#!/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.
--env is required and must contain RSMON_URL and RSMON_TOKEN.
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 [ -z "$ENV_FILE" ]; then
    printf '%s\n' '--env is required; use a mode-0600 file containing RSMON_URL and RSMON_TOKEN.' >&2
    exit 2
fi

ARGS=(install --binary "$BINARY" --env-file "$ENV_FILE")
if [ "$START_SERVICE" -eq 0 ]; then
    ARGS+=(--no-start)
fi
exec "$BINARY" "${ARGS[@]}"