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

ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
BINARY="${RSMON_WORKER_BINARY:-${ROOT_DIR}/bin/rsmon-worker}"
ENV_FILE="${RSMON_WORKER_ENV_FILE:-}"
START_SERVICE=1

usage() {
    cat <<'USAGE'
Usage: sudo ./scripts/install-systemd.sh [--binary PATH] [--env PATH] [--no-start]

Installs rsmon-worker as /usr/local/bin/rsmon-worker and configures systemd.
If --env is omitted on a first install, an example file is installed and the
service is not started until its token and password are configured.
USAGE
}

while [ "$#" -gt 0 ]; do
    case "$1" in
        --binary)
            BINARY="${2:?--binary requires a path}"
            shift 2
            ;;
        --env)
            ENV_FILE="${2:?--env requires a path}"
            shift 2
            ;;
        --no-start)
            START_SERVICE=0
            shift
            ;;
        -h|--help)
            usage
            exit 0
            ;;
        *)
            printf 'Unknown argument: %s\n' "$1" >&2
            usage >&2
            exit 2
            ;;
    esac
done

if [ "$(id -u)" -ne 0 ]; then
    printf 'Run this installer as root.\n' >&2
    exit 1
fi

if [ ! -x "$BINARY" ]; then
    if command -v go >/dev/null 2>&1; then
        make -C "$ROOT_DIR" build
    else
        printf 'Worker binary not found at %s and Go is unavailable.\n' "$BINARY" >&2
        exit 1
    fi
fi

if ! command -v chromium >/dev/null 2>&1; then
    if command -v apt-get >/dev/null 2>&1; then
        apt-get update
        DEBIAN_FRONTEND=noninteractive apt-get install -y --no-install-recommends ca-certificates chromium libcap2-bin tzdata
    else
        printf 'Warning: Chromium is not installed; browser-backed HTTP checks will fail.\n' >&2
    fi
fi

if ! getent group rsmon-worker >/dev/null; then
    groupadd --system rsmon-worker
fi
if ! id rsmon-worker >/dev/null 2>&1; then
    useradd --system --gid rsmon-worker --home-dir /var/lib/rsmon-worker --create-home --shell /usr/sbin/nologin rsmon-worker
fi

install -d -m 0755 /etc/rsmon-worker
install -d -o rsmon-worker -g rsmon-worker -m 0750 /var/lib/rsmon-worker /var/lib/rsmon-worker/webapp /var/lib/rsmon-worker/cluster
install -m 0755 "$BINARY" /usr/local/bin/rsmon-worker
install -m 0644 "$ROOT_DIR/packaging/systemd/rsmon-worker.service" /etc/systemd/system/rsmon-worker.service

if [ -n "$ENV_FILE" ]; then
    install -m 0600 "$ENV_FILE" /etc/rsmon-worker/worker.env
elif [ ! -f /etc/rsmon-worker/worker.env ]; then
    install -m 0600 "$ROOT_DIR/packaging/systemd/worker.env.example" /etc/rsmon-worker/worker.env
    START_SERVICE=0
    printf 'Installed /etc/rsmon-worker/worker.env; configure it before starting the service.\n'
fi

if command -v setcap >/dev/null 2>&1; then
    setcap cap_net_raw=+ep /usr/local/bin/rsmon-worker || true
fi

systemctl daemon-reload
systemctl enable rsmon-worker.service
if [ "$START_SERVICE" -eq 1 ]; then
    systemctl restart rsmon-worker.service
    systemctl --no-pager --full status rsmon-worker.service
else
    printf 'Start after configuration with: systemctl start rsmon-worker\n'
fi