import '../questions_db.dart';
import 'market_data_db.dart';
import 'trading_config.dart';
import 'trading_config_db.dart';
import 'trading_pipeline.dart';

/// Snapshot row seeded by [TradingDevActions.forceFireDip], returned for UI/CLI feedback.
class SeededSnapshot {
  SeededSnapshot({
    required this.symbol,
    required this.metric,
    required this.price,
    required this.asOf,
    required this.created,
  });

  final String symbol;
  final String metric;
  final num price;
  final DateTime asOf;

  /// `true` if this snapshot was newly inserted; `false` if a fresh one already
  /// existed and was reused.
  final bool created;

  Map<String, dynamic> toJson() => <String, dynamic>{
        'symbol': symbol,
        'metric': metric,
        'price': price,
        'asOf': asOf.toIso8601String(),
        'created': created,
      };
}

/// Outcome of [TradingDevActions.forceFireDip].
class ForceFireResult {
  ForceFireResult({
    required this.snapshots,
    required this.evaluation,
    this.skipReason,
  });

  /// Snapshots that were inserted or reused for the forced dip.
  final List<SeededSnapshot> snapshots;

  /// `null` when the config was disabled or had no dip rule.
  final TradingEvaluationResult? evaluation;

  /// Non-null when the action short-circuited (e.g. config disabled).
  final String? skipReason;

  Map<String, dynamic> toJson() => <String, dynamic>{
        'snapshots': snapshots.map((SeededSnapshot s) => s.toJson()).toList(),
        'evaluation': evaluation == null
            ? null
            : <String, dynamic>{
                'questionsCreated': evaluation!.questionsCreated,
                'rulesFired': evaluation!.rulesFired,
                'rulesSkipped': evaluation!.rulesSkipped,
              },
        if (skipReason != null) 'skipReason': skipReason,
      };
}

/// Dev-only utilities that bypass market hours / real Alpaca data to exercise
/// the trading flow end-to-end through the UI.
///
/// Used by [tradingDevHandler] when `TRADING_DEV_ENDPOINTS_ENABLED=true`.
class TradingDevActions {
  TradingDevActions({
    required QuestionsDb questionsDb,
    required MarketDataDb marketDataDb,
    required TradingConfigDb tradingConfigDb,
    required TradingPipeline tradingPipeline,
    DateTime Function()? clock,
    num syntheticRefPrice = 500,
    num syntheticOvershootPct = 0.5,
  })  : _questionsDb = questionsDb,
        _marketDataDb = marketDataDb,
        _tradingConfigDb = tradingConfigDb,
        _tradingPipeline = tradingPipeline,
        _clock = clock ?? DateTime.now,
        _syntheticRefPrice = syntheticRefPrice,
        _syntheticOvershootPct = syntheticOvershootPct;

  final QuestionsDb _questionsDb;
  final MarketDataDb _marketDataDb;
  final TradingConfigDb _tradingConfigDb;
  final TradingPipeline _tradingPipeline;
  final DateTime Function() _clock;
  final num _syntheticRefPrice;
  final num _syntheticOvershootPct;

  /// Seeds dipped snapshots for every `price_below_pct_of_ref` rule in the
  /// user's effective config, then immediately runs [TradingPipeline.evaluate].
  ///
  /// For each rule, the dipped `last_trade` is positioned
  /// [syntheticOvershootPct] percentage points beyond the rule's threshold
  /// so the rule unambiguously fires. The `ref_metric` snapshot is reused when
  /// a fresh one already exists, otherwise a synthetic one is inserted.
  Future<ForceFireResult> forceFireDip(String firebaseUid) async {
    final EffectiveTradingConfig? config =
        await _tradingConfigDb.resolveEffectiveConfig(firebaseUid);
    if (config == null) {
      return ForceFireResult(
        snapshots: <SeededSnapshot>[],
        evaluation: null,
        skipReason: 'no_config',
      );
    }
    if (!config.enabled) {
      return ForceFireResult(
        snapshots: <SeededSnapshot>[],
        evaluation: null,
        skipReason: 'disabled',
      );
    }

    final List<SeededSnapshot> seeded = <SeededSnapshot>[];
    final DateTime now = _clock().toUtc();

    // Ensure no stale unanswered trading question is parked on the queue so
    // the open-question guard in TradingPipeline doesn't suppress the dev fire.
    await _cancelOpenTradingQuestions(firebaseUid);

    for (final TradingRuleConfig rule in config.rules) {
      if (rule.type != 'price_below_pct_of_ref') continue;

      final MarketDataSnapshot? existingRef =
          await _marketDataDb.latestForSymbol(rule.symbol, rule.refMetric);
      late final num refPrice;
      if (existingRef != null && existingRef.price != null) {
        refPrice = existingRef.price!;
        seeded.add(SeededSnapshot(
          symbol: rule.symbol,
          metric: rule.refMetric,
          price: refPrice,
          asOf: existingRef.asOf,
          created: false,
        ));
      } else {
        refPrice = _syntheticRefPrice;
        final DateTime refAsOf = now.subtract(const Duration(days: 1));
        await _marketDataDb.insertSnapshot(
          symbol: rule.symbol,
          metric: rule.refMetric,
          price: refPrice,
          asOf: refAsOf,
        );
        seeded.add(SeededSnapshot(
          symbol: rule.symbol,
          metric: rule.refMetric,
          price: refPrice,
          asOf: refAsOf,
          created: true,
        ));
      }

      // Compute a last_trade price `overshoot` pct beyond the threshold so
      // the rule fires unambiguously. Example: thresholdPct=-1.5,
      // overshoot=0.5 → last_trade is 2.0% below ref.
      final num targetPct = rule.thresholdPct - _syntheticOvershootPct;
      final num lastTradePrice = refPrice * (1 + targetPct / 100);
      final DateTime tradeAsOf = now.subtract(const Duration(seconds: 30));

      await _marketDataDb.insertSnapshot(
        symbol: rule.symbol,
        metric: 'last_trade',
        price: lastTradePrice,
        asOf: tradeAsOf,
      );
      seeded.add(SeededSnapshot(
        symbol: rule.symbol,
        metric: 'last_trade',
        price: lastTradePrice,
        asOf: tradeAsOf,
        created: true,
      ));
    }

    final TradingEvaluationResult evaluation =
        await _tradingPipeline.evaluate(firebaseUid);

    return ForceFireResult(snapshots: seeded, evaluation: evaluation);
  }

  /// Marks any unanswered `pipeline_key=trading` question with `user_response=0`
  /// so a re-fire isn't blocked by the open-question guard. (Skipped answers
  /// don't stage orders.)
  Future<void> _cancelOpenTradingQuestions(String firebaseUid) async {
    final List<Map<String, dynamic>> open =
        await _questionsDb.listUnansweredQuestions(firebaseUid);
    for (final Map<String, dynamic> q in open) {
      if (q['pipelineKey'] != 'trading') continue;
      await _questionsDb.submitAnswer(
        questionId: q['id']! as String,
        assignedUserId: firebaseUid,
        userResponse: 0,
      );
    }
  }
}