#!/usr/bin/env bash
set -euo pipefail

REMOTE_HOST="${REMOTE_HOST:-${VPS_HOST:-}}"
REMOTE_USER="${REMOTE_USER:-${VPS_USER:-}}"
if [ -z "$REMOTE_HOST" ]; then
  echo "Set REMOTE_HOST to the SSH host or IP address, for example a local NAS hostname." >&2
  exit 2
fi
if [ -z "$REMOTE_USER" ]; then
  echo "Set REMOTE_USER to the non-root sudo SSH user." >&2
  exit 2
fi
APP_USER="${APP_USER:-mailcat}"
APP_DIR="${APP_DIR:-/opt/mailcat}"
SERVICE_NAME="${SERVICE_NAME:-mailcat-sort-backup}"
ACCOUNT="${ACCOUNT:-backup}"
REMOTE_PATH="${REMOTE_PATH:-/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin}"

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
ARCHIVE="$(mktemp -t mailcat-deploy.XXXXXX.tar.gz)"
REMOTE_SCRIPT="$(mktemp -t mailcat-remote-deploy.XXXXXX.sh)"

cleanup() {
  rm -f "$ARCHIVE"
  rm -f "$REMOTE_SCRIPT"
}
trap cleanup EXIT

tar \
  --exclude ".git" \
  --exclude "__pycache__" \
  --exclude "mailbox" \
  --exclude "config.json" \
  --exclude "*.log" \
  --exclude "backup_log.json" \
  --exclude "verplaats_log*.json" \
  --exclude "sort_mail_daemon_state.json" \
  --exclude "mailing_lists_cache*.json" \
  --exclude "*.pyc" \
  -C "$ROOT_DIR" \
  -czf "$ARCHIVE" .

cat > "$REMOTE_SCRIPT" <<'REMOTE'
set -euo pipefail

export PATH="$REMOTE_PATH:$PATH"
sudo -v

find_command() {
  local name="$1"
  shift
  if command -v "$name" >/dev/null 2>&1; then
    command -v "$name"
    return 0
  fi
  for candidate in "$@"; do
    if [ -x "$candidate" ]; then
      printf '%s\n' "$candidate"
      return 0
    fi
  done
  return 1
}

if ! id "$APP_USER" >/dev/null 2>&1; then
  if USERADD="$(find_command useradd /usr/local/bin/useradd /usr/local/sbin/useradd /usr/sbin/useradd /sbin/useradd)"; then
    NOLOGIN="$(find_command nologin /usr/local/bin/nologin /usr/local/sbin/nologin /usr/sbin/nologin /sbin/nologin || true)"
    if [ -n "$NOLOGIN" ]; then
      sudo "$USERADD" --system --home "$APP_DIR" --shell "$NOLOGIN" "$APP_USER"
    else
      sudo "$USERADD" --system --home "$APP_DIR" "$APP_USER"
    fi
  else
    APP_USER="$(id -un)"
    echo "useradd not found on remote host; using existing SSH user '$APP_USER' for the service." >&2
  fi
fi
APP_GROUP="$(id -gn "$APP_USER")"

sudo mkdir -p "$APP_DIR" /var/lib/mailcat /var/log/mailcat
sudo tar -xzf /tmp/mailcat-deploy.tar.gz -C "$APP_DIR"
sudo chown -R "$APP_USER:$APP_GROUP" "$APP_DIR" /var/lib/mailcat /var/log/mailcat
sudo chmod 750 "$APP_DIR"

if [ ! -f "$APP_DIR/config.json" ]; then
  echo "Missing $APP_DIR/config.json on remote host. Create it with mode 600 before starting the service." >&2
fi
sudo chmod 600 "$APP_DIR/config.json" 2>/dev/null || true
sudo chown "$APP_USER:$APP_GROUP" "$APP_DIR/config.json" 2>/dev/null || true

sudo install -m 0644 "$APP_DIR/systemd/mailcat-sort.service" "/etc/systemd/system/$SERVICE_NAME.service"
sudo sed -i \
  -e "s#__APP_USER__#$APP_USER#g" \
  -e "s#__APP_GROUP__#$APP_GROUP#g" \
  -e "s#__APP_DIR__#$APP_DIR#g" \
  -e "s#__ACCOUNT__#$ACCOUNT#g" \
  "/etc/systemd/system/$SERVICE_NAME.service"

sudo systemctl daemon-reload
sudo systemctl enable "$SERVICE_NAME.service"
rm -f /tmp/mailcat-deploy.tar.gz /tmp/mailcat-remote-deploy.sh

echo "Deployment complete."
echo "Create/check $APP_DIR/config.json, then run:"
echo "  sudo systemctl start $SERVICE_NAME.service"
echo "  sudo journalctl -u $SERVICE_NAME.service -f"
REMOTE

scp "$ARCHIVE" "$REMOTE_USER@$REMOTE_HOST:/tmp/mailcat-deploy.tar.gz"
scp "$REMOTE_SCRIPT" "$REMOTE_USER@$REMOTE_HOST:/tmp/mailcat-remote-deploy.sh"

REMOTE_COMMAND=$(printf "APP_USER=%q APP_DIR=%q SERVICE_NAME=%q ACCOUNT=%q REMOTE_PATH=%q bash /tmp/mailcat-remote-deploy.sh" "$APP_USER" "$APP_DIR" "$SERVICE_NAME" "$ACCOUNT" "$REMOTE_PATH")
ssh -tt "$REMOTE_USER@$REMOTE_HOST" "$REMOTE_COMMAND"