class ValidClassNameSniff

class ValidClassNameSniff implements Sniff {
    
    /**
     * Returns an array of tokens this test wants to listen for.
     *
     * @return array<int|string>
     */
    public function register() {
        return [
            T_CLASS,
            T_INTERFACE,
            T_TRAIT,
            T_ENUM,
        ];
    }
    
    //end register()
    
    /**
     * Processes this test, when one of its tokens is encountered.
     *
     * @param \PHP_CodeSniffer\Files\File $phpcsFile The current file being processed.
     * @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();
        $className = $phpcsFile->findNext(T_STRING, $stackPtr);
        $name = trim($tokens[$className]['content']);
        $errorData = [
            ucfirst($tokens[$stackPtr]['content']),
        ];
        // Make sure the first letter is a capital.
        if (preg_match('|^[A-Z]|', $name) === 0) {
            $error = '%s name must begin with a capital letter';
            $phpcsFile->addError($error, $stackPtr, 'StartWithCapital', $errorData);
        }
        // Check that each new word starts with a capital as well, but don't
        // check the first word, as it is checked above.
        $validName = true;
        $nameBits = explode('_', $name);
        $firstBit = array_shift($nameBits);
        foreach ($nameBits as $bit) {
            if ($bit === '' || $bit[0] !== strtoupper($bit[0])) {
                $validName = false;
                break;
            }
        }
        if ($validName === false) {
            // Strip underscores because they cause the suggested name
            // to be incorrect.
            $nameBits = explode('_', trim($name, '_'));
            $firstBit = array_shift($nameBits);
            if ($firstBit === '') {
                $error = '%s name is not valid';
                $phpcsFile->addError($error, $stackPtr, 'Invalid', $errorData);
            }
            else {
                $newName = strtoupper($firstBit[0]) . substr($firstBit, 1) . '_';
                foreach ($nameBits as $bit) {
                    if ($bit !== '') {
                        $newName .= strtoupper($bit[0]) . substr($bit, 1) . '_';
                    }
                }
                $newName = rtrim($newName, '_');
                $error = '%s name is not valid; consider %s instead';
                $data = $errorData;
                $data[] = $newName;
                $phpcsFile->addError($error, $stackPtr, 'Invalid', $data);
            }
        }
        
        //end if
    }
    
    //end process()

}