Nixfiles/neovim/completion.nix

{
  extraConfigLuaPre = ''
    local has_words_before = function()
      unpack = unpack or table.unpack
      local line, col = unpack(vim.api.nvim_win_get_cursor(0))
      return col ~= 0 and vim.api.nvim_buf_get_lines(0, line - 1, line, true)[1]:sub(col, col):match("%s") == nil
    end
    local luasnip = require("luasnip")
  '';

  plugins.cmp = {
    enable = true;

    settings = {
      snippet.expand = ''
        function(args)
          require('luasnip').lsp_expand(args.body)
        end
      '';
      mapping = {
        "<CR>" = "cmp.mapping.confirm({select = true })";
        "<C-d>" = "cmp.mapping.scroll_docs(-4)";
        "<C-f>" = "cmp.mapping.scroll_docs(4)";
        "<C-Space>" = "cmp.mapping.complete()";
        "<Tab>" = # lua
          ''
            cmp.mapping(function(fallback)
              if cmp.visible() then
                cmp.select_next_item()
              -- You could replace the expand_or_jumpable() calls with expand_or_locally_jumpable()
              -- they way you will only jump inside the snippet region
              elseif luasnip.expand_or_locally_jumpable() then
                luasnip.expand_or_jump()
              elseif has_words_before() then
                cmp.complete()
              else
                fallback()
              end
            end, { "i", "s" })
          '';
        "<S-Tab>" = # lua
          ''
            cmp.mapping(function(fallback)
              if cmp.visible() then
                cmp.select_prev_item()
              elseif luasnip.jumpable(-1) then
                luasnip.jump(-1)
              else
                fallback()
              end
            end, { "i", "s" })
          '';
        "<Down>" = "cmp.mapping(cmp.mapping.select_next_item({ behavior = cmp.SelectBehavior.Select }), {'i'})";
        "<Up>" = "cmp.mapping(cmp.mapping.select_prev_item({ behavior = cmp.SelectBehavior.Select }), {'i'})";
      };

      sources = [
        { name = "luasnip"; }
        { name = "nvim_lsp"; }
        { name = "path"; }
        { name = "buffer"; }
        { name = "calc"; }
        { name = "git"; }
        { name = "omni"; }
      ];
    };
  };
}