part of '../ast.dart';

class UpsertClause extends AstNode implements HasWhereClause {
  final List<IndexedColumn> /*?*/ onColumns;
  @override
  Expression where;

  UpsertAction action;

  UpsertClause({this.onColumns, this.where, @required this.action});

  @override
  R accept<A, R>(AstVisitor<A, R> visitor, A arg) {
    return visitor.visitUpsertClause(this, arg);
  }

  @override
  void transformChildren<A>(Transformer<A> transformer, A arg) {
    transformer.transformChildren(onColumns, this, arg);
    where = transformer.transformNullableChild(where, this, arg);
    action = transformer.transformChild(action, this, arg);
  }

  @override
  Iterable<AstNode> get childNodes {
    return [
      if (onColumns != null) ...onColumns,
      if (where != null) where,
      action,
    ];
  }
}

abstract class UpsertAction extends AstNode {}

class DoNothing extends UpsertAction {
  @override
  R accept<A, R>(AstVisitor<A, R> visitor, A arg) {
    return visitor.visitDoNothing(this, arg);
  }

  @override
  void transformChildren<A>(Transformer<A> transformer, A arg) {}

  @override
  Iterable<AstNode> get childNodes => const [];
}

class DoUpdate extends UpsertAction implements HasWhereClause {
  final List<SetComponent> set;
  @override
  Expression where;

  DoUpdate(this.set, {this.where});

  @override
  R accept<A, R>(AstVisitor<A, R> visitor, A arg) {
    return visitor.visitDoUpdate(this, arg);
  }

  @override
  void transformChildren<A>(Transformer<A> transformer, A arg) {
    transformer.transformChildren(set, this, arg);
    where = transformer.transformNullableChild(where, this, arg);
  }

  @override
  Iterable<AstNode> get childNodes => [...set, if (where != null) where];
}