return {
  'nvim-treesitter/nvim-treesitter',
  dependencies = {
    {
      'nvim-treesitter/nvim-treesitter-context',
      opts = {
        max_lines = 4,
        multiline_threshold = 2,
      },
    },
    {
      'mizlan/iswap.nvim',
      enabled = false,
    }
  },
  lazy = false,
  branch = 'main',
  --build = ':TSUpdate',
  config = function()
    local ts = require('nvim-treesitter')

    -- State tracking for async parser loading
    local parsers_loaded = {}
    local parsers_pending = {}
    local parsers_failed = {}

    local ns = vim.api.nvim_create_namespace('treesitter.async')

    -- Helper to start highlighting and indentation
    local function start(buf, lang)
      local ok = pcall(vim.treesitter.start, buf, lang)
      if ok then
      --   vim.bo[buf].indentexpr = "v:lua.require'nvim-treesitter'.indentexpr()"
      end
      return ok
    end

    -- Install core parsers after lazy.nvim finishes loading all plugins
    vim.api.nvim_create_autocmd('User', {
      pattern = 'LazyDone',
      once = true,
      callback = function()
        ts.install({
          "arduino",
          "awk",
          "bash",
          "bibtex",
          "bitbake",
          "c",
          "cmake",
          --"comment",
          "cpp",
          "csv",
          "devicetree",
          "diff",
          "fish",
          "gitattributes",
          "gitcommit",
          "gitignore",
          "git_config",
          "git_rebase",
          "html",
          "vimdoc",
          "http",
          "ini",
          "jq",
          "json",
          --"latex",
          "lua",
          "make",
          "markdown",
          "markdown_inline",
          "matlab",
          "ninja",
          "proto",
          "python",
          "regex",
          "rust",
          "toml",
          "vim",
          "yaml",
        }, {
          max_jobs = 8,
        })
      end,
    })

    -- Decoration provider for async parser loading
    vim.api.nvim_set_decoration_provider(ns, {
      on_start = vim.schedule_wrap(function()
        if #parsers_pending == 0 then
          return false
        end
        for _, data in ipairs(parsers_pending) do
          if vim.api.nvim_buf_is_valid(data.buf) then
            if start(data.buf, data.lang) then
              parsers_loaded[data.lang] = true
            else
              parsers_failed[data.lang] = true
            end
          end
        end
        parsers_pending = {}
      end),
    })

    local group = vim.api.nvim_create_augroup('TreesitterSetup', { clear = true })

    local ignore_filetypes = {
      'checkhealth',
      'lazy',
      'mason',
      'snacks_dashboard',
      'snacks_notif',
      'snacks_win',
    }

    -- Auto-install parsers and enable highlighting on FileType
    vim.api.nvim_create_autocmd('FileType', {
      group = group,
      desc = 'Enable treesitter highlighting and indentation (non-blocking)',
      callback = function(event)
        if vim.tbl_contains(ignore_filetypes, event.match) then
          return
        end

        local lang = vim.treesitter.language.get_lang(event.match) or event.match
        local buf = event.buf

        if parsers_failed[lang] then
          return
        end

        if parsers_loaded[lang] then
          -- Parser already loaded, start immediately (fast path)
          start(buf, lang)
        else
          -- Queue for async loading
          table.insert(parsers_pending, { buf = buf, lang = lang })
        end

        -- Auto-install missing parsers (async, no-op if already installed)
        ts.install({ lang })
      end,
    })
  end
}