#!/usr/bin/env bash
# This script upgrades Nix to specific version.
# https://nixos.org/manual/nix/stable/installation/upgrading.html
set -eo pipefail

GIT_ROOT=$(cd "${BASH_SOURCE%/*}" && git rev-parse --show-toplevel)
source "${GIT_ROOT}/scripts/colors.sh"
source "${GIT_ROOT}/nix/scripts/source.sh"
source "${GIT_ROOT}/nix/scripts/version.sh"

nix_upgrade() {
    echo -e "Upgrading Nix interpreter to: ${GRN}${NIX_VERSION}${RST}" >&2
    nix-channel --update
    nix-env --install --attr "nixpkgs.${NIX_PACKAGE}" "nixpkgs.cacert"
    if [[ "$(uname -s)" == "Darwin" ]]; then
        echo "Restarting Nix daemon Launchd service" >&2
        launchctl unload /Library/LaunchDaemons/org.nixos.nix-daemon.plist
        launchctl load   /Library/LaunchDaemons/org.nixos.nix-daemon.plist
    elif [[ "$(uname -s)" == "Linux" ]] && [[ "$(nix_install_type)" == "multi" ]]; then
        echo "Restarting Nix daemon Systemd service" >&2
        systemctl daemon-reload
        systemctl restart nix-daemon
    fi
}

# Allow for sourcing the script
if [[ "${BASH_SOURCE[0]}" != "$0" ]]; then
    return
fi

if [[ "$(nix_current_version)" == "${NIX_VERSION}" ]]; then
    echo -e "Nix interpreter already on version: ${GRN}${NIX_VERSION}${RST}"
    exit 0
fi

NIX_INSTALL_TYPE=$(nix_install_type)
if [[ "${NIX_INSTALL_TYPE}" == "nixos" ]]; then
    echo -e "${YLW}WARNING:${RST} Upgrade Nix in your NixOS configuration!" >&2
    exit 0
elif [[ "${NIX_INSTALL_TYPE}" == "single" ]]; then
    nix_upgrade
elif [[ "${NIX_INSTALL_TYPE}" == "multi" ]]; then
    sudo -i bash -c "source ${PWD}/${0}; nix_upgrade"
fi