local cmp = require('cmp')

local source_mapping = {
	buffer = '[Buffer]',
	nvim_lsp = '[LSP]',
	nvim_lua = '[Lua]',
	cmp_tabnine = '[TN]',
	path = '[Path]',
}

cmp.setup({
	mapping = cmp.mapping.preset.insert({
		['<C-y>'] = cmp.mapping.confirm({ select = true }),
		['<C-d>'] = cmp.mapping.scroll_docs(-4),
		['<C-u>'] = cmp.mapping.scroll_docs(4),
		['<C-Space>'] = cmp.mapping.complete(),
	}),
	snippet = {
		expand = function(args)
				require('luasnip').lsp_expand(args.body)
		end,
	},
	formatting = {
		format = function(entry, vim_item)
			local menu = source_mapping[entry.source.name]
			vim_item.menu = menu
			return vim_item
		end
	},
	sources = cmp.config.sources({
		{ name = 'nvim_lsp' },
		{ name = 'luasnip' },
	}, {
		{ name = 'buffer' },
	})
})

-- инициализация LSP для различных ЯП
local lspconfig = require('lspconfig')
local util = require('lspconfig/util')

local function config(_config)
	return vim.tbl_deep_extend('force', {
		capabilities = require('cmp_nvim_lsp').default_capabilities(vim.lsp.protocol.make_client_capabilities()),
	}, _config or {})
end

-- иницализация gopls LSP для Go
-- https://github.com/golang/tools/blob/master/gopls/doc/vim.md#neovim-install
lspconfig.gopls.setup(config({
	on_attach = on_attach,
	cmd = { 'gopls', 'serve' },
	filetypes = { 'go', 'go.mod' },
	root_dir = util.root_pattern('go.work', 'go.mod', '.git'),
	settings = {
		gopls = {
			analyses = {
				unusedparams = true,
				shadow = true,
			},
			staticcheck = true,
		}
	}
}))