local M = {}

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

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

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

  return nil
end

function M.headline_level(headline)
  local heading_content = headline:field "heading_content"
  if not heading_content or #heading_content == 0 then
    return 0
  end
  local _, level = heading_content[1]:start()
  return level - 1
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.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