#!/usr/bin/env bash
# Re-points the existing LAN dev self-hosted runner from GitHub Actions to
# Forgejo Actions. Run on the SAME machine that already runs the GitHub
# runner (see DEPLOY-DEV.md) — this replaces that runner, it doesn't add a
# second one. Sudo-free, systemd --user, same pattern as the app service.
#
# This is THE runner (docs/runbooks/implementation-handoff.md Track B step 5
# — canonical placement is the desktop, not a Swarm-hosted container), so it
# registers with BOTH labels the workflows need, where one runner used to be
# two: general CI/build/deploy.yml jobs (`docker`, containerized via this
# machine's own already-installed Docker — no Docker-in-Docker sidecar needed,
# unlike the Swarm-hosted design this replaces, since a real host with a real
# Docker install needs no such indirection) and the LAN-deploy job
# (`thermograph-lan`, bare/host-native — it writes to ~/thermograph-dev and
# restarts a systemd --user service, which only works running directly on the
# host, not inside a container).
#
#   bash deploy/forgejo/register-lan-runner.sh <forgejo_url> <registration_token>
#
# Get <registration_token> from the Forgejo web UI:
#   repo -> Settings -> Actions -> Runners -> Create new Runner
# (or an org/instance-level runner page, if you want it to serve more than
# this one repo — same as the GitHub runner did).
set -euo pipefail

FORGEJO_URL="${1:?usage: $0 <forgejo_url> <registration_token>}"
TOKEN="${2:?}"
RUNNER_DIR="${RUNNER_DIR:-$HOME/forgejo-runner}"
LABELS="${LABELS:-docker:docker://node:20-bookworm,thermograph-lan}"

echo "==> Stopping and disabling the old GitHub Actions runner service, if present"
systemctl --user stop github-actions-runner 2>/dev/null || true
systemctl --user disable github-actions-runner 2>/dev/null || true

if ! id -nG "$USER" 2>/dev/null | grep -qw docker; then
  echo "WARNING: $USER is not in the 'docker' group — the 'docker:docker://...'"
  echo "labeled jobs (general CI) will fail to start a container until this is"
  echo "fixed: sudo usermod -aG docker $USER && (log out and back in)."
fi

echo "==> Installing forgejo-runner into $RUNNER_DIR"
mkdir -p "$RUNNER_DIR"
cd "$RUNNER_DIR"
if [ ! -x ./forgejo-runner ]; then
  ARCH="$(uname -m)"
  case "$ARCH" in
    x86_64) BIN_ARCH=amd64 ;;
    aarch64) BIN_ARCH=arm64 ;;
    *) echo "Unsupported arch: $ARCH — download the right binary by hand from" \
            "https://code.forgejo.org/forgejo/runner/releases" >&2; exit 1 ;;
  esac
  VER="${FORGEJO_RUNNER_VERSION:-6.3.1}"
  curl -fsSL -o forgejo-runner \
    "https://code.forgejo.org/forgejo/runner/releases/download/v${VER}/forgejo-runner-${VER}-linux-${BIN_ARCH}"
  chmod +x forgejo-runner
fi

echo "==> Registering with $FORGEJO_URL (label: $LABELS)"
./forgejo-runner register --no-interactive \
  --instance "$FORGEJO_URL" \
  --token "$TOKEN" \
  --name "thermograph-lan-$(hostname -s)" \
  --labels "$LABELS"

echo "==> Runner config (docker.sock automount, so docker:-labeled jobs like"
echo "    build-push.yml can actually run 'docker build/push' -- generated"
echo "    config only overridden on the one setting that matters here)"
./forgejo-runner generate-config \
  | sed 's/docker_host: "-"/docker_host: "automount"/' \
  > "${RUNNER_DIR}/config.yaml"

echo "==> systemd --user unit"
mkdir -p "$HOME/.config/systemd/user"
cat > "$HOME/.config/systemd/user/forgejo-runner.service" <<EOF
[Unit]
Description=Forgejo Actions runner (docker + thermograph-lan)
After=network-online.target

[Service]
WorkingDirectory=${RUNNER_DIR}
ExecStart=${RUNNER_DIR}/forgejo-runner daemon -c config.yaml
Restart=on-failure
RestartSec=5

[Install]
WantedBy=default.target
EOF

systemctl --user daemon-reload
systemctl --user enable --now forgejo-runner
loginctl enable-linger "$USER" 2>/dev/null || true

cat <<EOF

Done. The runner now serves Forgejo, not GitHub — one runner, both labels
($LABELS), replacing what used to be a separate Swarm-hosted runner for
general CI plus this machine's own GitHub runner for LAN deploys.
  status:  systemctl --user status forgejo-runner
  logs:    journalctl --user -u forgejo-runner -f
  restart: systemctl --user restart forgejo-runner

The old github-actions-runner unit was stopped and disabled but not deleted —
remove ~/actions-runner by hand once you've confirmed Forgejo deploys work.
EOF