import 'package:flutter/services.dart';
import 'package:package_info_plus/package_info_plus.dart';
import 'package:shared_preferences/shared_preferences.dart';

class NotaVersionPluri {
  const NotaVersionPluri({
    required this.version,
    required this.resumen,
    required this.markdown,
  });

  final String version;
  final String resumen;
  final String markdown;
}

class ContenidoAyudaPluri {
  const ContenidoAyudaPluri({
    required this.onboarding,
    required this.notas,
    required this.versionActual,
  });

  final String onboarding;
  final List<NotaVersionPluri> notas;
  final String versionActual;
}

class ServicioContenidoApp {
  static const _keyOnboardingVisto = 'pluri_onboarding_visto_v1';
  static const _keyVersionVista = 'pluri_ultima_version_novedades_v1';
  static const _versiones = ['0.1.47'];

  Future<bool> debeMostrarInicio() async {
    final prefs = await SharedPreferences.getInstance();
    final info = await PackageInfo.fromPlatform();
    final versionActual = info.version;
    return !(prefs.getBool(_keyOnboardingVisto) ?? false) ||
        prefs.getString(_keyVersionVista) != versionActual;
  }

  Future<void> marcarVisto() async {
    final prefs = await SharedPreferences.getInstance();
    final info = await PackageInfo.fromPlatform();
    await prefs.setBool(_keyOnboardingVisto, true);
    await prefs.setString(_keyVersionVista, info.version);
  }

  Future<ContenidoAyudaPluri> cargar(
    String codigoIdioma, {
    bool soloPendientes = false,
  }) async {
    final info = await PackageInfo.fromPlatform();
    final prefs = await SharedPreferences.getInstance();
    final ultimaVista = prefs.getString(_keyVersionVista);
    final idioma = _idiomaSoportado(codigoIdioma);
    final mostrarOnboarding =
        !soloPendientes || !(prefs.getBool(_keyOnboardingVisto) ?? false);
    final onboarding =
        mostrarOnboarding
            ? await _cargarMarkdown(
              'assets/content/onboarding/$idioma.md',
              fallback: 'assets/content/onboarding/en.md',
            )
            : '';
    final notas = <NotaVersionPluri>[];
    for (final version in _versiones) {
      if (soloPendientes &&
          ultimaVista != null &&
          _compararVersiones(version, ultimaVista.split('+').first) <= 0) {
        continue;
      }
      final markdown = await _cargarMarkdown(
        'assets/content/updates/$idioma/$version.md',
        fallback: 'assets/content/updates/en/$version.md',
      );
      if (markdown.trim().isEmpty) continue;
      notas.add(
        NotaVersionPluri(
          version: version,
          resumen: _resumen(markdown),
          markdown: markdown,
        ),
      );
    }
    return ContenidoAyudaPluri(
      onboarding: onboarding,
      notas: notas,
      versionActual: _versionCompleta(info),
    );
  }

  Future<String> _cargarMarkdown(
    String path, {
    required String fallback,
  }) async {
    try {
      return await rootBundle.loadString(path);
    } catch (_) {
      return rootBundle.loadString(fallback);
    }
  }

  String _idiomaSoportado(String codigo) {
    const soportados = {
      'ar',
      'bn',
      'de',
      'en',
      'es',
      'fr',
      'hi',
      'id',
      'it',
      'ja',
      'pt',
      'ru',
      'zh',
    };
    return soportados.contains(codigo) ? codigo : 'en';
  }

  String _resumen(String markdown) {
    for (final line in markdown.split('\n')) {
      final limpia = line.trim();
      if (limpia.toLowerCase().startsWith('resumen:')) {
        return limpia.substring(limpia.indexOf(':') + 1).trim();
      }
      if (limpia.toLowerCase().startsWith('summary:')) {
        return limpia.substring(limpia.indexOf(':') + 1).trim();
      }
      if (limpia.contains(':')) {
        final etiqueta = limpia.substring(0, limpia.indexOf(':')).toLowerCase();
        const etiquetasResumen = {
          'résumé',
          'zusammenfassung',
          'riepilogo',
          'resumo',
          'ملخص',
          'সারাংশ',
          'सारांश',
          'ringkasan',
          '概要',
          '摘要',
          'резюме',
        };
        if (etiquetasResumen.contains(etiqueta)) {
          return limpia.substring(limpia.indexOf(':') + 1).trim();
        }
      }
    }
    return '';
  }

  String _versionCompleta(PackageInfo info) =>
      '${info.version}+${info.buildNumber}';

  int _compararVersiones(String a, String b) {
    final pa = a.split('.').map((e) => int.tryParse(e) ?? 0).toList();
    final pb = b.split('.').map((e) => int.tryParse(e) ?? 0).toList();
    for (var i = 0; i < 3; i++) {
      final va = i < pa.length ? pa[i] : 0;
      final vb = i < pb.length ? pb[i] : 0;
      if (va != vb) return va.compareTo(vb);
    }
    return 0;
  }
}