Max file name sorting

program maxLines;

{$APPTYPE CONSOLE}

uses
  SysUtils, Windows, Classes, ShlObj, IOUtils, Generics.Collections,  Generics.Defaults;

type
  TLines = class
  private
    FLineLength: Integer;
    FLines: TList<Integer>;
  public
    constructor Create(aLineLength, aLine: Integer);
    property LineLength: Integer read FLineLength write FLineLength;
    property Lines: TList<Integer> read FLines;
  end;

constructor TLines.Create(aLineLength, aLine: Integer);
begin
  inherited Create;
  FLines := TList<Integer>.Create();
  FLineLength:= aLineLength;
  FLines.Add(aLine);
end;

function CompareByLineLength(const Left, Right: TLines): Integer;
begin
  Result := Left.LineLength - Right.LineLength;
end;

function GetDocumentsPath: string;
var
  LStr: array[0 .. MAX_PATH] of Char;
begin
  SetLastError(ERROR_SUCCESS);
  if SHGetFolderPath(0, CSIDL_PERSONAL, 0, 0, @LStr) = S_OK then
    Result := LStr;
end;

procedure PrintList(FList: TList<TLines>);
var element: TLines; Line: Integer;
begin
  for element in FList do begin
    Write(Format('%d: ', [element.LineLength]));
    for Line in element.Lines do
      Write(Format('%d ', [Line]));
    Writeln;
  end;
end;

const
  LinesMax = 10;
var
  fs: TStringStream;
  fsReader: TStreamReader;
  FLines: TList<TLines>;
  CurrentLine, CurrentLineLength, LineIndex: Integer;
  FLine: TLines;
  FileName: String;
begin
  CurrentLine:= 0;
  FLines := TList<TLines>.Create(TComparer<TLines>.Construct(CompareByLineLength));
  fs:= TStringStream.Create('', TEncoding.UTF8);
  fsReader:= TStreamReader.Create(fs, TEncoding.UTF8);
  try
    try
      fs.LoadFromFile(TPath.Combine(GetDocumentsPath, '123.txt'));
      while not fsReader.EndOfStream do begin
        Inc(CurrentLine);
        FileName:= fsReader.ReadLine;
        CurrentLineLength:= Length(ExtractFileName(FileName));
        FLine := TLines.Create(CurrentLineLength, CurrentLine);
        if FLines.BinarySearch(FLine, LineIndex) then
        begin
          FLines[LineIndex].Lines.Add(CurrentLine);
        end
        else if LineIndex > 0 then begin
          if FLines.Count = LinesMax then begin
            FLines.Extract(FLines[0]);
            FLines.Insert(LineIndex-1, FLine);
          end else
            FLines.Insert(LineIndex, FLine);
        end else begin
          if FLines.Count < LinesMax then FLines.Insert(0, FLine);
        end;
      end;
      PrintList(FLines);
      Readln;
    except
      on E: Exception do begin
        Writeln(E.ClassName, ': ', E.Message);
        Readln;
      end;
    end;
  finally
    fs.Free;
  end;
end.