(local cmp (require :cmp))

(fn has-words-before []
  (let [(line col) (unpack (vim.api.nvim_win_get_cursor 0))
        cur-line (. (vim.api.nvim_buf_get_lines 0
                                          (- line 1)
                                          line
                                          true
                      1))]
    (and (not= col 0)
         (= (: (: cur-line :sub col col) :match "%s")
            nil))))

(let [lspkind (require :lspkind)]
  (cmp.setup {:formatting {:format (lspkind.cmp_format {:mode "symbol_text"
                                                        :maxwidth 50})
                           :show_labelDetails true}
              :snippet {:expand (fn [args] (vim.snippet.expand args.body))}
              :sources [{:name "buffer"}      {:name "nvim_lsp"} 
                        {:name "look"}        {:name "path"}
                        {:name "calc"}        {:name "spell"}
                        {:name "tags"}]
              :mapping {"<C-d>" (cmp.mapping.scroll_docs -4)
                        "<C-u>" (cmp.mapping.scroll_docs 4)
                        "<C-g>" (cmp.mapping.close)
                        "<CR>" (cmp.mapping.confirm {:select true})
                        "<Tab>" (cmp.mapping (fn [fallback]
                                               (if (cmp.visible) (cmp.select_next_item)
                                                   (has-words-before) (cmp.complete)
                                                   (fallback))) 
                                             [:i :s])
                        "<S-Tab>" (cmp.mapping (fn [fallback]
                                                 (if (cmp.visible) (cmp.select_prev_item)
                                                     (fallback))) 
                                               [:i :s])}}))