private void indentBlockWithFormatter(@NotNull Project project,  @NotNull Editor editor, int startOffset, int endOffset) {

    // Algorithm: the main idea is to process the first line of the pasted block, adjust its indent if necessary, calculate indent
    // adjustment string and apply to each line of the pasted block starting from the second one.
    //
    // We differentiate the following possible states here:
    //   --- pasted block doesn't start new line, i.e. there are non-white space symbols before it at the first line.
    //      Example:
    //         old content [pasted line 1
    //                pasted line 2]
    //      Indent adjustment string is just the first line indent then.
    //
    //   --- pasted block starts with empty line(s)
    //      Example:
    //         old content [
    //            pasted line 1
    //            pasted line 2]
    //      We parse existing indents of the pasted block then, adjust its first non-blank line via formatter and adjust indent
    //      of subsequent pasted lines in order to preserve old indentation.
    //
    //   --- pasted block is located at the new line and starts with white space symbols.
    //       Example:
    //          [   pasted line 1
    //                 pasted line 2]
    //       We parse existing indents of the pasted block then, adjust its first line via formatter and adjust indent of the pasted lines
    //       starting from the second one in order to preserve old indentation.
    //
    //   --- pasted block is located at the new line but doesn't start with white space symbols.
    //       Example:
    //           [pasted line 1
    //         pasted line 2]
    //       We adjust the first line via formatter then and apply first line's indent to all subsequent pasted lines.

    final Document document = editor.getDocument();
    final CharSequence chars = document.getCharsSequence();
    final int firstLine = document.getLineNumber(startOffset);
    final int firstLineStart = document.getLineStartOffset(firstLine);

    // There is a possible case that we paste block that ends with new line that is empty or contains only white space symbols.
    // We want to preserve indent for the original document line where paste was performed.
    // Example:
    //   Original:
    //       if (test) {
    //   <caret>    }
    //
    //   Pasting: 'int i = 1;\n'
    //   Expected:
    //       if (test) {
    //           int i = 1;
    //       }
    boolean saveLastLineIndent = false;
    for (int i = endOffset - 1; i >= startOffset; i--) {
      final char c = chars.charAt(i);
      if (c == '\n') {
        saveLastLineIndent = true;
        break;
      }
      if (c != ' ' && c != '\t') {
        break;
      }
    }

    final int lastLine;
    if (saveLastLineIndent) {
      lastLine = document.getLineNumber(endOffset) - 1;
      // Remove white space symbols at the pasted text if any.
      int start = document.getLineStartOffset(lastLine + 1);
      if (start < endOffset) {
        int i = CharArrayUtil.shiftForward(chars, start, " \t");
        if (i > start) {
          i = Math.min(i, endOffset);
          document.deleteString(start, i);
        }
      }

      // Insert white space from the start line of the pasted block.
      int indentToKeepEndOffset = Math.min(startOffset, CharArrayUtil.shiftForward(chars, firstLineStart, " \t"));
      if (indentToKeepEndOffset > firstLineStart) {
        document.insertString(start, chars.subSequence(firstLineStart, indentToKeepEndOffset));
      }
    }
    else {
      lastLine = document.getLineNumber(endOffset);
    }

    final int i = CharArrayUtil.shiftBackward(chars, startOffset - 1, " \t");

    // Handle a situation when pasted block doesn't start a new line.
    if (chars.charAt(startOffset) != '\n' && i > 0 && chars.charAt(i) != '\n') {
      int firstNonWsOffset = CharArrayUtil.shiftForward(chars, firstLineStart, " \t");
      if (firstNonWsOffset > firstLineStart) {
        CharSequence toInsert = chars.subSequence(firstLineStart, firstNonWsOffset);
        indentLines(document, firstLine + 1, lastLine, toInsert);
      }
      return;
    }

    final int j = CharArrayUtil.shiftForward(chars, startOffset, " \t\n");
    if (j >= endOffset) {
      // Pasted text contains white space/line feed symbols only, do nothing.
      return;
    }

    final int anchorLine = document.getLineNumber(j);
    final int anchorLineStart = document.getLineStartOffset(anchorLine);
    adjustLineIndent(project, editor, j);

    // Handle situation when pasted block starts with non-white space symbols.
    if (anchorLine == firstLine && j == startOffset) {
      int indentOffset = CharArrayUtil.shiftForward(chars, firstLineStart, " \t");
      if (indentOffset > firstLineStart) {
        CharSequence toInsert = chars.subSequence(firstLineStart, indentOffset);
        indentLines(document, firstLine + 1, lastLine, toInsert);
      }
      return;
    }

    // Handle situation when pasted block starts from white space symbols. Assume that the pasted text started at the line start,
    // i.e. correct indentation level is stored at the blocks structure.
    final int firstNonWsOffset = CharArrayUtil.shiftForward(chars, anchorLineStart, " \t");
    final int diff = firstNonWsOffset - j;
    if (diff == 0) {
      return;
    }
    if (diff > 0) {
      CharSequence toInsert = chars.subSequence(anchorLineStart, anchorLineStart + diff);
      indentLines(document, anchorLine + 1, lastLine, toInsert);
      return;
    }

    // We've pasted text to the non-first column and exact white space between the line start and caret position on the moment of paste
    // has been removed by formatter during 'adjust line indent'
    // Example:
    //       copied text:
    //                 '   line1
    //                       line2'
    //       after paste:
    //          line start -> '   I   line1
    //                              line2' (I - caret position during 'paste')
    //       formatter removed white space between the line start and caret position, so, current document state is:
    //                        '   line1
    //                              line2'
    if (anchorLine == firstLine && -diff == startOffset - firstLineStart) {
      return;
    }
    if (anchorLine != firstLine || -diff > startOffset - firstLineStart) {
      final int desiredSymbolsToRemove;
      if (anchorLine == firstLine) {
        desiredSymbolsToRemove = -diff - (startOffset - firstLineStart);
      }
      else {
        desiredSymbolsToRemove = -diff;
      }

      Runnable unindentTask = () -> {
        for (int line = anchorLine + 1; line <= lastLine; line++) {
          int currentLineStart = document.getLineStartOffset(line);
          int currentLineIndentOffset = CharArrayUtil.shiftForward(chars, currentLineStart, " \t");
          int symbolsToRemove = Math.min(currentLineIndentOffset - currentLineStart, desiredSymbolsToRemove);
          if (symbolsToRemove > 0) {
            document.deleteString(currentLineStart, currentLineStart + symbolsToRemove);
          }
        }
      };
      DocumentUtil.executeInBulk(document, lastLine - anchorLine > LINE_LIMIT_FOR_BULK_CHANGE, unindentTask);
    }
    else {
      CharSequence toInsert = chars.subSequence(anchorLineStart, diff + startOffset);
      indentLines(document, anchorLine + 1, lastLine, toInsert);
    }
  }
private void indentBlockWithFormatter(@NotNull Project project,  @NotNull Editor editor, int startOffset, int endOffset)