unit Myc.Ast;

interface

uses
    System.Classes,
    System.SysUtils,
    System.Generics.Collections,
    System.Generics.Defaults,
    Myc.Data.Scalar,
    Myc.Data.Value,
    Myc.Ast.Nodes,
    Myc.Ast.Scope;

type
    // Record acting as a namespace for the factory functions.
    TAst = record
    public
        type
            TRegisterLibraryProc = reference to procedure(const Scope: IExecutionScope);
    private
        class var
            FLibraries: TList<TRegisterLibraryProc>;
        class constructor Create;
        class destructor Destroy;
    public
        class procedure RegisterLibrary(const AProc: TRegisterLibraryProc); static;
        class function CreateScope(Parent: IExecutionScope; const Descriptor: IScopeDescriptor = nil): IExecutionScope; static;

        // --- Existing factory functions ---
        class function Constant(AValue: TScalar): IConstantNode; static;
        class function Identifier(AName: string): IIdentifierNode; static;
        class function BinaryExpr(ALeft: IAstNode; AOperator: TBinaryOperator; ARight: IAstNode): IBinaryExpressionNode; static;
        class function UnaryExpr(const AOperator: TUnaryOperator; const ARight: IAstNode): IUnaryExpressionNode; static;
        class function IfExpr(const ACondition: IAstNode; const AThenBranch, AElseBranch: IAstNode): IIfExpressionNode; static;
        class function TernaryExpr(const ACondition: IAstNode; const AThenBranch, AElseBranch: IAstNode): ITernaryExpressionNode; static;
        class function LambdaExpr(const AParameters: TArray<IIdentifierNode>; const ABody: IAstNode): ILambdaExpressionNode; static;
        class function FunctionCall(const ACallee: IAstNode; const AArguments: TArray<IAstNode>): IFunctionCallNode; static;
        class function Block(const AExpressions: array of IAstNode): IBlockExpressionNode; static;
        class function VarDecl(const AIdentifier: IIdentifierNode; AInitializer: IAstNode): IVariableDeclarationNode; static;
        class function Assign(const AIdentifier: IIdentifierNode; const AValue: IAstNode): IAssignmentNode; static;
        class function AssignResult(const AValue: IAstNode): IAssignmentNode; static; deprecated;
        class function Indexer(const ABase: IAstNode; const AIndex: IAstNode): IIndexerNode; static;
        class function MemberAccess(const ABase: IAstNode; const AMember: IIdentifierNode): IMemberAccessNode; static;
        class function CreateSeries(const ADefinition: String): ICreateSeriesNode; static;
        class function AddSeriesItem(
            const ASeries: IIdentifierNode;
            const AValue: IAstNode;
            const ALookback: IAstNode = nil
        ): IAddSeriesItemNode; static;
        class function SeriesLength(const ASeries: IIdentifierNode): ISeriesLengthNode; static;
    end;

    // Common base class for AST nodes to reduce boilerplate.
    TAstNode = class(TInterfacedObject, IAstNode)
    public
        function Accept(const Visitor: IAstVisitor): TDataValue; virtual; abstract;
    end;

    TConstantNode = class(TAstNode, IConstantNode)
    private
        FValue: TScalar;
        function GetValue: TScalar;
    public
        constructor Create(AValue: TScalar);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TIdentifierNode = class(TAstNode, IIdentifierNode)
    private
        FName: string;
        // --- Annotation fields added for the binder ---
        FResolvedAddress: TResolvedAddress;
        function GetName: string;
        function GetAddress: TResolvedAddress; inline;
    public
        constructor Create(AName: string);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
        property Name: string read FName;
        property Address: TResolvedAddress read FResolvedAddress write FResolvedAddress;
    end;

    TBinaryExpressionNode = class(TAstNode, IBinaryExpressionNode)
    private
        FLeft: IAstNode;
        FOperator: TBinaryOperator;
        FRight: IAstNode;
        function GetLeft: IAstNode;
        function GetOperator: TBinaryOperator;
        function GetRight: IAstNode;
    public
        constructor Create(ALeft: IAstNode; AOperator: TBinaryOperator; ARight: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TUnaryExpressionNode = class(TAstNode, IUnaryExpressionNode)
    private
        FOperator: TUnaryOperator;
        FRight: IAstNode;
        function GetOperator: TUnaryOperator;
        function GetRight: IAstNode;
    public
        constructor Create(const AOperator: TUnaryOperator; const ARight: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TIfExpressionNode = class(TAstNode, IIfExpressionNode)
    private
        FCondition: IAstNode;
        FThenBranch: IAstNode;
        FElseBranch: IAstNode;
        function GetCondition: IAstNode;
        function GetThenBranch: IAstNode;
        function GetElseBranch: IAstNode;
    public
        constructor Create(const ACondition, AThenBranch, AElseBranch: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TTernaryExpressionNode = class(TAstNode, ITernaryExpressionNode)
    private
        FCondition: IAstNode;
        FThenBranch: IAstNode;
        FElseBranch: IAstNode;
        function GetCondition: IAstNode;
        function GetThenBranch: IAstNode;
        function GetElseBranch: IAstNode;
    public
        constructor Create(const ACondition, AThenBranch, AElseBranch: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TLambdaExpressionNode = class(TAstNode, ILambdaExpressionNode)
    private
        FParameters: TArray<IIdentifierNode>;
        FBody: IAstNode;
        FScopeDescriptor: IScopeDescriptor;
        FUpvalues: TArray<TResolvedAddress>;
        FHasNestedLambdas: Boolean;
        function GetParameters: TArray<IIdentifierNode>;
        function GetBody: IAstNode;
        function GetScopeDescriptor: IScopeDescriptor;
        function GetUpvalues: TArray<TResolvedAddress>;
        function GetHasNestedLambdas: Boolean;
    public
        constructor Create(const AParameters: TArray<IIdentifierNode>; const ABody: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
        property HasNestedLambdas: Boolean read FHasNestedLambdas write FHasNestedLambdas;
        property ScopeDescriptor: IScopeDescriptor read FScopeDescriptor write FScopeDescriptor;
        property Upvalues: TArray<TResolvedAddress> read FUpvalues write FUpvalues;
    end;

    TFunctionCallNode = class(TAstNode, IFunctionCallNode)
    private
        FCallee: IAstNode;
        FArguments: TArray<IAstNode>;
        FIsTailCall: Boolean;
        function GetCallee: IAstNode;
        function GetArguments: TArray<IAstNode>;
        function GetIsTailCall: Boolean;
    public
        constructor Create(const ACallee: IAstNode; const AArguments: TArray<IAstNode>);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
        property IsTailCall: Boolean read FIsTailCall write FIsTailCall;
    end;

    TBlockExpressionNode = class(TAstNode, IBlockExpressionNode)
    private
        FExpressions: TList<IAstNode>;
        function GetExpressions: TList<IAstNode>;
    public
        constructor Create(const AExpressions: array of IAstNode);
        destructor Destroy; override;
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TVariableDeclarationNode = class(TAstNode, IVariableDeclarationNode)
    private
        FIdentifier: IIdentifierNode;
        FInitializer: IAstNode;
        function GetIdentifier: IIdentifierNode;
        function GetInitializer: IAstNode;
    public
        constructor Create(const AIdentifier: IIdentifierNode; AInitializer: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TAssignmentNode = class(TAstNode, IAssignmentNode)
    private
        FIdentifier: IIdentifierNode;
        FValue: IAstNode;
        function GetIdentifier: IIdentifierNode;
        function GetValue: IAstNode;
    public
        constructor Create(const AIdentifier: IIdentifierNode; const AValue: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TIndexerNode = class(TAstNode, IIndexerNode)
    private
        FBase: IAstNode;
        FIndex: IAstNode;
        function GetBase: IAstNode;
        function GetIndex: IAstNode;
    public
        constructor Create(const ABase: IAstNode; const AIndex: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TMemberAccessNode = class(TAstNode, IMemberAccessNode)
    private
        FBase: IAstNode;
        FMember: IIdentifierNode;
        function GetBase: IAstNode;
        function GetMember: IIdentifierNode;
    public
        constructor Create(const ABase: IAstNode; const AMember: IIdentifierNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TCreateSeriesNode = class(TAstNode, ICreateSeriesNode)
    private
        FDefinition: String;
        function GetDefinition: String;
    public
        constructor Create(const ADefinition: String);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TAddSeriesItemNode = class(TAstNode, IAddSeriesItemNode)
    private
        FSeries: IIdentifierNode;
        FValue: IAstNode;
        FLookback: IAstNode;
        function GetSeries: IIdentifierNode;
        function GetValue: IAstNode;
        function GetLookback: IAstNode;
    public
        constructor Create(const ASeries: IIdentifierNode; const AValue: IAstNode; const ALookback: IAstNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

    TSeriesLengthNode = class(TAstNode, ISeriesLengthNode)
    private
        FSeries: IIdentifierNode;
        function GetSeries: IIdentifierNode;
    public
        constructor Create(const ASeries: IIdentifierNode);
        function Accept(const Visitor: IAstVisitor): TDataValue; override;
    end;

implementation

uses
    Myc.Ast.Traverser;

{ TConstantNode }

constructor TConstantNode.Create(AValue: TScalar);
begin
    inherited Create;
    FValue := AValue;
end;

function TConstantNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitConstant(Self);
end;

function TConstantNode.GetValue: TScalar;
begin
    Result := FValue;
end;

{ TIdentifierNode }

constructor TIdentifierNode.Create(AName: string);
begin
    inherited Create;
    FName := AName;
end;

function TIdentifierNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitIdentifier(Self);
end;

function TIdentifierNode.GetName: string;
begin
    Result := FName;
end;

function TIdentifierNode.GetAddress: TResolvedAddress;
begin
    Result := FResolvedAddress;
end;

{ TBinaryExpressionNode }

constructor TBinaryExpressionNode.Create(ALeft: IAstNode; AOperator: TBinaryOperator; ARight: IAstNode);
begin
    inherited Create;
    FLeft := ALeft;
    FOperator := AOperator;
    FRight := ARight;
end;

function TBinaryExpressionNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitBinaryExpression(Self);
end;

function TBinaryExpressionNode.GetLeft: IAstNode;
begin
    Result := FLeft;
end;

function TBinaryExpressionNode.GetOperator: TBinaryOperator;
begin
    Result := FOperator;
end;

function TBinaryExpressionNode.GetRight: IAstNode;
begin
    Result := FRight;
end;

{ TUnaryExpressionNode }

constructor TUnaryExpressionNode.Create(const AOperator: TUnaryOperator; const ARight: IAstNode);
begin
    inherited Create;
    FOperator := AOperator;
    FRight := ARight;
end;

function TUnaryExpressionNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitUnaryExpression(Self);
end;

function TUnaryExpressionNode.GetOperator: TUnaryOperator;
begin
    Result := FOperator;
end;

function TUnaryExpressionNode.GetRight: IAstNode;
begin
    Result := FRight;
end;

{ TIfExpressionNode }

constructor TIfExpressionNode.Create(const ACondition, AThenBranch, AElseBranch: IAstNode);
begin
    inherited Create;
    FCondition := ACondition;
    FThenBranch := AThenBranch;
    FElseBranch := AElseBranch;
end;

function TIfExpressionNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitIfExpression(Self);
end;

function TIfExpressionNode.GetCondition: IAstNode;
begin
    Result := FCondition;
end;

function TIfExpressionNode.GetElseBranch: IAstNode;
begin
    Result := FElseBranch;
end;

function TIfExpressionNode.GetThenBranch: IAstNode;
begin
    Result := FThenBranch;
end;

{ TTernaryExpressionNode }

constructor TTernaryExpressionNode.Create(const ACondition, AThenBranch, AElseBranch: IAstNode);
begin
    inherited Create;
    FCondition := ACondition;
    FThenBranch := AThenBranch;
    FElseBranch := AElseBranch;
end;

function TTernaryExpressionNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitTernaryExpression(Self);
end;

function TTernaryExpressionNode.GetCondition: IAstNode;
begin
    Result := FCondition;
end;

function TTernaryExpressionNode.GetElseBranch: IAstNode;
begin
    Result := FElseBranch;
end;

function TTernaryExpressionNode.GetThenBranch: IAstNode;
begin
    Result := FThenBranch;
end;

{ TLambdaExpressionNode }

constructor TLambdaExpressionNode.Create(const AParameters: TArray<IIdentifierNode>; const ABody: IAstNode);
begin
    inherited Create;
    FBody := ABody;
    FParameters := AParameters;
    FScopeDescriptor := nil;
end;

function TLambdaExpressionNode.GetUpvalues: TArray<TResolvedAddress>;
begin
    Result := FUpvalues;
end;

function TLambdaExpressionNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitLambdaExpression(Self);
end;

function TLambdaExpressionNode.GetBody: IAstNode;
begin
    Result := FBody;
end;

function TLambdaExpressionNode.GetHasNestedLambdas: Boolean;
begin
    Result := FHasNestedLambdas;
end;

function TLambdaExpressionNode.GetParameters: TArray<IIdentifierNode>;
begin
    Result := FParameters;
end;

function TLambdaExpressionNode.GetScopeDescriptor: IScopeDescriptor;
begin
    Result := FScopeDescriptor;
end;

{ TFunctionCallNode }

constructor TFunctionCallNode.Create(const ACallee: IAstNode; const AArguments: TArray<IAstNode>);
begin
    inherited Create;
    FCallee := ACallee;
    FArguments := AArguments;
    FIsTailCall := False;
end;

function TFunctionCallNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitFunctionCall(Self);
end;

function TFunctionCallNode.GetArguments: TArray<IAstNode>;
begin
    Result := FArguments;
end;

function TFunctionCallNode.GetCallee: IAstNode;
begin
    Result := FCallee;
end;

function TFunctionCallNode.GetIsTailCall: Boolean;
begin
    Result := FIsTailCall;
end;

{ TBlockExpressionNode }

constructor TBlockExpressionNode.Create(const AExpressions: array of IAstNode);
var
    expr: IAstNode;
begin
    inherited Create;
    FExpressions := TList<IAstNode>.Create;
    for expr in AExpressions do
        FExpressions.Add(expr);
end;

destructor TBlockExpressionNode.Destroy;
begin
    FExpressions.Free;
    inherited;
end;

function TBlockExpressionNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitBlockExpression(Self);
end;

function TBlockExpressionNode.GetExpressions: TList<IAstNode>;
begin
    Result := FExpressions;
end;

{ TVariableDeclarationNode }

constructor TVariableDeclarationNode.Create(const AIdentifier: IIdentifierNode; AInitializer: IAstNode);
begin
    inherited Create;
    FIdentifier := AIdentifier;
    FInitializer := AInitializer;
end;

function TVariableDeclarationNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitVariableDeclaration(Self);
end;

function TVariableDeclarationNode.GetIdentifier: IIdentifierNode;
begin
    Result := FIdentifier;
end;

function TVariableDeclarationNode.GetInitializer: IAstNode;
begin
    Result := FInitializer;
end;

{ TAssignmentNode }

constructor TAssignmentNode.Create(const AIdentifier: IIdentifierNode; const AValue: IAstNode);
begin
    inherited Create;
    FIdentifier := AIdentifier;
    FValue := AValue;
end;

function TAssignmentNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitAssignment(Self);
end;

function TAssignmentNode.GetIdentifier: IIdentifierNode;
begin
    Result := FIdentifier;
end;

function TAssignmentNode.GetValue: IAstNode;
begin
    Result := FValue;
end;

{ TIndexerNode }

constructor TIndexerNode.Create(const ABase, AIndex: IAstNode);
begin
    inherited Create;
    FBase := ABase;
    FIndex := AIndex;
end;

function TIndexerNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitIndexer(Self);
end;

function TIndexerNode.GetBase: IAstNode;
begin
    Result := FBase;
end;

function TIndexerNode.GetIndex: IAstNode;
begin
    Result := FIndex;
end;

{ TMemberAccessNode }

constructor TMemberAccessNode.Create(const ABase: IAstNode; const AMember: IIdentifierNode);
begin
    inherited Create;
    FBase := ABase;
    FMember := AMember;
end;

function TMemberAccessNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitMemberAccess(Self);
end;

function TMemberAccessNode.GetBase: IAstNode;
begin
    Result := FBase;
end;

function TMemberAccessNode.GetMember: IIdentifierNode;
begin
    Result := FMember;
end;

{ TCreateSeriesNode }

constructor TCreateSeriesNode.Create(const ADefinition: String);
begin
    inherited Create;
    FDefinition := ADefinition;
end;

function TCreateSeriesNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitCreateSeries(Self);
end;

function TCreateSeriesNode.GetDefinition: String;
begin
    Result := FDefinition;
end;

{ TAddSeriesItemNode }

constructor TAddSeriesItemNode.Create(const ASeries: IIdentifierNode; const AValue, ALookback: IAstNode);
begin
    inherited Create;
    FSeries := ASeries;
    FValue := AValue;
    FLookback := ALookback;
end;

function TAddSeriesItemNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitAddSeriesItem(Self);
end;

function TAddSeriesItemNode.GetLookback: IAstNode;
begin
    Result := FLookback;
end;

function TAddSeriesItemNode.GetSeries: IIdentifierNode;
begin
    Result := FSeries;
end;

function TAddSeriesItemNode.GetValue: IAstNode;
begin
    Result := FValue;
end;

{ TSeriesLengthNode }

constructor TSeriesLengthNode.Create(const ASeries: IIdentifierNode);
begin
    inherited Create;
    FSeries := ASeries;
end;

function TSeriesLengthNode.Accept(const Visitor: IAstVisitor): TDataValue;
begin
    Result := Visitor.VisitSeriesLength(Self);
end;

function TSeriesLengthNode.GetSeries: IIdentifierNode;
begin
    Result := FSeries;
end;

{ TAst }

class constructor TAst.Create;
begin
    FLibraries := TList<TRegisterLibraryProc>.Create;
end;

class destructor TAst.Destroy;
begin
    FLibraries.Free;
end;

class procedure TAst.RegisterLibrary(const AProc: TRegisterLibraryProc);
begin
    FLibraries.Add(AProc);
end;

class function TAst.AddSeriesItem(const ASeries: IIdentifierNode; const AValue: IAstNode; const ALookback: IAstNode): IAddSeriesItemNode;
begin
    Result := TAddSeriesItemNode.Create(ASeries, AValue, ALookback);
end;

class function TAst.Assign(const AIdentifier: IIdentifierNode; const AValue: IAstNode): IAssignmentNode;
begin
    Result := TAssignmentNode.Create(AIdentifier, AValue);
end;

class function TAst.AssignResult(const AValue: IAstNode): IAssignmentNode;
begin
    Result := Assign(TAst.Identifier('Result'), AValue);
end;

class function TAst.Block(const AExpressions: array of IAstNode): IBlockExpressionNode;
begin
    Result := TBlockExpressionNode.Create(AExpressions);
end;

class function TAst.Constant(AValue: TScalar): IConstantNode;
begin
    Result := TConstantNode.Create(AValue);
end;

class function TAst.CreateSeries(const ADefinition: String): ICreateSeriesNode;
begin
    Result := TCreateSeriesNode.Create(ADefinition);
end;

class function TAst.BinaryExpr(ALeft: IAstNode; AOperator: TBinaryOperator; ARight: IAstNode): IBinaryExpressionNode;
begin
    Result := TBinaryExpressionNode.Create(ALeft, AOperator, ARight);
end;

class function TAst.CreateScope(Parent: IExecutionScope; const Descriptor: IScopeDescriptor = nil): IExecutionScope;
var
    proc: TRegisterLibraryProc;
begin
    Result := TExecutionScope.Create(Parent, Descriptor, nil);

    if Parent = nil then
    begin
        // When creating a root scope, automatically register all standard libraries.
        for proc in FLibraries do
            proc(Result);
    end;
end;

class function TAst.FunctionCall(const ACallee: IAstNode; const AArguments: TArray<IAstNode>): IFunctionCallNode;
begin
    Result := TFunctionCallNode.Create(ACallee, AArguments);
end;

class function TAst.Identifier(AName: string): IIdentifierNode;
begin
    Result := TIdentifierNode.Create(AName);
end;

class function TAst.IfExpr(const ACondition: IAstNode; const AThenBranch, AElseBranch: IAstNode): IIfExpressionNode;
begin
    Result := TIfExpressionNode.Create(ACondition, AThenBranch, AElseBranch);
end;

class function TAst.Indexer(const ABase: IAstNode; const AIndex: IAstNode): IIndexerNode;
begin
    Result := TIndexerNode.Create(ABase, AIndex);
end;

class function TAst.MemberAccess(const ABase: IAstNode; const AMember: IIdentifierNode): IMemberAccessNode;
begin
    Result := TMemberAccessNode.Create(ABase, AMember);
end;

class function TAst.SeriesLength(const ASeries: IIdentifierNode): ISeriesLengthNode;
begin
    Result := TSeriesLengthNode.Create(ASeries);
end;

class function TAst.TernaryExpr(const ACondition: IAstNode; const AThenBranch, AElseBranch: IAstNode): ITernaryExpressionNode;
begin
    Result := TTernaryExpressionNode.Create(ACondition, AThenBranch, AElseBranch);
end;

class function TAst.LambdaExpr(const AParameters: TArray<IIdentifierNode>; const ABody: IAstNode): ILambdaExpressionNode;
begin
    Result := TLambdaExpressionNode.Create(AParameters, ABody);
end;

class function TAst.UnaryExpr(const AOperator: TUnaryOperator; const ARight: IAstNode): IUnaryExpressionNode;
begin
    Result := TUnaryExpressionNode.Create(AOperator, ARight);
end;

class function TAst.VarDecl(const AIdentifier: IIdentifierNode; AInitializer: IAstNode): IVariableDeclarationNode;
begin
    Result := TVariableDeclarationNode.Create(AIdentifier, AInitializer);
end;

end.