local has_words_before = function()
	local line, col = table.unpack(vim.api.nvim_win_get_cursor(0))
	return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
end

local feedkey = function(key, mode)
	vim.api.nvim_feedkeys(vim.api.nvim_replace_termcodes(key, true, true, true), mode, true)
end

local cmp = require("cmp")
local lspkind = require("lspkind")

cmp.setup({
	sources = {
		{ name = "nvim_lsp" },
		{ name = "cmp_tabnine" },
		{ name = "treesitter" },
		{ name = "buffer" },
		{ name = "path" },
		{ name = "vsnip" },
		-- { name = "copilot" },
	},

	snippet = {
		expand = function(args)
			vim.fn["vsnip#anonymous"](args.body)
		end,
	},

	formatting = {
		format = lspkind.cmp_format({
			with_text = true,
			menu = {
				buffer = "[Buf]",
				nvim_lsp = "[LSP]",
				nvim_lua = "[Lua]",
				latex_symbols = "[Latex]",
				treesitter = "[TS]",
				cmp_tabnine = "[TN]",
				vsnip = "[Snip]",
			},
		}),
	},

	mapping = {
		["<CR>"] = cmp.mapping.confirm({ select = true }),
		["<Tab>"] = cmp.mapping(function(fallback)
			if cmp.visible() then
				cmp.select_next_item()
			elseif vim.fn["vsnip#available"](1) == 1 then
				feedkey("<Plug>(vsnip-expand-or-jump)", "")
			elseif has_words_before() then
				cmp.complete()
			else
				fallback()
			end
		end, {
			"i",
			"s",
		}),

		["<S-Tab>"] = cmp.mapping(function()
			if cmp.visible() then
				cmp.select_prev_item()
			elseif vim.fn["vsnip#jumpable"](-1) == 1 then
				feedkey("<Plug>(vsnip-jump-prev)", "")
			end
		end, {
			"i",
			"s",
		}),
	},
})