local function config()
  local cmp = require 'cmp'
  local luasnip = require 'luasnip'

  local function expand(args)
    luasnip.lsp_expand(args.body)
  end

  local function tab_mapping(fallback)
    if cmp.visible() then
      cmp.select_next_item()
    elseif luasnip.expand_or_locally_jumpable() then
      luasnip.expand_or_jump()
    else
      fallback()
    end
  end

  local function back_tab_mapping(fallback)
    if cmp.visible() then
      cmp.select_prev_item()
    elseif luasnip.locally_jumpable(-1) then
      luasnip.jump(-1)
    else
      fallback()
    end
  end

  cmp.setup {
    enabled = true,

    snippet = { expand = expand },
    sources = {
      { name = 'nvim_lsp' },
      { name = 'luasnip' },
    },

    mapping = cmp.mapping.preset.insert {
      ['<C-n>'] = cmp.mapping.select_next_item(),
      ['<C-p>'] = cmp.mapping.select_prev_item(),
      ['<C-d>'] = cmp.mapping.scroll_docs(-4),
      ['<C-f>'] = cmp.mapping.scroll_docs(4),
      ['<C-Space>'] = cmp.mapping.complete({}),
      ['<Tab>'] = cmp.mapping(tab_mapping, { 'i', 's' }),
      ['<S-Tab>'] = cmp.mapping(back_tab_mapping, { 'i', 's' }),
      ['<CR>'] = cmp.mapping.confirm {
        behavior = cmp.ConfirmBehavior.Replace,
        select = true,
      },
    },
  }
end

return {
  'hrsh7th/nvim-cmp',
  name = 'cmp',
  config = config,
  dependencies = {
    'saadparwaiz1/cmp_luasnip',
    'hrsh7th/cmp-nvim-lsp',
  },
}