class EmptyPHPStatementSniff

class EmptyPHPStatementSniff implements Sniff {
    
    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array<int|string>
     */
    public function register() {
        return [
            T_SEMICOLON,
            T_CLOSE_TAG,
        ];
    }
    
    //end register()
    
    /**
     * Processes this test, when one of its tokens is encountered.
     *
     * @param \PHP_CodeSniffer\Files\File $phpcsFile The file being scanned.
     * @param int                         $stackPtr  The position of the current token
     *                                               in the stack passed in $tokens.
     *
     * @return void
     */
    public function process(File $phpcsFile, $stackPtr) {
        $tokens = $phpcsFile->getTokens();
        switch ($tokens[$stackPtr]['type']) {
            // Detect `something();;`.
            case 'T_SEMICOLON':
                $prevNonEmpty = $phpcsFile->findPrevious(Tokens::$emptyTokens, $stackPtr - 1, null, true);
                if ($prevNonEmpty === false) {
                    return;
                }
                if ($tokens[$prevNonEmpty]['code'] !== T_SEMICOLON && $tokens[$prevNonEmpty]['code'] !== T_OPEN_TAG && $tokens[$prevNonEmpty]['code'] !== T_OPEN_TAG_WITH_ECHO) {
                    if (isset($tokens[$prevNonEmpty]['scope_condition']) === false) {
                        return;
                    }
                    if ($tokens[$prevNonEmpty]['scope_opener'] !== $prevNonEmpty && $tokens[$prevNonEmpty]['code'] !== T_CLOSE_CURLY_BRACKET) {
                        return;
                    }
                    $scopeOwner = $tokens[$tokens[$prevNonEmpty]['scope_condition']]['code'];
                    if ($scopeOwner === T_CLOSURE || $scopeOwner === T_ANON_CLASS || $scopeOwner === T_MATCH) {
                        return;
                    }
                    // Else, it's something like `if (foo) {};` and the semicolon is not needed.
                }
                if (isset($tokens[$stackPtr]['nested_parenthesis']) === true) {
                    $nested = $tokens[$stackPtr]['nested_parenthesis'];
                    $lastCloser = array_pop($nested);
                    if (isset($tokens[$lastCloser]['parenthesis_owner']) === true && $tokens[$tokens[$lastCloser]['parenthesis_owner']]['code'] === T_FOR) {
                        // Empty for() condition.
                        return;
                    }
                }
                $fix = $phpcsFile->addFixableWarning('Empty PHP statement detected: superfluous semicolon.', $stackPtr, 'SemicolonWithoutCodeDetected');
                if ($fix === true) {
                    $phpcsFile->fixer
                        ->beginChangeset();
                    if ($tokens[$prevNonEmpty]['code'] === T_OPEN_TAG || $tokens[$prevNonEmpty]['code'] === T_OPEN_TAG_WITH_ECHO) {
                        // Check for superfluous whitespace after the semicolon which will be
                        // removed as the `<?php ` open tag token already contains whitespace,
                        // either a space or a new line.
                        if ($tokens[$stackPtr + 1]['code'] === T_WHITESPACE) {
                            $replacement = str_replace(' ', '', $tokens[$stackPtr + 1]['content']);
                            $phpcsFile->fixer
                                ->replaceToken($stackPtr + 1, $replacement);
                        }
                    }
                    for ($i = $stackPtr; $i > $prevNonEmpty; $i--) {
                        if ($tokens[$i]['code'] !== T_SEMICOLON && $tokens[$i]['code'] !== T_WHITESPACE) {
                            break;
                        }
                        $phpcsFile->fixer
                            ->replaceToken($i, '');
                    }
                    $phpcsFile->fixer
                        ->endChangeset();
                }
                
                //end if
                break;
            // Detect `<?php ? >`.
            case 'T_CLOSE_TAG':
                $prevNonEmpty = $phpcsFile->findPrevious(T_WHITESPACE, $stackPtr - 1, null, true);
                if ($prevNonEmpty === false || $tokens[$prevNonEmpty]['code'] !== T_OPEN_TAG && $tokens[$prevNonEmpty]['code'] !== T_OPEN_TAG_WITH_ECHO) {
                    return;
                }
                $fix = $phpcsFile->addFixableWarning('Empty PHP open/close tag combination detected.', $prevNonEmpty, 'EmptyPHPOpenCloseTagsDetected');
                if ($fix === true) {
                    $phpcsFile->fixer
                        ->beginChangeset();
                    for ($i = $prevNonEmpty; $i <= $stackPtr; $i++) {
                        $phpcsFile->fixer
                            ->replaceToken($i, '');
                    }
                    $phpcsFile->fixer
                        ->endChangeset();
                }
                break;
            default:
                // Deliberately left empty.
                break;
        }
        
        //end switch
    }
    
    //end process()

}