import 'dart:async';
import 'dart:convert';

import 'package:adjust_sdk/adjust_attribution.dart';
import 'package:adjust_sdk/adjust.dart';
import 'package:flutter/foundation.dart';
import 'package:play_install_referrer/play_install_referrer.dart';

/// 归因信息服务（优先从 Adjust 获取，fallback 使用 Play Install Referrer）
class ReferrerService {
  ReferrerService._();

  static String? _cachedReferrer;
  static String _referrerSource = 'gg';
  static final Completer<String?> _completer = Completer<String?>();

  /// attribution 回调的 Completer，与 getAttributionWithTimeout 竞速，谁先返回用谁
  static final Completer<AdjustAttribution?> _attributionCallbackCompleter =
      Completer<AdjustAttribution?>();

  static const int _adjustTimeoutMs = 15000;

  /// 由 Adjust attributionCallback 调用，首次安装时归因往往通过此回调返回（晚于 getAttributionWithTimeout）
  static void receiveAttributionFromCallback(AdjustAttribution attribution) {
    if (!_attributionCallbackCompleter.isCompleted) {
      _attributionCallbackCompleter.complete(attribution);
    }
  }

  /// 归因来源：Adjust 为 android_adjust，Play Install Referrer 为 gg
  static String get referrerSource => _referrerSource;

  /// JSON 可编码的 costAmount：保留字段，非有限数字用字符串避免 encode 抛错
  static Object? _jsonEncodableCostAmount(num? v) {
    if (v == null) return null;
    if (v is double && !v.isFinite) return v.toString();
    return v;
  }

  /// 将完整 AdjustAttribution 序列化为 JSON（供 digest / Base64），不省略任何键
  static String _attributionToDigest(AdjustAttribution attr) {
    final map = <String, dynamic>{
      'trackerToken': attr.trackerToken,
      'trackerName': attr.trackerName,
      'network': attr.network,
      'campaign': attr.campaign,
      'adgroup': attr.adgroup,
      'creative': attr.creative,
      'clickLabel': attr.clickLabel,
      'costType': attr.costType,
      'costAmount': _jsonEncodableCostAmount(attr.costAmount),
      'costCurrency': attr.costCurrency,
      'jsonResponse': attr.jsonResponse,
      'fbInstallReferrer': attr.fbInstallReferrer,
    };
    try {
      return jsonEncode(map);
    } catch (_) {
      return '';
    }
  }

  /// 获取 referrer/digest，优先从 Adjust 归因获取，fallback 使用 Play Install Referrer
  /// 同时监听 attributionCallback，首次安装时归因往往通过回调返回（可能晚于 getAttributionWithTimeout）
  static Future<String?> getReferrer() async {
    if (_cachedReferrer != null) return _cachedReferrer;
    if (_completer.isCompleted) return _completer.future;

    var digest = '';
    try {
      // 竞速：getAttributionWithTimeout 与 attribution 回调，谁先返回用谁
      final attribution = await Future.any<AdjustAttribution?>([
        (() async {
          try {
            return await Adjust.getAttributionWithTimeout(_adjustTimeoutMs);
          } catch (_) {
            return null;
          }
        })(),
        _attributionCallbackCompleter.future,
      ]);
      if (attribution != null) {
        final raw = _attributionToDigest(attribution);
        if (raw.isNotEmpty) {
          _referrerSource = 'android_adjust';
          digest = base64Encode(utf8.encode(raw));
        }
      }
    } catch (_) {
      digest = '';
    }

    if (digest.isEmpty) {
      _referrerSource = 'gg';
      if (defaultTargetPlatform == TargetPlatform.android) {
        try {
          final details = await PlayInstallReferrer.installReferrer;
          digest = details.installReferrer ?? '';
        } catch (_) {
          digest = '';
        }
      }
    }

    _cachedReferrer = digest;
    if (!_completer.isCompleted) _completer.complete(_cachedReferrer);
    return _cachedReferrer;
  }

  /// 初始化并缓存 referrer（建议在 app 启动时调用）
  static Future<void> init() async {
    await getReferrer();
  }

  /// 仅 Adjust 归因 digest（Base64 JSON），用于 /v1/user/referrer accolade=android_adjust
  static Future<String> getAdjustReferrerDigest() async {
    try {
      final attr = await Adjust.getAttribution();
      final raw = _attributionToDigest(attr);
      if (raw.isEmpty) return '';
      return base64Encode(utf8.encode(raw));
    } catch (_) {
      return '';
    }
  }

  /// 仅 Google Play Install Referrer 字符串，用于 /v1/user/referrer accolade=gg
  static Future<String> getGgReferrerDigest() async {
    if (defaultTargetPlatform != TargetPlatform.android) return '';
    try {
      final details = await PlayInstallReferrer.installReferrer;
      return details.installReferrer ?? '';
    } catch (_) {
      return '';
    }
  }
}