unit Myc.Data.Types.Arrays;

interface

uses
    System.Generics.Collections,
    System.SysUtils,
    Myc.Data.Types;

type
    TImplDataArrayValue = class; // fwd

    // Implements the array data type.
    TImplDataArrayType = class(TInterfacedObject, IDataType, IDataArrayType)
    private
        FElementType: IDataType;
        function GetElementType: IDataType;
        function GetName: String;
        function GetKind: TDataKind;
    public
        constructor Create(const AElementType: IDataType);
        function CreateValue(const AItems: array of IDataValue): IDataArrayValue;
    end;

    // Implements the array data value.
    TImplDataArrayValue = class(TInterfacedObject, IDataValue, IDataArrayValue)
    private
        FArrayType: IDataArrayType;
        FItems: TArray<IDataValue>;
        function GetDataType: IDataType;
        function GetElementCount: Integer;
        function GetItem(Idx: Integer): IDataValue;
    public
        constructor Create(const AArrayType: IDataArrayType; const AItems: array of IDataValue);
    end;

implementation

uses
    System.SyncObjs;

{ TImplDataArrayValue }

constructor TImplDataArrayValue.Create(const AArrayType: IDataArrayType; const AItems: array of IDataValue);
var
    i: Integer;
begin
    inherited Create;
    FArrayType := AArrayType;
    SetLength(FItems, Length(AItems));
    for i := 0 to High(AItems) do
        FItems[i] := AItems[i];
end;

function TImplDataArrayValue.GetDataType: IDataType;
begin
    Result := FArrayType;
end;

function TImplDataArrayValue.GetElementCount: Integer;
begin
    Result := Length(FItems);
end;

function TImplDataArrayValue.GetItem(Idx: Integer): IDataValue;
begin
    Result := FItems[Idx];
end;

{ TImplDataArrayType }

constructor TImplDataArrayType.Create(const AElementType: IDataType);
begin
    inherited Create;
    FElementType := AElementType;
end;

function TImplDataArrayType.CreateValue(const AItems: array of IDataValue): IDataArrayValue;
var
    item: IDataValue;
    i: Integer;
begin
    // Validate that all items match the element type of this array type.
    i := 0;
    for item in AItems do
    begin
        if (item.DataType <> FElementType) then
            raise EArgumentException.CreateFmt(
                'Invalid data type for item at index %d. Expected ''%s'', but got ''%s''.',
                [i, FElementType.Name, item.DataType.Name]);
        inc(i);
    end;
    Result := TImplDataArrayValue.Create(Self, AItems);
end;

function TImplDataArrayType.GetElementType: IDataType;
begin
    Result := FElementType;
end;

function TImplDataArrayType.GetName: String;
begin
    Result := Format('Array<%s>', [FElementType.Name]);
end;

function TImplDataArrayType.GetKind: TDataKind;
begin
    Result := dkArray;
end;

end.