class IdentificatorHelper

class IdentificatorHelper {
    public static function getContent(File $phpcsFile, int $startPointer, int $endPointer) : string {
        $tokens = $phpcsFile->getTokens();
        $variableContent = '';
        for ($i = $startPointer; $i <= $endPointer; $i++) {
            if (in_array($tokens[$i]['code'], TokenHelper::$ineffectiveTokenCodes, true)) {
                continue;
            }
            $variableContent .= $tokens[$i]['content'];
        }
        return $variableContent;
    }
    public static function findStartPointer(File $phpcsFile, int $endPointer) : ?int {
        $tokens = $phpcsFile->getTokens();
        if (in_array($tokens[$endPointer]['code'], TokenHelper::getNameTokenCodes(), true)) {
            
            /** @var int $previousPointer */
            $previousPointer = TokenHelper::findPreviousEffective($phpcsFile, $endPointer - 1);
            if (in_array($tokens[$previousPointer]['code'], [
                T_OBJECT_OPERATOR,
                T_NULLSAFE_OBJECT_OPERATOR,
                T_DOUBLE_COLON,
            ], true)) {
                $pointerBeforeOperator = TokenHelper::findPreviousEffective($phpcsFile, $previousPointer - 1);
                if ($tokens[$pointerBeforeOperator]['code'] !== T_CLOSE_PARENTHESIS) {
                    return self::getStartPointerBeforeOperator($phpcsFile, $previousPointer);
                }
            }
            return $endPointer;
        }
        if (in_array($tokens[$endPointer]['code'], [
            T_CLOSE_CURLY_BRACKET,
            T_CLOSE_SQUARE_BRACKET,
        ], true)) {
            return self::getStartPointerBeforeVariablePart($phpcsFile, $tokens[$endPointer]['bracket_opener']);
        }
        if ($tokens[$endPointer]['code'] === T_VARIABLE) {
            return self::getStartPointerBeforeVariablePart($phpcsFile, $endPointer);
        }
        return null;
    }
    public static function findEndPointer(File $phpcsFile, int $startPointer) : ?int {
        $tokens = $phpcsFile->getTokens();
        $nameTokenCodes = TokenHelper::getNameTokenCodes();
        if (in_array($tokens[$startPointer]['code'], $nameTokenCodes, true)) {
            $startPointer = TokenHelper::findNextExcluding($phpcsFile, $nameTokenCodes, $startPointer + 1) - 1;
        }
        elseif ($tokens[$startPointer]['code'] === T_DOLLAR) {
            $startPointer = TokenHelper::findNextEffective($phpcsFile, $startPointer + 1);
        }
        
        /** @var int $nextPointer */
        $nextPointer = TokenHelper::findNextEffective($phpcsFile, $startPointer + 1);
        if (in_array($tokens[$startPointer]['code'], array_merge([
            T_SELF,
            T_STATIC,
            T_PARENT,
        ], $nameTokenCodes), true) && $tokens[$nextPointer]['code'] === T_DOUBLE_COLON) {
            return self::getEndPointerAfterOperator($phpcsFile, $nextPointer);
        }
        if ($tokens[$startPointer]['code'] === T_VARIABLE) {
            if (in_array($tokens[$nextPointer]['code'], [
                T_DOUBLE_COLON,
                T_OBJECT_OPERATOR,
                T_NULLSAFE_OBJECT_OPERATOR,
            ], true)) {
                return self::getEndPointerAfterOperator($phpcsFile, $nextPointer);
            }
            if ($tokens[$nextPointer]['code'] === T_OPEN_SQUARE_BRACKET) {
                return self::getEndPointerAfterVariablePart($phpcsFile, $startPointer);
            }
            return $startPointer;
        }
        return null;
    }
    private static function getStartPointerBeforeOperator(File $phpcsFile, int $operatorPointer) : int {
        $tokens = $phpcsFile->getTokens();
        $nameTokenCodes = TokenHelper::getNameTokenCodes();
        
        /** @var int $previousPointer */
        $previousPointer = TokenHelper::findPreviousEffective($phpcsFile, $operatorPointer - 1);
        if (in_array($tokens[$previousPointer]['code'], $nameTokenCodes, true)) {
            $previousPointer = TokenHelper::findPreviousExcluding($phpcsFile, $nameTokenCodes, $previousPointer - 1) + 1;
        }
        if ($tokens[$operatorPointer]['code'] === T_DOUBLE_COLON && in_array($tokens[$previousPointer]['code'], array_merge([
            T_SELF,
            T_STATIC,
            T_PARENT,
        ], $nameTokenCodes), true)) {
            return $previousPointer;
        }
        if (in_array($tokens[$previousPointer]['code'], $nameTokenCodes, true)) {
            
            /** @var int $possibleOperatorPointer */
            $possibleOperatorPointer = TokenHelper::findPreviousEffective($phpcsFile, $previousPointer - 1);
            if (in_array($tokens[$possibleOperatorPointer]['code'], [
                T_OBJECT_OPERATOR,
                T_NULLSAFE_OBJECT_OPERATOR,
            ], true)) {
                return self::getStartPointerBeforeOperator($phpcsFile, $possibleOperatorPointer);
            }
        }
        if (in_array($tokens[$previousPointer]['code'], [
            T_CLOSE_CURLY_BRACKET,
            T_CLOSE_SQUARE_BRACKET,
        ], true)) {
            return self::getStartPointerBeforeVariablePart($phpcsFile, $tokens[$previousPointer]['bracket_opener']);
        }
        return self::getStartPointerBeforeVariablePart($phpcsFile, $previousPointer);
    }
    private static function getStartPointerBeforeVariablePart(File $phpcsFile, int $variablePartPointer) : int {
        $tokens = $phpcsFile->getTokens();
        
        /** @var int $previousPointer */
        $previousPointer = TokenHelper::findPreviousEffective($phpcsFile, $variablePartPointer - 1);
        if ($tokens[$previousPointer]['code'] === T_DOLLAR) {
            
            /** @var int $previousPointer */
            $previousPointer = TokenHelper::findPreviousEffective($phpcsFile, $previousPointer - 1);
        }
        if (in_array($tokens[$previousPointer]['code'], [
            T_OBJECT_OPERATOR,
            T_NULLSAFE_OBJECT_OPERATOR,
            T_DOUBLE_COLON,
        ], true)) {
            return self::getStartPointerBeforeOperator($phpcsFile, $previousPointer);
        }
        if ($tokens[$previousPointer]['code'] === T_CLOSE_SQUARE_BRACKET) {
            return self::getStartPointerBeforeVariablePart($phpcsFile, $tokens[$previousPointer]['bracket_opener']);
        }
        if ($tokens[$previousPointer]['code'] === T_CLOSE_CURLY_BRACKET && !array_key_exists('scope_condition', $tokens[$previousPointer])) {
            return self::getStartPointerBeforeVariablePart($phpcsFile, $tokens[$previousPointer]['bracket_opener']);
        }
        if (in_array($tokens[$previousPointer]['code'], array_merge([
            T_VARIABLE,
        ], TokenHelper::getNameTokenCodes()), true)) {
            return self::getStartPointerBeforeVariablePart($phpcsFile, $previousPointer);
        }
        return $variablePartPointer;
    }
    private static function getEndPointerAfterOperator(File $phpcsFile, int $operatorPointer) : int {
        $tokens = $phpcsFile->getTokens();
        
        /** @var int $nextPointer */
        $nextPointer = TokenHelper::findNextEffective($phpcsFile, $operatorPointer + 1);
        if ($tokens[$nextPointer]['code'] === T_DOLLAR) {
            
            /** @var int $nextPointer */
            $nextPointer = TokenHelper::findNextEffective($phpcsFile, $nextPointer + 1);
        }
        if ($tokens[$nextPointer]['code'] === T_OPEN_CURLY_BRACKET) {
            return self::getEndPointerAfterVariablePart($phpcsFile, $tokens[$nextPointer]['bracket_closer']);
        }
        return self::getEndPointerAfterVariablePart($phpcsFile, $nextPointer);
    }
    private static function getEndPointerAfterVariablePart(File $phpcsFile, int $variablePartPointer) : int {
        $tokens = $phpcsFile->getTokens();
        
        /** @var int $nextPointer */
        $nextPointer = TokenHelper::findNextEffective($phpcsFile, $variablePartPointer + 1);
        if (in_array($tokens[$nextPointer]['code'], [
            T_OBJECT_OPERATOR,
            T_NULLSAFE_OBJECT_OPERATOR,
            T_DOUBLE_COLON,
        ], true)) {
            return self::getEndPointerAfterOperator($phpcsFile, $nextPointer);
        }
        if ($tokens[$nextPointer]['code'] === T_OPEN_SQUARE_BRACKET) {
            return self::getEndPointerAfterVariablePart($phpcsFile, $tokens[$nextPointer]['bracket_closer']);
        }
        return $variablePartPointer;
    }

}