wp_install( string $blog_title, string $user_name, string $user_email, bool $public, string $deprecated = '', string $user_password = '', string $language = '' )

function wp_install( $blog_title, $user_name, $user_email, $public, $deprecated = '', $user_password = '', $language = '' ) {
	if ( !empty( $deprecated ) )
		_deprecated_argument( __FUNCTION__, 'WP-2.6.0' );

	wp_check_mysql_version();
	wp_cache_flush();
	make_db_current_silent();
	populate_options();
	populate_roles();

	update_option('blogname', $blog_title);
	update_option('admin_email', $user_email);
	update_option('blog_public', $public);

	// Freshness of site - in the future, this could get more specific about actions taken, perhaps.
	update_option( 'fresh_site', 1 );

	if ( $language ) {
		update_option( 'WPLANG', $language );
	}

	$guessurl = wp_guess_url();

	update_option('siteurl', $guessurl);

	// If not a public blog, don't ping.
	if ( ! $public )
		update_option('default_pingback_flag', 0);

	/*
	 * Create default user. If the user already exists, the user tables are
	 * being shared among sites. Just set the role in that case.
	 */
	$user_id = username_exists($user_name);
	$user_password = trim($user_password);
	$email_password = false;
	if ( !$user_id && empty($user_password) ) {
		$user_password = wp_generate_password( 12, false );
		$message = __('<strong><em>Note that password</em></strong> carefully! It is a <em>random</em> password that was generated just for you.');
		$user_id = wp_create_user($user_name, $user_password, $user_email);
		update_user_option($user_id, 'default_password_nag', true, true);
		$email_password = true;
	} elseif ( ! $user_id ) {
		// Password has been provided
		$message = '<em>'.__('Your chosen password.').'</em>';
		$user_id = wp_create_user($user_name, $user_password, $user_email);
	} else {
		$message = __('User already exists. Password inherited.');
	}

	$user = new WP_User($user_id);
	$user->set_role('administrator');

	wp_install_defaults($user_id);

	wp_install_maybe_enable_pretty_permalinks();

	flush_rewrite_rules();

	wp_new_blog_notification($blog_title, $guessurl, $user_id, ($email_password ? $user_password : __('The password you chose during installation.') ) );

	wp_cache_flush();

	/**
	 * Fires after a site is fully installed.
	 *
	 * @since WP-3.9.0
	 *
	 * @param WP_User $user The site owner.
	 */
	do_action( 'wp_install', $user );

	return array('url' => $guessurl, 'user_id' => $user_id, 'password' => $user_password, 'password_message' => $message);
}