nix/home/program/bash/module/Nix.nix

{ const, ... }:
{
  text = ''
    export _nix_system_config="git+${const.url}"

    # Rebuild system.
    # Optionally force the hostname.
    # Usage: nixos_rebuild [HOSTNAME]
    function nixos_rebuild() {
      local target="''${1}"
      [[ "''${target}" = "" ]] && target="''${HOSTNAME}"

      nixos-rebuild boot --refresh --option eval-cache false --flake "''${_nix_system_config}#''${target}"
    }

    # Rebuild and switch system.
    # Optionally force the hostname.
    # Usage: nixos_switch [HOSTNAME]
    function nixos_switch() {
      local target="''${1}"
      [[ "''${target}" = "" ]] && target="''${HOSTNAME}"

      nixos-rebuild switch --refresh --option eval-cache false --flake "''${_nix_system_config}#''${target}"
    }

    # Spawn shell with specified nix environment.
    # Uses flake.nix in current dir by default.
    # Usage: shell [NAME]
    function shell() {
      local target="''${1}"
      [[ "''${target}" = "" ]] && target="default"

      # Create Nix GC root in .NixRoot{NAME}.
      nix build ".#devShells.''${NIX_CURRENT_SYSTEM}.''${target}" -o ".NixRoot''${target^}"

      SHELL_NAME="''${target}" nix develop ".#devShells.''${NIX_CURRENT_SYSTEM}.''${target}"
    }

    # Spawn temporary nix-shell with specified packages.
    # Usage: tmpshell <PACKAGES>
    function tmpshell() {
      local IFS=$'\n'
      local input=("''${@}")
      local pkgs=()
      local tag="''${SHELL_NAME}"

      if [[ "''${input}" = "" ]]; then
        help tmpshell
        return 2
      fi

      [[ "''${tag}" = "" ]] && tag="''${1}"

      for pkg in ''${input[@]}; do
        pkgs+=("nixpkgs#''${pkg}")
      done

      SHELL_NAME="''${tag}" NIXPKGS_ALLOW_UNFREE=1 nix shell --impure ''${pkgs[@]}
    }

    # Build live image.
    function nixos_live() {
      nix build "''${_nix_system_config}#nixosConfigurations.live.config.system.build.isoImage" --refresh ''${@}
    }

    # List nixos generations.
    function nixos_generations() {
      nix-env -p /nix/var/nix/profiles/system --list-generations
    }

    # Switch nix-on-droid.
    function nixdroid_switch() {
      nix-on-droid switch --flake "''${_nix_system_config}" ''${@}
    }

    # Nix auto-run wrapper.
    # Usage: , <COMMAND>
    function ,() {
      NIX_AUTO_RUN=1 ''${@}
    }

    # Autocomplete with available hosts.
    function _comp_hosts() {
      local IFS=$'\n'
      local targets=($(ls ~/.config/linux/system/host/))

      _autocomplete_first ''${targets[@]}
    }

    complete -F _comp_hosts nix_switch nix_rebuild
  '';
}