Added ISolver, TSolver, TSolverEngine for the next puzzle solver

AdventOfCode.lpi

@@ -37,6 +37,10 @@
         <Filename Value="solvers\UTrebuchet.pas"/>
         <IsPartOfProject Value="True"/>
       </Unit>
+      <Unit>
+        <Filename Value="USolver.pas"/>
+        <IsPartOfProject Value="True"/>
+      </Unit>
     </Units>
   </ProjectOptions>
   <CompilerOptions>

AdventOfCode.lpr

@@ -24,6 +24,7 @@ uses
   cthreads,
   {$ENDIF}
   Classes, SysUtils, CustApp,
+  USolver,
   UTrebuchet, UCubeConundrum;
 
 type
@@ -44,10 +45,14 @@ type
 { TAdventOfCode }
 
 procedure TAdventOfCode.RunPuzzleSolutions;
+var
+  engine: TSolverEngine;
 begin
   WriteLn('### Advent of Code 2023 ###');
   TTrebuchet.Run;
   TCubeConundrum.Run;
+  engine := TSolverEngine.Create;
+  engine.Free;
 end;
 
 procedure TAdventOfCode.DoRun;

USolver.pas

@@ -0,0 +1,138 @@
+{
+  Solutions to the Advent Of Code.
+  Copyright (C) 2023  Stefan Müller
+
+  This program is free software: you can redistribute it and/or modify it under
+  the terms of the GNU General Public License as published by the Free Software
+  Foundation, either version 3 of the License, or (at your option) any later
+  version.
+
+  This program is distributed in the hope that it will be useful, but WITHOUT
+  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+  FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more details.
+
+  You should have received a copy of the GNU General Public License along with
+  this program.  If not, see <http://www.gnu.org/licenses/>.
+}
+
+unit USolver;
+
+{$mode ObjFPC}{$H+}
+{$interfaces corba}
+
+interface
+
+uses
+  Classes, SysUtils;
+
+type
+
+  { ISolver }
+
+  ISolver = interface
+    procedure Init;
+    procedure ProcessDataLine(const ALine: string);
+    procedure Finish;
+    procedure Free;
+    function GetDataFileName: string;
+    function GetPuzzleName: string;
+    function GetResultPart1: Integer;
+    function GetResultPart2: Integer;
+    property DataFileName: string read GetDataFileName;
+    property PuzzleName: string read GetPuzzleName;
+    property ResultPart1: Integer read GetResultPart1;
+    property ResultPart2: Integer read GetResultPart2;
+  end;
+
+  { TSolver }
+
+  TSolver = class abstract(ISolver)
+  protected
+    FPart1, FPart2: Integer;
+  public
+    procedure Init; virtual;
+    procedure ProcessDataLine(const ALine: string); virtual; abstract;
+    procedure Finish; virtual; abstract;
+    procedure Free; virtual;
+    function GetDataFileName: string; virtual; abstract;
+    function GetPuzzleName: string; virtual; abstract;
+    function GetResultPart1: Integer; virtual;
+    function GetResultPart2: Integer; virtual;
+  end;
+
+  { TSolverEngine }
+
+  TSolverEngine = class
+  private
+    procedure ProcessData(constref ASolver: ISolver);
+  public
+    procedure Run(constref ASolver: ISolver);
+    procedure RunAndFree(constref ASolver: ISolver);
+  end;
+
+implementation
+
+{ TSolver }
+
+procedure TSolver.Init;
+begin
+  FPart1 := 0;
+  FPart2 := 0;
+end;
+
+procedure TSolver.Free;
+begin
+  Free;
+end;
+
+function TSolver.GetResultPart1: Integer;
+begin
+  Result := FPart1;
+end;
+
+function TSolver.GetResultPart2: Integer;
+begin
+  Result := FPart2;
+end;
+
+{ TSolverEngine }
+
+procedure TSolverEngine.ProcessData(constref ASolver: ISolver);
+var
+  data: TextFile;
+  s: string;
+begin
+  ASolver.Init;
+
+  AssignFile(data, ConcatPaths(['data', ASolver.DataFileName]));
+  try
+    reset(data);
+    while (not EOF(data)) do
+    begin
+      readln(data, s);
+      ASolver.ProcessDataLine(s);
+    end;
+  finally
+    CloseFile(data)
+  end;
+
+  ASolver.Finish;
+end;
+
+procedure TSolverEngine.Run(constref ASolver: ISolver);
+begin
+  WriteLn;
+  WriteLn('--- ', ASolver.PuzzleName, ' ---');
+  ProcessData(ASolver);
+  WriteLn('Part 1: ', ASolver.ResultPart1);
+  WriteLn('Part 2: ', ASolver.ResultPart2);
+end;
+
+procedure TSolverEngine.RunAndFree(constref ASolver: ISolver);
+begin
+  Run(ASolver);
+  ASolver.Free;
+end;
+
+end.
+