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;

import org.distorted.objectlib.tablebases.TablebasesCube2;

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

public class SolverCube2 extends SolverTablebase

{

  private static final int ERROR_CORNER_135_MISSING = -1;

  private static final int ERROR_CORNER_134_MISSING = -2;

  private static final int ERROR_CORNER_125_MISSING = -3;

  private static final int ERROR_CORNER_124_MISSING = -4;

  private static final int ERROR_CORNER_035_MISSING = -5;

  private static final int ERROR_CORNER_034_MISSING = -6;

  private static final int ERROR_CORNER_025_MISSING = -7;

  private static final int ERROR_CORNER_024_MISSING = -8;

  private static final int ERROR_CORNERS_CANNOT     = -9;

  private static final int ERROR_CORNER_TWISTED     = -10;

  TablebasesAbstract mSolver;

  private final int[] mFaceColors;

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

  private void fillCornerTwists(int[] output, int[][] corners, int[] perm)

    {

    for(int i=0; i<8; i++)

      {

      int[] c = corners[perm[i]];

           if( c[0]==mFaceColors[0] || c[0]==mFaceColors[1] ) output[i] = 0;

      else if( c[1]==mFaceColors[0] || c[1]==mFaceColors[1] ) output[i] = 1;

      else                                                    output[i] = 2;

      }

    }

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

  private int cornerIndex(int[][] corners, int i1, int i2, int i3)

    {

    int c1 = mFaceColors[i1];

    int c2 = mFaceColors[i2];

    int c3 = mFaceColors[i3];

    for(int i=0; i<8; i++)

      {

      int[] cor = corners[i];

      if( (cor[0]==c1 && cor[1]==c2 && cor[2]==c3) ||

          (cor[0]==c2 && cor[1]==c3 && cor[2]==c1) ||

          (cor[0]==c3 && cor[1]==c1 && cor[2]==c2)  ) return i;

      }

    return -1;

    }

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

  private int retCornerPermutation(int[] output, int[][] corners)

    {

    for(int i=0; i<8; i++) output[i] = -1;

    output[0] = cornerIndex(corners, 1,2,5);

    output[1] = cornerIndex(corners, 1,4,2);

    output[2] = cornerIndex(corners, 1,5,3);

    output[3] = cornerIndex(corners, 1,3,4);

    output[4] = cornerIndex(corners, 0,5,2);

    output[5] = cornerIndex(corners, 0,2,4);

    output[6] = cornerIndex(corners, 0,3,5);

    output[7] = cornerIndex(corners, 0,4,3);

    if( output[0]==-1 ) return ERROR_CORNER_125_MISSING;

    if( output[1]==-1 ) return ERROR_CORNER_124_MISSING;

    if( output[2]==-1 ) return ERROR_CORNER_135_MISSING;

    if( output[3]==-1 ) return ERROR_CORNER_134_MISSING;

    if( output[4]==-1 ) return ERROR_CORNER_025_MISSING;

    if( output[5]==-1 ) return ERROR_CORNER_024_MISSING;

    if( output[6]==-1 ) return ERROR_CORNER_035_MISSING;

    if( output[7]==-1 ) return ERROR_CORNER_034_MISSING;

    return 0;

    }

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

  private int findColor(int[][] corners, int c1, int c2)

    {

    for(int i=0; i<8; i++)

      {

      int[] cor = corners[i];

      if( cor[0]==c1 && cor[1]==c2 ) return cor[2];

      if( cor[1]==c1 && cor[2]==c2 ) return cor[0];

      if( cor[2]==c1 && cor[0]==c2 ) return cor[1];

      }

    return -1;

    }

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

  private int computeFaceColors(int[][] corners)

    {

    mFaceColors[1] = corners[1][0];

    mFaceColors[2] = corners[1][2];

    mFaceColors[4] = corners[1][1];

    mFaceColors[0] = findColor(corners,mFaceColors[2],mFaceColors[4]);

    mFaceColors[3] = findColor(corners,mFaceColors[4],mFaceColors[1]);

    mFaceColors[5] = findColor(corners,mFaceColors[1],mFaceColors[2]);

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

      {

      int color = mFaceColors[i];

      if( color<0 ) return ERROR_CORNERS_CANNOT;

      for(int j=i+1; j<6; j++)

        if( mFaceColors[j]==color ) return ERROR_CORNERS_CANNOT;

      }

    return 0;

    }

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

  public SolverCube2(Resources res, TwistyObject object)

    {

    super(res,object);

    mFaceColors = new int[6];

    }

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

  public int tablebaseIndex(TwistyObject object)

    {

    int[][] corners= new int[8][3];

    corners[0][0] = object.getCubitFaceStickerIndex(0,1);

    corners[0][1] = object.getCubitFaceStickerIndex(0,3);

    corners[0][2] = object.getCubitFaceStickerIndex(0,5);

    corners[1][0] = object.getCubitFaceStickerIndex(1,3);

    corners[1][1] = object.getCubitFaceStickerIndex(1,5);

    corners[1][2] = object.getCubitFaceStickerIndex(1,1);

    corners[2][0] = object.getCubitFaceStickerIndex(2,5);

    corners[2][1] = object.getCubitFaceStickerIndex(2,1);

    corners[2][2] = object.getCubitFaceStickerIndex(2,3);

    corners[3][0] = object.getCubitFaceStickerIndex(3,1);

    corners[3][1] = object.getCubitFaceStickerIndex(3,3);

    corners[3][2] = object.getCubitFaceStickerIndex(3,5);

    corners[4][0] = object.getCubitFaceStickerIndex(4,1);

    corners[4][1] = object.getCubitFaceStickerIndex(4,3);

    corners[4][2] = object.getCubitFaceStickerIndex(4,5);

    corners[5][0] = object.getCubitFaceStickerIndex(5,1);

    corners[5][1] = object.getCubitFaceStickerIndex(5,3);

    corners[5][2] = object.getCubitFaceStickerIndex(5,5);

    corners[6][0] = object.getCubitFaceStickerIndex(6,1);

    corners[6][1] = object.getCubitFaceStickerIndex(6,3);

    corners[6][2] = object.getCubitFaceStickerIndex(6,5);

    corners[7][0] = object.getCubitFaceStickerIndex(7,1);

    corners[7][1] = object.getCubitFaceStickerIndex(7,3);

    corners[7][2] = object.getCubitFaceStickerIndex(7,5);

    int result0 = computeFaceColors(corners);

    if( result0<0 ) return result0;

    int[] perm = new int[8];

    int result1 = retCornerPermutation(perm,corners);

    if( result1<0 ) return result1;

    int[] perm7 = TablebasesCube2.shrinkPerm(perm);

    int permNum = TablebaseHelpers.computePermutationNum(perm7);

    int[] twist = new int[8];

    fillCornerTwists(twist,corners,perm);

    int totalTwist = 0;

    for(int i=0; i<8; i++) totalTwist += twist[i];

    if( ((totalTwist)%3) != 0 ) return ERROR_CORNER_TWISTED;

    int twistNum = twist[0] + 3*(twist[2] + 3*(twist[3] + 3*(twist[4] + 3*(twist[5] + 3*twist[6]))));

    return twistNum + 729*permNum;

    }

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

  private int getColorIndex4(int face)

    {

    switch(mFaceColors[face])

      {

      case 0: return R.string.color_yellow4;

      case 1: return R.string.color_white4;

      case 2: return R.string.color_blue4;

      case 3: return R.string.color_green4;

      case 4: return R.string.color_red4;

      case 5: return R.string.color_orange4;

      }

    return -1;

    }

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

  private int getColorIndex3(int face)

    {

    switch(mFaceColors[face])

      {

      case 0: return R.string.color_yellow3;

      case 1: return R.string.color_white3;

      case 2: return R.string.color_blue3;

      case 3: return R.string.color_green3;

      case 4: return R.string.color_red3;

      case 5: return R.string.color_orange3;

      }

    return -1;

    }

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

  private String cornerError(Resources res, int face0, int face1, int face2)

    {

    int j0 = getColorIndex3(face0);

    int j1 = getColorIndex3(face1);

    int j2 = getColorIndex4(face2);

    String c0 = res.getString(j0);

    String c1 = res.getString(j1);

    String c2 = res.getString(j2);

    return res.getString(R.string.solver_generic_missing_corner,c0,c1,c2);

    }

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

  public String error(int index, Resources res)

    {

    switch(index)

      {

      case ERROR_CORNER_135_MISSING: return cornerError(res,1,3,5);

      case ERROR_CORNER_134_MISSING: return cornerError(res,1,3,4);

      case ERROR_CORNER_125_MISSING: return cornerError(res,1,2,5);

      case ERROR_CORNER_124_MISSING: return cornerError(res,1,2,4);

      case ERROR_CORNER_035_MISSING: return cornerError(res,0,3,5);

      case ERROR_CORNER_034_MISSING: return cornerError(res,0,3,4);

      case ERROR_CORNER_025_MISSING: return cornerError(res,0,2,5);

      case ERROR_CORNER_024_MISSING: return cornerError(res,0,2,4);

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

      case ERROR_CORNER_TWISTED    : return res.getString(R.string.solver_generic_corner_twist);

      }

    return null;

    }

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

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

    {

    if( mSolver==null )

      {

      mSolver = ImplementedTablebasesList.createUnpacked(ObjectSignatures.CUBE_2);

      if( mSolver!=null )

        {

        int level = 5;

        mSolver.createTablebase(level);

        mSolver.testPruning(level);

        }

      }

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

    }

}