local cmp = require'cmp'

cmp.setup({
  snippet = {
    expand = function(args)
      vim.snippet.expand(args.body)
    end,
  },
  window = {
    completion = cmp.config.window.bordered(),
    documentation = cmp.config.window.bordered(),
  },
  mapping = {
    ['<Tab>'] = function(fallback)
      if cmp.visible() then
        if not cmp.select_next_item() then
          if vim.bo.buftype ~= 'prompt' and has_words_before() then
            cmp.complete()
          else
            fallback()
          end
        end
      else
        return vim.cmd(">")
      end
    end,

    ['<S-Tab>'] = function(fallback)
      if cmp.visible() then
        if not cmp.select_prev_item() then
          if vim.bo.buftype ~= 'prompt' and has_words_before() then
            cmp.complete()
          else
            fallback()
          end
        end
      else
        return vim.cmd("<")
      end
    end,
    ['<CR>'] = cmp.mapping.confirm({ select = true }),
  },
  sources = cmp.config.sources({
    { name = 'nvim_lsp' },
    { name = 'buffer' },
  })
})