protected fun prepareDocumentAndGetStartOffsets()

in vim-engine/src/main/kotlin/com/maddyhome/idea/vim/put/VimPutBase.kt [397:496]
90 lines of code
16 McCabe index (conditional complexity)

  protected fun prepareDocumentAndGetStartOffsets(
    vimEditor: VimEditor,
    vimCaret: VimCaret,
    typeInRegister: SelectionType,
    data: PutData,
    additionalData: Map<String, Any>,
  ): List<Int> {
    val application = injector.application
    val visualSelection = data.visualSelection
    if (visualSelection != null) {
      return when {
        visualSelection.typeInEditor.isChar && typeInRegister.isLine -> {
          application.runWriteAction { (vimEditor as MutableVimEditor).insertText(vimCaret, vimCaret.offset, "\n") }
          listOf(vimCaret.offset + 1)
        }

        visualSelection.typeInEditor.isBlock -> {
          val firstSelectedLine = additionalData["firstSelectedLine"] as Int
          val selectedLines = additionalData["selectedLines"] as Int
          val startColumnOfSelection = additionalData["startColumnOfSelection"] as Int
          val line = (if (data.insertTextBeforeCaret) firstSelectedLine else firstSelectedLine + selectedLines)
            .coerceAtMost(vimEditor.lineCount() - 1)
          when (typeInRegister) {
            SelectionType.LINE_WISE -> when {
              data.insertTextBeforeCaret -> listOf(vimEditor.getLineStartOffset(line))
              else -> {
                val pos = vimEditor.getLineEndOffset(line, true)
                application.runWriteAction { (vimEditor as MutableVimEditor).insertText(vimCaret, pos, "\n") }
                listOf(pos + 1)
              }
            }

            SelectionType.CHARACTER_WISE -> (firstSelectedLine + selectedLines downTo firstSelectedLine)
              .map { vimEditor.bufferPositionToOffset(BufferPosition(it, startColumnOfSelection)) }

            SelectionType.BLOCK_WISE -> listOf(
              vimEditor.bufferPositionToOffset(
                BufferPosition(
                  firstSelectedLine,
                  startColumnOfSelection,
                ),
              ),
            )
          }
        }

        visualSelection.typeInEditor.isLine -> {
          val lastChar = if (vimEditor.fileSize() > 0) {
            vimEditor.getText(TextRange(vimEditor.fileSize().toInt() - 1, vimEditor.fileSize().toInt()))[0]
          } else {
            null
          }
          if (vimCaret.offset == vimEditor.fileSize().toInt() && vimEditor.fileSize()
              .toInt() != 0 && lastChar != '\n'
          ) {
            application.runWriteAction { (vimEditor as MutableVimEditor).insertText(vimCaret, vimCaret.offset, "\n") }
            listOf(vimCaret.offset + 1)
          } else {
            listOf(vimCaret.offset)
          }
        }

        else -> listOf(vimCaret.offset)
      }
    } else {
      if (data.insertTextBeforeCaret) {
        return when (typeInRegister) {
          SelectionType.LINE_WISE -> listOf(injector.motion.moveCaretToCurrentLineStart(vimEditor, vimCaret))
          else -> listOf(vimCaret.offset)
        }
      }

      var startOffset: Int
      val line = if (data.putToLine < 0) vimCaret.getBufferPosition().line else data.putToLine
      when (typeInRegister) {
        SelectionType.LINE_WISE -> {
          startOffset =
            min(vimEditor.text().length, injector.motion.moveCaretToLineEnd(vimEditor, line, true) + 1)
          // At the end of a notebook cell the next symbol is a guard,
          // so we add a newline to be able to paste. Fixes VIM-2577
          if (startOffset > 0 && vimEditor.document.getOffsetGuard(startOffset) != null) {
            application.runWriteAction { (vimEditor as MutableVimEditor).insertText(vimCaret, (startOffset - 1), "\n") }
          }
          if (startOffset > 0 && startOffset == vimEditor.text().length && vimEditor.text()[startOffset - 1] != '\n') {
            application.runWriteAction { (vimEditor as MutableVimEditor).insertText(vimCaret, startOffset, "\n") }
            startOffset++
          }
        }

        else -> {
          startOffset = vimCaret.offset
          if (!vimEditor.isLineEmpty(line, false)) {
            startOffset++
          }
        }
      }

      return if (startOffset > vimEditor.text().length) listOf(vimEditor.text().length) else listOf(startOffset)
    }
  }