build.sh

#!/usr/bin/env bash
cd $(dirname "$0")

if [[ "$1" == "-h" || "$1" == "--help" ]]
then
    exec echo "
Usage:
  $0 [OPTION]

Options:
  -h, --help: Open help page.
  -d, --default: Use default settings.
  -c, --custom: After that, type the value of each question, separate them with <SPC>, and press <RET>.
  -r <hostname>, --remote <hostname>: Build configuration for <hostname> in your device and copy to it.
"
fi

# ~~ Interaction ~~
if [[ "$1" != "-d" && "$1" != "--default" ]]
then
    if [[ "$1" == "-r" || "$1" == "--remote" ]]
    then
        hname="$2"
        nix build path:.\#nixosConfigurations.$hname.config.system.build.toplevel
        exec nix copy ./result --to ssh://$hname
    else
        if [[ "$1" == "-c" || "$1" == "--custom" ]]
        then
	    flag="$2"
	    subcommand="$3"
	    hname="$4"
	    other=""
	    while [[ $# -ne 4 ]]
	    do
	        other+=" $5"
	        shift
	    done
        else
	    echo -e "\nWhich \033[1moperation\033[0m do you like to perform?
        \033[31m- build a LiveCD            \033[0m(b)
        \033[33m- install from a LiveCD     \033[0m(i)
        \033[1;32m- update your configuration \033[0m(\033[1;4mu\033[0m)"
	    read -p ">> " flag

	    if [[ "$flag" != "b" && "$flag" != "B" ]]
	    then
	        echo -e "\nWhich rebuild \033[1;34msubcommand\033[0m do you like to use? (\033[1;4mswitch\033[0m/boot/test/build/dry-build/...)"
	        read -p ">> " subcommand

	        echo -e "\nWhat will be your \033[1;35mideal hostname\033[0m? (\033[1;4m$(hostname)\033[0m/...)"
	        read -p ">> " hname

	        echo -e "\nIf you have other option, such as '--no-build-nix', '--show-trace', '--verbose', please indicate here; or simply press <RET>."
	        read -p ">> " other

	        echo
	    fi
        fi
    fi
fi

# ~~ Auto Completion ~~
if [[ -z "$flag" ]] ; then flag="u"; fi
if [[ -z "$subcommand" ]] ; then subcommand="switch"; fi
if [[ -z "$hname" ]] ; then hname=$(hostname); fi
if [[ "$other" == " " ]]; then other=""; fi

if [[ -z "$1" ]]
then
    echo -e "\033[1;31mHint:\033[0m Next time you can type '\033[1;31m$0 -c $flag $subcommand $hname $other\033[0m' to execute the same operation.\n"
fi

if [[ "$other" == "" ]]; then other="--keep-going --verbose"; fi


# ~~ Action ~~
# 1. LiveCD
if [[ "$flag" == "b" || "$flag" == "B" ]]
then
    rsync -rL --delete ~/clash-configuration ./clash-configuration-temp
    nix build path:.\#nixosConfigurations.livecd.config.system.build.isoImage
    exec rm -rf ./clash-configuration-temp
fi


# 2. normal build
if [[ "$flag" == "i" || "$flag" == "I" ]]
then
    # TODO: Use `nixos-generate-config` or some other things to automatically update hardware-configuration.nix
    # nixos-generate-config --root /mnt
    # cp /mnt/etc/hardware-configuration.nix ...towhere?
    echo -e "Oops! It requires you to \033[1;31mcheck your privilege\033[0m..."
    exec sudo nixos-install --flake "path:.#$hname" $other
elif [[ "$flag" == "u" || "$flag" == "U" ]]
then
    if [[ "$subcommand" != *"build" ]]
    then
	echo -e "Oops! It requires you to \033[1;31mcheck your privilege\033[0m..."
	exec sudo nixos-rebuild $subcommand --flake "path:.#$hname" $other
    else
	exec nixos-rebuild $subcommand --flake "path:.#$hname" $other
    fi
fi

# ~~ Error ~~
echo -e "\n\033[1;31mInvalid input!\033[0m Exiting the build script..."
exit 1