/// SDK 配置管理类：统一管理所有 SDK 相关的配置常量
class SdkConfig {
  SdkConfig._();

  // ==================== 默认值常量（单一来源）====================
  // 字段声明和 reset() 均引用这些常量，避免三处重复。

  static const int _defaultMaxQueueSize = 5000;
  static const int _defaultAutoUploadThreshold = 10;
  static const int _defaultMaxBatchSize = 500;
  static const int _defaultIsolateEncodingThreshold = 100;
  static const Duration _defaultUploadInterval = Duration(seconds: 5);
  static const Duration _defaultPageLoadTimeout = Duration(seconds: 5);
  static const Duration _defaultClickThrottleDuration =
      Duration(milliseconds: 300);
  static const Duration _defaultConnectionTimeout = Duration(seconds: 10);
  static const Duration _defaultReadTimeout = Duration(seconds: 30);
  static const Duration _defaultSpeedTestTimeout = Duration(seconds: 5);
  static const Duration _defaultConfigRequestTimeout = Duration(seconds: 10);
  static const int _defaultMaxBackoffLevel = 5;
  static const Duration _defaultBaseRetryDelay = Duration(seconds: 2);
  static const Duration _defaultMaxRetryDelay = Duration(seconds: 60);
  static const String _defaultCacheFileName = 'data_plus_events_cache.jsonl';
  static const String _defaultDebugReportEventLogFileName =
      'data_plus_report_events_debug.jsonl';
  static const bool _defaultEnableDebugReportLog = false;
  static const String _defaultEventTypeConfigCacheFileName =
      'analytics_event_types_config.json';
  static const String _defaultDomainCacheFileName =
      'data_plus_domains_cache.json';
  static const int _defaultMaxCacheLines = 2000;
  static const int _defaultMaxCacheBytes = 2 * 1024 * 1024;
  static const int _defaultTombstoneCompactionThreshold = 200;
  static const String _defaultTombstoneFileName =
      'data_plus_events_tombstone.txt';
  static const int _defaultMaxJsonSize = 5 * 1024 * 1024;
  static const int _defaultMaxSingleEventSize = 300 * 1024;
  static const int _defaultMaxConfigResponseSize = 1 * 1024 * 1024;
  static const int _defaultMaxPageStackSize = 100;
  static const int _defaultMaxAdImpressionCapacity = 10000;
  static const int _defaultCacheBufferThreshold = 10;
  static const Duration _defaultCacheFlushInterval = Duration(seconds: 5);

  // ==================== 事件队列配置 ====================

  /// 事件队列最大容量限制，防止内存无限增长
  static int maxQueueSize = _defaultMaxQueueSize;

  /// 自动上报阈值：队列达到此数量时立即触发上报
  static int autoUploadThreshold = _defaultAutoUploadThreshold;

  /// 单次上报的最大事件数量限制，避免请求过大导致超时
  static int maxBatchSize = _defaultMaxBatchSize;

  /// JSON 编码的批次大小阈值，超过此大小使用 isolate 编码
  static int isolateEncodingThreshold = _defaultIsolateEncodingThreshold;

  // ==================== 定时器配置 ====================

  /// 定时上报间隔（秒）
  static Duration uploadInterval = _defaultUploadInterval;

  /// 页面加载超时时间（秒）
  static Duration pageLoadTimeout = _defaultPageLoadTimeout;

  /// 点击事件节流时间（毫秒）
  static Duration clickThrottleDuration = _defaultClickThrottleDuration;

  // ==================== 网络超时配置 ====================

  /// HTTP 连接超时时间
  static Duration connectionTimeout = _defaultConnectionTimeout;

  /// HTTP 读取超时时间
  static Duration readTimeout = _defaultReadTimeout;

  /// HTTP 写入超时时间（与连接超时相同）
  static Duration get writeTimeout => connectionTimeout;

  /// HTTP 总超时时间（连接 + 写入 + 读取）
  static Duration get totalRequestTimeout =>
      connectionTimeout + writeTimeout + readTimeout;

  /// 域名测速超时时间
  static Duration speedTestTimeout = _defaultSpeedTestTimeout;

  /// 配置请求超时时间
  static Duration configRequestTimeout = _defaultConfigRequestTimeout;

  // ==================== 加密配置 ====================

  /// AES-GCM 解密密钥（固定密钥，用于 decryptResponseAuto 等）
  static const String decryptKey =
      'en1BNo0VBrN/zi+mI2LO7E9W40ehCBYwC+frBn8s3rQ';

  // ==================== 重试配置 ====================

  /// 最大退避级别
  static int maxBackoffLevel = _defaultMaxBackoffLevel;

  /// 基础延迟时间
  static Duration baseRetryDelay = _defaultBaseRetryDelay;

  /// 最大延迟时间
  static Duration maxRetryDelay = _defaultMaxRetryDelay;

  // ==================== 缓存配置 ====================

  /// 事件缓存文件名
  static String cacheFileName = _defaultCacheFileName;

  /// Debug 包完整事件 JSONL 文件名（Native 平台 applicationDocumentsDirectory 下）
  static String debugReportEventLogFileName =
      _defaultDebugReportEventLogFileName;

  /// 是否启用调试事件日志。
  ///
  /// 默认关闭；开启后才会本地记录上传事件完整 JSONL，并打印 accepted event 完整 JSON。
  static bool enableDebugReportLog = _defaultEnableDebugReportLog;

  /// 事件类型配置缓存文件名
  static String eventTypeConfigCacheFileName =
      _defaultEventTypeConfigCacheFileName;

  /// 域名列表缓存文件名
  static String domainCacheFileName = _defaultDomainCacheFileName;

  /// 最大缓存行数限制，防止文件过大导致内存问题
  /// 默认 2000 行，避免在网络不稳定时生成过大的缓存文件
  static int maxCacheLines = _defaultMaxCacheLines;

  /// 缓存文件最大字节数限制，超过后从文件开头裁剪旧事件
  /// 默认 2MB
  static int maxCacheBytes = _defaultMaxCacheBytes;

  /// tombstone 触发压缩的 event_id 数量阈值
  /// 默认 200：每积累 200 条已上报 ID 就压缩一次主缓存文件
  static int tombstoneCompactionThreshold =
      _defaultTombstoneCompactionThreshold;

  /// tombstone 缓存文件名
  static String tombstoneFileName = _defaultTombstoneFileName;

  /// 持久化 buffer 攒批阈值（达到此数量立即写盘）
  static int cacheBufferThreshold = _defaultCacheBufferThreshold;

  /// 持久化 buffer 定时刷写间隔
  static Duration cacheFlushInterval = _defaultCacheFlushInterval;

  // ==================== 请求大小限制 ====================

  /// JSON 最大大小限制（5MB）
  static int maxJsonSize = _defaultMaxJsonSize;

  /// 单条事件最大字节数限制，超过则丢弃（300KB）
  static int maxSingleEventSize = _defaultMaxSingleEventSize;

  /// 配置接口响应体最大字节数限制（1MB），防止恶意/异常服务器返回超大数据导致 OOM
  static int maxConfigResponseSize = _defaultMaxConfigResponseSize;

  // ==================== 容量配置 ====================

  /// 页面栈最大容量
  static int maxPageStackSize = _defaultMaxPageStackSize;

  /// 广告去重最大容量
  static int maxAdImpressionCapacity = _defaultMaxAdImpressionCapacity;

  // ==================== 配置方法 ====================

  /// 配置所有 SDK 参数
  ///
  /// 示例：
  /// ```dart
  /// SdkConfig.configure(
  ///   maxQueueSize: 20000,
  ///   uploadInterval: Duration(seconds: 30),
  ///   connectionTimeout: Duration(seconds: 15),
  /// );
  /// ```
  static void configure({
    int? maxQueueSize,
    int? autoUploadThreshold,
    int? maxBatchSize,
    int? isolateEncodingThreshold,
    Duration? uploadInterval,
    Duration? pageLoadTimeout,
    Duration? clickThrottleDuration,
    Duration? connectionTimeout,
    Duration? readTimeout,
    Duration? speedTestTimeout,
    Duration? configRequestTimeout,
    int? maxBackoffLevel,
    Duration? baseRetryDelay,
    Duration? maxRetryDelay,
    String? cacheFileName,
    String? debugReportEventLogFileName,
    bool? enableDebugReportLog,
    String? eventTypeConfigCacheFileName,
    String? domainCacheFileName,
    int? maxCacheLines,
    int? maxCacheBytes,
    int? maxJsonSize,
    int? maxSingleEventSize,
    int? maxPageStackSize,
    int? maxAdImpressionCapacity,
  }) {
    if (maxQueueSize != null && maxQueueSize > 0) {
      SdkConfig.maxQueueSize = maxQueueSize;
    }
    if (autoUploadThreshold != null && autoUploadThreshold > 0) {
      SdkConfig.autoUploadThreshold = autoUploadThreshold;
    }
    if (maxBatchSize != null && maxBatchSize > 0) {
      SdkConfig.maxBatchSize = maxBatchSize;
    }
    if (isolateEncodingThreshold != null && isolateEncodingThreshold > 0) {
      SdkConfig.isolateEncodingThreshold = isolateEncodingThreshold;
    }
    if (uploadInterval != null) {
      SdkConfig.uploadInterval = uploadInterval;
    }
    if (pageLoadTimeout != null) {
      SdkConfig.pageLoadTimeout = pageLoadTimeout;
    }
    if (clickThrottleDuration != null) {
      SdkConfig.clickThrottleDuration = clickThrottleDuration;
    }
    if (connectionTimeout != null) {
      SdkConfig.connectionTimeout = connectionTimeout;
    }
    if (readTimeout != null) {
      SdkConfig.readTimeout = readTimeout;
    }
    if (speedTestTimeout != null) {
      SdkConfig.speedTestTimeout = speedTestTimeout;
    }
    if (configRequestTimeout != null) {
      SdkConfig.configRequestTimeout = configRequestTimeout;
    }
    if (maxBackoffLevel != null && maxBackoffLevel >= 0) {
      SdkConfig.maxBackoffLevel = maxBackoffLevel;
    }
    if (baseRetryDelay != null) {
      SdkConfig.baseRetryDelay = baseRetryDelay;
    }
    if (maxRetryDelay != null) {
      SdkConfig.maxRetryDelay = maxRetryDelay;
    }
    if (cacheFileName != null &&
        cacheFileName.isNotEmpty &&
        !cacheFileName.contains('/') &&
        !cacheFileName.contains('\\') &&
        !cacheFileName.contains('..')) {
      SdkConfig.cacheFileName = cacheFileName;
    }
    if (debugReportEventLogFileName != null &&
        debugReportEventLogFileName.isNotEmpty &&
        !debugReportEventLogFileName.contains('/') &&
        !debugReportEventLogFileName.contains('\\') &&
        !debugReportEventLogFileName.contains('..')) {
      SdkConfig.debugReportEventLogFileName = debugReportEventLogFileName;
    }
    if (enableDebugReportLog != null) {
      SdkConfig.enableDebugReportLog = enableDebugReportLog;
    }
    if (eventTypeConfigCacheFileName != null &&
        eventTypeConfigCacheFileName.isNotEmpty &&
        !eventTypeConfigCacheFileName.contains('/') &&
        !eventTypeConfigCacheFileName.contains('\\') &&
        !eventTypeConfigCacheFileName.contains('..')) {
      SdkConfig.eventTypeConfigCacheFileName = eventTypeConfigCacheFileName;
    }
    if (domainCacheFileName != null &&
        domainCacheFileName.isNotEmpty &&
        !domainCacheFileName.contains('/') &&
        !domainCacheFileName.contains('\\') &&
        !domainCacheFileName.contains('..')) {
      SdkConfig.domainCacheFileName = domainCacheFileName;
    }
    if (maxCacheLines != null && maxCacheLines > 0) {
      SdkConfig.maxCacheLines = maxCacheLines;
    }
    if (maxCacheBytes != null && maxCacheBytes > 0) {
      SdkConfig.maxCacheBytes = maxCacheBytes;
    }
    if (maxJsonSize != null && maxJsonSize > 0) {
      SdkConfig.maxJsonSize = maxJsonSize;
    }
    if (maxSingleEventSize != null && maxSingleEventSize > 0) {
      SdkConfig.maxSingleEventSize = maxSingleEventSize;
    }
    if (maxPageStackSize != null && maxPageStackSize > 0) {
      SdkConfig.maxPageStackSize = maxPageStackSize;
    }
    if (maxAdImpressionCapacity != null && maxAdImpressionCapacity > 0) {
      SdkConfig.maxAdImpressionCapacity = maxAdImpressionCapacity;
    }
  }

  /// 重置所有配置为默认值
  static void reset() {
    maxQueueSize = _defaultMaxQueueSize;
    autoUploadThreshold = _defaultAutoUploadThreshold;
    maxBatchSize = _defaultMaxBatchSize;
    isolateEncodingThreshold = _defaultIsolateEncodingThreshold;
    uploadInterval = _defaultUploadInterval;
    pageLoadTimeout = _defaultPageLoadTimeout;
    clickThrottleDuration = _defaultClickThrottleDuration;
    connectionTimeout = _defaultConnectionTimeout;
    readTimeout = _defaultReadTimeout;
    speedTestTimeout = _defaultSpeedTestTimeout;
    configRequestTimeout = _defaultConfigRequestTimeout;
    maxBackoffLevel = _defaultMaxBackoffLevel;
    baseRetryDelay = _defaultBaseRetryDelay;
    maxRetryDelay = _defaultMaxRetryDelay;
    cacheFileName = _defaultCacheFileName;
    debugReportEventLogFileName = _defaultDebugReportEventLogFileName;
    enableDebugReportLog = _defaultEnableDebugReportLog;
    eventTypeConfigCacheFileName = _defaultEventTypeConfigCacheFileName;
    domainCacheFileName = _defaultDomainCacheFileName;
    maxCacheLines = _defaultMaxCacheLines;
    maxCacheBytes = _defaultMaxCacheBytes;
    tombstoneCompactionThreshold = _defaultTombstoneCompactionThreshold;
    tombstoneFileName = _defaultTombstoneFileName;
    cacheBufferThreshold = _defaultCacheBufferThreshold;
    cacheFlushInterval = _defaultCacheFlushInterval;
    maxJsonSize = _defaultMaxJsonSize;
    maxSingleEventSize = _defaultMaxSingleEventSize;
    maxConfigResponseSize = _defaultMaxConfigResponseSize;
    maxPageStackSize = _defaultMaxPageStackSize;
    maxAdImpressionCapacity = _defaultMaxAdImpressionCapacity;
  }
}