import 'package:shared_preferences/shared_preferences.dart';
import 'package:tm_app/core/constants/pref_keys.dart';
import 'package:tm_app/core/utils/logger.dart';
import 'package:tm_app/core/utils/result.dart';
import 'package:tm_app/data/services/company_ai_service.dart';
import 'package:tm_app/data/services/model/onboarding_response/onboarding_response.dart';
import 'package:tm_app/data/services/model/recommend_response/recommend_response.dart';

/// Outcome of [CompanyAiRepository.maybeStartOnboarding].
enum AiOnboardingOutcome {
  /// Onboarding was started against the AI service.
  started,

  /// Skipped: the company has no documents and no website yet.
  skippedNoData,

  /// Skipped: this profile version was already onboarded.
  skippedUnchanged,

  /// The onboarding request failed (network/server). Safe to retry later.
  failed,
}

/// Coordinates AI onboarding and recommendation calls.
///
/// Onboarding is asynchronous on the AI side and only needs to run when the
/// company's documents or website change, so this repository fingerprints that
/// data in [SharedPreferences] and skips redundant calls — mirroring the
/// `onCompanyProfileReady` guidance in the mobile integration guide.
class CompanyAiRepository {
  CompanyAiRepository({
    required CompanyAiService companyAiService,
    required SharedPreferences prefs,
  }) : _companyAiService = companyAiService,
       _prefs = prefs;

  final CompanyAiService _companyAiService;
  final SharedPreferences _prefs;

  /// Starts onboarding only when the company has data to index and its
  /// fingerprint differs from the last successful run.
  Future<AiOnboardingOutcome> maybeStartOnboarding({
    required List<String> documentFileIds,
    required String? website,
  }) async {
    final hasWebsite = website != null && website.trim().isNotEmpty;
    if (documentFileIds.isEmpty && !hasWebsite) {
      return AiOnboardingOutcome.skippedNoData;
    }

    final fingerprint = _fingerprint(documentFileIds, website);
    if (fingerprint == _prefs.getString(PrefKeys.onboardingFingerprint)) {
      return AiOnboardingOutcome.skippedUnchanged;
    }

    final result = await _companyAiService.startOnboarding();
    switch (result) {
      case Ok<OnboardingResponse>():
        await _prefs.setString(PrefKeys.onboardingFingerprint, fingerprint);
        await _prefs.setInt(
          PrefKeys.onboardingStartedAt,
          DateTime.now().millisecondsSinceEpoch,
        );
        AppLogger().info('✅ AI onboarding started for fingerprint $fingerprint');
        return AiOnboardingOutcome.started;
      case Error<OnboardingResponse>():
        // Don't persist the fingerprint so the next profile load retries.
        AppLogger().logWarning('⚠️ AI onboarding failed: ${result.error}');
        return AiOnboardingOutcome.failed;
    }
  }

  Future<Result<RecommendResponse>> getRecommendations() {
    return _companyAiService.getRecommendations();
  }

  /// Epoch milliseconds of the last started onboarding, or null if none.
  int? lastOnboardingStartedAt() =>
      _prefs.getInt(PrefKeys.onboardingStartedAt);

  /// Stable, order-independent fingerprint of the data the AI service indexes.
  /// Stored verbatim (it is not sensitive) so it compares reliably across app
  /// launches, unlike [String.hashCode].
  String _fingerprint(List<String> documentFileIds, String? website) {
    final ids = [...documentFileIds]..sort();
    return '${ids.join(',')}|${website?.trim() ?? ''}';
  }
}