#!/bin/bash

# Check if running as root
if [ "$(id -u)" != "0" ]; then
    if command -v sudo >/dev/null 2>&1; then
        exec sudo "$0" "$@"
    else
        echo "This script must be run as root. Please either:"
        echo "1. Run this script as root (su root)"
        echo "2. Install sudo and run with sudo"
        exit 1
    fi
fi

version=0.0.1
# Define default values
PORT=45876

# Read command line options
while getopts ":k:p:uh" opt; do
  case $opt in
    k) KEY="$OPTARG";;
    p) PORT="$OPTARG";;
    u) UNINSTALL="true";;
    h) printf "Beszel Agent installation script\n\n"
       printf "Usage: ./install-agent.sh [options]\n\n"
       printf "Options: \n"
       printf "  -k  : SSH key (required, or interactive if not provided)\n"
       printf "  -p  : Port (default: $PORT)\n"
       printf "  -u  : Uninstall the Beszel Agent\n"
       printf "  -h  : Display this help message\n"
       exit 0;;
    \?) echo "Invalid option: -$OPTARG"; exit 1;;
  esac
done

if [ "$UNINSTALL" = "true" ]; then
  # Stop and disable the Beszel Agent service
  echo "Stopping and disabling the Beszel Agent service..."
  systemctl stop beszel-agent.service
  systemctl disable beszel-agent.service

  # Remove the systemd service file
  echo "Removing the systemd service file..."
  rm /etc/systemd/system/beszel-agent.service

  # Reload the systemd daemon
  echo "Reloading the systemd daemon..."
  systemctl daemon-reload

  # Remove the Beszel Agent directory
  echo "Removing the Beszel Agent directory..."
  rm -rf /opt/beszel-agent

  # Remove the dedicated user for the Beszel Agent service
  echo "Removing the dedicated user for the Beszel Agent service..."
  userdel beszel

  echo "The Beszel Agent has been uninstalled successfully!"
else
  # Function to check if a package is installed
  package_installed() {
    command -v "$1" >/dev/null 2>&1
  }

  # Check for package manager and install necessary packages if not installed
  if package_installed apt-get; then
    if ! package_installed tar || ! package_installed curl; then
      apt-get update
      apt-get install -y tar curl
    fi
  elif package_installed yum; then
    if ! package_installed tar || ! package_installed curl; then
      yum install -y tar curl
    fi
  elif package_installed pacman; then
    if ! package_installed tar || ! package_installed curl; then
      pacman -Sy --noconfirm tar curl
    fi
  else
    echo "Warning: Please ensure 'tar' and 'curl' are installed."
  fi

  # If no SSH key is provided, ask for the SSH key interactively
  if [ -z "$KEY" ]; then
    read -p "Enter your SSH key: " KEY
  fi

  # Create a dedicated user for the service if it doesn't exist
  if ! id -u beszel > /dev/null 2>&1; then
    echo "Creating a dedicated user for the Beszel Agent service..."
    useradd -M -s /bin/false beszel
  fi
  # Add the user to the docker group to allow access to the Docker socket
  usermod -aG docker beszel

  # Create the directory for the Beszel Agent
  if [ ! -d "/opt/beszel-agent" ]; then
    echo "Creating the directory for the Beszel Agent..."
    mkdir -p /opt/beszel-agent
    chown beszel:beszel /opt/beszel-agent
    chmod 755 /opt/beszel-agent
  fi

  # Download and install the Beszel Agent
  echo "Downloading and installing the Beszel Agent..."
  curl -sL "https://github.com/henrygd/beszel/releases/latest/download/beszel-agent_$(uname -s)_$(uname -m | sed 's/x86_64/amd64/' | sed 's/armv7l/arm/' | sed 's/aarch64/arm64/').tar.gz" | tar -xz -O beszel-agent | tee ./beszel-agent >/dev/null
  mv ./beszel-agent /opt/beszel-agent/beszel-agent
  chown beszel:beszel /opt/beszel-agent/beszel-agent
  chmod 755 /opt/beszel-agent/beszel-agent

  # Create the systemd service
  echo "Creating the systemd service for the Beszel Agent..."
  tee /etc/systemd/system/beszel-agent.service <<EOF
[Unit]
Description=Beszel Agent Service
After=network.target

[Service]
Environment="PORT=$PORT"
Environment="KEY=$KEY"
# Environment="EXTRA_FILESYSTEMS=sdb"
ExecStart=/opt/beszel-agent/beszel-agent
User=beszel
Restart=always

[Install]
WantedBy=multi-user.target
EOF

  # Load and start the service
  printf "\nLoading and starting the Beszel Agent service...\n"
  systemctl daemon-reload
  systemctl enable beszel-agent.service
  systemctl start beszel-agent.service

  # Wait for the service to start or fail
  sleep 1

  # Check if the service is running
  if [ "$(systemctl is-active beszel-agent.service)" != "active" ]; then
    echo "Error: The Beszel Agent service is not running."
    echo "$(systemctl status beszel-agent.service)"
    exit 1
  fi

  echo "The Beszel Agent has been installed and configured successfully! It is now running on port $PORT."
fi