import 'market_history_four_hour_slot.dart';

/// One Alpaca backfill request bucket: a UTC 4-hour slot and its symbols.
class BackfillSyncItem {
  const BackfillSyncItem({
    required this.slotStart,
    required this.symbols,
  });

  final DateTime slotStart;
  final List<String> symbols;

  Map<String, dynamic> toJson() => <String, dynamic>{
        'slotStart': MarketHistoryFourHourSlot.slotStartWire(slotStart),
        'symbols': symbols,
      };

  static BackfillSyncItem? tryFromJson(dynamic raw) {
    if (raw is! Map<String, dynamic>) {
      return null;
    }
    final String? slotStartRaw = raw['slotStart'] as String?;
    if (slotStartRaw == null) {
      return null;
    }
    final DateTime? slotStart = DateTime.tryParse(slotStartRaw)?.toUtc();
    if (slotStart == null) {
      return null;
    }
    final List<dynamic> symbolRaw =
        raw['symbols'] as List<dynamic>? ?? <dynamic>[];
    final List<String> symbols = symbolRaw
        .map((dynamic value) => value.toString())
        .where((String value) => value.isNotEmpty)
        .toList(growable: false);
    return BackfillSyncItem(slotStart: slotStart, symbols: symbols);
  }

  static List<BackfillSyncItem> listFromJson(dynamic raw) {
    if (raw == null) {
      return <BackfillSyncItem>[];
    }
    if (raw is! List<dynamic>) {
      return <BackfillSyncItem>[];
    }
    final List<BackfillSyncItem> items = <BackfillSyncItem>[];
    for (final dynamic entry in raw) {
      final BackfillSyncItem? item = tryFromJson(entry);
      if (item != null) {
        items.add(item);
      }
    }
    return items;
  }

  static List<Map<String, dynamic>> encodeList(List<BackfillSyncItem> items) {
    return items.map((BackfillSyncItem item) => item.toJson()).toList();
  }
}