import 'dart:convert';

import 'package:capstone_project/utils/agrigator.dart';
import 'package:http/http.dart' as http;


const _baseUrl = 'http://duriin.imbenji.net';


// pair of (article, semantic distance from the query / seed). distance is
// null when the underlying endpoint doesnt return one.
class SimilarHit {
  final FeedItem item;
  final double? distance;

  SimilarHit({required this.item, this.distance});
}


class DuriinService {

  Future<List<FeedItem>> search({
    required String ticker,
    required String companyName,
    required DateTime from,
    required DateTime to,
    int limit = 100,
  }) async {
    final fromStr = from.toUtc().toIso8601String();
    final toStr = to.toUtc().toIso8601String();


    // build the keyword set: the ticker itself plus the company brand name
    // (first token of the registered name — "NVIDIA Corporation" -> "NVIDIA",
    // "Apple Inc" -> "Apple"). the full legal name rarely appears verbatim in
    // articles so matching on it would miss most hits.
    final keywords = <String>{};
    final t = ticker.trim();
    if (t.isNotEmpty) keywords.add(t);

    final brand = companyName.trim().split(RegExp(r"\s+")).firstOrNull ?? "";
    if (brand.isNotEmpty) keywords.add(brand);

    final hits = await _fetchHits(queryParams: {
      'keyword': keywords.toList(),
      'keyword_mode': 'or',
      'from': fromStr,
      'to': toStr,
      'limit': '$limit',
      'order': 'newest',
    });

    final items = hits.map((h) => h.item).toList();

    print('Duriin: ${items.length} articles for $ticker / $companyName (kw=${keywords.join(",")})');
    return items;
  }


  // neighbours of a given article via the vector index. used by the event
  // clusterer to build real clusters instead of arbitrary time slices.
  Future<List<SimilarHit>> findSimilar(int articleId, {int limit = 25}) async {
    return _fetchHits(queryParams: {
      'similar_to_article': '$articleId',
      'limit': '$limit',
    });
  }


  Future<List<SimilarHit>> _fetchHits({required Map<String, dynamic> queryParams}) async {
    final uri = Uri.parse(_baseUrl).replace(
      path: '/articles',
      queryParameters: queryParams,
    );

    try {
      final response = await http.get(uri);

      if (response.statusCode != 200) {
        print('Duriin: HTTP ${response.statusCode} for $uri');
        return [];
      }

      final body = response.body.trim();
      if (body.isEmpty) return [];

      final list = jsonDecode(body) as List<dynamic>;

      return list.map((raw) {
        final m = raw as Map<String, dynamic>;

        final id = m['id'] is int
            ? m['id'] as int
            : int.tryParse('${m['id']}');

        final item = FeedItem(
          id: id,
          title: (m['title'] ?? '').toString(),
          description: (m['description'] ?? '').toString(),
          content: (m['content'] ?? '').toString(),
          link: (m['url'] ?? '').toString(),
          source: (m['source'] ?? '').toString().isNotEmpty ? m['source'].toString() : null,
          pubDate: m['pub_date'] != null ? DateTime.tryParse(m['pub_date'].toString()) : null,
        );

        final distRaw = m['distance'];
        final distance = distRaw is num ? distRaw.toDouble() : null;

        return SimilarHit(item: item, distance: distance);
      }).where((h) => h.item.title.isNotEmpty && h.item.link.isNotEmpty).toList();

    } catch (e) {
      print('Duriin fetch error: $e');
      return [];
    }
  }
}