#! /usr/bin/env bash
set -xeuo pipefail
declare username host system config_nix config_tf

# INSTANTIATE
command=(nix-instantiate --argstr system "$system" --argstr config_nix "$config_nix" --argstr config_tf "$config_tf" ./nixos.nix)
# instantiate the config in /nix/store
"${command[@]}" -A out_path

# DEPLOY
sshOpts=(
  -o BatchMode=yes
  -o StrictHostKeyChecking=no
  # TODO set key for production
  # ${if key-file == null then "" else "-i ${key-file}"}
  # NOTE the below options are for tests
  -o ConnectTimeout=1
  -o ServerAliveInterval=1
)
destination="$username@$host"
# get the realized derivation to deploy
outPath=$(nix-store --realize "$("${command[@]}" --show-trace --eval --strict --json | jq -r '.drv_path')")
# deploy the config by nix-copy-closure
NIX_SSHOPTS="${sshOpts[*]}" nix-copy-closure --to "$destination" "$outPath" --gzip --use-substitutes
# switch the remote host to the config
# NOTE checks here are for tests - in production time-outs could be a real thing, rather than indicator of success!
# shellcheck disable=SC2029
output=$(ssh "${sshOpts[@]}" "$destination" "nix-env --profile /nix/var/nix/profiles/system --set $outPath; nohup $outPath/bin/switch-to-configuration switch &" 2>&1) || echo "status code: $?"
echo "output: $output"
if [[ $output != *"Timeout, server $host not responding"* ]]; then
  echo "non-timeout error: $output"
  exit 1
else
  exit 0
fi