#!/usr/bin/env bash
set -Eeuo pipefail
SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
# shellcheck source=common.sh
source "$SCRIPT_DIR/common.sh"
cd "$PROJECT_ROOT"

RUN_TESTS=1

usage() {
  cat <<'TXT'
Update an existing systemd/LXC GREE Controller installation from this source tree.

Usage:
  sudo ./scripts/update.sh
  sudo ./scripts/update.sh --skip-tests

The updater:
  1. builds and tests the new release while the old service is still running,
  2. stops the service,
  3. backs up the binary, systemd unit, environment file and SQLite database,
  4. installs the new binary and unit,
  5. restarts and checks /api/health,
  6. rolls back the binary/unit/database automatically if startup fails.
TXT
}

while [[ $# -gt 0 ]]; do
  case "$1" in
    --skip-tests) RUN_TESTS=0; shift ;;
    -h|--help) usage; exit 0 ;;
    *) echo "Unknown argument: $1" >&2; usage; exit 2 ;;
  esac
done

require_root
require_systemd
[[ -x "$INSTALL_BINARY" ]] || fail "No installed binary at $INSTALL_BINARY. Run scripts/install.sh first."
[[ -f "$SERVICE_FILE" ]] || fail "No installed systemd unit at $SERVICE_FILE. Run scripts/install.sh first."

install_build_dependencies
ensure_rust
version="$(project_version)"
say "Preparing update to GREE Controller ${version:-unknown}"

if [[ "$RUN_TESTS" -eq 1 ]]; then
  say "Running Rust tests before touching the running service"
  cargo test --all-targets
fi
say "Building release binary"
cargo build --release

stamp="$(backup_timestamp)"
backup_dir="$BACKUP_ROOT/$stamp"
install -d -o root -g root -m 0700 "$backup_dir"
db_path="$(database_path)"

rollback() {
  local rc=$?
  trap - ERR
  set +e
  warn "Update failed; restoring previous installation from $backup_dir"
  systemctl stop "$SERVICE_NAME" >/dev/null 2>&1 || true
  if [[ -f "$backup_dir/gree-controller.binary" ]]; then
    install -o root -g root -m 0755 "$backup_dir/gree-controller.binary" "$INSTALL_BINARY"
  fi
  if [[ -f "$backup_dir/gree-controller.service" ]]; then
    install -o root -g root -m 0644 "$backup_dir/gree-controller.service" "$SERVICE_FILE"
  fi
  if [[ -f "$backup_dir/gree-controller.env" ]]; then
    install -o root -g root -m 0600 "$backup_dir/gree-controller.env" "$ENV_FILE"
  fi
  if [[ -f "$backup_dir/gree-controller.db" ]]; then
    install -o "$SERVICE_USER" -g "$SERVICE_GROUP" -m 0640 "$backup_dir/gree-controller.db" "$db_path"
  fi
  rm -f "${db_path}-wal" "${db_path}-shm"
  systemctl daemon-reload
  systemctl start "$SERVICE_NAME" >/dev/null 2>&1 || true
  exit "$rc"
}
trap rollback ERR

say "Stopping service for a consistent SQLite backup"
systemctl stop "$SERVICE_NAME"

cp -a "$INSTALL_BINARY" "$backup_dir/gree-controller.binary"
cp -a "$SERVICE_FILE" "$backup_dir/gree-controller.service"
[[ -f "$ENV_FILE" ]] && cp -a "$ENV_FILE" "$backup_dir/gree-controller.env"
if [[ -f "$db_path" ]]; then
  cp -a "$db_path" "$backup_dir/gree-controller.db"
fi
say "Backup created: $backup_dir"

say "Installing new release binary"
install -o root -g root -m 0755 target/release/gree-controller "$INSTALL_BINARY.new"
mv -f "$INSTALL_BINARY.new" "$INSTALL_BINARY"
install -o root -g root -m 0644 systemd/gree-controller.service "$SERVICE_FILE"
systemctl daemon-reload
systemctl start "$SERVICE_NAME"

if ! wait_for_health 80; then
  journalctl -u "$SERVICE_NAME" -n 100 --no-pager || true
  false
fi

trap - ERR
say "Update complete"
printf 'Version: %s\n' "${version:-unknown}"
printf 'Panel:   %s\n' "$(panel_url)"
printf 'Backup:  %s\n' "$backup_dir"