-- Installes the nvim-treesitter plugin.
vim.pack.add({
  "https://github.com/nvim-treesitter/nvim-treesitter",
}, { confirm = false })

-- Installs parsers.
require("nvim-treesitter").install({
  -- Bundled parsers.
  "c",
  "lua",
  "markdown",
  "markdown_inline",
  "query",
  "vim",
  "vimdoc",
  -- Extra parsers.
  "bash",
  "diff",
  "git_rebase",
  "gitcommit",
  "go",
  "json",
  "python",
  "vhdl",
})

-- Runs `:TSUpdate` when the nvim-treesitter plugin is installed or
-- updated.
vim.api.nvim_create_autocmd({ "PackChanged" }, {
  callback = function(ev)
    if
      ev.data.spec.name == "nvim-treesitter"
      and (ev.data.kind == "install" or ev.data.kind == "update")
    then
      vim.schedule(function()
        vim.cmd.TSUpdate()
      end)
    end
  end,
})

-- Enables treesitter on supported filetypes.
vim.api.nvim_create_autocmd("FileType", {
  callback = function(ev)
    if pcall(vim.treesitter.start) then
      -- If treesitter was enabled and folding queries are installed,
      -- use the queries for folding.
      if vim.treesitter.query.get(ev.match, "folds") then
        vim.wo[0][0].foldexpr = "v:lua.vim.treesitter.foldexpr()"
        vim.wo[0][0].foldmethod = "expr"
      end
    end
  end,
})