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

132 lines
3.9 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 AstStageProject : AstStage
{
public AstStageProject() {}
public AstStageProject(IEnumerable<AstLet> id, IEnumerable<AstLet> fields, bool exclude = false)
{
_id.AddRange(id);
Exclude = exclude;
foreach (var field in fields.OfType<AstNodeBase>())
Add(field);
}
public void AddId(AstLet field)
{
_id.Add(field);
}
private List<AstLet> _id = [];
public IReadOnlyList<AstLet> IdFields => _id;
public IReadOnlyList<AstLet> Fields => Children.OfType<AstLet>().ToList();
public bool Exclude { get; internal set; }
public override void Append(StringBuilder sb, int indent)
{
bool first;
if ( Exclude || IdFields.Count == 0)
sb.AppendLine($"{Spaces(indent)}PROJECT{(Exclude ? " EXCLUDE" : "")}");
else
{
sb.AppendLine($"{Spaces(indent)}PROJECT ID {{");
first = true;
foreach (var field in IdFields)
{
if ( !first )
sb.AppendLine(",");
else
first = false;
field.Append(sb, indent + 2);
}
sb.AppendLine();
sb.AppendLine($"{Spaces(indent+1)}}}");
}
first = true;
foreach (var field in Fields)
{
if ( !first )
sb.AppendLine(",");
else
first = false;
if ( field is AstLetExpression let)
{
if ( (let.Expression is AstExpressionVariable ev) && string.IsNullOrWhiteSpace(let.Name))
{
sb.Append($"{Spaces(indent + 1)}");
ev.Append(sb, indent + 1);
}
else
let.Append(sb, indent + 1);
}
else
field.Append(sb, indent + 1);
}
sb.AppendLine();
}
public override JsonNode? AsJson()
{
var fields = new JsonObject();
if ( IdFields.Count > 0 )
{
var idFields = new JsonObject();
foreach (var field in IdFields)
{
if ( field is AstLetExpression let)
AddFields(let, idFields);
}
fields.Add("_id", idFields);
}
foreach (var field in Fields)
{
if ( field is AstLetExpression let)
AddFields(let, fields);
}
var stage = new JsonObject([ new("$project", fields)]);
return ApplyOptions(stage);
}
private void AddFields(AstLetExpression field, JsonObject fields)
{
var name = field.Name;
if ( string.IsNullOrWhiteSpace(name) )
name = (field.Expression as AstExpressionVariable)?.Name;
if ( string.IsNullOrWhiteSpace(name) )
throw new ($"{field.Expression} must have a name");
if ( (field.Expression is AstExpressionVariable ev) && string.IsNullOrWhiteSpace(field.Name))
fields.Add(ev.Name, JsonValue.Create(Exclude ? 0 : 1));
else
fields.Add(name, field.Expression.AsJson());
}
}