import 'package:relationship_saver/features/local/local_models.dart';

class ShareCaptureDraftSuggester {
  const ShareCaptureDraftSuggester._();

  static final RegExp _birthdayPattern = RegExp(
    r'\bbirthday\b',
    caseSensitive: false,
  );
  static final RegExp _anniversaryPattern = RegExp(
    r'\banniversary\b',
    caseSensitive: false,
  );
  static final RegExp _giftPattern = RegExp(
    r'\b(gift|present|flowers|scarf|book for her|book for him)\b',
    caseSensitive: false,
  );
  static final RegExp _placePattern = RegExp(
    r'\b(restaurant|cafe|coffee shop|bar|bistro|museum|park|hotel|beach|address|reservation)\b',
    caseSensitive: false,
  );
  static final RegExp _activityPattern = RegExp(
    r'\b(concert|movie|hike|walk|trip|class|event|show|plan|weekend|tickets?)\b',
    caseSensitive: false,
  );
  static final RegExp _negativePreferencePattern = RegExp(
    r"\b(hates?|dislikes?|allergic to|doesn't like|does not like|dont like)\b",
    caseSensitive: false,
  );
  static final RegExp _positivePreferencePattern = RegExp(
    r'\b(loves?|likes?|favorite|prefers?|enjoys?)\b',
    caseSensitive: false,
  );
  static final RegExp _isoDatePattern = RegExp(
    r'\b(\d{4})-(\d{1,2})-(\d{1,2})\b',
  );
  static final RegExp _dotDatePattern = RegExp(
    r'\b(\d{1,2})\.(\d{1,2})\.(\d{2,4})\b',
  );
  static final RegExp _monthNameDatePattern = RegExp(
    r'\b(january|february|march|april|may|june|july|august|september|october|november|december)\s+(\d{1,2})(?:,\s*(\d{4}))?\b',
    caseSensitive: false,
  );

  static CapturedFactDraft suggestForPayload(SharedPayload payload) {
    final String text = payload.rawText.trim().isNotEmpty
        ? payload.rawText.trim()
        : (payload.url ?? '').trim();
    final String normalized = text.toLowerCase();
    final Uri? uri = payload.url == null ? null : Uri.tryParse(payload.url!);
    final String host = uri?.host.toLowerCase() ?? '';

    final _SuggestedImportantDate? importantDate = _suggestImportantDate(text);
    if (importantDate != null) {
      return CapturedFactDraft(
        type: CapturedFactType.importantDate,
        text: importantDate.label,
        label: importantDate.label,
        dateValue: importantDate.date,
        isSensitive: false,
        needsReview: true,
      );
    }

    if (_giftPattern.hasMatch(normalized)) {
      return CapturedFactDraft(
        type: CapturedFactType.giftIdea,
        text: text,
        label: 'Gift idea',
        isSensitive: false,
        needsReview: true,
      );
    }

    if (_looksLikePlace(normalized, host)) {
      return CapturedFactDraft(
        type: CapturedFactType.placeIdea,
        text: text,
        label: 'Place idea',
        isSensitive: false,
        needsReview: true,
      );
    }

    if (_looksLikeActivity(normalized, host)) {
      return CapturedFactDraft(
        type: CapturedFactType.activityIdea,
        text: text,
        label: 'Activity idea',
        isSensitive: false,
        needsReview: true,
      );
    }

    if (_negativePreferencePattern.hasMatch(normalized)) {
      return CapturedFactDraft(
        type: CapturedFactType.dislike,
        text: text,
        label: 'Preference',
        isSensitive: normalized.contains('allergic'),
        needsReview: true,
      );
    }

    if (_positivePreferencePattern.hasMatch(normalized)) {
      return CapturedFactDraft(
        type: CapturedFactType.like,
        text: text,
        label: 'Preference',
        isSensitive: false,
        needsReview: true,
      );
    }

    return CapturedFactDraft(
      type: CapturedFactType.note,
      text: text,
      label: payload.url == null ? null : 'Shared link',
      isSensitive: false,
      needsReview: payload.url != null,
    );
  }

  static bool _looksLikePlace(String normalized, String host) {
    if (_placePattern.hasMatch(normalized)) {
      return true;
    }
    return host.contains('maps.apple.com') ||
        host.contains('google.com') && normalized.contains('maps') ||
        host.contains('tripadvisor.') ||
        host.contains('opentable.') ||
        host.contains('thefork.');
  }

  static bool _looksLikeActivity(String normalized, String host) {
    if (_activityPattern.hasMatch(normalized)) {
      return true;
    }
    return host.contains('eventbrite.') ||
        host.contains('meetup.') ||
        host.contains('ticketmaster.');
  }

  static _SuggestedImportantDate? _suggestImportantDate(String text) {
    final DateTime? date = _parseDate(text);
    if (date == null) {
      return null;
    }

    final String normalized = text.toLowerCase();
    if (_birthdayPattern.hasMatch(normalized)) {
      return _SuggestedImportantDate(date: date, label: 'Birthday');
    }
    if (_anniversaryPattern.hasMatch(normalized)) {
      return _SuggestedImportantDate(date: date, label: 'Anniversary');
    }
    return null;
  }

  static DateTime? _parseDate(String text) {
    final RegExpMatch? isoMatch = _isoDatePattern.firstMatch(text);
    if (isoMatch != null) {
      return _safeDate(
        int.parse(isoMatch.group(1)!),
        int.parse(isoMatch.group(2)!),
        int.parse(isoMatch.group(3)!),
      );
    }

    final RegExpMatch? dotMatch = _dotDatePattern.firstMatch(text);
    if (dotMatch != null) {
      final int year = int.parse(dotMatch.group(3)!);
      return _safeDate(
        year < 100 ? 2000 + year : year,
        int.parse(dotMatch.group(2)!),
        int.parse(dotMatch.group(1)!),
      );
    }

    final RegExpMatch? monthNameMatch = _monthNameDatePattern.firstMatch(text);
    if (monthNameMatch != null) {
      final int? month = _monthNameToInt(monthNameMatch.group(1)!);
      if (month == null) {
        return null;
      }
      final int day = int.parse(monthNameMatch.group(2)!);
      final int year = monthNameMatch.group(3) == null
          ? DateTime.now().year
          : int.parse(monthNameMatch.group(3)!);
      return _safeDate(year, month, day);
    }

    return null;
  }

  static DateTime? _safeDate(int year, int month, int day) {
    try {
      final DateTime value = DateTime(year, month, day);
      if (value.year != year || value.month != month || value.day != day) {
        return null;
      }
      return value;
    } catch (_) {
      return null;
    }
  }

  static int? _monthNameToInt(String input) {
    return switch (input.toLowerCase()) {
      'january' => 1,
      'february' => 2,
      'march' => 3,
      'april' => 4,
      'may' => 5,
      'june' => 6,
      'july' => 7,
      'august' => 8,
      'september' => 9,
      'october' => 10,
      'november' => 11,
      'december' => 12,
      _ => null,
    };
  }
}

class _SuggestedImportantDate {
  const _SuggestedImportantDate({required this.date, required this.label});

  final DateTime date;
  final String label;
}