{ pkgs, lib, ... }:

let
  # Base script header and common setup for all device types
  baseScriptHeader = ''
    #!/usr/bin/env bash
    set -euo pipefail

    # The device type is baked into the script at build time
    readonly NUMBUS_DEVICE_TYPE="${deviceType}"

    # Common utility function for consistent output
    numbus_echo() {
      echo "[Numbus CLI - $NUMBUS_DEVICE_TYPE] $*"
    }
  '';

  # --- Device-specific script definitions ---

  serverScript = baseScriptHeader + ''
    case "$1" in
      test)
        numbus_echo "Hello World! This is a Numbus Server."
        ;;
      status)
        numbus_echo "Checking system status for Server..."
        numbus_echo "--- Podman Containers ---"
        podman ps || numbus_echo "No Podman containers found or Podman not running."
        systemctl list-units --type=service "numbus-*" --no-pager || numbus_echo "No Numbus services found."
        ;;
      upgrade)
        numbus_echo "Pulling latest configuration and upgrading for Server..."
        # Add server-specific upgrade logic here (e.g., nixos-rebuild switch)
        ;;
      *)
        numbus_echo "Numbus CLI (Server edition)"
        echo ""
        echo "Usage: numbus <command>"
        echo ""
        echo "Commands:"
        echo "  test     - Print a test message"
        numbus_echo "  status   - Show status of Numbus services (Podman, systemd)"
        numbus_echo "  upgrade  - Upgrade the server configuration"
        ;;
    esac
  '';

  backupScript = baseScriptHeader + ''
    case "$1" in
      test)
        numbus_echo "Hello World! This is a Numbus Backup Server."
        ;;
      status)
        numbus_echo "Checking system status for Backup Server..."
        systemctl list-units --type=service "numbus-*" --no-pager || numbus_echo "No Numbus services found."
        # Add backup-specific status checks here (e.g., SnapRAID status, rsync jobs)
        ;;
      restore)
        numbus_echo "Starting interactive restore wizard for Backup Server..."
        # Add backup-specific restore logic here
        ;;
      upgrade)
        numbus_echo "Pulling latest configuration and upgrading for Backup Server..."
        # Add backup-specific upgrade logic here
        ;;
      *)
        numbus_echo "Numbus CLI (Backup Server edition)"
        echo ""
        echo "Usage: numbus <command>"
        echo ""
        echo "Commands:"
        numbus_echo "  test     - Print a test message"
        numbus_echo "  status   - Show status of Numbus services"
        numbus_echo "  restore  - Start interactive restore wizard"
        numbus_echo "  upgrade  - Upgrade the backup server configuration"
        ;;
    esac
  '';

  computerScript = baseScriptHeader + ''
    case "$1" in
      test)
        numbus_echo "Hello World! This is a Numbus Computer."
        ;;
      status)
        numbus_echo "Checking system status for Computer..."
        systemctl list-units --type=service "numbus-*" --no-pager || numbus_echo "No Numbus services found."
        # Add computer-specific status checks (e.g., GPU status, Flatpak updates)
        ;;
      upgrade)
        numbus_echo "Pulling latest configuration and upgrading for Computer..."
        # Add computer-specific upgrade logic here
        ;;
      *)
        numbus_echo "Numbus CLI (Computer edition)"
        echo ""
        echo "Usage: numbus <command>"
        echo ""
        echo "Commands:"
        numbus_echo "  test     - Print a test message"
        numbus_echo "  status   - Show status of Numbus services"
        numbus_echo "  upgrade  - Upgrade the computer configuration"
        ;;
    esac
  '';

  tvScript = baseScriptHeader + ''
    case "$1" in
      test)
        numbus_echo "Hello World! This is a Numbus TV."
        ;;
      status)
        numbus_echo "Checking system status for TV..."
        systemctl list-units --type=service "numbus-*" --no-pager || numbus_echo "No Numbus services found."
        # Add TV-specific status checks (e.g., media server status, remote connectivity)
        ;;
      remote)
        numbus_echo "Pairing a new Bluetooth remote for TV..."
        # Add TV-specific remote pairing logic here
        ;;
      upgrade)
        numbus_echo "Pulling latest configuration and upgrading for TV..."
        # Add TV-specific upgrade logic here
        ;;
      *)
        numbus_echo "Numbus CLI (TV edition)"
        echo ""
        echo "Usage: numbus <command>"
        echo ""
        numbus_echo "Commands:"
        numbus_echo "  test     - Print a test message"
        numbus_echo "  status   - Show status of Numbus services"
        numbus_echo "  remote   - Pair a new Bluetooth remote"
        numbus_echo "  upgrade  - Upgrade the TV configuration"
        ;;
    esac
  '';

  # Use lib.switch to select the correct script based on deviceType
  selectedScript = lib.switch deviceType {
    server = serverScript;
    backup = backupScript;
    computer = computerScript;
    tv = tvScript;
  } (throw "Unknown Numbus device type: ${deviceType}"); # Fail if an unknown deviceType is encountered

  # Define the numbus-cli package using the selected script
  numbus = pkgs.writeShellScriptBin "numbus" selectedScript;

in {
  environment.systemPackages = [ numbus ];

  # Add a useful alias so people can check the type via env
  environment.variables.NUMBUS_DEVICE_TYPE = deviceType;
}