local M = {}


-- Reference: https://github.com/hrsh7th/nvim-cmp#recommended-configuration
function M.config()
  local cmp = require "cmp"

  cmp.setup({
    snippet = {
      -- REQUIRED - you must specify a snippet engine
      expand = function(args)
        -- vim.fn["vsnip#anonymous"](args.body) -- For `vsnip` users.
        require('luasnip').lsp_expand(args.body) -- For `luasnip` users.
        -- require('snippy').expand_snippet(args.body) -- For `snippy` users.
        -- vim.fn["UltiSnips#Anon"](args.body) -- For `ultisnips` users.
      end,
    },
    window = {
      completion = cmp.config.window.bordered(),
      documentation = cmp.config.window.bordered(),
    },
    mapping = cmp.mapping.preset.insert({
      ['<C-b>'] = cmp.mapping.scroll_docs(-4),
      ['<C-f>'] = cmp.mapping.scroll_docs(4),
      ['<C-CR>'] = cmp.mapping.complete(),
      ['<C-e>'] = cmp.mapping.abort(),
      ['<CR>'] = cmp.mapping.confirm({ select = true }), -- Accept currently selected item. Set `select` to `false` to only confirm explicitly selected items.
    }),
    sources = cmp.config.sources({
      { name = 'nvim_lsp' },
      -- { name = 'vsnip' }, -- For vsnip users.
      { name = 'luasnip' }, -- For luasnip users.
      -- { name = 'ultisnips' }, -- For ultisnips users.
      -- { name = 'snippy' }, -- For snippy users.
    }, {
      { name = 'buffer' },
    })
  })

  -- Set configuration for specific filetype.
  cmp.setup.filetype('gitcommit', {
    sources = cmp.config.sources({
      { name = 'git' }, -- You can specify the `git` source if [you were installed it](https://github.com/petertriho/cmp-git).
    }, {
      { name = 'buffer' },
    })
  })

  -- Use buffer source for `/` and `?` (if you enabled `native_menu`, this won't work anymore).
  cmp.setup.cmdline({ '/', '?' }, {
    mapping = cmp.mapping.preset.cmdline(),
    sources = {
      { name = 'buffer' }
    }
  })

  -- Use cmdline & path source for ':' (if you enabled `native_menu`, this won't work anymore).
  cmp.setup.cmdline(':', {
    mapping = cmp.mapping.preset.cmdline(),
    sources = cmp.config.sources({
      { name = 'path' }
    }, {
      { name = 'cmdline' }
    })
  })
end


---@param config table
---@return table
return function(config)
  return vim.tbl_extend("keep", config, M)
end