// Smart Home Automation CLI - Dart
// Assignment 1 - Problem 1
// File: NaifAlkanhal_251000447_Smart Home Automation Problem1.txt
//
// How to run (after saving as .dart if needed):
//   dart run smart_home.dart
//
// Note: This submission is saved as .txt per instructions, but the content is valid Dart code.

import 'dart:io';

const int minTempC = 15;
const int maxTempC = 30;

enum SecurityState { armed, disarmed }

class SmartHomeSystem {
  bool lightsOn;
  int thermostatC;
  SecurityState securityState;

  SmartHomeSystem({
    required this.lightsOn,
    required this.thermostatC,
    required this.securityState,
  });

  void toggleLights() {
    lightsOn = !lightsOn;
    stdout.writeln('Lights are now ${lightsOn ? "ON" : "OFF"}.');
  }

  void setThermostat(int newTempC) {
    thermostatC = newTempC;
    stdout.writeln('Thermostat set to ${thermostatC}°C.');
  }

  void toggleSecurity() {
    securityState =
        (securityState == SecurityState.armed) ? SecurityState.disarmed : SecurityState.armed;
    final statusText = securityState == SecurityState.armed ? 'ARMED' : 'DISARMED';
    stdout.writeln('Security system is now $statusText.');
  }

  String _tempLabelFizzBuzz(int tempC) {
    // FizzBuzz-like requirement:
    // multiple of 3 => "Cool Day"
    // multiple of 5 => "Warm Day"
    // multiple of both => "Perfect Day"
    final bool mult3 = (tempC % 3 == 0);
    final bool mult5 = (tempC % 5 == 0);

    if (mult3 && mult5) return 'Perfect Day';
    if (mult3) return 'Cool Day';
    if (mult5) return 'Warm Day';
    return '';
  }

  void showStatus() {
    final lightsText = lightsOn ? 'ON' : 'OFF';

    final securityText =
        (securityState == SecurityState.armed) ? 'armed' : 'disarmed';
    // String operation example: convert to upper-case for display
    final securityDisplay = securityText.toUpperCase();

    final label = _tempLabelFizzBuzz(thermostatC);
    final tempLine = label.isEmpty
        ? '${thermostatC}°C'
        : '${thermostatC}°C - $label';

    stdout.writeln('\nSystem Status:');
    stdout.writeln('- Lights: $lightsText');
    stdout.writeln('- Thermostat: $tempLine');
    stdout.writeln('- Security System: $securityDisplay\n');
  }
}

String _readLineTrimmed() {
  return (stdin.readLineSync() ?? '').trim();
}

int _readMenuChoice({required int min, required int max}) {
  while (true) {
    stdout.write('Enter your choice: ');
    final input = _readLineTrimmed();
    final value = int.tryParse(input);

    if (value != null && value >= min && value <= max) {
      return value;
    }
    stdout.writeln('Invalid choice. Please enter a number between $min and $max.');
  }
}

int _readTemperatureC() {
  while (true) {
    stdout.write('Set thermostat temperature ($minTempC°C - $maxTempC°C): ');
    final input = _readLineTrimmed();
    final value = int.tryParse(input);

    // Logical & relational operators for validation as required
    if (value != null && value >= minTempC && value <= maxTempC) {
      return value;
    }
    stdout.writeln('Invalid temperature. Please enter a value between $minTempC and $maxTempC.');
  }
}

void main() {
  final system = SmartHomeSystem(
    // Default values per requirements:
    lightsOn: false,           // lightsOff
    thermostatC: 20,           // 20°C
    securityState: SecurityState.disarmed,
  );

  stdout.writeln('Welcome to the Smart Home System!');

  bool running = true;
  while (running) {
    stdout.writeln('\nPlease choose an action:');
    stdout.writeln('1. Toggle lights');
    stdout.writeln('2. Set thermostat temperature');
    stdout.writeln('3. Arm/disarm security system');
    stdout.writeln('4. View system status');
    stdout.writeln('5. Exit');

    final choice = _readMenuChoice(min: 1, max: 5);

    // Control flow requirement: if/else for user choices
    if (choice == 1) {
      // Switch requirement: handle device commands (lights, thermostat, security)
      const device = 'lights';
      switch (device) {
        case 'lights':
          system.toggleLights();
          break;
        case 'thermostat':
          // Not used here
          break;
        case 'security':
          // Not used here
          break;
        default:
          stdout.writeln('Unknown device.');
      }
    } else if (choice == 2) {
      const device = 'thermostat';
      switch (device) {
        case 'lights':
          // Not used here
          break;
        case 'thermostat':
          final temp = _readTemperatureC();
          system.setThermostat(temp);
          break;
        case 'security':
          // Not used here
          break;
        default:
          stdout.writeln('Unknown device.');
      }
    } else if (choice == 3) {
      const device = 'security';
      switch (device) {
        case 'lights':
          // Not used here
          break;
        case 'thermostat':
          // Not used here
          break;
        case 'security':
          system.toggleSecurity();
          break;
        default:
          stdout.writeln('Unknown device.');
      }
    } else if (choice == 4) {
      system.showStatus();
    } else {
      stdout.writeln('Exiting the system. Goodbye!');
      running = false;
    }
  }
}