#!/usr/bin/env bash
# NodeMesh Agent Installer
# Usage: curl -sSL https://nodemesh.app/install.sh | bash -s -- --token YOUR_TOKEN
#        or: bash install.sh --token YOUR_TOKEN
#
# This script:
#  1. Detects the host OS/arch
#  2. Downloads the nodemesh-agent binary
#  3. Creates the config at /etc/nodemesh/agent.env
#  4. Installs and starts a systemd service

set -euo pipefail

BACKEND_ADDR="${NODEMESH_BACKEND_ADDR:-api.nodemesh.app:9000}"
DOWNLOAD_BASE="${NODEMESH_DOWNLOAD_BASE:-https://nodemesh.app/releases}"
INSTALL_DIR="/usr/local/bin"
CONFIG_DIR="/etc/nodemesh"
DATA_DIR="/opt/nodemesh/data/instances"
SERVICE_FILE="/etc/systemd/system/nodemesh-agent.service"
TOKEN=""

# ── parse flags ───────────────────────────────────────────────────────────────
while [[ $# -gt 0 ]]; do
  case "$1" in
    --token)
      TOKEN="$2"
      shift 2
      ;;
    --backend)
      BACKEND_ADDR="$2"
      shift 2
      ;;
    --data-dir)
      DATA_DIR="$2"
      shift 2
      ;;
    *)
      echo "Unknown flag: $1" >&2
      exit 1
      ;;
  esac
done

if [[ -z "$TOKEN" ]]; then
  echo "NodeMesh Agent Installer"
  echo ""
  read -rp "Paste your pairing token: " TOKEN
fi

if [[ -z "$TOKEN" ]]; then
  echo "Error: pairing token is required." >&2
  exit 1
fi

# ── detect platform ───────────────────────────────────────────────────────────
OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
ARCH="$(uname -m)"
case "$ARCH" in
  x86_64)  ARCH="amd64" ;;
  aarch64) ARCH="arm64" ;;
  armv7l)  ARCH="arm"   ;;
  *)
    echo "Unsupported architecture: $ARCH" >&2
    exit 1
    ;;
esac

if [[ "$OS" != "linux" ]]; then
  echo "Only Linux is supported by the NodeMesh agent." >&2
  exit 1
fi

BINARY="nodemesh-agent-linux-${ARCH}"
DOWNLOAD_URL="${DOWNLOAD_BASE}/${BINARY}"

# ── check for systemd ─────────────────────────────────────────────────────────
if ! command -v systemctl &>/dev/null; then
  echo "Error: systemd is required to install the NodeMesh agent service." >&2
  exit 1
fi

# ── download binary ───────────────────────────────────────────────────────────
echo "→ Downloading NodeMesh agent (${ARCH})…"
TMP="$(mktemp)"
if command -v curl &>/dev/null; then
  curl -sSL "$DOWNLOAD_URL" -o "$TMP"
elif command -v wget &>/dev/null; then
  wget -qO "$TMP" "$DOWNLOAD_URL"
else
  echo "Error: curl or wget is required." >&2
  exit 1
fi
chmod +x "$TMP"
mv "$TMP" "${INSTALL_DIR}/nodemesh-agent"
echo "  ✓ Installed to ${INSTALL_DIR}/nodemesh-agent"

# ── create config ─────────────────────────────────────────────────────────────
echo "→ Writing config to ${CONFIG_DIR}/agent.env…"
mkdir -p "$CONFIG_DIR"
cat > "${CONFIG_DIR}/agent.env" <<EOF
NODEMESH_AGENT_BACKEND_ADDR=${BACKEND_ADDR}
NODEMESH_AGENT_TOKEN=${TOKEN}
NODEMESH_DATA_DIR=${DATA_DIR}
EOF
chmod 600 "${CONFIG_DIR}/agent.env"
mkdir -p "$DATA_DIR"
echo "  ✓ Config written"

# ── install systemd service ───────────────────────────────────────────────────
echo "→ Installing systemd service…"
cat > "$SERVICE_FILE" <<EOF
[Unit]
Description=NodeMesh Agent
After=network-online.target
Wants=network-online.target

[Service]
Type=simple
EnvironmentFile=${CONFIG_DIR}/agent.env
ExecStart=${INSTALL_DIR}/nodemesh-agent
Restart=on-failure
RestartSec=5s
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target
EOF
systemctl daemon-reload
systemctl enable --now nodemesh-agent
echo "  ✓ Service installed and started"

echo ""
echo "✓ NodeMesh agent is running."
echo "  View logs: journalctl -u nodemesh-agent -f"
echo "  Check status: systemctl status nodemesh-agent"