<?php declare(strict_types = 1);

namespace SlevomatCodingStandard\Sniffs\Namespaces;

use PHP_CodeSniffer\Files\File;
use PHP_CodeSniffer\Sniffs\Sniff;
use SlevomatCodingStandard\Helpers\FixerHelper;
use SlevomatCodingStandard\Helpers\NamespaceHelper;
use SlevomatCodingStandard\Helpers\StringHelper;
use SlevomatCodingStandard\Helpers\TokenHelper;
use SlevomatCodingStandard\Helpers\UseStatementHelper;
use function sprintf;
use function strlen;
use function substr;
use const T_AS;
use const T_SEMICOLON;
use const T_USE;

class UseFromSameNamespaceSniff implements Sniff
{

	public const CODE_USE_FROM_SAME_NAMESPACE = 'UseFromSameNamespace';

	/**
	 * @return array<int, (int|string)>
	 */
	public function register(): array
	{
		return [
			T_USE,
		];
	}

	public function process(File $phpcsFile, int $usePointer): void
	{
		if (!UseStatementHelper::isImportUse($phpcsFile, $usePointer)) {
			return;
		}

		$namespaceName = NamespaceHelper::findCurrentNamespaceName($phpcsFile, $usePointer);
		$namespaceName ??= '';

		$usedTypeName = UseStatementHelper::getFullyQualifiedTypeNameFromUse($phpcsFile, $usePointer);
		if (!StringHelper::startsWith($usedTypeName, $namespaceName)) {
			return;
		}

		$asPointer = $this->findAsPointer($phpcsFile, $usePointer);
		if ($asPointer !== null) {
			return;
		}

		$usedTypeNameRest = substr($usedTypeName, strlen($namespaceName));
		if (!NamespaceHelper::isFullyQualifiedName($usedTypeNameRest) && $namespaceName !== '') {
			return;
		}

		if (NamespaceHelper::hasNamespace($usedTypeNameRest)) {
			return;
		}

		$fix = $phpcsFile->addFixableError(sprintf(
			'Use %s is from the same namespace – that is prohibited.',
			$usedTypeName,
		), $usePointer, self::CODE_USE_FROM_SAME_NAMESPACE);
		if (!$fix) {
			return;
		}

		$endPointer = TokenHelper::findNext($phpcsFile, T_SEMICOLON, $usePointer) + 1;

		$phpcsFile->fixer->beginChangeset();

		FixerHelper::removeBetweenIncluding($phpcsFile, $usePointer, $endPointer);

		$phpcsFile->fixer->endChangeset();
	}

	private function findAsPointer(File $phpcsFile, int $startPointer): ?int
	{
		return TokenHelper::findNextLocal($phpcsFile, T_AS, $startPointer);
	}

}
