local M = {}

function M.find_headline(node)
  if node:type() == "headline" then
    return node
  end

  if node:type() == "section" then
    -- The headline is always the first child of a section
    return node:child("headline")[1]
  end

  if node:parent() then
    return M.find_headline(node:parent())
  end

  return nil
end

function M.get_node_at_cursor(cursor)
  if not cursor then
    return vim.treesitter.get_node()
  end

  return vim.treesitter.get_node {
    bufnr = 0,
    pos = { cursor[1] - 1, cursor[2] },
  }
end

function M.headline_level(headline)
  local _, level = headline:field("stars")[1]:end_()
  return level + 1
end

function M.closest_headline_node(cursor)
  local node = M.get_node_at_cursor(cursor)

  if not node then
    return nil
  end

  return M.find_headline(node)
end

return M