local add = vim.pack.add
local now_if_args, later = Config.now_if_args, Config.later

now_if_args(function()
	-- Define hook to update tree-sitter parsers after plugin is updated
	local ts_update = function()
		vim.cmd("TSUpdate")
	end
	Config.on_packchanged("nvim-treesitter", { "update" }, ts_update, ":TSUpdate")

	add({
		"https://github.com/nvim-treesitter/nvim-treesitter",
		"https://github.com/nvim-treesitter/nvim-treesitter-textobjects",
	})

	local languages = {
		"lua",
		"vimdoc",
		"markdown",
		"go",
		"yaml",
		"html",
	}
	local isnt_installed = function(lang)
		return #vim.api.nvim_get_runtime_file("parser/" .. lang .. ".*", false) == 0
	end
	local to_install = vim.tbl_filter(isnt_installed, languages)
	if #to_install > 0 then
		require("nvim-treesitter").install(to_install)
	end

	-- Enable tree-sitter after opening a file for a target language
	local filetypes = {}
	for _, lang in ipairs(languages) do
		for _, ft in ipairs(vim.treesitter.language.get_filetypes(lang)) do
			table.insert(filetypes, ft)
		end
	end
	local ts_start = function(ev)
		vim.treesitter.start(ev.buf)
	end
	Config.new_autocmd("FileType", filetypes, ts_start, "Start tree-sitter")
end)

-- Language servers ===========================================================

-- Language Server Protocol (LSP) is a set of conventions that power creation of
-- language specific tools. It requires two parts:
-- - Server - program that performs language specific computations.
-- - Client - program that asks server for computations and shows results.
--
-- Here Neovim itself is a client (see `:h vim.lsp`). Language servers need to
-- be installed separately based on your OS, CLI tools, and preferences.
-- See note about 'mason.nvim' at the bottom of the file.
--
-- Neovim's team collects commonly used configurations for most language servers
-- inside 'neovim/nvim-lspconfig' plugin.
--
-- Add it now if file (and not 'mini.starter') is shown after startup.
--
-- Troubleshooting:
-- - Run `:checkhealth vim.lsp` to see potential issues.
now_if_args(function()
	add({ "https://github.com/neovim/nvim-lspconfig" })

	-- Use `:h vim.lsp.enable()` to automatically enable language server based on
	-- the rules provided by 'nvim-lspconfig'.
	vim.lsp.enable({
		"gopls",
		"lua_ls",
		"yamlls",
	})

	-- Use `:h vim.lsp.config()` or 'after/lsp/' directory to configure servers.
	-- Uncomment and tweak the following `vim.lsp.enable()` call to enable servers.
	-- vim.lsp.config({
	-- -- For example, if `lua-language-server` is installed, use `'lua_ls'` entry
	-- })
end)

-- Formatting =================================================================

-- Programs dedicated to text formatting (a.k.a. formatters) are very useful.
-- Neovim has built-in tools for text formatting (see `:h gq` and `:h 'formatprg'`).
-- They can be used to configure external programs, but it might become tedious.
--
-- The 'stevearc/conform.nvim' plugin is a good and maintained solution for easier
-- formatting setup.
later(function()
	add({ "https://github.com/stevearc/conform.nvim" })

	-- See also:
	-- - `:h Conform`
	-- - `:h conform-options`
	-- - `:h conform-formatters`
	require("conform").setup({
		default_format_opts = {
			-- Allow formatting from LSP server if no dedicated formatter is available
			lsp_format = "fallback",
		},
		format_on_save = {
			lsp_format = "fallback",
			timeout_ms = 500,
		},
		-- Map of filetype to formatters
		-- Make sure that necessary CLI tool is available
		-- formatters_by_ft = { lua = { 'stylua' } },
		formatters_by_ft = {
			go = { "gofumpt", "goimports" },
			lua = { "stylua" },
		},
	})
end)

-- Snippets ===================================================================

-- Although 'mini.snippets' provides functionality to manage snippet files, it
-- deliberately doesn't come with those.
--
-- The 'rafamadriz/friendly-snippets' is currently the largest collection of
-- snippet files. They are organized in 'snippets/' directory (mostly) per language.
-- 'mini.snippets' is designed to work with it as seamlessly as possible.
-- See `:h MiniSnippets.gen_loader.from_lang()`.
-- later(function()
-- 	add({ "https://github.com/rafamadriz/friendly-snippets" })
-- end)

-- Honorable mentions =========================================================

-- 'mason-org/mason.nvim' (a.k.a. "Mason") is a great tool (package manager) for
-- installing external language servers, formatters, and linters. It provides
-- a unified interface for installing, updating, and deleting such programs.
--
-- The caveat is that these programs will be set up to be mostly used inside Neovim.
-- If you need them to work elsewhere, consider using other package managers.
--
-- You can use it like so:
now_if_args(function()
	add({ "https://github.com/mason-org/mason.nvim" })
	require("mason").setup()
end)