingslashit( $redirect_url ), 301 );
	} elseif ( is_home() && ! is_front_page() ) {
		wp_redirect( $redirect_url . trailingslashit( '/blog' ), 301 );
	} elseif ( is_single() ) {
		wp_redirect( $redirect, 301 );
	}
}
add_action( 'template_redirect', 'vasimpleredirect_redirect', - 1 );