import 'dart:convert';

import 'package:http/http.dart' as http;

import '../models/rotation_config.dart';

/// Provides holiday lookup via Nager.Date.
class HolidaysService {
  /// Fetches Philippine public holidays for [year].
  ///
  /// Returns a list of [Holiday] instances.
  static Future<List<Holiday>> fetchPhilippinesHolidays(int year) async {
    final uri = Uri.https('date.nager.at', '/api/v3/PublicHolidays/$year/PH');
    final response = await http.get(uri);
    if (response.statusCode != 200) {
      throw Exception('Failed to fetch holidays: ${response.statusCode}');
    }

    final decoded = jsonDecode(response.body);
    if (decoded is! List) {
      throw Exception('Unexpected holiday response format');
    }

    return decoded
        .whereType<Map<String, dynamic>>()
        .map((item) {
          final dateString = item['date'] as String?;
          final name =
              item['localName'] as String? ??
              item['name'] as String? ??
              'Holiday';

          if (dateString == null) {
            return null;
          }

          final parsed = DateTime.tryParse(dateString);
          if (parsed == null) {
            return null;
          }

          return Holiday(
            date: DateTime(parsed.year, parsed.month, parsed.day),
            name: name,
            source: 'nager',
          );
        })
        .whereType<Holiday>()
        .toList();
  }
}