import 'dart:convert';

import 'package:postgres/postgres.dart';
import 'package:uuid/uuid.dart';

/// Persisted trade order audit row.
class TradeOrder {
  TradeOrder({
    required this.id,
    required this.firebaseUid,
    required this.clientOrderId,
    required this.symbol,
    required this.side,
    required this.orderType,
    required this.status,
    this.alpacaOrderId,
    this.notionalUsd,
    this.qty,
    this.questionId,
    this.ruleId,
    this.submittedAt,
    this.filledAt,
    this.raw,
    this.createdAt,
  });

  final String id;
  final String firebaseUid;
  final String clientOrderId;
  final String? alpacaOrderId;
  final String symbol;
  final String side;
  final String orderType;
  final num? notionalUsd;
  final num? qty;
  final String status;
  final String? questionId;
  final String? ruleId;
  final DateTime? submittedAt;
  final DateTime? filledAt;
  final Map<String, dynamic>? raw;
  final DateTime? createdAt;
}

/// Postgres access for [trade_orders].
class TradeOrdersDb {
  TradeOrdersDb(this._connection);

  final Connection _connection;
  static const Uuid _uuid = Uuid();

  /// Counts non-terminal orders submitted at or after [since].
  ///
  /// Used by guardrails for `max_orders_per_day` (pass UTC start-of-day) and
  /// rolling-window order-count checks.
  Future<int> countOrdersSince(String firebaseUid, DateTime since) async {
    final Result result = await _connection.execute(
      Sql.named(
        '''
        SELECT COUNT(*)
        FROM trade_orders
        WHERE firebase_uid = @uid
          AND submitted_at IS NOT NULL
          AND submitted_at >= @since
          AND status NOT IN ('rejected', 'canceled', 'failed')
        ''',
      ),
      parameters: <String, dynamic>{
        'uid': firebaseUid,
        'since': since.toUtc(),
      },
    );
    if (result.isEmpty) return 0;
    final Object? raw = result.first[0];
    if (raw is num) return raw.toInt();
    return num.parse(raw.toString()).toInt();
  }

  /// Sums `notional_usd` of non-terminal orders submitted at or after [since].
  ///
  /// Used by guardrails for the rolling 4-hour notional cap.
  Future<num> notionalUsdInWindow(String firebaseUid, DateTime since) async {
    final Result result = await _connection.execute(
      Sql.named(
        '''
        SELECT COALESCE(SUM(notional_usd), 0)
        FROM trade_orders
        WHERE firebase_uid = @uid
          AND submitted_at IS NOT NULL
          AND submitted_at >= @since
          AND status NOT IN ('rejected', 'canceled', 'failed')
        ''',
      ),
      parameters: <String, dynamic>{
        'uid': firebaseUid,
        'since': since.toUtc(),
      },
    );
    if (result.isEmpty) return 0;
    final Object? raw = result.first[0];
    if (raw is num) return raw;
    return num.parse(raw.toString());
  }

  Future<TradeOrder?> findByClientOrderId(String clientOrderId) async {
    final Result result = await _connection.execute(
      Sql.named(
        '''
        SELECT id, firebase_uid, client_order_id, alpaca_order_id, symbol, side,
               order_type, notional_usd, qty, status, question_id, rule_id,
               submitted_at, filled_at, raw, created_at
        FROM trade_orders
        WHERE client_order_id = @client_order_id
        ''',
      ),
      parameters: <String, dynamic>{'client_order_id': clientOrderId},
    );
    if (result.isEmpty) {
      return null;
    }
    return _rowToOrder(result.first);
  }

  /// Inserts a pending order. Returns existing row if [clientOrderId] already exists.
  Future<TradeOrder> insertOrder({
    required String firebaseUid,
    required String clientOrderId,
    required String symbol,
    required String side,
    required String orderType,
    required String status,
    String? alpacaOrderId,
    num? notionalUsd,
    num? qty,
    String? questionId,
    String? ruleId,
    Map<String, dynamic>? raw,
  }) async {
    final TradeOrder? existing = await findByClientOrderId(clientOrderId);
    if (existing != null) {
      return existing;
    }

    final String id = _uuid.v4();
    try {
      final Result result = await _connection.execute(
        Sql.named(
          '''
          INSERT INTO trade_orders (
            id, firebase_uid, client_order_id, alpaca_order_id, symbol, side,
            order_type, notional_usd, qty, status, question_id, rule_id, raw,
            submitted_at
          ) VALUES (
            @id::uuid, @uid, @client_order_id, @alpaca_order_id, @symbol, @side,
            @order_type, @notional_usd, @qty, @status, @question_id::uuid,
            @rule_id, @raw::jsonb, @submitted_at
          )
          RETURNING id, firebase_uid, client_order_id, alpaca_order_id, symbol, side,
                    order_type, notional_usd, qty, status, question_id, rule_id,
                    submitted_at, filled_at, raw, created_at
          ''',
        ),
        parameters: <String, dynamic>{
          'id': id,
          'uid': firebaseUid,
          'client_order_id': clientOrderId,
          'alpaca_order_id': alpacaOrderId,
          'symbol': symbol,
          'side': side,
          'order_type': orderType,
          'notional_usd': notionalUsd,
          'qty': qty,
          'status': status,
          'question_id': questionId,
          'rule_id': ruleId,
          'raw': raw == null ? null : jsonEncode(raw),
          'submitted_at': DateTime.now().toUtc(),
        },
      );
      return _rowToOrder(result.first);
    } on ServerException catch (e) {
      if (e.code == '23505') {
        final TradeOrder? raced = await findByClientOrderId(clientOrderId);
        if (raced != null) {
          return raced;
        }
      }
      rethrow;
    }
  }

  TradeOrder _rowToOrder(ResultRow row) {
    final Object idValue = row[0]!;
    final String id = idValue is String ? idValue : idValue.toString();
    final Object? questionRaw = row[10];
    final String? questionId =
        questionRaw == null ? null : questionRaw.toString();

    final Object? rawValue = row[14];
    Map<String, dynamic>? raw;
    if (rawValue is Map<String, dynamic>) {
      raw = rawValue;
    } else if (rawValue != null) {
      raw = jsonDecode(rawValue.toString()) as Map<String, dynamic>;
    }

    return TradeOrder(
      id: id,
      firebaseUid: row[1]! as String,
      clientOrderId: row[2]! as String,
      alpacaOrderId: row[3] as String?,
      symbol: row[4]! as String,
      side: row[5]! as String,
      orderType: row[6]! as String,
      notionalUsd: _readOptionalNumeric(row[7]),
      qty: _readOptionalNumeric(row[8]),
      status: row[9]! as String,
      questionId: questionId,
      ruleId: row[11] as String?,
      submittedAt: row[12] as DateTime?,
      filledAt: row[13] as DateTime?,
      raw: raw,
      createdAt: row[15] as DateTime?,
    );
  }

  static num? _readOptionalNumeric(Object? value) {
    if (value == null) {
      return null;
    }
    if (value is num) {
      return value;
    }
    if (value is String) {
      return num.parse(value);
    }
    return num.parse(value.toString());
  }
}