-- why barotrauma's GUI libraries don't have this implemented by default? this is stupid

local function updateServerMessageScrollBasedOnCaret(textBox, listBox)
	local caretY = textBox.CaretScreenPos.Y
	local bottomCaretExtent = textBox.Font.LineHeight * 1.5
	local topCaretExtent = -textBox.Font.LineHeight * 0.5

	if caretY + bottomCaretExtent > listBox.Rect.Bottom then
		listBox.ScrollBar.BarScroll = (caretY - textBox.Rect.Top - listBox.Rect.Height + bottomCaretExtent)
			/ (textBox.Rect.Height - listBox.Rect.Height)
	elseif caretY + topCaretExtent < listBox.Rect.Top then
		listBox.ScrollBar.BarScroll = (caretY - textBox.Rect.Top + topCaretExtent)
			/ (textBox.Rect.Height - listBox.Rect.Height)
	end
end

local function CreateMultiLineTextBox(rectransform, text, size)
	local multineListBox = GUI.ListBox(GUI.RectTransform(Vector2(1, size or 0.2), rectransform))

	local textBox = GUI.TextBox(
		GUI.RectTransform(Vector2(1, 1), multineListBox.Content.RectTransform),
		text,
		nil,
		nil,
		nil,
		true,
		"GUITextBoxNoBorder"
	)

	textBox.add_OnSelected(function()
		updateServerMessageScrollBasedOnCaret(textBox, multineListBox)
	end)

	textBox.OnTextChangedDelegate = function()
		local textSize = textBox.Font.MeasureString(textBox.WrappedText)
		textBox.RectTransform.NonScaledSize =
			Point(textBox.RectTransform.NonScaledSize.X, math.max(multineListBox.Content.Rect.Height, textSize.Y + 10))
		multineListBox.UpdateScrollBarSize()

		return true
	end

	textBox.OnEnterPressed = function()
		local str = textBox.Text
		local caretIndex = textBox.CaretIndex

		textBox.Text = str:sub(1, caretIndex) .. "\n" .. str:sub(caretIndex + 1)
		textBox.CaretIndex = caretIndex + 1

		return true
	end

	return textBox
end

return CreateMultiLineTextBox