ListFormatter.php

<?php

/*
 * This file is part of the ICanBoogie package.
 *
 * (c) Olivier Laviale <olivier.laviale@gmail.com>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace ICanBoogie\CLDR;

use ICanBoogie\CLDR\Locale\ListPattern;

/**
 * Formats variable-length lists of things such as "Monday, Tuesday, Friday, and Saturday".
 *
 * @see http://www.unicode.org/reports/tr35/tr35-general.html#ListPatterns
 */
class ListFormatter implements Formatter
{
	/**
	 * Formats a variable-length lists of scalars.
	 *
	 * @param scalar[] $list
	 */
	public function __invoke(array $list, ListPattern $list_pattern): string
	{
		return $this->format($list, $list_pattern);
	}

	/**
	 * Formats a variable-length lists of scalars.
	 *
	 * @param scalar[] $list
	 */
	public function format(array $list, ListPattern $list_pattern): string
	{
		$list = array_values($list);

		switch (count($list))
		{
			case 0:
				return "";

			case 1:
				return (string) current($list);

			case 2:
				return $this->format_pattern($list_pattern->two, (string) $list[0], (string) $list[1]);

			default:
				$n = count($list) - 1;
				$v1 = $list[$n];

				for ($i = $n - 1 ; $i > -1 ; $i--)
				{
					$v0 = $list[$i];

					if ($i === 0)
					{
						$pattern = $list_pattern->start;
					}
					else if ($i + 1 === $n)
					{
						$pattern = $list_pattern->end;
					}
					else
					{
						$pattern = $list_pattern->middle;
					}

					$v1 = $this->format_pattern($pattern, (string) $v0, (string) $v1);
				}

				return $v1;
		}
	}

	private function format_pattern(string $pattern, string $v0, string $v1): string
	{
		return strtr($pattern, [

			'{0}' => $v0,
			'{1}' => $v1

		]);
	}
}