#!/usr/bin/env bash
# Install and register a repository-scoped Gitea Actions runner on a dedicated Linux CI host.
# This script must be run on the CI host, not on the Gitea application server.

set -Eeuo pipefail

readonly RUNNER_VERSION="${RUNNER_VERSION:-0.2.11}"
readonly RUNNER_USER="${RUNNER_USER:-gitea-runner}"
readonly RUNNER_HOME="${RUNNER_HOME:-/opt/gitea-runner}"
readonly INSTANCE_URL="${INSTANCE_URL:-https://git.mozdit.hu}"
readonly RUNNER_NAME="${RUNNER_NAME:-mozdit-ci-01}"
readonly RUNNER_LABELS="${RUNNER_LABELS:-ubuntu-latest:host}"

fail() {
  printf 'HIBA: %s\n' "$*" >&2
  exit 1
}

require_command() {
  command -v "$1" >/dev/null 2>&1 || fail "Hiányzó parancs: $1"
}

if [[ "${EUID}" -ne 0 ]]; then
  fail "Futtasd sudo-val: sudo ./scripts/install-gitea-runner.sh"
fi

require_command curl
require_command docker
require_command node
require_command npm

docker info >/dev/null 2>&1 || fail "A Docker daemon nem érhető el. Indítsd el, majd futtasd újra a scriptet."
docker compose version >/dev/null 2>&1 || fail "Hiányzik a Docker Compose v2 (docker compose)."

case "$(uname -m)" in
  x86_64) runner_arch="amd64" ;;
  aarch64|arm64) runner_arch="arm64" ;;
  *) fail "Nem támogatott CPU-architektúra: $(uname -m)" ;;
esac

readonly RUNNER_ARCH="${runner_arch}"
readonly RUNNER_URL="https://dl.gitea.com/gitea-runner/${RUNNER_VERSION}/act_runner-${RUNNER_VERSION}-linux-${RUNNER_ARCH}"

if ! id -u "${RUNNER_USER}" >/dev/null 2>&1; then
  useradd --system --create-home --home-dir "${RUNNER_HOME}" --shell /usr/sbin/nologin "${RUNNER_USER}"
fi

usermod -aG docker "${RUNNER_USER}"
install -d -o "${RUNNER_USER}" -g "${RUNNER_USER}" -m 0750 "${RUNNER_HOME}"

tmp_binary="$(mktemp)"
trap 'rm -f "${tmp_binary}"' EXIT
curl --fail --location --retry 3 --output "${tmp_binary}" "${RUNNER_URL}"
install -o root -g root -m 0755 "${tmp_binary}" "${RUNNER_HOME}/act_runner"

"${RUNNER_HOME}/act_runner" --version

if [[ ! -f "${RUNNER_HOME}/.runner" ]]; then
  if [[ -z "${GITEA_RUNNER_REGISTRATION_TOKEN:-}" ]]; then
    read -r -s -p "Gitea runner regisztrációs token: " GITEA_RUNNER_REGISTRATION_TOKEN
    printf '\n'
  fi
  [[ -n "${GITEA_RUNNER_REGISTRATION_TOKEN}" ]] || fail "Üres regisztrációs token."

  # The token is intentionally neither written to disk nor printed by this script.
  runuser -u "${RUNNER_USER}" -- "${RUNNER_HOME}/act_runner" register --no-interactive \
    --instance "${INSTANCE_URL}" \
    --token "${GITEA_RUNNER_REGISTRATION_TOKEN}" \
    --name "${RUNNER_NAME}" \
    --labels "${RUNNER_LABELS}"
else
  printf 'A runner már regisztrálva van, a regisztráció kihagyva.\n'
fi

install -m 0644 /dev/stdin /etc/systemd/system/gitea-act-runner.service <<EOF
[Unit]
Description=Gitea Actions Runner (${RUNNER_NAME})
After=network-online.target docker.service
Wants=network-online.target

[Service]
User=${RUNNER_USER}
WorkingDirectory=${RUNNER_HOME}
ExecStart=${RUNNER_HOME}/act_runner daemon
Restart=always
RestartSec=5
NoNewPrivileges=true
PrivateTmp=true

[Install]
WantedBy=multi-user.target
EOF

systemctl daemon-reload
systemctl enable --now gitea-act-runner.service
systemctl --no-pager --full status gitea-act-runner.service

printf '\nKész. Ellenőrizd a Gitea felületén: Settings → Actions → Runners; az állapotnak Idle-nak kell lennie.\n'