Magic Cube

///////////////////////////////////////////////////////////////////////////////////////////////////

// Copyright 2023 Leszek Koltunski                                                               //

//                                                                                               //

// This file is part of Magic Cube.                                                              //

//                                                                                               //

// Magic Cube is proprietary software licensed under an EULA which you should have received      //

// along with the code. If not, check https://distorted.org/magic/License-Magic-Cube.html        //

///////////////////////////////////////////////////////////////////////////////////////////////////

package org.distorted.solvers;

import android.content.res.Resources;

import org.distorted.main.R;

import org.distorted.objectlib.main.ObjectSignatures;

import org.distorted.objectlib.main.TwistyObject;

import org.distorted.objectlib.tablebases.ImplementedTablebasesList;

import org.distorted.objectlib.tablebases.TablebaseHelpers;

import org.distorted.objectlib.tablebases.TablebasesAbstract;

///////////////////////////////////////////////////////////////////////////////////////////////////

public class SolverIvyCube extends SolverTablebase

{

  private static final int ERROR_CENTER_O_MISSING = -1;

  private static final int ERROR_CENTER_W_MISSING = -2;

  private static final int ERROR_CENTER_G_MISSING = -3;

  private static final int ERROR_CENTER_Y_MISSING = -4;

  private static final int ERROR_CENTER_B_MISSING = -5;

  private static final int ERROR_CENTER_R_MISSING = -6;

  private static final int ERROR_TWO_CENTERS_SWAP = -7;

  private static final int ERROR_CORNERS_CANNOT   = -8;

  TablebasesAbstract mSolver;

///////////////////////////////////////////////////////////////////////////////////////////////////

  private int checkAllCentersPresent(int[] centers)

    {

    int numCenters = centers.length;

    for(int color=0; color<numCenters; color++)

      {

      boolean error = true;

      int center;

      for(center=0; center<numCenters; center++)

        if( centers[center]==color )

          {

          error = false;

          break;

          }

      if( error )

        {

        switch(color)

          {

          case 0: return ERROR_CENTER_Y_MISSING;

          case 1: return ERROR_CENTER_W_MISSING;

          case 2: return ERROR_CENTER_B_MISSING;

          case 3: return ERROR_CENTER_G_MISSING;

          case 4: return ERROR_CENTER_R_MISSING;

          case 5: return ERROR_CENTER_O_MISSING;

          }

        }

      }

    return 0;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private boolean checkCommonColor(int[] buffer, int index, int[] c1, int[] c2)

    {

    if( c1[0]==c1[1] || c1[0]==c1[2] || c1[1]==c1[2] ) return false;

    if( c2[0]==c2[1] || c2[0]==c2[2] || c2[1]==c2[2] ) return false;

    if( c1[0]==c2[0] && c1[1]!=c2[1] && c1[1]!=c2[2] && c1[2]!=c2[1] && c1[2]!=c2[2] )

      {

      buffer[index] = c1[0];

      return true;

      }

    if( c1[0]==c2[1] && c1[1]!=c2[0] && c1[1]!=c2[2] && c1[2]!=c2[0] && c1[2]!=c2[2] )

      {

      buffer[index] = c1[0];

      return true;

      }

    if( c1[0]==c2[2] && c1[1]!=c2[0] && c1[1]!=c2[1] && c1[2]!=c2[0] && c1[2]!=c2[1] )

      {

      buffer[index] = c1[0];

      return true;

      }

    if( c1[1]==c2[0] && c1[0]!=c2[1] && c1[0]!=c2[2] && c1[2]!=c2[1] && c1[2]!=c2[2] )

      {

      buffer[index] = c1[1];

      return true;

      }

    if( c1[1]==c2[1] && c1[0]!=c2[0] && c1[0]!=c2[2] && c1[2]!=c2[0] && c1[2]!=c2[2] )

      {

      buffer[index] = c1[1];

      return true;

      }

    if( c1[1]==c2[2] && c1[0]!=c2[0] && c1[0]!=c2[1] && c1[2]!=c2[0] && c1[2]!=c2[1] )

      {

      buffer[index] = c1[1];

      return true;

      }

    if( c1[2]==c2[0] && c1[1]!=c2[1] && c1[1]!=c2[2] && c1[0]!=c2[1] && c1[0]!=c2[2] )

      {

      buffer[index] = c1[2];

      return true;

      }

    if( c1[2]==c2[1] && c1[1]!=c2[0] && c1[1]!=c2[2] && c1[0]!=c2[0] && c1[0]!=c2[2] )

      {

      buffer[index] = c1[2];

      return true;

      }

    if( c1[2]==c2[2] && c1[1]!=c2[0] && c1[1]!=c2[1] && c1[0]!=c2[0] && c1[0]!=c2[1] )

      {

      buffer[index] = c1[2];

      return true;

      }

    return false;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private int computeFaceColor(int[] buffer, int[][] corners)

    {

    boolean success0 = checkCommonColor(buffer,0,corners[0],corners[3]);

    if( !success0 ) return ERROR_CORNERS_CANNOT;

    boolean success1 = checkCommonColor(buffer,1,corners[1],corners[2]);

    if( !success1 ) return ERROR_CORNERS_CANNOT;

    boolean success2 = checkCommonColor(buffer,2,corners[0],corners[1]);

    if( !success2 ) return ERROR_CORNERS_CANNOT;

    boolean success3 = checkCommonColor(buffer,3,corners[2],corners[3]);

    if( !success3 ) return ERROR_CORNERS_CANNOT;

    boolean success4 = checkCommonColor(buffer,4,corners[0],corners[2]);

    if( !success4 ) return ERROR_CORNERS_CANNOT;

    boolean success5 = checkCommonColor(buffer,5,corners[1],corners[3]);

    if( !success5 ) return ERROR_CORNERS_CANNOT;

    return 0;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  private int computeCenterColors(int[] buffer, int[] faceColors, int[] centers)

    {

    int numCenters = faceColors.length;

    for(int color=0; color<numCenters; color++)

      for(int center=0; center<numCenters; center++)

        if( centers[center]==faceColors[color] )

          {

          buffer[center]=color;

          }

    return TablebaseHelpers.permutationIsEven(buffer) ? 0 : ERROR_TWO_CENTERS_SWAP;

    }

////////////////////////////////////////////////////////////////////////////////////////

  private int computeCornerTwist(int[] corner, int color)

    {

    if( corner[0]==color ) return 0;

    if( corner[1]==color ) return 1;

    return 2;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  public SolverIvyCube(Resources res, TwistyObject object)

    {

    super(res,object);

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  public int tablebaseIndex(TwistyObject object)

    {

    int[][] corners     = new int[4][3];

    int[] centers       = new int[6];

    int[] twist         = new int[4];

    int[] face_colors   = new int[6];

    int[] center_colors = new int[6];

    for(int i=0; i<4; i++)

      for(int j=0; j<3; j++)

        corners[i][j] = object.getCubitFaceStickerIndex(i,j);

    for(int i=0; i<6; i++)

      centers[i] = object.getCubitFaceStickerIndex(i+4,0) - 6;

    int result1 = checkAllCentersPresent(centers);

    if( result1<0 ) return result1;

    int result2 = computeFaceColor(face_colors,corners);

    if( result2<0 ) return result2;

    int result3 = computeCenterColors(center_colors, face_colors, centers);

    if( result3<0 ) return result3;

    twist[0] = computeCornerTwist(corners[0],face_colors[4]);

    twist[1] = computeCornerTwist(corners[1],face_colors[5]);

    twist[2] = computeCornerTwist(corners[2],face_colors[4]);

    twist[3] = computeCornerTwist(corners[3],face_colors[5]);

    int perm_num = TablebaseHelpers.computeEvenPermutationNum(center_colors);

    return perm_num + 360*(twist[0]+ 3*(twist[1]+ 3*(twist[2]+ 3*twist[3])));

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  public String error(int index, Resources res)

    {

    switch(index)

      {

      case ERROR_CENTER_W_MISSING  : String colorW = res.getString(R.string.color_white2);

                                     return res.getString(R.string.solver_generic_missing_center,colorW);

      case ERROR_CENTER_O_MISSING  : String colorO = res.getString(R.string.color_orange2);

                                     return res.getString(R.string.solver_generic_missing_center,colorO);

      case ERROR_CENTER_G_MISSING  : String colorG = res.getString(R.string.color_green2);

                                     return res.getString(R.string.solver_generic_missing_center,colorG);

      case ERROR_CENTER_Y_MISSING  : String colorY = res.getString(R.string.color_yellow2);

                                     return res.getString(R.string.solver_generic_missing_center,colorY);

      case ERROR_CENTER_B_MISSING  : String colorB = res.getString(R.string.color_blue2);

                                     return res.getString(R.string.solver_generic_missing_center,colorB);

      case ERROR_CENTER_R_MISSING  : String colorR = res.getString(R.string.color_red2);

                                     return res.getString(R.string.solver_generic_missing_center,colorR);

      case ERROR_TWO_CENTERS_SWAP  : return res.getString(R.string.solver_generic_two_centers);

      case ERROR_CORNERS_CANNOT    : return res.getString(R.string.solver_generic_corners_cannot);

      }

    return null;

    }

///////////////////////////////////////////////////////////////////////////////////////////////////

  public int[][] solution(int index, Resources res)

    {

    if( mSolver==null )

      {

      mSolver = ImplementedTablebasesList.createPacked(res, ObjectSignatures.IVY_2);

      }

    return mSolver!=null ? mSolver.solution(index,null) : null;

    }

}