nvim.nix/config/plugins/ui/lualine.nix

{...}: {
  plugins.lualine = {
    enable = true;
    globalstatus = true;
    theme = "gruvbox-material";

    # Load our extensions
    extensions = [
      "neo-tree"
    ];

    # Icons for our separators
    componentSeparators = {
      left = "";
      right = "";
    };
    sectionSeparators = {
      left = "";
      right = "";
    };

    # Display components in tabline
    tabline = {
      lualine_a = [{name = "buffers";}];
      lualine_x = [{name = "hostname";}];
      lualine_z = [{name = "encoding";}];
    };

    # Lualine has sections as shown below
    # +-------------------------------------------------+
    # | A | B | C                             X | Y | Z |
    # +-------------------------------------------------+
    sections = {
      # Section A
      lualine_a = [{name = "mode";}];

      # Section B
      lualine_b = [
        # Git branch
        {
          name = "branch";
          icon = "";
        }

        # Git diff status
        {
          name = "diff";
          extraConfig.symbols = {
            added = "+";
            modified = "~";
            removed = "-";
          };
        }
      ];

      # Section C
      lualine_c = [{name = "filename";}];

      # Section X
      lualine_x = [
        # Diagnostic count from nvim_lsp
        {
          name = "diagnostics";
          extraConfig = {
            sources = ["nvim_lsp"];
            symbols = {
              error = "error:";
              warn = "warning:";
              info = "info:";
              hint = "hint:";
            };
          };
        }
      ];

      # Section Y
      lualine_y = [{name = "progress";}];

      # Section Z
      lualine_z = [{name = "location";}];
    };
  };
}