import 'package:jiffy/jiffy.dart';

class DTInterval {
  late Jiffy start;
  late Jiffy end;
  DTInterval(this.start, this.end);
  @override
  String toString() =>
      "<${start.format(pattern: "ddMMMyy HH:mm")} - ${end.format(pattern: "ddMMMyy HH:mm")}>";

  bool include(Jiffy x) {
    return x.isSameOrAfter(start) && x.isSameOrBefore(end);
  }

  bool isOverlap(DTInterval x) {
    return x.start.isSameOrBefore(end) && x.end.isSameOrAfter(start);
  }

  bool contains(DTInterval x) {
    return include(x.start) && include(x.end);
  }

  DTInterval? intersection(DTInterval x) {
    if (!isOverlap(x)) {
      return null;
    } else {
      return DTInterval(start.max(x.start), end.min(x.end));
    }
  }

  List<DTInterval> intersectionmany(List<DTInterval> x) {
    return x.map((e) => intersection(e)).nonNulls.toList();
  }

  List<DTInterval> minus(DTInterval x) {
    if (!isOverlap(x)) {
      return [this];
    } else if (x.include(start) && x.include(end)) {
      return [];
    } else if (x.include(start)) {
      return [DTInterval(x.end, end)];
    } else if (x.include(end)) {
      return [DTInterval(start, x.start)];
    } else {
      return [DTInterval(start, x.start), DTInterval(x.end, end)];
    }
  }

  // List<DTInterval> minus(DTInterval other) {
  //   List<DTInterval> result = [];
  //   if (start.isBefore(other.start) && end.isAfter(other.start)) {
  //     result.add(DTInterval(start, other.start));
  //   }
  //   if (start.isBefore(other.end) && end.isAfter(other.end)) {
  //     result.add(DTInterval(other.end, end));
  //   }
  //   return result;
  // }

  Duration get duration => end.dateTime.difference(start.dateTime);
  // Duration get duration => Duration(
  //     milliseconds: end.diff(start, unit: Unit.millisecond).abs().ceil());

  bool isEmpty() {
    return start.isSameOrAfter(end);
  }

  DTInterval toUtc() {
    return DTInterval(start.toUtc(), end.toUtc());
  }
}

extension JiffyExtensions on Jiffy? {
  Jiffy? latest(Jiffy? val2) {
    if (this == null) return val2;
    if (val2 == null) return this;
    if (this!.isBefore(val2)) {
      return val2;
    } else {
      return this;
    }
  }

  Jiffy? earliset(Jiffy? val2) {
    if (this == null) return val2;
    if (val2 == null) return this;
    if (this!.isAfter(val2)) {
      return val2;
    } else {
      return this;
    }
  }

  Jiffy max(Jiffy val2) {
    if (this!.isBefore(val2)) {
      return val2;
    } else {
      return this!;
    }
  }

  Jiffy min(Jiffy val2) {
    if (this!.isAfter(val2)) {
      return val2;
    } else {
      return this!;
    }
  }
}