// lib/remote/remote_client.dart
import 'dart:convert';
import 'package:http/http.dart' as http;
import 'remote_models.dart';
import 'auth_client.dart';

class RemoteJsonClient {
  final Uri indexUri;         // es. https://prova.patachina.it/photos/
  final RemoteAuth? auth;     // opzionale: se presente, aggiunge Bearer

  RemoteJsonClient(
    String baseUrl,
    String indexPath, {
    this.auth,
  }) : indexUri = Uri.parse(baseUrl.endsWith('/') ? baseUrl : '$baseUrl/')
            .resolve(indexPath);

  Future<List<RemotePhotoItem>> fetchAll() async {
    Map<String, String> headers = {};
    if (auth != null) {
      headers = await auth!.authHeaders();
    }

    // DEBUG: stampa la URL precisa
    // ignore: avoid_print
    print('[remote-client] GET $indexUri');

    http.Response res;
    try {
      res = await http.get(indexUri, headers: headers).timeout(const Duration(seconds: 20));
    } catch (e) {
      throw Exception('Errore rete su $indexUri: $e');
    }

    // Retry 1 volta in caso di 401 (token scaduto/invalidato)
    if (res.statusCode == 401 && auth != null) {
      headers = await auth!.refreshAndHeaders();
      res = await http.get(indexUri, headers: headers).timeout(const Duration(seconds: 20));
    }

    // Follow 30x mantenendo Authorization
    if ({301, 302, 307, 308}.contains(res.statusCode) && res.headers['location'] != null) {
      final loc = res.headers['location']!;
      final redirectUri = indexUri.resolve(loc);
      res = await http.get(redirectUri, headers: headers).timeout(const Duration(seconds: 20));
    }
    if (res.statusCode != 200) {
      final snippet = utf8.decode(res.bodyBytes.take(200).toList());
      throw Exception('HTTP ${res.statusCode} ${res.reasonPhrase} su $indexUri. Body: $snippet');
    }

    final body = utf8.decode(res.bodyBytes);

    // Qui siamo espliciti: ci aspettiamo SEMPRE una lista top-level
    final dynamic decoded = json.decode(body);
    if (decoded is! List) {
      throw Exception('JSON inatteso: atteso array top-level, ricevuto ${decoded.runtimeType}');
    }

    final List<dynamic> rawList = decoded;

    // --- DIAGNOSTICA: conteggio pattern dai dati del SERVER (non stampo il JSON intero)
    int withOriginal = 0, withoutOriginal = 0, leadingSlash = 0, noLeadingSlash = 0;
    for (final e in rawList) {
      if (e is Map<String, dynamic>) {
        final p = (e['path'] ?? '').toString();
        if (p.startsWith('/')) {
          leadingSlash++;
        } else {
          noLeadingSlash++;
        }
        if (p.contains('/original/')) {
          withOriginal++;
        } else {
          withoutOriginal++;
        }
      }
    }
    // ignore: avoid_print
    print('[remote-client] SERVER paths: withOriginal=$withOriginal '
          'withoutOriginal=$withoutOriginal leadingSlash=$leadingSlash noLeadingSlash=$noLeadingSlash');

    // Costruiamo a mano la List<RemotePhotoItem>, tipizzata esplicitamente
    final List<RemotePhotoItem> items = rawList.map<RemotePhotoItem>((e) {
      if (e is! Map<String, dynamic>) {
        throw Exception('Elemento JSON non è una mappa: ${e.runtimeType} -> $e');
      }
      return RemotePhotoItem.fromJson(e);
    }).toList();

    return items;
  }
}