#!/bin/bash
set -e
set -o pipefail

rand64()
{
	set -- "${1:-64}"
	[ "$1" -ge 4 ] &&
	set -- "$1" "$(head -c "$(($1 * 3 / 4))" < /dev/urandom | base64)" &&
	[ "${#2}" = "$1" ] &&
	printf '%s\n' "$2"
}

rand26()
{
	set -- "${1:-32}" &&
	[ "$1" -ge 4 ] &&
	set -- "$1" "$(tr -cd a-z </dev/urandom | head -c "$1")" &&
	[ "${#2}" = "$1" ] &&
	printf '%s\n' "$2"
}

usage()
{
	cat <<END >&2
Usage:
	$0 <--fqdn>
	$0 <hostname> <db name> <username>
	$0 <-h | --help>

  With --fqdn, parameters are derived from \$(hostname --fqdn) or
  locally: $(hostname --fqdn)
END
}

case "$# $1" in
	"1 --fqdn" )
		DB_HOST=$(hostname --fqdn)
		DB_NAME=wordpress@$DB_HOST
		DB_USER=$DB_NAME
		;;
	"3 "* )
		DB_NAME=$1
		DB_USER=$2
		DB_HOST=$3
		;;
	"1 -h" | "1 --help" )
		usage
		exit 0
		;;
	* )
		usage
		exit 1
		;;
esac
for v in DB_NAME DB_USER DB_HOST
do
	[ "${!v}" ] && continue
	printf 'Error: a required environment variable is not defined: $%s\n' \
		"$v" >&2
	exit 1
done
if ! [ -v DB_PASSWORD ]
then
	DB_PASSWORD=$(rand26 32)
fi

declare -a WP_SALT_VARS=(
	AUTH_KEY
	SECURE_AUTH_KEY
	LOGGED_IN_KEY
	NONCE_KEY
	AUTH_SALT
	SECURE_AUTH_SALT
	LOGGED_IN_SALT
	NONCE_SALT
)
for v in "${WP_SALT_VARS[@]}"
do
	[ -v "$v" ] && [ -n "${!v}" ] && continue
	eval "$v=\$(rand64)" &&
	eval "[ \${#$v} -gt 16 ]" || exit 4
done

cat <<END
<?php
/**
 * The base configuration for WordPress
 *
 * The wp-config.php creation script uses this file during the installation.
 * You don't have to use the web site, you can copy this file to "wp-config.php"
 * and fill in the values.
 *
 * This file contains the following configurations:
 *
 * * Database settings
 * * Secret keys
 * * Database table prefix
 * * ABSPATH
 *
 * @link https://wordpress.org/support/article/editing-wp-config-php/
 *
 * @package WordPress
 */

// ** Database settings - You can get this info from your web host ** //
/** The name of the database for WordPress */
define( 'DB_NAME', '$DB_NAME' );

/** Database username */
define( 'DB_USER', '$DB_USER' );

/** Database password */
define( 'DB_PASSWORD', '$DB_PASSWORD' );

/** Database hostname */
define( 'DB_HOST', 'localhost' );

/** Database charset to use in creating database tables. */
define( 'DB_CHARSET', 'utf8' );

/** The database collate type. Don't change this if in doubt. */
define( 'DB_COLLATE', '' );

/**#@+
 * Authentication unique keys and salts.
 *
 * Change these to different unique phrases! You can generate these using
 * the {@link https://api.wordpress.org/secret-key/1.1/salt/ WordPress.org secret-key service}.
 *
 * You can change these at any point in time to invalidate all existing cookies.
 * This will force all users to have to log in again.
 *
 * @since 2.6.0
 */
define( 'AUTH_KEY',         '$AUTH_KEY' );
define( 'SECURE_AUTH_KEY',  '$SECURE_AUTH_KEY' );
define( 'LOGGED_IN_KEY',    '$LOGGED_IN_KEY' );
define( 'NONCE_KEY',        '$NONCE_KEY' );
define( 'AUTH_SALT',        '$AUTH_SALT' );
define( 'SECURE_AUTH_SALT', '$SECURE_AUTH_SALT' );
define( 'LOGGED_IN_SALT',   '$LOGGED_IN_SALT' );
define( 'NONCE_SALT',       '$NONCE_SALT' );

/**#@-*/

/**
 * WordPress database table prefix.
 *
 * You can have multiple installations in one database if you give each
 * a unique prefix. Only numbers, letters, and underscores please!
 */
\$table_prefix = 'wp_';

/**
 * For developers: WordPress debugging mode.
 *
 * Change this to true to enable the display of notices during development.
 * It is strongly recommended that plugin and theme developers use WP_DEBUG
 * in their development environments.
 *
 * For information on other constants that can be used for debugging,
 * visit the documentation.
 *
 * @link https://wordpress.org/support/article/debugging-in-wordpress/
 */
define( 'WP_DEBUG', false );

/* Add any custom values between this line and the "stop editing" line. */



/* That's all, stop editing! Happy publishing. */

/** Absolute path to the WordPress directory. */
if ( ! defined( 'ABSPATH' ) ) {
	define( 'ABSPATH', __DIR__ . '/' );
}

/** Sets up WordPress vars and included files. */
require_once ABSPATH . 'wp-settings.php';
END