<?php
/**
 * Part of the Joomla Framework String Package
 *
 * @copyright  Copyright (C) 2005 - 2021 Open Source Matters, Inc. All rights reserved.
 * @license    GNU General Public License version 2 or later; see LICENSE
 */

namespace Joomla\String;

/**
 * Joomla Framework String Normalise Class
 *
 * @since  1.0
 */
abstract class Normalise
{
	/**
	 * Method to convert a string from camel case.
	 *
	 * This method offers two modes. Grouped allows for splitting on groups of uppercase characters as follows:
	 *
	 * "FooBarABCDef"            becomes  array("Foo", "Bar", "ABC", "Def")
	 * "JFooBar"                 becomes  array("J", "Foo", "Bar")
	 * "J001FooBar002"           becomes  array("J001", "Foo", "Bar002")
	 * "abcDef"                  becomes  array("abc", "Def")
	 * "abc_defGhi_Jkl"          becomes  array("abc_def", "Ghi_Jkl")
	 * "ThisIsA_NASAAstronaut"   becomes  array("This", "Is", "A_NASA", "Astronaut"))
	 * "JohnFitzgerald_Kennedy"  becomes  array("John", "Fitzgerald_Kennedy"))
	 *
	 * Non-grouped will split strings at each uppercase character.
	 *
	 * @param   string   $input    The string input (ASCII only).
	 * @param   boolean  $grouped  Optionally allows splitting on groups of uppercase characters.
	 *
	 * @return  array|string  The space separated string, as an array if grouped.
	 *
	 * @since   1.0
	 */
	public static function fromCamelCase($input, $grouped = false)
	{
		return $grouped
			? preg_split('/(?<=[^A-Z_])(?=[A-Z])|(?<=[A-Z])(?=[A-Z][^A-Z_])/x', $input)
			: trim(preg_replace('#([A-Z])#', ' $1', $input));
	}

	/**
	 * Method to convert a string into camel case.
	 *
	 * @param   string  $input  The string input (ASCII only).
	 *
	 * @return  string  The camel case string.
	 *
	 * @since   1.0
	 */
	public static function toCamelCase($input)
	{
		// Convert words to uppercase and then remove spaces.
		$input = static::toSpaceSeparated($input);
		$input = ucwords($input);
		$input = str_ireplace(' ', '', $input);

		return $input;
	}

	/**
	 * Method to convert a string into dash separated form.
	 *
	 * @param   string  $input  The string input (ASCII only).
	 *
	 * @return  string  The dash separated string.
	 *
	 * @since   1.0
	 */
	public static function toDashSeparated($input)
	{
		// Convert spaces and underscores to dashes.
		return preg_replace('#[ \-_]+#', '-', $input);
	}

	/**
	 * Method to convert a string into space separated form.
	 *
	 * @param   string  $input  The string input (ASCII only).
	 *
	 * @return  string  The space separated string.
	 *
	 * @since   1.0
	 */
	public static function toSpaceSeparated($input)
	{
		// Convert underscores and dashes to spaces.
		return preg_replace('#[ \-_]+#', ' ', $input);
	}

	/**
	 * Method to convert a string into underscore separated form.
	 *
	 * @param   string  $input  The string input (ASCII only).
	 *
	 * @return  string  The underscore separated string.
	 *
	 * @since   1.0
	 */
	public static function toUnderscoreSeparated($input)
	{
		// Convert spaces and dashes to underscores.
		return preg_replace('#[ \-_]+#', '_', $input);
	}

	/**
	 * Method to convert a string into variable form.
	 *
	 * @param   string  $input  The string input (ASCII only).
	 *
	 * @return  string  The variable string.
	 *
	 * @since   1.0
	 */
	public static function toVariable($input)
	{
		// Remove dashes and underscores, then convert to camel case.
		$input = static::toCamelCase($input);

		// Remove leading digits.
		$input = preg_replace('#^[0-9]+#', '', $input);

		// Lowercase the first character.
		$input = lcfirst($input);

		return $input;
	}

	/**
	 * Method to convert a string into key form.
	 *
	 * @param   string  $input  The string input (ASCII only).
	 *
	 * @return  string  The key string.
	 *
	 * @since   1.0
	 */
	public static function toKey($input)
	{
		// Remove spaces and dashes, then convert to lower case.
		return strtolower(static::toUnderscoreSeparated($input));
	}
}
