// Author: fruit.com.cn

import 'package:flutter/foundation.dart';
import 'package:shared_preferences/shared_preferences.dart';

import 'app_config.dart';

/// Debug-only runtime server endpoint persisted outside build-time defines.
abstract final class ServerEndpoint {
  /// Preference key used for the runtime server address.
  static const String preferenceKey = 'dev.api_base_url';

  /// Returns a normalized http(s) URL, or null for invalid input.
  static String? normalize(String? raw) {
    final value = raw?.trim() ?? '';
    final uri = Uri.tryParse(value);
    if (uri == null ||
        (uri.scheme != 'http' && uri.scheme != 'https') ||
        uri.host.isEmpty) {
      return null;
    }
    return value.replaceFirst(RegExp(r'/+$'), '');
  }

  /// Resolves runtime > dart-define > default using normalized valid values.
  static String resolve({
    required String? stored,
    required String compiled,
    required String fallback,
  }) {
    return normalize(stored) ??
        normalize(compiled) ??
        normalize(fallback) ??
        fallback;
  }

  /// Loads the persisted override before the app creates its ApiClient.
  ///
  /// In release builds this returns immediately without reading preferences.
  static Future<void> load({
    bool debug = kDebugMode,
    SharedPreferencesAsync? preferences,
  }) async {
    if (!debug) return;
    try {
      final prefs = preferences ?? SharedPreferencesAsync();
      final stored = await prefs.getString(preferenceKey);
      AppConfig.applyRuntimeBaseUrl(
        resolve(
          stored: stored,
          compiled: AppConfig.compiledBaseUrl,
          fallback: AppConfig.defaultBaseUrl,
        ),
      );
    } catch (_) {
      AppConfig.clearRuntimeBaseUrl();
    }
  }

  /// Persists a normalized runtime endpoint.
  static Future<bool> save(
    String raw, {
    SharedPreferencesAsync? preferences,
  }) async {
    final normalized = normalize(raw);
    if (normalized == null) return false;
    try {
      await (preferences ?? SharedPreferencesAsync()).setString(
        preferenceKey,
        normalized,
      );
      return true;
    } catch (_) {
      return false;
    }
  }

  /// Removes the persisted runtime endpoint.
  static Future<void> clear({SharedPreferencesAsync? preferences}) async {
    try {
      await (preferences ?? SharedPreferencesAsync()).remove(preferenceKey);
    } catch (_) {
      // Clearing an optional developer override is best effort.
    }
  }
}