-- Pandoc Lua filter: wrap Hungarian experiment and thought-question sections
-- in the PDF edition's tcolorbox environments.

function Pandoc(doc)
  local new_blocks = {}
  local in_box = false
  local box_type = ""
  local box_level = 0

  local function open_box(name)
    table.insert(new_blocks, pandoc.RawBlock("latex", "\\begin{" .. name .. "}"))
    in_box = true
    box_type = name
  end

  local function close_box()
    table.insert(new_blocks, pandoc.RawBlock("latex", "\\end{" .. box_type .. "}"))
    in_box = false
    box_type = ""
  end

  for _, block in ipairs(doc.blocks) do
    if block.t == "Header" then
      local heading = pandoc.utils.stringify(block)
      local is_experiment =
        heading:match("^%d+%-%d+%.? [Kk]ísérlet") or
        heading:match("^[Kk]ísérlet %d+%-%d+")
      local is_questions = heading:match("[Kk]érdések")

      if is_experiment then
        if in_box then close_box() end
        box_level = block.level
        block.classes:insert("unnumbered")
        open_box("experimentbox")
        table.insert(new_blocks, block)

      elseif is_questions then
        if in_box then close_box() end
        box_level = block.level
        block.classes:insert("unnumbered")
        open_box("questionbox")
        table.insert(new_blocks, block)

      elseif in_box then
        if box_type == "experimentbox" or block.level <= box_level then
          close_box()
        end
        table.insert(new_blocks, block)

      else
        table.insert(new_blocks, block)
      end
    else
      table.insert(new_blocks, block)
    end
  end

  if in_box then close_box() end
  doc.blocks = new_blocks
  return doc
end