#!/usr/bin/env bash
# Installs deploy-watch.sh as a systemd service so it survives reboots and
# restarts on failure. Run on the host that runs `docker compose` for this
# stack (i.e. where ./deploy-trigger and the repo checkout actually live).
#
# Usage: sudo ./scripts/install-deploy-watch.sh [user]
#   user  account to run the watcher as (must be in the `docker` group).
#         Defaults to $SUDO_USER, or the current user if not run via sudo.

set -euo pipefail

if [ "$(id -u)" -ne 0 ]; then
  echo "Run this with sudo (writes to /etc/systemd/system)." >&2
  exit 1
fi

SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
REPO_DIR="$(dirname "$SCRIPT_DIR")"
DEPLOY_USER="${1:-${SUDO_USER:-$(id -un)}}"
UNIT_NAME="deploy-watch-hwilliams-dev.service"
UNIT_DEST="/etc/systemd/system/$UNIT_NAME"
# Compose service name from docker-compose.yml.
SERVICE="portfolio"
if ! id "$DEPLOY_USER" >/dev/null 2>&1; then
  echo "User '$DEPLOY_USER' does not exist." >&2
  exit 1
fi

if ! id -nG "$DEPLOY_USER" | grep -qw docker; then
  echo "Warning: '$DEPLOY_USER' is not in the 'docker' group;" \
       "docker compose calls in deploy-watch.sh will fail until you add it" \
       "(sudo usermod -aG docker $DEPLOY_USER) and re-login." >&2
fi

TRIGGER_DIR="$REPO_DIR/deploy-trigger"
# The web container (uid/gid 1001, see Dockerfile) writes the flag through a
# bind mount and the watcher deletes it, so both need write access.
CONTAINER_GID=1001
mkdir -p "$TRIGGER_DIR"
chown "$DEPLOY_USER:$CONTAINER_GID" "$TRIGGER_DIR"
chmod 2775 "$TRIGGER_DIR"
if ! sudo -u "$DEPLOY_USER" test -w "$TRIGGER_DIR"; then
  echo "Warning: '$DEPLOY_USER' cannot write to $TRIGGER_DIR;" \
       "the watcher will fail to clear the trigger file and restart-loop." >&2
fi

chmod +x "$SCRIPT_DIR/deploy-watch.sh"

sed \
  -e "s|__REPO_DIR__|$REPO_DIR|g" \
  -e "s|__SERVICE__|$SERVICE|g" \
  -e "s|__DEPLOY_USER__|$DEPLOY_USER|g" \
  "$SCRIPT_DIR/deploy-watch.service" > "$UNIT_DEST"

systemctl daemon-reload
systemctl enable "$UNIT_NAME"
# restart (not start) so a reinstall picks up changes to the unit or script.
systemctl restart "$UNIT_NAME"

echo "Installed and started $UNIT_NAME (repo: $REPO_DIR, user: $DEPLOY_USER)."
echo "Check status with: systemctl status $UNIT_NAME"
echo "Follow logs with:  journalctl -u $UNIT_NAME -f"