minisql/src/main/scala/miniql/ast/StatelessTransformer.scala

package minisql.ast

trait StatelessTransformer {

  def apply(e: Ast): Ast =
    e match {
      case e: Query                 => apply(e)
      case e: Operation             => apply(e)
      case e: Action                => apply(e)
      case e: Value                 => apply(e)
      case e: Assignment            => apply(e)
      case Function(params, body)   => Function(params, apply(body))
      case e: Ident                 => e
      case e: ExternalIdent         => e
      case e: Property              => apply(e)
      case Infix(a, b, pure, paren) => Infix(a, b.map(apply), pure, paren)
      case e: OptionOperation       => apply(e)
      case e: IterableOperation     => apply(e)
      case If(a, b, c)              => If(apply(a), apply(b), apply(c))
      case e: Dynamic               => e
      case e: Lift                  => e
      case Block(statements)        => Block(statements.map(apply))
      case Val(name, body)          => Val(name, apply(body))
      case o: Ordering              => o
      case e: OnConflict.Excluded   => e
      case e: OnConflict.Existing   => e
    }

  def apply(o: OptionOperation): OptionOperation =
    o match {
      case OptionTableFlatMap(a, b, c) =>
        OptionTableFlatMap(apply(a), b, apply(c))
      case OptionTableMap(a, b, c) => OptionTableMap(apply(a), b, apply(c))
      case OptionTableExists(a, b, c) =>
        OptionTableExists(apply(a), b, apply(c))
      case OptionTableForall(a, b, c) =>
        OptionTableForall(apply(a), b, apply(c))
      case OptionFlatten(a)       => OptionFlatten(apply(a))
      case OptionGetOrElse(a, b)  => OptionGetOrElse(apply(a), apply(b))
      case OptionFlatMap(a, b, c) => OptionFlatMap(apply(a), b, apply(c))
      case OptionMap(a, b, c)     => OptionMap(apply(a), b, apply(c))
      case OptionForall(a, b, c)  => OptionForall(apply(a), b, apply(c))
      case OptionExists(a, b, c)  => OptionExists(apply(a), b, apply(c))
      case OptionContains(a, b)   => OptionContains(apply(a), apply(b))
      case OptionIsEmpty(a)       => OptionIsEmpty(apply(a))
      case OptionNonEmpty(a)      => OptionNonEmpty(apply(a))
      case OptionIsDefined(a)     => OptionIsDefined(apply(a))
      case OptionSome(a)          => OptionSome(apply(a))
      case OptionApply(a)         => OptionApply(apply(a))
      case OptionOrNull(a)        => OptionOrNull(apply(a))
      case OptionGetOrNull(a)     => OptionGetOrNull(apply(a))
      case OptionNone             => OptionNone
    }

  def apply(o: IterableOperation): IterableOperation =
    o match {
      case MapContains(a, b)  => MapContains(apply(a), apply(b))
      case SetContains(a, b)  => SetContains(apply(a), apply(b))
      case ListContains(a, b) => ListContains(apply(a), apply(b))
    }

  def apply(e: Query): Query =
    e match {
      case e: Entity          => e
      case Filter(a, b, c)    => Filter(apply(a), b, apply(c))
      case Map(a, b, c)       => Map(apply(a), b, apply(c))
      case FlatMap(a, b, c)   => FlatMap(apply(a), b, apply(c))
      case ConcatMap(a, b, c) => ConcatMap(apply(a), b, apply(c))
      case SortBy(a, b, c, d) => SortBy(apply(a), b, apply(c), d)
      case GroupBy(a, b, c)   => GroupBy(apply(a), b, apply(c))
      case Aggregation(o, a)  => Aggregation(o, apply(a))
      case Take(a, b)         => Take(apply(a), apply(b))
      case Drop(a, b)         => Drop(apply(a), apply(b))
      case Union(a, b)        => Union(apply(a), apply(b))
      case UnionAll(a, b)     => UnionAll(apply(a), apply(b))
      case Join(t, a, b, iA, iB, on) =>
        Join(t, apply(a), apply(b), iA, iB, apply(on))
      case FlatJoin(t, a, iA, on) =>
        FlatJoin(t, apply(a), iA, apply(on))
      case Distinct(a)          => Distinct(apply(a))
      case DistinctOn(a, iA, b) => DistinctOn(apply(a), iA, apply(b))
      case Nested(a)            => Nested(apply(a))
    }

  def apply(e: Assignment): Assignment =
    e match {
      case Assignment(a, b, c) => Assignment(a, apply(b), apply(c))
    }

  def apply(e: Property): Property =
    e match {
      case Property.Opinionated(a, name, renameable, visibility) =>
        Property.Opinionated(apply(a), name, renameable, visibility)
    }

  def apply(e: Operation): Operation =
    e match {
      case UnaryOperation(o, a)     => UnaryOperation(o, apply(a))
      case BinaryOperation(a, b, c) => BinaryOperation(apply(a), b, apply(c))
      case FunctionApply(function, values) =>
        FunctionApply(apply(function), values.map(apply))
    }

  def apply(e: Value): Value =
    e match {
      case e: Constant   => e
      case NullValue     => NullValue
      case Tuple(values) => Tuple(values.map(apply))
      case CaseClass(tuples) => {
        val (keys, values) = tuples.unzip
        CaseClass(keys.zip(values.map(apply)))
      }
    }

  def apply(e: Action): Action =
    e match {
      case Update(query, assignments) =>
        Update(apply(query), assignments.map(apply))
      case Insert(query, assignments) =>
        Insert(apply(query), assignments.map(apply))
      case Delete(query) => Delete(apply(query))
      case Returning(query, alias, property) =>
        Returning(apply(query), alias, apply(property))
      case ReturningGenerated(query, alias, property) =>
        ReturningGenerated(apply(query), alias, apply(property))
      case Foreach(query, alias, body) =>
        Foreach(apply(query), alias, apply(body))
      case OnConflict(query, target, action) =>
        OnConflict(apply(query), apply(target), apply(action))
    }

  def apply(e: OnConflict.Target): OnConflict.Target =
    e match {
      case OnConflict.NoTarget => e
      case OnConflict.Properties(props) =>
        OnConflict.Properties(props.map(apply))
    }

  def apply(e: OnConflict.Action): OnConflict.Action =
    e match {
      case OnConflict.Ignore          => e
      case OnConflict.Update(assigns) => OnConflict.Update(assigns.map(apply))
    }

}