/* SwitchSecond.cpp - Coins swapping program.

  The playing board is 5 squares.  Think of one coin each on the two left-most squares, 
  with "heads" shown on those coins.  The middle square is blank, and the two right-most
  squares each have a coin, with "tails" shown.  The object is to swap the coins.  
  
    For the sake of the program, we will represent "heads" as 'X', and "tails" as 'O'. The 
    starting board configuration is then:
    XX OO
    and the final board configuration is:
    OO XX
    
      An X can only move to the right, and an O can only move to the left.  On each move you
      can move any piece into an adjacent square, or you can jump over an opposite piece into
      a blank square.  Thus an X can jump an O, but an X cannot jump another X (and similarly for O
      jumping X).
      
*/


#include <iostream>
using namespace std;


// display identifying information
void displayIDinformation()
{
   cout<< "Name: Dale Reed\n"
       << "Date... etc. \n";
}

    
// display instructions
void displayInstructions()
{
	cout<< "Welcome to the coin swap program.  'X' represents heads, 'O'\n"
       << "represents tails.  To make a move, simply enter the number of \n"
       << "the square of the piece you wish to move or -1 to exit.\n"
       << "\n";
}

         
// display board
void displayBoard(char p1, char p2, char p3, char p4, char p5)
{
   cout<< "1 2 3 4 5\n"
       << p1 << " " << p2 << " " << p3 << " " << p4 << " " << p5 << "\n";
}

        
// Prompt for and get the position of the piece to move
void promptAndGetPieceToMove(int &pieceToMove)
{
      cout<< "Enter the square of the piece to move: ";
      cin>> pieceToMove;
      // See if -1 was entered to exit the program.  
      if (pieceToMove == -1) {
         cout<< "Thanks for playing, goodbye. \n\n";
         exit( 0);
      }
      cout<< "You selected to move from square " << pieceToMove << "\n\n";
}


// Find what direction we're moving
void findDirectionWereMoving( int pieceToMove, int &direction, char p1, char p2, char p3, char p4, char p5)
{
      // assume it is not a blank, i.e. perfect input
      switch ( pieceToMove) {
         case 1: p1=='X' ? direction=1 : direction=-1; break;
         case 2: p2=='X' ? direction=1 : direction=-1; break;
         case 3: p3=='X' ? direction=1 : direction=-1; break;
         case 4: p4=='X' ? direction=1 : direction=-1; break;
         case 5: p5=='X' ? direction=1 : direction=-1; break;
         default: cout<< "*** Error 1\n\n"; break;
      }
}


// Using direction, find neighbor and destination position 
void findNeighborAndDestination(int pieceToMove, int direction, char &neighbor, 
                                int &destination, char &jumpDestination, 
                                char p1, char p2, char p3, char p4, char p5)
{
   switch ( pieceToMove + direction) {
   case 1: neighbor = p1; destination = 1; break;
   case 2: neighbor = p2; destination = 2; break;
   case 3: neighbor = p3; destination = 3; break;
   case 4: neighbor = p4; destination = 4; break;
   case 5: neighbor = p5; destination = 5; break;
   default: cout<< "*** Error 2\n\n"; break;
   }
   
   if ( neighbor != ' ') {
      // find destination when jumping
      switch ( pieceToMove + (direction*2)) {
      case 1: jumpDestination = p1; destination = 1; break;
      case 2: jumpDestination = p2; destination = 2; break;
      case 3: jumpDestination = p3; destination = 3; break;
      case 4: jumpDestination = p4; destination = 4; break;
      case 5: jumpDestination = p5; destination = 5; break;
      default: cout<< "*** Error 3\n\n"; break;
      }
   }
   
}


// Make the move
void movePieceIntoDestinationAndClearSource( int destination, int direction, int pieceToMove, 
                                             char &p1, char &p2, char &p3, char &p4, char &p5)
{
   char pieceBeingMoved;   // piece to move character
   // set the type of piece to be moved
   if ( direction == 1) {
      pieceBeingMoved = 'X';
   }
   else {
      pieceBeingMoved = 'O';
   }
   
   switch ( destination) {
   case 1: p1 = pieceBeingMoved; break;
   case 2: p2 = pieceBeingMoved; break;
   case 3: p3 = pieceBeingMoved; break;
   case 4: p4 = pieceBeingMoved; break;
   case 5: p5 = pieceBeingMoved; break;
   default: cout<< "*** Error 4\n\n"; break;
   }
   // clear out the pieceToMove
   switch ( pieceToMove) {
   case 1: p1 = ' '; break;
   case 2: p2 = ' '; break;
   case 3: p3 = ' '; break;
   case 4: p4 = ' '; break;
   case 5: p5 = ' '; break;
   default: cout<< "*** Error 5\n\n"; break;
   }

}


// Move the piece        
void moveThePiece(int pieceToMove, char &p1, char &p2, char &p3, char &p4, char &p5)
{
   char neighbor;          // character stored in neighbor, in direction to move
   char jumpDestination;   // character stored in destination if a jump is made
   int destination;        // destination square number for move
   int direction = -1;

   // Find what direction we're moving
   findDirectionWereMoving( pieceToMove, direction, p1,p2,p3,p4,p5);
   
   // Using direction, find neighbor and destination position 
   findNeighborAndDestination( pieceToMove, direction, neighbor, 
                               destination, jumpDestination, p1,p2,p3,p4,p5);
    
   // Make the move
   movePieceIntoDestinationAndClearSource( destination, direction, pieceToMove, p1,p2,p3,p4,p5);
}

        
// See if we're done yet
void seeIfWereDoneYet(bool &notDone, char p1, char p2, char p3, char p4, char p5)
{
      if ( (p1=='O') && (p2=='O') && (p3 == ' ') && (p4=='X') && (p5 == 'X')) {
         // We ARE done
         notDone = false;
         cout<< "Congratulations, you did it!\n\n";
      }
}



int main()
{	
   // declare variables
   char p1 = 'X';    // The 5 'p' variables are the 5 pieces on the game board
   char p2 = 'X';
   char p3 = ' ';
   char p4 = 'O';
   char p5 = 'O';
   bool notDone = true;    // flag telling whether or not the game is done
   int pieceToMove = -1;   // location of piece to be moved
   
   // display identifying information
   displayIDinformation();
    
   // display instructions
   displayInstructions();
    
   while ( notDone) {
      
      // display board
      displayBoard( p1,p2,p3,p4,p5);
      
      // Prompt for and get the position of the piece to move
      promptAndGetPieceToMove( pieceToMove);
       
      // Move the piece, assuming it is a valid move
      moveThePiece( pieceToMove, p1,p2,p3,p4,p5);
      
      // See if we're done yet
      seeIfWereDoneYet( notDone, p1,p2,p3,p4,p5);
 
   }

	return 0;
}