import 'dart:math';

/// Provides lightweight, offline activity suggestions using heuristics.
class ActivitySuggestionService {
  /// Returns a list of suggestion strings based on [city] and [weatherCode].
  ///
  /// [weatherCode] is a simple tag: `sunny`, `rain`, `cold`, `default`.
  List<String> suggestions({
    required String city,
    String weatherCode = 'default',
  }) {
    final base = <String>[
      'Free walking tour de $city',
      'Spot photo au coucher du soleil',
      'Café local pour travailler/charger',
      'Parc ou rooftop tranquille',
    ];

    if (weatherCode == 'rain') {
      base.addAll([
        'Musée immanquable de $city',
        'Escape game ou activité indoor',
        'Food court couvert pour goûter local',
      ]);
    } else if (weatherCode == 'cold') {
      base.addAll(['Spa / bains chauds', 'Visite guidée en intérieur']);
    } else {
      base.addAll([
        'Balade vélo ou trottinette',
        'Pique-nique au parc central',
        'Vue panoramique / rooftop',
      ]);
    }

    // Shuffle slightly for variation.
    base.shuffle(Random(city.hashCode));
    return base.take(6).toList();
  }
}