MycLib/Src/AST/Myc.Ast.JSON.pas

unit Myc.Ast.Json;

interface

uses
    System.SysUtils,
    System.Generics.Collections,
    System.JSON,
    Myc.Data.Scalar,
    Myc.Data.Value,
    Myc.Ast,
    Myc.Ast.Visitor,
    Myc.Ast.Nodes;

type
    IJsonAstConverter = interface
        function Serialize(const RootNode: IAstNode): TJSONObject;
        function Deserialize(const AJson: TJSONObject): IAstNode;
    end;

    TJsonAstConverter = class(TAstVisitor<TJSONObject>, IJsonAstConverter)
    private
        procedure DataValueToJson(const AValue: TDataValue; const AParent: TJSONObject; const AName: string);
        function JsonToNode(const AJson: TJSONValue; const ExpectedType: string = ''): IAstNode;
        function JsonToDataValue(const AObj: TJSONObject; const AName: string): TDataValue;

        // Deserialization Helpers
        function JsonToConstantNode(const AObj: TJSONObject): IConstantNode;
        function JsonToIdentifierNode(const AObj: TJSONObject): IIdentifierNode;
        function JsonToKeywordNode(const AObj: TJSONObject): IKeywordNode;
        function JsonToIfExprNode(const AObj: TJSONObject): IIfExpressionNode;
        function JsonToCondExprNode(const AObj: TJSONObject): ICondExpressionNode;
        function JsonToTernaryExprNode(const AObj: TJSONObject): IAstNode;
        function JsonToLambdaExprNode(const AObj: TJSONObject): ILambdaExpressionNode;
        function JsonToMacroDefNode(const AObj: TJSONObject): IMacroDefinitionNode;
        function JsonToQuasiquoteNode(const AObj: TJSONObject): IQuasiquoteNode;
        function JsonToUnquoteNode(const AObj: TJSONObject): IUnquoteNode;
        function JsonToUnquoteSplicingNode(const AObj: TJSONObject): IUnquoteSplicingNode;
        function JsonToFunctionCallNode(const AObj: TJSONObject): IFunctionCallNode;
        function JsonToMacroExpansionNode(const AObj: TJSONObject): IMacroExpansionNode;
        function JsonToRecurNode(const AObj: TJSONObject): IRecurNode;
        function JsonToBlockNode(const AObj: TJSONObject): IBlockExpressionNode;
        function JsonToVarDeclNode(const AObj: TJSONObject): IVariableDeclarationNode;
        function JsonToAssignmentNode(const AObj: TJSONObject): IAssignmentNode;
        function JsonToIndexerNode(const AObj: TJSONObject): IIndexerNode;
        function JsonToMemberAccessNode(const AObj: TJSONObject): IMemberAccessNode;
        function JsonToRecordLiteralNode(const AObj: TJSONObject): IRecordLiteralNode;
        function JsonToCreateSeriesNode(const AObj: TJSONObject): ICreateSeriesNode;
        function JsonToAddSeriesItemNode(const AObj: TJSONObject): IAddSeriesItemNode;
        function JsonToSeriesLengthNode(const AObj: TJSONObject): ISeriesLengthNode;
        function JsonToNopNode(const AObj: TJSONObject): INopNode;
        function JsonToTupleNode(const AObj: TJSONObject): ITupleNode;
        function JsonToPipeNode(const AObj: TJSONObject): IPipeNode;

    strict private
        // Serialization Visitors
        function VisitConstant(const Node: IAstNode): TJSONObject;
        function VisitIdentifier(const Node: IAstNode): TJSONObject;
        function VisitKeyword(const Node: IAstNode): TJSONObject;
        function VisitTuple(const Node: IAstNode): TJSONObject;
        function VisitRecordField(const Node: IAstNode): TJSONObject;
        function VisitIfExpression(const Node: IAstNode): TJSONObject;
        function VisitCondExpression(const Node: IAstNode): TJSONObject;
        function VisitLambdaExpression(const Node: IAstNode): TJSONObject;
        function VisitMacroDefinition(const Node: IAstNode): TJSONObject;
        function VisitQuasiquote(const Node: IAstNode): TJSONObject;
        function VisitUnquote(const Node: IAstNode): TJSONObject;
        function VisitUnquoteSplicing(const Node: IAstNode): TJSONObject;
        function VisitFunctionCall(const Node: IAstNode): TJSONObject;
        function VisitMacroExpansionNode(const Node: IAstNode): TJSONObject;
        function VisitRecurNode(const Node: IAstNode): TJSONObject;
        function VisitBlockExpression(const Node: IAstNode): TJSONObject;
        function VisitVariableDeclaration(const Node: IAstNode): TJSONObject;
        function VisitAssignment(const Node: IAstNode): TJSONObject;
        function VisitIndexer(const Node: IAstNode): TJSONObject;
        function VisitMemberAccess(const Node: IAstNode): TJSONObject;
        function VisitRecordLiteral(const Node: IAstNode): TJSONObject;
        function VisitCreateSeries(const Node: IAstNode): TJSONObject;
        function VisitAddSeriesItem(const Node: IAstNode): TJSONObject;
        function VisitSeriesLength(const Node: IAstNode): TJSONObject;
        function VisitNop(const Node: IAstNode): TJSONObject;
        function VisitPipe(const Node: IAstNode): TJSONObject;

    protected
        procedure SetupHandlers; override;

    public
        constructor Create;
        function Serialize(const RootNode: IAstNode): TJSONObject;
        function Deserialize(const AJson: TJSONObject): IAstNode;
    end;

implementation

uses
    Myc.Data.Keyword,
    Myc.Ast.Identities;

{ TJsonAstConverter }

constructor TJsonAstConverter.Create;
begin
    inherited;
end;

procedure TJsonAstConverter.SetupHandlers;
begin
    Register(akConstant, VisitConstant);
    Register(akIdentifier, VisitIdentifier);
    Register(akKeyword, VisitKeyword);
    Register(akTuple, VisitTuple);
    Register(akRecordField, VisitRecordField);
    Register(akIfExpression, VisitIfExpression);
    Register(akCondExpression, VisitCondExpression);
    Register(akLambdaExpression, VisitLambdaExpression);
    Register(akFunctionCall, VisitFunctionCall);
    Register(akMacroExpansion, VisitMacroExpansionNode);
    Register(akBlockExpression, VisitBlockExpression);
    Register(akVariableDeclaration, VisitVariableDeclaration);
    Register(akAssignment, VisitAssignment);
    Register(akMacroDefinition, VisitMacroDefinition);
    Register(akQuasiquote, VisitQuasiquote);
    Register(akUnquote, VisitUnquote);
    Register(akUnquoteSplicing, VisitUnquoteSplicing);
    Register(akIndexer, VisitIndexer);
    Register(akMemberAccess, VisitMemberAccess);
    Register(akRecordLiteral, VisitRecordLiteral);
    Register(akCreateSeries, VisitCreateSeries);
    Register(akAddSeriesItem, VisitAddSeriesItem);
    Register(akSeriesLength, VisitSeriesLength);
    Register(akRecur, VisitRecurNode);
    Register(akNop, VisitNop);
    Register(akPipe, VisitPipe);
end;

function TJsonAstConverter.Serialize(const RootNode: IAstNode): TJSONObject;
begin
    if not Assigned(RootNode) then
        exit(nil);
    Result := Visit(RootNode);
end;

function TJsonAstConverter.Deserialize(const AJson: TJSONObject): IAstNode;
begin
    Result := JsonToNode(AJson);
end;

procedure TJsonAstConverter.DataValueToJson(const AValue: TDataValue; const AParent: TJSONObject; const AName: string);
var
    valObj, scalarObj: TJSONObject;
begin
    valObj := TJSONObject.Create;
    valObj.AddPair('Kind', TJSONString.Create(AValue.Kind.ToString));

    case AValue.Kind of
        vkScalar:
        begin
            scalarObj := TJSONObject.Create;
            scalarObj.AddPair('Kind', TJSONString.Create(AValue.AsScalar.Kind.ToString));
            case AValue.AsScalar.Kind of
                TScalar.TKind.Ordinal: scalarObj.AddPair('Value', TJSONNumber.Create(AValue.AsScalar.Value.AsInt64));
                TScalar.TKind.Float: scalarObj.AddPair('Value', TJSONNumber.Create(AValue.AsScalar.Value.AsDouble));
                TScalar.TKind.Boolean: scalarObj.AddPair('Value', TJSONBool.Create(AValue.AsScalar.Value.AsInt64 <> 0));
                TScalar.TKind.DateTime: scalarObj.AddPair('Value', TJSONNumber.Create(AValue.AsScalar.Value.AsDouble));
                TScalar.TKind.Keyword:
                    scalarObj.AddPair('Value', TJSONString.Create(TKeywordRegistry.GetName(AValue.AsScalar.Value.AsInt64)));
            end;
            valObj.AddPair('Value', scalarObj);
        end;
        vkText: valObj.AddPair('Value', TJSONString.Create(AValue.AsText));
        vkVoid:;
    else
        raise ENotSupportedException.Create('Unsupported TDataValue kind for constant serialization.');
    end;

    AParent.AddPair(AName, valObj);
end;

function TJsonAstConverter.VisitConstant(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Constant'));
    DataValueToJson(Node.AsConstant.Value, Result, 'Value');
end;

function TJsonAstConverter.VisitIdentifier(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Identifier'));
    Result.AddPair('Name', TJSONString.Create(Node.AsIdentifier.Name));
end;

function TJsonAstConverter.VisitKeyword(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Keyword'));
    Result.AddPair('Name', TJSONString.Create(Node.AsKeyword.Value.Name));
end;

function TJsonAstConverter.VisitTuple(const Node: IAstNode): TJSONObject;
var
    T: ITupleNode;
    elemsArray: TJSONArray;
    i: Integer;
    elements: TArray<IAstNode>;
begin
    T := Node.AsTuple;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Tuple'));
    elemsArray := TJSONArray.Create;

    elements := T.Elements;
    for i := 0 to High(elements) do
        elemsArray.Add(Visit(elements[i]));

    Result.AddPair('Elements', elemsArray);
end;

function TJsonAstConverter.VisitIfExpression(const Node: IAstNode): TJSONObject;
var
    E: IIfExpressionNode;
    elseObj: TJSONValue;
begin
    E := Node.AsIfExpression;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('IfExpr'));
    Result.AddPair('Condition', Visit(E.Condition));
    Result.AddPair('ThenBranch', Visit(E.ThenBranch));
    if Assigned(E.ElseBranch) then
        elseObj := Visit(E.ElseBranch)
    else
        elseObj := TJSONNull.Create;
    Result.AddPair('ElseBranch', elseObj);
end;

function TJsonAstConverter.VisitCondExpression(const Node: IAstNode): TJSONObject;
var
    E: ICondExpressionNode;
    pairsArray: TJSONArray;
    pairObj: TJSONObject;
    elseObj: TJSONValue;
    i: Integer;
begin
    E := Node.AsCondExpression;
    pairsArray := TJSONArray.Create;
    for i := 0 to High(E.Pairs) do
    begin
        pairObj := TJSONObject.Create;
        pairObj.AddPair('Condition', Visit(E.Pairs[i].Condition));
        pairObj.AddPair('Branch', Visit(E.Pairs[i].Branch));
        pairsArray.Add(pairObj);
    end;
    if Assigned(E.ElseBranch) then
        elseObj := Visit(E.ElseBranch)
    else
        elseObj := TJSONNull.Create;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('CondExpr'));
    Result.AddPair('Pairs', pairsArray);
    Result.AddPair('ElseBranch', elseObj);
end;

function TJsonAstConverter.VisitLambdaExpression(const Node: IAstNode): TJSONObject;
var
    L: ILambdaExpressionNode;
begin
    L := Node.AsLambdaExpression;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('LambdaExpr'));
    Result.AddPair('Parameters', Visit(L.Parameters));
    Result.AddPair('Body', Visit(L.Body));
end;

function TJsonAstConverter.VisitMacroDefinition(const Node: IAstNode): TJSONObject;
var
    M: IMacroDefinitionNode;
begin
    M := Node.AsMacroDefinition;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('MacroDef'));
    Result.AddPair('Name', Visit(M.Name));
    Result.AddPair('Parameters', Visit(M.Parameters));
    Result.AddPair('Body', Visit(M.Body));
end;

function TJsonAstConverter.VisitQuasiquote(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Quasiquote'));
    Result.AddPair('Expression', Visit(Node.AsQuasiquote.Expression));
end;

function TJsonAstConverter.VisitUnquote(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Unquote'));
    Result.AddPair('Expression', Visit(Node.AsUnquote.Expression));
end;

function TJsonAstConverter.VisitUnquoteSplicing(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('UnquoteSplicing'));
    Result.AddPair('Expression', Visit(Node.AsUnquoteSplicing.Expression));
end;

function TJsonAstConverter.VisitFunctionCall(const Node: IAstNode): TJSONObject;
var
    C: IFunctionCallNode;
begin
    C := Node.AsFunctionCall;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('FunctionCall'));
    Result.AddPair('Callee', Visit(C.Callee));
    Result.AddPair('Arguments', Visit(C.Arguments));
end;

function TJsonAstConverter.VisitMacroExpansionNode(const Node: IAstNode): TJSONObject;
var
    M: IMacroExpansionNode;
begin
    M := Node.AsMacroExpansion;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('MacroExpansion'));
    Result.AddPair('Callee', Visit(M.CallNode.Callee));
    Result.AddPair('Arguments', Visit(M.CallNode.Arguments));
    Result.AddPair('ExpandedBody', Visit(M.ExpandedBody));
end;

function TJsonAstConverter.VisitRecurNode(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Recur'));
    Result.AddPair('Arguments', Visit(Node.AsRecur.Arguments));
end;

function TJsonAstConverter.VisitBlockExpression(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Block'));
    Result.AddPair('Expressions', Visit(Node.AsBlockExpression.Expressions));
end;

function TJsonAstConverter.VisitVariableDeclaration(const Node: IAstNode): TJSONObject;
var
    V: IVariableDeclarationNode;
    initObj: TJSONValue;
begin
    V := Node.AsVariableDeclaration;
    if Assigned(V.Initializer) then
        initObj := Visit(V.Initializer)
    else
        initObj := TJSONNull.Create;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('VarDecl'));
    Result.AddPair('Identifier', Visit(V.Target));
    Result.AddPair('Initializer', initObj);
end;

function TJsonAstConverter.VisitAssignment(const Node: IAstNode): TJSONObject;
var
    A: IAssignmentNode;
begin
    A := Node.AsAssignment;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Assignment'));
    Result.AddPair('Identifier', Visit(A.Target));
    Result.AddPair('Value', Visit(A.Value));
end;

function TJsonAstConverter.VisitIndexer(const Node: IAstNode): TJSONObject;
var
    I: IIndexerNode;
begin
    I := Node.AsIndexer;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Indexer'));
    Result.AddPair('Base', Visit(I.Base));
    Result.AddPair('Index', Visit(I.Index));
end;

function TJsonAstConverter.VisitMemberAccess(const Node: IAstNode): TJSONObject;
var
    M: IMemberAccessNode;
begin
    M := Node.AsMemberAccess;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('MemberAccess'));
    Result.AddPair('Base', Visit(M.Base));
    Result.AddPair('Member', Visit(M.Member));
end;

function TJsonAstConverter.VisitRecordLiteral(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('RecordLiteral'));
    Result.AddPair('Fields', Visit(Node.AsRecordLiteral.Fields));
end;

function TJsonAstConverter.VisitRecordField(const Node: IAstNode): TJSONObject;
var
    F: IRecordFieldNode;
begin
    F := Node.AsRecordField;
    Result := TJSONObject.Create;
    Result.AddPair('Name', TJSONString.Create(F.Key.Value.Name));
    Result.AddPair('Value', Visit(F.Value));
end;

function TJsonAstConverter.VisitCreateSeries(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('CreateSeries'));
    // REFACTORED: Now serialize the DefinitionNode structure instead of a raw string
    Result.AddPair('DefinitionNode', Visit(Node.AsCreateSeries.DefinitionNode));
end;

function TJsonAstConverter.VisitAddSeriesItem(const Node: IAstNode): TJSONObject;
var
    A: IAddSeriesItemNode;
    lookbackObj: TJSONValue;
begin
    A := Node.AsAddSeriesItem;
    if Assigned(A.Lookback) then
        lookbackObj := Visit(A.Lookback)
    else
        lookbackObj := TJSONNull.Create;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('AddSeriesItem'));
    Result.AddPair('Series', Visit(A.Series));
    Result.AddPair('Value', Visit(A.Value));
    Result.AddPair('Lookback', lookbackObj);
end;

function TJsonAstConverter.VisitSeriesLength(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('SeriesLength'));
    Result.AddPair('Series', Visit(Node.AsSeriesLength.Series));
end;

function TJsonAstConverter.VisitNop(const Node: IAstNode): TJSONObject;
begin
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Nop'));
end;

function TJsonAstConverter.VisitPipe(const Node: IAstNode): TJSONObject;
var
    P: IPipeNode;
begin
    P := Node.AsPipe;
    Result := TJSONObject.Create;
    Result.AddPair('NodeType', TJSONString.Create('Pipe'));
    Result.AddPair('Inputs', Visit(P.Inputs));
    Result.AddPair('Transformation', Visit(P.Transformation));
end;

{ Deserialization Handlers }

function TJsonAstConverter.JsonToDataValue(const AObj: TJSONObject; const AName: string): TDataValue;
var
    valObj, scalarObj: TJSONObject;
    kindStr: string;
begin
    valObj := AObj.GetValue<TJSONObject>(AName);
    kindStr := valObj.GetValue<string>('Kind');

    if SameText(kindStr, 'Scalar') then
    begin
        scalarObj := valObj.GetValue<TJSONObject>('Value');
        case TScalar.StringToKind(scalarObj.GetValue<string>('Kind')) of
            TScalar.TKind.Ordinal: Result := TScalar.FromInt64(scalarObj.GetValue<TJSONNumber>('Value').AsInt64);
            TScalar.TKind.Float: Result := TScalar.FromDouble(scalarObj.GetValue<TJSONNumber>('Value').AsDouble);
            TScalar.TKind.Boolean: Result := TScalar.FromBoolean(scalarObj.GetValue<TJSONBool>('Value').AsBoolean);
            TScalar.TKind.DateTime: Result := TScalar.FromDateTime(scalarObj.GetValue<TJSONNumber>('Value').AsDouble);
            TScalar.TKind.Keyword: Result := TScalar.FromKeyword(TKeywordRegistry.Intern(scalarObj.GetValue<string>('Value')));
        end;
    end
    else if SameText(kindStr, 'Text') then
        Result := valObj.GetValue<string>('Value')
    else if SameText(kindStr, 'Void') then
        Result := TDataValue.Void
    else
        raise ENotSupportedException.Create('Unsupported TDataValue kind.');
end;

function TJsonAstConverter.JsonToNode(const AJson: TJSONValue; const ExpectedType: string): IAstNode;
var
    obj: TJSONObject;
    nodeType: string;
begin
    if not (AJson is TJSONObject) then
        raise EInvalidCast.Create('Expected JSON object.');
    obj := AJson as TJSONObject;
    nodeType := obj.GetValue<string>('NodeType');

    if nodeType = 'Constant' then
        Result := JsonToConstantNode(obj)
    else if nodeType = 'Identifier' then
        Result := JsonToIdentifierNode(obj)
    else if nodeType = 'Keyword' then
        Result := JsonToKeywordNode(obj)
    else if nodeType = 'IfExpr' then
        Result := JsonToIfExprNode(obj)
    else if nodeType = 'CondExpr' then
        Result := JsonToCondExprNode(obj)
    else if nodeType = 'TernaryExpr' then
        Result := JsonToTernaryExprNode(obj)
    else if nodeType = 'LambdaExpr' then
        Result := JsonToLambdaExprNode(obj)
    else if nodeType = 'MacroDef' then
        Result := JsonToMacroDefNode(obj)
    else if nodeType = 'MacroExpansion' then
        Result := JsonToMacroExpansionNode(obj)
    else if nodeType = 'Quasiquote' then
        Result := JsonToQuasiquoteNode(obj)
    else if nodeType = 'Unquote' then
        Result := JsonToUnquoteNode(obj)
    else if nodeType = 'UnquoteSplicing' then
        Result := JsonToUnquoteSplicingNode(obj)
    else if nodeType = 'FunctionCall' then
        Result := JsonToFunctionCallNode(obj)
    else if nodeType = 'Recur' then
        Result := JsonToRecurNode(obj)
    else if nodeType = 'Block' then
        Result := JsonToBlockNode(obj)
    else if nodeType = 'VarDecl' then
        Result := JsonToVarDeclNode(obj)
    else if nodeType = 'Assignment' then
        Result := JsonToAssignmentNode(obj)
    else if nodeType = 'Indexer' then
        Result := JsonToIndexerNode(obj)
    else if nodeType = 'MemberAccess' then
        Result := JsonToMemberAccessNode(obj)
    else if nodeType = 'RecordLiteral' then
        Result := JsonToRecordLiteralNode(obj)
    else if nodeType = 'CreateSeries' then
        Result := JsonToCreateSeriesNode(obj)
    else if nodeType = 'AddSeriesItem' then
        Result := JsonToAddSeriesItemNode(obj)
    else if nodeType = 'SeriesLength' then
        Result := JsonToSeriesLengthNode(obj)
    else if nodeType = 'Nop' then
        Result := JsonToNopNode(obj)
    else if nodeType = 'Tuple' then
        Result := JsonToTupleNode(obj)
    else if nodeType = 'Pipe' then
        Result := JsonToPipeNode(obj)
    else
        raise ENotSupportedException.CreateFmt('Unsupported NodeType "%s".', [nodeType]);
end;

function TJsonAstConverter.JsonToConstantNode(const AObj: TJSONObject): IConstantNode;
begin
    Result := TAst.Constant(JsonToDataValue(AObj, 'Value'));
end;

function TJsonAstConverter.JsonToIdentifierNode(const AObj: TJSONObject): IIdentifierNode;
begin
    Result := TAst.Identifier(AObj.GetValue<string>('Name'));
end;

function TJsonAstConverter.JsonToKeywordNode(const AObj: TJSONObject): IKeywordNode;
begin
    Result := TAst.Keyword(AObj.GetValue<string>('Name'));
end;

function TJsonAstConverter.JsonToIfExprNode(const AObj: TJSONObject): IIfExpressionNode;
var
    elseNode: IAstNode;
begin
    if AObj.GetValue('ElseBranch') is TJSONNull then
        elseNode := nil
    else
        elseNode := JsonToNode(AObj.GetValue('ElseBranch'));
    Result := TAst.IfExpr(JsonToNode(AObj.GetValue('Condition')), JsonToNode(AObj.GetValue('ThenBranch')), elseNode);
end;

function TJsonAstConverter.JsonToCondExprNode(const AObj: TJSONObject): ICondExpressionNode;
var
    pairsArray: TJSONArray;
    pairs: TArray<TCondPair>;
    i: Integer;
    elseNode: IAstNode;
begin
    pairsArray := AObj.GetValue<TJSONArray>('Pairs');
    SetLength(pairs, pairsArray.Count);
    for i := 0 to pairsArray.Count - 1 do
        pairs[i] :=
            TCondPair.Create(
                JsonToNode((pairsArray.Items[i] as TJSONObject).GetValue('Condition')),
                JsonToNode((pairsArray.Items[i] as TJSONObject).GetValue('Branch'))
            );
    if AObj.GetValue('ElseBranch') is TJSONNull then
        elseNode := nil
    else
        elseNode := JsonToNode(AObj.GetValue('ElseBranch'));
    Result := TAst.CondExpr(pairs, elseNode);
end;

function TJsonAstConverter.JsonToTernaryExprNode(const AObj: TJSONObject): IAstNode;
begin
    Result :=
        TAst.TernaryExpr(
            JsonToNode(AObj.GetValue('Condition')),
            JsonToNode(AObj.GetValue('ThenBranch')),
            JsonToNode(AObj.GetValue('ElseBranch'))
        );
end;

function TJsonAstConverter.JsonToLambdaExprNode(const AObj: TJSONObject): ILambdaExpressionNode;
var
    identNodes: TList<IIdentifierNode>;
    node: IAstNode;
begin
    identNodes := TList<IIdentifierNode>.Create;
    try
        for node in JsonToNode(AObj.GetValue('Parameters')).AsTuple.Elements do
            identNodes.Add(node.AsIdentifier);
        Result := TAst.LambdaExpr(identNodes.ToArray, JsonToNode(AObj.GetValue('Body')));
    finally
        identNodes.Free;
    end;
end;

function TJsonAstConverter.JsonToMacroDefNode(const AObj: TJSONObject): IMacroDefinitionNode;
var
    identNodes: TList<IIdentifierNode>;
    node: IAstNode;
begin
    identNodes := TList<IIdentifierNode>.Create;
    try
        for node in JsonToNode(AObj.GetValue('Parameters')).AsTuple.Elements do
            identNodes.Add(node.AsIdentifier);
        Result :=
            TAst.MacroDef(
                JsonToIdentifierNode(AObj.GetValue('Name') as TJSONObject),
                identNodes.ToArray,
                JsonToNode(AObj.GetValue('Body'))
            );
    finally
        identNodes.Free;
    end;
end;

function TJsonAstConverter.JsonToQuasiquoteNode(const AObj: TJSONObject): IQuasiquoteNode;
begin
    Result := TAst.Quasiquote(JsonToNode(AObj.GetValue('Expression')));
end;

function TJsonAstConverter.JsonToUnquoteNode(const AObj: TJSONObject): IUnquoteNode;
begin
    Result := TAst.Unquote(JsonToNode(AObj.GetValue('Expression')));
end;

function TJsonAstConverter.JsonToUnquoteSplicingNode(const AObj: TJSONObject): IUnquoteSplicingNode;
begin
    Result := TAst.UnquoteSplicing(JsonToNode(AObj.GetValue('Expression')).AsQuasiquote);
end;

function TJsonAstConverter.JsonToFunctionCallNode(const AObj: TJSONObject): IFunctionCallNode;
begin
    Result := TAst.FunctionCall(JsonToNode(AObj.GetValue('Callee')), JsonToNode(AObj.GetValue('Arguments')).AsTuple.Elements);
end;

function TJsonAstConverter.JsonToMacroExpansionNode(const AObj: TJSONObject): IMacroExpansionNode;
var
    callee, expandedBody: IAstNode;
    argsTuple: ITupleNode;
begin
    callee := JsonToNode(AObj.GetValue('Callee'));
    expandedBody := JsonToNode(AObj.GetValue('ExpandedBody'));
    argsTuple := JsonToNode(AObj.GetValue('Arguments')).AsTuple;
    Result := TAst.MacroExpansionNode(TAst.FunctionCall(callee, argsTuple.Elements), expandedBody);
end;

function TJsonAstConverter.JsonToRecurNode(const AObj: TJSONObject): IRecurNode;
begin
    Result := TAst.Recur(JsonToNode(AObj.GetValue('Arguments')).AsTuple.Elements);
end;

function TJsonAstConverter.JsonToBlockNode(const AObj: TJSONObject): IBlockExpressionNode;
begin
    Result := TAst.Block(JsonToNode(AObj.GetValue('Expressions')).AsTuple.Elements);
end;

function TJsonAstConverter.JsonToVarDeclNode(const AObj: TJSONObject): IVariableDeclarationNode;
var
    initNode: IAstNode;
begin
    if AObj.GetValue('Initializer') is TJSONNull then
        initNode := nil
    else
        initNode := JsonToNode(AObj.GetValue('Initializer'));
    Result := TAst.VarDecl(JsonToIdentifierNode(AObj.GetValue('Identifier') as TJSONObject), initNode);
end;

function TJsonAstConverter.JsonToAssignmentNode(const AObj: TJSONObject): IAssignmentNode;
begin
    Result := TAst.Assign(JsonToIdentifierNode(AObj.GetValue('Identifier') as TJSONObject), JsonToNode(AObj.GetValue('Value')));
end;

function TJsonAstConverter.JsonToIndexerNode(const AObj: TJSONObject): IIndexerNode;
begin
    Result := TAst.Indexer(JsonToNode(AObj.GetValue('Base')), JsonToNode(AObj.GetValue('Index')));
end;

function TJsonAstConverter.JsonToMemberAccessNode(const AObj: TJSONObject): IMemberAccessNode;
begin
    Result := TAst.MemberAccess(JsonToNode(AObj.GetValue('Base')), JsonToKeywordNode(AObj.GetValue('Member') as TJSONObject).AsKeyword);
end;

function TJsonAstConverter.JsonToRecordLiteralNode(const AObj: TJSONObject): IRecordLiteralNode;
var
    fieldsArray: TJSONArray;
    fields: TList<IRecordFieldNode>;
    i: Integer;
begin
    fieldsArray := AObj.GetValue<TJSONArray>('Fields');
    fields := TList<IRecordFieldNode>.Create;
    try
        for i := 0 to fieldsArray.Count - 1 do
        begin
            var fieldObj := fieldsArray.Items[i] as TJSONObject;
            fields.Add(TAst.RecordField(TAst.Keyword(fieldObj.GetValue<string>('Name')), JsonToNode(fieldObj.GetValue('Value'))));
        end;
        Result := TAst.RecordLiteral(fields.ToArray);
    finally
        fields.Free;
    end;
end;

function TJsonAstConverter.JsonToCreateSeriesNode(const AObj: TJSONObject): ICreateSeriesNode;
begin
    // REFACTORED: Use the definition node from JSON
    Result := TAst.CreateSeries(JsonToNode(AObj.GetValue('DefinitionNode')));
end;

function TJsonAstConverter.JsonToAddSeriesItemNode(const AObj: TJSONObject): IAddSeriesItemNode;
var
    lookNode: IAstNode;
begin
    if AObj.GetValue('Lookback') is TJSONNull then
        lookNode := nil
    else
        lookNode := JsonToNode(AObj.GetValue('Lookback'));
    Result :=
        TAst.AddSeriesItem(JsonToIdentifierNode(AObj.GetValue('Series') as TJSONObject), JsonToNode(AObj.GetValue('Value')), lookNode);
end;

function TJsonAstConverter.JsonToSeriesLengthNode(const AObj: TJSONObject): ISeriesLengthNode;
begin
    Result := TAst.SeriesLength(JsonToIdentifierNode(AObj.GetValue('Series') as TJSONObject));
end;

function TJsonAstConverter.JsonToNopNode(const AObj: TJSONObject): INopNode;
begin
    Result := TAst.Nop.AsNop;
end;

function TJsonAstConverter.JsonToTupleNode(const AObj: TJSONObject): ITupleNode;
var
    elemsArray: TJSONArray;
    elems: TList<IAstNode>;
    i: Integer;
begin
    elemsArray := AObj.GetValue<TJSONArray>('Elements');
    elems := TList<IAstNode>.Create;
    try
        for i := 0 to elemsArray.Count - 1 do
            elems.Add(JsonToNode(elemsArray.Items[i]));
        Result := TAst.Tuple(elems.ToArray);
    finally
        elems.Free;
    end;
end;

function TJsonAstConverter.JsonToPipeNode(const AObj: TJSONObject): IPipeNode;
begin
    Result := TAst.Pipe(JsonToNode(AObj.GetValue('Inputs')).AsTuple, JsonToNode(AObj.GetValue('Transformation')).AsLambdaExpression);
end;

end.