class EmptyCommentSniff

class EmptyCommentSniff implements Sniff {
    public const CODE_EMPTY_COMMENT = 'EmptyComment';
    
    /**
     * @return array<int, (int|string)>
     */
    public function register() : array {
        return [
            T_DOC_COMMENT_OPEN_TAG,
            T_COMMENT,
        ];
    }
    
    /**
     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingNativeTypeHint
     * @param int $commentStartPointer
     */
    public function process(File $phpcsFile, $commentStartPointer) : void {
        $commentEndPointer = CommentHelper::getCommentEndPointer($phpcsFile, $commentStartPointer);
        if ($commentEndPointer === null) {
            // Part of block comment
            return;
        }
        $commentContent = $this->getCommentContent($phpcsFile, $commentStartPointer, $commentEndPointer);
        $isLineComment = CommentHelper::isLineComment($phpcsFile, $commentStartPointer);
        $isEmpty = $this->isEmpty($commentContent, $isLineComment);
        if (!$isEmpty) {
            return;
        }
        if ($isLineComment && $this->isPartOfMultiLineInlineComments($phpcsFile, $commentStartPointer, $commentEndPointer)) {
            return;
        }
        $fix = $phpcsFile->addFixableError('Empty comment', $commentStartPointer, self::CODE_EMPTY_COMMENT);
        if (!$fix) {
            return;
        }
        $tokens = $phpcsFile->getTokens();
        
        /** @var int $pointerBeforeWhitespaceBeforeComment */
        $pointerBeforeWhitespaceBeforeComment = TokenHelper::findPreviousNonWhitespace($phpcsFile, $commentStartPointer - 1);
        $whitespaceBeforeComment = $pointerBeforeWhitespaceBeforeComment !== $commentStartPointer - 1 ? TokenHelper::getContent($phpcsFile, $pointerBeforeWhitespaceBeforeComment + 1, $commentStartPointer - 1) : '';
        $fixedWhitespaceBeforeComment = preg_replace('~[ \\t]+$~', '', $whitespaceBeforeComment);
        $phpcsFile->fixer
            ->beginChangeset();
        FixerHelper::removeBetween($phpcsFile, $pointerBeforeWhitespaceBeforeComment, $commentStartPointer);
        $phpcsFile->fixer
            ->addContent($pointerBeforeWhitespaceBeforeComment, $fixedWhitespaceBeforeComment);
        FixerHelper::removeBetweenIncluding($phpcsFile, $commentStartPointer, $commentEndPointer);
        $whitespacePointerAfterComment = $commentEndPointer + 1;
        if ($tokens[$pointerBeforeWhitespaceBeforeComment]['line'] === $tokens[$commentStartPointer]['line']) {
            if (StringHelper::endsWith($tokens[$commentEndPointer]['content'], $phpcsFile->eolChar)) {
                $phpcsFile->fixer
                    ->addNewline($commentEndPointer);
            }
        }
        elseif (array_key_exists($whitespacePointerAfterComment, $tokens) && $tokens[$whitespacePointerAfterComment]['code'] === T_WHITESPACE) {
            $fixedWhitespaceAfterComment = preg_replace('~^[ \\t]*' . $phpcsFile->eolChar . '~', '', $tokens[$whitespacePointerAfterComment]['content']);
            $phpcsFile->fixer
                ->replaceToken($whitespacePointerAfterComment, $fixedWhitespaceAfterComment);
        }
        $phpcsFile->fixer
            ->endChangeset();
    }
    private function isEmpty(string $comment, bool $isLineComment) : bool {
        return $isLineComment ? (bool) preg_match('~^\\s*$~', $comment) : (bool) preg_match('~^[\\s\\*]*$~', $comment);
    }
    private function getCommentContent(File $phpcsFile, int $commentStartPointer, int $commentEndPointer) : string {
        $tokens = $phpcsFile->getTokens();
        if ($tokens[$commentStartPointer]['code'] === T_DOC_COMMENT_OPEN_TAG) {
            return TokenHelper::getContent($phpcsFile, $commentStartPointer + 1, $commentEndPointer - 1);
        }
        if (preg_match('~^(?://|#)(.*)~', $tokens[$commentStartPointer]['content'], $matches) !== 0) {
            return $matches[1];
        }
        return substr(TokenHelper::getContent($phpcsFile, $commentStartPointer, $commentEndPointer), 2, -2);
    }
    private function isPartOfMultiLineInlineComments(File $phpcsFile, int $commentStartPointer, int $commentEndPointer) : bool {
        if (!$this->isNonEmptyLineCommentBefore($phpcsFile, $commentStartPointer)) {
            return false;
        }
        return $this->isNonEmptyLineCommentAfter($phpcsFile, $commentEndPointer);
    }
    private function isNonEmptyLineCommentBefore(File $phpcsFile, int $commentStartPointer) : bool {
        $tokens = $phpcsFile->getTokens();
        
        /** @var int $beforeCommentStartPointer */
        $beforeCommentStartPointer = TokenHelper::findPreviousNonWhitespace($phpcsFile, $commentStartPointer - 1);
        if ($tokens[$beforeCommentStartPointer]['code'] !== T_COMMENT) {
            return false;
        }
        if (!CommentHelper::isLineComment($phpcsFile, $beforeCommentStartPointer)) {
            return false;
        }
        if ($tokens[$beforeCommentStartPointer]['line'] + 1 !== $tokens[$commentStartPointer]['line']) {
            return false;
        }
        
        /** @var int $beforeCommentEndPointer */
        $beforeCommentEndPointer = CommentHelper::getCommentEndPointer($phpcsFile, $beforeCommentStartPointer);
        if (!$this->isEmpty($this->getCommentContent($phpcsFile, $beforeCommentStartPointer, $beforeCommentEndPointer), true)) {
            return true;
        }
        return $this->isNonEmptyLineCommentBefore($phpcsFile, $beforeCommentStartPointer);
    }
    private function isNonEmptyLineCommentAfter(File $phpcsFile, int $commentEndPointer) : bool {
        $tokens = $phpcsFile->getTokens();
        $afterCommentStartPointer = TokenHelper::findNextNonWhitespace($phpcsFile, $commentEndPointer + 1);
        if ($afterCommentStartPointer === null) {
            return false;
        }
        if ($tokens[$afterCommentStartPointer]['code'] !== T_COMMENT) {
            return false;
        }
        if (!CommentHelper::isLineComment($phpcsFile, $afterCommentStartPointer)) {
            return false;
        }
        if ($tokens[$commentEndPointer]['line'] + 1 !== $tokens[$afterCommentStartPointer]['line']) {
            return false;
        }
        
        /** @var int $afterCommentEndPointer */
        $afterCommentEndPointer = CommentHelper::getCommentEndPointer($phpcsFile, $afterCommentStartPointer);
        if (!$this->isEmpty($this->getCommentContent($phpcsFile, $afterCommentStartPointer, $afterCommentEndPointer), true)) {
            return true;
        }
        return $this->isNonEmptyLineCommentAfter($phpcsFile, $afterCommentEndPointer);
    }

}