/// <summary>
/// Evaluates the node, using the variables provided in the <paramref name="Variables"/> collection.
/// </summary>
/// <param name="Variables">Variables collection.</param>
/// <returns>Result.</returns>
public override IElement Evaluate(Variables Variables)
{
IElement E;
int Top;
int Offset;
int i, c;
if (this.top != null)
{
E = this.top.Evaluate(Variables);
Top = (int)Expression.ToDouble(E.AssociatedObjectValue);
if (Top <= 0)
{
throw new ScriptRuntimeException("TOP must evaluate to a positive integer.", this.top);
}
}
else
{
Top = int.MaxValue;
}
if (this.offset != null)
{
E = this.offset.Evaluate(Variables);
Offset = (int)Expression.ToDouble(E.AssociatedObjectValue);
if (Offset < 0)
{
throw new ScriptRuntimeException("OFFSET must evaluate to a non-negative integer.", this.offset);
}
}
else
{
Offset = 0;
}
c = this.sources.Length;
if (c != 1)
{
throw new ScriptRuntimeException("Joinds between multiple sources not supported.", this);
}
E = this.sources[0].Evaluate(Variables);
if (!(E.AssociatedObjectValue is Type T))
{
throw new ScriptRuntimeException("Type expected.", this.sources[0]);
}
List <string> OrderBy = new List <string>();
bool CalculatedOrder = false;
if (this.orderBy != null)
{
foreach (KeyValuePair <ScriptNode, bool> Node in this.orderBy)
{
if (Node.Key is VariableReference Ref)
{
if (Node.Value)
{
OrderBy.Add(Ref.VariableName);
}
else
{
OrderBy.Add("-" + Ref.VariableName);
}
}
else
{
CalculatedOrder = true;
}
}
}
if (this.groupBy != null)
{
foreach (ScriptNode Node in this.groupBy)
{
if (Node is VariableReference Ref)
{
if (!OrderBy.Contains(Ref.VariableName))
{
OrderBy.Add(Ref.VariableName);
}
}
else
{
CalculatedOrder = true;
}
}
}
bool ManualPaging = this.groupBy != null || this.where != null;
bool ManualTop = Top != int.MaxValue && ManualPaging;
bool ManualOffset = Offset != 0 && ManualPaging;
IEnumerator e = Find(T, ManualOffset ? 0 : Offset, ManualTop ? int.MaxValue : Top, this.where, Variables, OrderBy.ToArray(), this);
LinkedList <IElement[]> Items = new LinkedList <IElement[]>();
Dictionary <string, int> Columns = new Dictionary <string, int>();
IElement[] Rec;
int NrRecords = 0;
if (this.columns != null)
{
c = this.columns.Length;
for (i = 0; i < c; i++)
{
if (this.columns[i] is VariableReference Ref)
{
Columns[Ref.VariableName] = i;
}
}
}
else
{
c = 0;
}
if (this.where != null)
{
e = new ConditionalEnumerator(e, Variables, this.where);
}
if (this.groupBy != null)
{
e = new GroupEnumerator(e, Variables, this.groupBy, this.groupByNames);
if (this.having != null)
{
e = new ConditionalEnumerator(e, Variables, this.having);
}
}
if (CalculatedOrder)
{
List <KeyValuePair <ScriptNode, bool> > Order = new List <KeyValuePair <ScriptNode, bool> >();
if (this.orderBy != null)
{
Order.AddRange(this.orderBy);
}
if (this.groupByNames != null)
{
foreach (ScriptNode Group in this.groupByNames)
{
if (Group != null)
{
Order.Add(new KeyValuePair <ScriptNode, bool>(Group, true));
}
}
}
e = new CustomOrderEnumerator(e, Variables, Order.ToArray());
}
while (e.MoveNext())
{
if (ManualOffset && Offset > 0)
{
Offset--;
continue;
}
object Item = e.Current;
ObjectProperties Properties = new ObjectProperties(Item, Variables);
if (this.columns is null)
{
Rec = new IElement[1] {
Expression.Encapsulate(Item)
}
}
;
else
{
Rec = new IElement[c];
for (i = 0; i < c; i++)
{
try
{
Rec[i] = this.columns[i].Evaluate(Properties);
}
catch (Exception ex)
{
ex = Log.UnnestException(ex);
Rec[i] = Expression.Encapsulate(ex);
}
}
}
Items.AddLast(Rec);
NrRecords++;
if (ManualTop && NrRecords >= Top)
{
break;
}
}
IElement[] Elements = new IElement[this.columns is null ? NrRecords : NrRecords * c];
/// <summary>
/// Evaluates the node asynchronously, using the variables provided in
/// the <paramref name="Variables"/> collection.
/// </summary>
/// <param name="Variables">Variables collection.</param>
/// <returns>Result.</returns>
public async Task <IElement> EvaluateAsync(Variables Variables)
{
IElement E;
int Top;
int Offset;
int i, c;
if (this.top != null)
{
E = this.top.Evaluate(Variables);
Top = (int)Expression.ToDouble(E.AssociatedObjectValue);
if (Top <= 0)
{
throw new ScriptRuntimeException("TOP must evaluate to a positive integer.", this.top);
}
}
else
{
Top = int.MaxValue;
}
if (this.offset != null)
{
E = this.offset.Evaluate(Variables);
Offset = (int)Expression.ToDouble(E.AssociatedObjectValue);
if (Offset < 0)
{
throw new ScriptRuntimeException("OFFSET must evaluate to a non-negative integer.", this.offset);
}
}
else
{
Offset = 0;
}
IDataSource Source = this.source.GetSource(Variables);
List <KeyValuePair <VariableReference, bool> > OrderBy = new List <KeyValuePair <VariableReference, bool> >();
bool CalculatedOrder = false;
if (this.orderBy != null)
{
foreach (KeyValuePair <ScriptNode, bool> Node in this.orderBy)
{
if (Node.Key is VariableReference Ref)
{
OrderBy.Add(new KeyValuePair <VariableReference, bool>(Ref, Node.Value));
}
else
{
CalculatedOrder = true;
break;
}
}
}
if (this.groupBy != null && !CalculatedOrder)
{
foreach (ScriptNode Node in this.groupBy)
{
if (Node is VariableReference Ref)
{
bool Found = false;
foreach (KeyValuePair <VariableReference, bool> P in OrderBy)
{
if (P.Key.VariableName == Ref.VariableName)
{
Found = true;
break;
}
}
if (!Found)
{
OrderBy.Add(new KeyValuePair <VariableReference, bool>(Ref, true));
}
}
else
{
CalculatedOrder = true;
break;
}
}
}
LinkedList <IElement[]> Items = new LinkedList <IElement[]>();
Dictionary <string, int> Columns = new Dictionary <string, int>();
IResultSetEnumerator e;
RecordEnumerator e2;
int NrRecords = 0;
if (this.columns != null)
{
c = this.columns.Length;
for (i = 0; i < c; i++)
{
if (this.columns[i] is VariableReference Ref)
{
Columns[Ref.VariableName] = i;
}
}
}
else
{
c = 0;
}
if (this.groupBy is null)
{
e = await Source.Find(Offset, Top, this.where, Variables, OrderBy.ToArray(), this);
Offset = 0;
Top = int.MaxValue;
}
else
{
e = await Source.Find(0, int.MaxValue, this.where, Variables, OrderBy.ToArray(), this);
}
if (this.groupBy != null)
{
e = new GroupEnumerator(e, Variables, this.groupBy, this.groupByNames);
if (this.having != null)
{
e = new ConditionalEnumerator(e, Variables, this.having);
}
}
if (CalculatedOrder)
{
List <KeyValuePair <ScriptNode, bool> > Order = new List <KeyValuePair <ScriptNode, bool> >();
if (this.orderBy != null)
{
Order.AddRange(this.orderBy);
}
if (this.groupByNames != null)
{
foreach (ScriptNode Group in this.groupByNames)
{
if (Group != null)
{
Order.Add(new KeyValuePair <ScriptNode, bool>(Group, true));
}
}
}
e = new CustomOrderEnumerator(e, Variables, Order.ToArray());
}
if (Offset > 0)
{
e = new OffsetEnumerator(e, Offset);
}
if (Top != int.MaxValue)
{
e = new MaxCountEnumerator(e, Top);
}
if (this.distinct)
{
e2 = new DistinctEnumerator(e, this.columns, Variables);
}
else
{
e2 = new RecordEnumerator(e, this.columns, Variables);
}
while (await e2.MoveNextAsync())
{
Items.AddLast(e2.CurrentRecord);
NrRecords++;
}
IElement[] Elements = new IElement[this.columns is null ? NrRecords : NrRecords * c];