class RequireArrowFunctionSniff

class RequireArrowFunctionSniff implements Sniff {
    public const CODE_REQUIRED_ARROW_FUNCTION = 'RequiredArrowFunction';
    
    /** @var bool */
    public $allowNested = true;
    
    /** @var bool|null */
    public $enable = null;
    
    /**
     * @return array<int, (int|string)>
     */
    public function register() : array {
        return [
            T_CLOSURE,
        ];
    }
    
    /**
     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingNativeTypeHint
     * @param int $closurePointer
     */
    public function process(File $phpcsFile, $closurePointer) : void {
        $this->enable = SniffSettingsHelper::isEnabledByPhpVersion($this->enable, 70400);
        if (!$this->enable) {
            return;
        }
        $tokens = $phpcsFile->getTokens();
        $returnPointer = TokenHelper::findNextEffective($phpcsFile, $tokens[$closurePointer]['scope_opener'] + 1);
        if ($tokens[$returnPointer]['code'] !== T_RETURN) {
            return;
        }
        $usePointer = TokenHelper::findNextEffective($phpcsFile, $tokens[$closurePointer]['parenthesis_closer'] + 1);
        if ($tokens[$usePointer]['code'] === T_USE) {
            $useOpenParenthesisPointer = TokenHelper::findNextEffective($phpcsFile, $usePointer + 1);
            if (TokenHelper::findNext($phpcsFile, T_BITWISE_AND, $useOpenParenthesisPointer + 1, $tokens[$useOpenParenthesisPointer]['parenthesis_closer']) !== null) {
                return;
            }
        }
        if (!$this->allowNested) {
            $closureOrArrowFunctionPointer = TokenHelper::findNext($phpcsFile, [
                T_CLOSURE,
                T_FN,
            ], $tokens[$closurePointer]['scope_opener'] + 1, $tokens[$closurePointer]['scope_closer']);
            if ($closureOrArrowFunctionPointer !== null) {
                return;
            }
        }
        $fix = $phpcsFile->addFixableError('Use arrow function.', $closurePointer, self::CODE_REQUIRED_ARROW_FUNCTION);
        if (!$fix) {
            return;
        }
        $pointerAfterReturn = TokenHelper::findNextNonWhitespace($phpcsFile, $returnPointer + 1);
        $semicolonAfterReturn = $this->findSemicolon($phpcsFile, $returnPointer);
        $usePointer = TokenHelper::findNext($phpcsFile, T_USE, $tokens[$closurePointer]['parenthesis_closer'] + 1, $tokens[$closurePointer]['scope_opener']);
        $nonWhitespacePointerBeforeScopeOpener = TokenHelper::findPreviousExcluding($phpcsFile, T_WHITESPACE, $tokens[$closurePointer]['scope_opener'] - 1);
        $nonWhitespacePointerAfterUseParenthesisCloser = null;
        if ($usePointer !== null) {
            $useParenthesiCloserPointer = TokenHelper::findNext($phpcsFile, T_CLOSE_PARENTHESIS, $usePointer + 1);
            $nonWhitespacePointerAfterUseParenthesisCloser = TokenHelper::findNextExcluding($phpcsFile, T_WHITESPACE, $useParenthesiCloserPointer + 1);
        }
        $phpcsFile->fixer
            ->beginChangeset();
        $phpcsFile->fixer
            ->replaceToken($closurePointer, 'fn');
        if ($nonWhitespacePointerAfterUseParenthesisCloser !== null) {
            FixerHelper::removeBetween($phpcsFile, $tokens[$closurePointer]['parenthesis_closer'], $nonWhitespacePointerAfterUseParenthesisCloser);
        }
        FixerHelper::removeBetween($phpcsFile, $nonWhitespacePointerBeforeScopeOpener, $pointerAfterReturn);
        $phpcsFile->fixer
            ->addContent($nonWhitespacePointerBeforeScopeOpener, ' => ');
        FixerHelper::removeBetweenIncluding($phpcsFile, $semicolonAfterReturn, $tokens[$closurePointer]['scope_closer']);
        $phpcsFile->fixer
            ->endChangeset();
    }
    private function findSemicolon(File $phpcsFile, int $pointer) : int {
        $tokens = $phpcsFile->getTokens();
        $semicolonPointer = null;
        for ($i = $pointer + 1; $i < count($tokens) - 1; $i++) {
            if ($tokens[$i]['code'] !== T_SEMICOLON) {
                continue;
            }
            if (!ScopeHelper::isInSameScope($phpcsFile, $pointer, $i)) {
                continue;
            }
            $semicolonPointer = $i;
            break;
        }
        
        /** @var int $semicolonPointer */
        $semicolonPointer = $semicolonPointer;
        return $semicolonPointer;
    }

}