#!/usr/bin/env bash
# Pull the latest LLeMbas into the deployment and restart the service.
#
# Run this after pushing. It fetches, hard-resets the deployment checkout to the
# remote branch, reinstalls dependencies if they changed, and restarts. Nothing
# is ever edited in place under the deployment prefix, so a hard reset is safe
# and avoids merge conflicts from a dirty tree.
set -euo pipefail

SERVICE_USER="${SERVICE_USER:-lembas}"
PREFIX="${PREFIX:-/srv/lembas}"
BRANCH="${LEMBAS_BRANCH:-main}"

APP="$PREFIX/app"
VENV="$PREFIX/venv"

if [[ ! -d "$APP/.git" ]]; then
  echo "No deployment at $APP. Run deploy/install.sh first." >&2
  exit 1
fi

git_as() { sudo -u "$SERVICE_USER" git -C "$APP" "$@"; }

before=$(git_as rev-parse HEAD)

echo "== fetching =="
git_as fetch --quiet origin "$BRANCH"
git_as reset --hard --quiet "origin/$BRANCH"

after=$(git_as rev-parse HEAD)

if [[ "$before" == "$after" ]]; then
  echo "   already at ${after:0:7}, nothing to pull"
else
  echo "   ${before:0:7} -> ${after:0:7}"
  git_as --no-pager log --oneline "$before..$after" | sed 's/^/     /'
fi

# Cheap and idempotent; catches a dependency added since the last deploy.
echo "== dependencies =="
sudo -u "$SERVICE_USER" "$VENV/bin/pip" install --quiet -e "$APP"

echo "== restart =="
sudo systemctl restart lembas
sleep 2

if systemctl is-active --quiet lembas; then
  echo "   lembas is running"
else
  echo "   lembas FAILED to start:" >&2
  sudo journalctl -u lembas -n 30 --no-pager >&2
  exit 1
fi