#!/usr/bin/env bash
# Revert ALL Kontra additions from /etc/nixos/configuration.nix on .13.
# Restores the untouched pre-Kontra backup, then rebuilds (removes systemd kontra + pull + caddy vhosts).
# Run as:  sudo bash revert-kontra-nix.sh
set -euo pipefail

CFG=/etc/nixos/configuration.nix
PRE=/etc/nixos/configuration.nix.bak-kontra-20260908-195305   # first backup = pre-Kontra (no additions)

if [ ! -f "$PRE" ]; then
  echo "!! pre-Kontra backup not found at $PRE — aborting (nothing reverted)."
  exit 1
fi

# Safety: confirm the CURRENT file actually contains Kontra markers before overwriting
if ! grep -q "KONTRA" "$CFG"; then
  echo "!! Current configuration.nix has no Kontra markers. Leaving as-is."
  exit 0
fi

echo "== restoring pre-Kontra configuration.nix"
cp -a "$PRE" "$CFG"
echo "   restored. Kontra markers now: $(grep -c CONTRA "$CFG" || true)"

echo "== Nix syntax check"
nix-instantiate --parse "$CFG" >/dev/null && echo "OK" || { echo "SYNTAX FAIL — no change made"; exit 1; }

echo "== nixos-rebuild switch (removes kontra service + timer + caddy vhosts)"
nixos-rebuild switch --show-trace 2>&1 | tail -20

echo "== confirm removal"
systemctl --no-pager list-units --all 2>/dev/null | grep -i kontra || echo "   no kontra units (clean)"
echo "DONE — Kontra Nix additions reverted."