--@class util.ui
local M = {}

-- foldtext for Neovim < 0.10.0
function M.foldtext()
  return vim.api.nvim_buf_get_lines(0, vim.v.lnum - 1, vim.v.lnum, false)[1]
end

-- optimized treesitter foldexpr for Neovim >= 0.10.0
function M.foldexpr()
  local buf = vim.api.nvim_get_current_buf()
  if vim.b[buf].ts_folds == nil then
    -- as long as we don't have a filetype, don't bother
    -- checking if treesitter is available (it won't)
    if vim.bo[buf].filetype == "" then
      return "0"
    end
    if vim.bo[buf].filetype:find("dashboard") then
      vim.b[buf].ts_folds = false
    else
      vim.b[buf].ts_folds = pcall(vim.treesitter.get_parser, buf)
    end
  end
  return vim.b[buf].ts_folds and vim.treesitter.foldexpr() or "0"
end

return M