// lib/services/market/market_service.dart
//
// سرویس برای endpoint بازار (market-service) در API gateway جدید:
//   - GET /market  (paginated) → لیست symbolها با داده‌ی OHLCV.
//
// داده‌ی خام Hlocvt را به مدل قدیمی NewStatisticModel (CategoryList/Content/
// Data) map می‌کنیم تا UI نبض صنعت بدون تغییر کار کند.

import 'dart:async';
import 'dart:convert';
import 'dart:developer' as dev;
import 'dart:io' show SocketException;

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

import 'package:didvan/config/auth_config.dart';
import 'package:didvan/models/new_statistic/new_statistics_model.dart';
import 'package:didvan/services/auth/auth_interceptor.dart';
import 'package:didvan/services/auth/token_storage.dart';

class MarketServiceResult {
  final bool isSuccess;
  final int? statusCode;
  final List<CategoryList>? lists;
  final String? errorMessage;

  const MarketServiceResult({
    required this.isSuccess,
    this.statusCode,
    this.lists,
    this.errorMessage,
  });
}

/// نتیجه‌ی دریافت آیتم‌های خام بازار (برای صفحه‌ی «همه»).
class MarketItemsResult {
  final bool isSuccess;
  final int? statusCode;
  final List<Map<String, dynamic>>? items;
  final String? errorMessage;

  const MarketItemsResult({
    required this.isSuccess,
    this.statusCode,
    this.items,
    this.errorMessage,
  });
}

class MarketService {
  MarketService._();
  static final MarketService instance = MarketService._();

  String get _base => AuthConfig.apiBaseUrl;
  static const _timeout = Duration(seconds: 30);

  /// دریافت داده‌ی بازار و map به CategoryList ها.
  Future<MarketServiceResult> getMarketData({int limit = 50}) async {
    await AuthInterceptor.ensureFreshToken();
    try {
      final uri = Uri.parse('$_base/market').replace(queryParameters: {
        'limit': limit.toString(),
        'page': '1',
      });
      final response = await _withRetry(
        () => http.get(uri, headers: _headers()).timeout(_timeout),
      );

      dev.log('GET /market -> status=${response.statusCode}, '
          'bodyLen=${response.body.length}', name: 'MarketService');

      if (response.statusCode == 200) {
        final body = json.decode(response.body);
        final List items = body is Map && body['data'] is List
            ? body['data'] as List
            : (body is List ? body : const []);
        dev.log('GET /market -> parsed ${items.length} items',
            name: 'MarketService');

        final contents = <Content>[];
        for (final raw in items) {
          if (raw is! Map) continue;
          final c = _mapToContent(Map<String, dynamic>.from(raw));
          if (c != null) contents.add(c);
        }

        // همه را در یک گروه "بازارها" قرار می‌دهیم. (بک‌اند جدید
        // دسته‌بندی ندارد؛ در صورت افزوده شدن، اینجا گروه‌بندی می‌شود.)
        final lists = <CategoryList>[
          CategoryList(category: 1, header: 'بازارها', contents: contents),
        ];
        return MarketServiceResult(
          isSuccess: true,
          statusCode: 200,
          lists: lists,
        );
      }

      return MarketServiceResult(
        isSuccess: false,
        statusCode: response.statusCode,
        errorMessage:
            _extractError(response.body) ?? 'خطا در دریافت داده‌ی بازار.',
      );
    } catch (e) {
      dev.log('getMarketData error: $e', name: 'MarketService');
      return const MarketServiceResult(
        isSuccess: false,
        errorMessage: 'خطا در ارتباط با سرور.',
      );
    }
  }

  /// دریافت آیتم‌های خام بازار (List از Map). برای صفحه‌ی «همه» که خودش
  /// هر آیتم را به مدل GeneralItem map می‌کند.
  Future<MarketItemsResult> getMarketItems({
    int page = 1,
    int limit = 100,
  }) async {
    await AuthInterceptor.ensureFreshToken();
    try {
      final uri = Uri.parse('$_base/market').replace(queryParameters: {
        'limit': limit.toString(),
        'page': page.toString(),
      });
      final response = await _withRetry(
        () => http.get(uri, headers: _headers()).timeout(_timeout),
      );

      dev.log('GET /market (items) -> status=${response.statusCode}',
          name: 'MarketService');

      if (response.statusCode == 200) {
        final body = json.decode(response.body);
        final List items = body is Map && body['data'] is List
            ? body['data'] as List
            : (body is List ? body : const []);
        final mapped = items
            .whereType<Map>()
            .map((e) => Map<String, dynamic>.from(e))
            .toList();
        return MarketItemsResult(
          isSuccess: true,
          statusCode: 200,
          items: mapped,
        );
      }

      return MarketItemsResult(
        isSuccess: false,
        statusCode: response.statusCode,
        errorMessage:
            _extractError(response.body) ?? 'خطا در دریافت داده‌ی بازار.',
      );
    } catch (e) {
      dev.log('getMarketItems error: $e', name: 'MarketService');
      return const MarketItemsResult(
        isSuccess: false,
        errorMessage: 'خطا در ارتباط با سرور.',
      );
    }
  }

  /// تبدیل یک Hlocvt به Content مدل قدیمی.
  /// آخرین قیمت = close.last، درصد تغییر از دو close آخر محاسبه می‌شود.
  Content? _mapToContent(Map<String, dynamic> json) {
    try {
      final closeRaw = json['close'];
      final closes = (closeRaw is List)
          ? closeRaw.map((e) => (e as num).toDouble()).toList()
          : <double>[];

      String price = '-';
      num changePercent = 0;
      String direction = 'none';

      if (closes.isNotEmpty) {
        final last = closes.last;
        price = _formatNumber(last);
        if (closes.length >= 2) {
          final prev = closes[closes.length - 2];
          if (prev != 0) {
            final change = ((last - prev) / prev) * 100;
            changePercent = double.parse(change.toStringAsFixed(2));
            direction = change > 0 ? 'high' : (change < 0 ? 'low' : 'none');
          }
        }
      }

      final symbolId = (json['symbolId'] ?? json['id'] ?? '').toString();

      // آخرین 10 قیمت برای نمودار کوچک.
      final chartPrices =
          closes.length > 10 ? closes.sublist(closes.length - 10) : closes;

      return Content(
        id: symbolId.hashCode,
        label: symbolId,
        title: (json['title'] ?? symbolId).toString(),
        marked: false,
        data: Data(
          p: price,
          dp: changePercent,
          dt: direction,
          prices: chartPrices,
        ),
      );
    } catch (e) {
      dev.log('mapToContent error: $e', name: 'MarketService');
      return null;
    }
  }

  String _formatNumber(double v) {
    // جداسازی سه‌رقمی ساده.
    final s = v.toStringAsFixed(v.truncateToDouble() == v ? 0 : 2);
    final parts = s.split('.');
    final intPart = parts[0];
    final buf = StringBuffer();
    for (var i = 0; i < intPart.length; i++) {
      if (i > 0 && (intPart.length - i) % 3 == 0) buf.write(',');
      buf.write(intPart[i]);
    }
    return parts.length > 1 ? '${buf.toString()}.${parts[1]}' : buf.toString();
  }

  // ----------------- Helpers -----------------

  Map<String, String> _headers() {
    final headers = <String, String>{
      'Accept': 'application/json',
      'Content-Type': 'application/json',
    };
    final t = TokenStorage.accessToken;
    if (t != null && t.isNotEmpty) headers['Authorization'] = 'Bearer $t';
    return headers;
  }

  Future<T> _withRetry<T>(Future<T> Function() body) async {
    for (var attempt = 0; attempt < 3; attempt++) {
      try {
        return await body();
      } on SocketException {
        if (attempt == 2) rethrow;
        await Future.delayed(Duration(milliseconds: 250 * (attempt + 1)));
      } on http.ClientException {
        if (attempt == 2) rethrow;
        await Future.delayed(Duration(milliseconds: 250 * (attempt + 1)));
      } on TimeoutException {
        if (attempt == 2) rethrow;
      }
    }
    throw StateError('retry loop exited without return');
  }

  String? _extractError(String body) {
    if (body.isEmpty) return null;
    try {
      final data = json.decode(body);
      if (data is Map) {
        final msg = data['message'] ?? data['error'] ?? data['msg'];
        if (msg is String && msg.isNotEmpty) return msg;
        if (msg is List && msg.isNotEmpty) return msg.first.toString();
      }
    } catch (_) {}
    return null;
  }
}