/// HTTP client placeholder that talks to a public sample API.
library;

import 'dart:convert';

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

import '../models/item.dart';

/// Fetches catalog items from JSONPlaceholder.
///
/// This is intentionally a thin, replaceable client. Swap [baseUrl] and
/// [Item.fromJson] when you point the app at a real backend.
class ItemApi {
  ItemApi({http.Client? client, this.baseUrl = defaultBaseUrl})
      : _client = client ?? http.Client();

  static const defaultBaseUrl = 'https://jsonplaceholder.typicode.com';

  final http.Client _client;
  final String baseUrl;

  /// GET `/posts` and map each record to an [Item].
  Future<List<Item>> fetchItems({int limit = 12}) async {
    final uri = Uri.parse('$baseUrl/posts');
    final response = await _client.get(
      uri,
      headers: const {'Accept': 'application/json'},
    );

    if (response.statusCode < 200 || response.statusCode >= 300) {
      throw ItemApiException(
        'Request failed (${response.statusCode})',
        statusCode: response.statusCode,
      );
    }

    final decoded = jsonDecode(response.body);
    if (decoded is! List) {
      throw const ItemApiException('Unexpected response shape');
    }

    return decoded
        .whereType<Map<String, dynamic>>()
        .take(limit)
        .map(Item.fromJson)
        .toList(growable: false);
  }

  void close() => _client.close();
}

class ItemApiException implements Exception {
  const ItemApiException(this.message, {this.statusCode});

  final String message;
  final int? statusCode;

  @override
  String toString() => message;
}