/* LifeGame.java defines the non-trivial LifeGame operations.
 * Author: Charles Hoot, for Hands On Java.
 * Modified from code by: Joel Adams, for Hands On C++.
 * Date: July 2000.
 */ 

import hoj.*; // ReadFile

public class LifeGame {

	private int gameArray[][];
	private int myRows, myCols;
	
	// the constructor
	public LifeGame(String fileName) {
		int r, c;
		ReadFile in = new ReadFile(fileName);
		myRows = in.readInt();
		myCols = in.readInt();
		
		//add a border of cells around the ones we will use
		//we will put zeros there so that it will be
		//easier to do the generation update
		gameArray = new int[myRows+2][myCols+2];
		
		//initialize all the cells with zeros
		for(r=0; r<myRows+2; r++)
			for(c=0; c<myCols+2; c++)
				gameArray[r][c] = 0;

		//read in the cells from the file
		for(r=1; r<=myRows; r++)
			for(c=1; c<=myCols; c++)
				gameArray[r][c] = in.readInt();
	}

	// access the number of columns in array
	public int columns() {
		return myCols;
	}

	// access the number of rows in the array
	public int rows() {
		return myRows;
	}
	
	// access the cell value
	public int cellValue(int row, int col){
		return gameArray[row+1][col+1];
	}
	
	// mutator to compute the next generation
	public void nextGeneration() {
		int cellCount;
		int newGeneration[][] = new int[myRows+2][myCols+2];
		
		for(int r=1; r<=myRows; r++){
			for(int c=1; c<=myCols; c++){
				// we don't have to worry about the edges
				// since we placed an extra cells with
				// zeros there
				cellCount =   gameArray[r-1][c-1]
							+ gameArray[r-1][c]
							+ gameArray[r-1][c+1]
							+ gameArray[r][c-1]
							+ gameArray[r][c+1]
							+ gameArray[r+1][c-1]
							+ gameArray[r+1][c]
							+ gameArray[r+1][c+1];
							
				switch(cellCount) {
					case 0:
					case 1:
					case 4:
					case 5:
					case 6:
					case 7:
					case 8:
						// cell death
							newGeneration[r][c] = 0;
							break;
					case 2:
						// no change
							newGeneration[r][c] = gameArray[r][c];
							break;
					case 3:
						// cell birth
							newGeneration[r][c] = 1;
							break;
					default:
						System.err.println("Bad count " + cellCount 
										+ " for cell [" + r + "][" + c + "]"); 
							break;
				}
				
			} //end of column loop
		}//end of row loop
						
		//copy the new generation into the array
		for(int r=1; r<=myRows; r++)
			for(int c=1; c<=myCols; c++)
				gameArray[r][c] = newGeneration[r][c];

	}

	// override the toString method to display the array
	public String toString() {
		String representation = "";
		for(int r=1; r<=myRows; r++){
			for(int c=1; c<=myCols; c++){
				if(gameArray[r][c] == 1)
					representation = representation + "X ";
				else
					representation = representation + "  ";

			}
			representation = representation + "\n";
		}
		return representation;
	}
	
} // end of the class