#!/bin/sh
set -eu

# Must run as root
if [ "$(id -u)" -ne 0 ]; then
  echo "Error: please run as root (e.g., sudo $0)" >&2
  exit 1
fi

URL="https://install.joingallop.com/gallop-agent"
BIN="/usr/local/bin/gallop-agent"
SERVICE="/etc/systemd/system/gallop-agent.service"

# Pick downloader
if command -v wget >/dev/null 2>&1; then
  DL_WGET=1
elif command -v curl >/dev/null 2>&1; then
  DL_WGET=0
else
  echo "Error: need wget or curl installed." >&2
  exit 1
fi

echo "Installing gallop-agent binary to $BIN..."
if [ "$DL_WGET" -eq 1 ]; then
  wget -qO "$BIN" "$URL"
else
  curl -fsSL -o "$BIN" "$URL"
fi

if [ ! -s "$BIN" ]; then
  echo "Error: download failed (file is empty)." >&2
  exit 1
fi

chmod 0755 "$BIN"

# Create service user (optional but recommended)
if ! id -u gallop-agent >/dev/null 2>&1; then
  useradd --system --no-create-home --shell /usr/sbin/nologin gallop-agent
fi

# Create systemd unit
echo "Creating systemd service at $SERVICE..."
cat > "$SERVICE" <<'EOF'
[Unit]
Description=Gallop Agent
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
User=root
Group=root
ExecStart=/usr/local/bin/gallop-agent
Restart=always
RestartSec=5

[Install]
WantedBy=multi-user.target
EOF

# Create writable dirs referenced above
install -d -m 0755 -o gallop-agent -g gallop-agent /var/lib/gallop-agent /var/log/gallop-agent

# Reload and enable/start
systemctl daemon-reload
systemctl enable --now gallop-agent

echo "Done."
echo "Status:"
systemctl --no-pager --full status gallop-agent || true
echo "Logs:"
echo "  journalctl -u gallop-agent -f"