Alexander Shabarshov 2a7a24c9e7 Initial contribution
2025-11-03 14:43:26 +00:00

125 lines
3.6 KiB
C#

/*
* dbMango
*
* Copyright 2025 Deutsche Bank AG
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
namespace Rms.Risk.Mango.Language.Ast;
public class AstStageJoin : AstStage
{
public AstStageJoin()
{
}
public AstStageJoin(string collection, string asField, IEnumerable<AstEquivalence> on, IEnumerable<AstLet> let, AstPipeline? pipeline = null)
{
Init(collection, asField, on, let, pipeline);
}
public void Init(string collection, string asField, IEnumerable<AstEquivalence> on, IEnumerable<AstLet> let, AstPipeline? pipeline = null)
{
Collection = collection.Trim('\"');
AsField = PreprocessFieldName(asField);
foreach(var x in on)
Add(x);
foreach(var x in let)
Add(x);
if (pipeline != null)
Add(pipeline);
}
public string Collection { get; private set;} = "";
public string AsField { get; private set; } = "";
public IReadOnlyList<AstEquivalence> On => Children.OfType<AstEquivalence>().ToList();
public IReadOnlyList<AstLet> Let => Children.OfType<AstLet>().ToList();
public AstPipeline? Pipeline => Children.OfType<AstPipeline>().FirstOrDefault();
public override void Append(StringBuilder sb, int indent)
{
sb.Append($"{Spaces(indent)}JOIN \"{Collection}\" AS ");
AppendField(sb, AsField);
sb.AppendLine($" ON");
var first = true;
foreach (var field in On)
{
if ( !first )
sb.AppendLine(",");
else
first = false;
field.Append(sb, indent + 1);
}
sb.AppendLine();
if ( Let.Count > 0 )
{
sb.AppendLine($"{Spaces(indent+1)}LET");
foreach (var field in Let)
{
field.Append(sb, indent + 2);
}
sb.AppendLine();
}
if( Pipeline != null )
{
sb.AppendLine($"{Spaces(indent + 1)}PIPELINE {{");
Pipeline.Append(sb, indent + 2);
sb.AppendLine($"{Spaces(indent + 1)}}}");
}
}
public override JsonNode? AsJson()
{
var eqv = On.First();
var stage = new JsonObject
{
{
"$lookup",
new JsonObject
{
{"from", Collection},
{"localField", JsonValue.Create(eqv.Left.Name)},
{"foreignField", JsonValue.Create(eqv.Right.Name)}
}
}
};
var body = (JsonObject)stage.ElementAt(0).Value!;
if (!string.IsNullOrWhiteSpace(AsField))
{
body.Add( new("as", JsonValue.Create(AsField)) );
}
if ( Let?.Count > 0 )
{
var fields =AstLet.AsJson(Let);
body.Add( new("let", fields) );
}
if ( Pipeline != null )
body.Add( new("pipeline", Pipeline.AsJson()) );
return ApplyOptions(stage);
}
}