import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import java.util.*;
import java.awt.event.*;
import java.io.*;

/*
   Name of Lab: Terrain- Grid Class
   Your Name: Jennette Shepard
   Your Class: Comp Sci 210
   Date: 4/3/08
 
   This class reads the grid from the file and puts the values into an
   array that will be sent to the GridGIS class to be rendered.
   
   *I would also like to credit Professor Laura Toma because much of the
   *code I used was looked at from the class BoggleGUI
 */
public class Grid{
    
    //variable to track the line
    //numbers of the file and the
    //text of each line
    private int line = 0;
    private String lineText;
    
    //number of rows and columns for the grid
    public static int numCols = 0;
    public static int numRows = 0;
    
    //NODATA_value variable
    public static int noDataValue = 0;
    
    //variable to track how many numbers
    //have been added to the array
    private int intNum = 0;
    
    //array to hold elevations values
    public static Integer[][] numsFromFile = 
        new Integer[numRows + 1][numCols + 1];
    
        
    private static final int HEADER_LENGTH = 6;
    
    //reads values from file and adds them to array
    //accounts for header at top
    public Grid(String fileName){
        //grid = new Integer[][];
        
        //error opening file
        boolean EOF = false;

        System.err.print("Reading word list from file " 
            + fileName 
            + "...");
            
        //Opens file   
        try{
            LineNumberReader input = new LineNumberReader(new FileReader(fileName));
            
            //reads lines whilst there are lines to read
            while((lineText = input.readLine()) != null){

                //keeps track of ze lines!
                line = input.getLineNumber();
                
                //if the line you are looking at is
                //in the header portion
                if(line <= HEADER_LENGTH){
                    //if you have found the line
                    //containing the column number
                    if (lineText.startsWith("ncols")){
                        //remove everything after the prefix
                        //of the line
                        lineText = lineText.substring(lineText.indexOf('s')
                            +1, lineText.length());
                        
                        //remove the extra spaces on
                        //the rest of the line
                        lineText = lineText.trim();
                        
                        //create a scanner and search
                        //remaining text for an int
                        Scanner s = new Scanner(lineText);
                        if(s.hasNextInt()){
                            //if int is found, count
                            //it as the number of columns
                            numCols = s.nextInt();
                        }else{
                            //else let user know number of columns
                            //was untraceable
                            System.err.println("number of columns" +
                                " cannot be found");
                        }
                    }
                    //if you have found the line
                    //containing the row number
                    if (lineText.startsWith("nrows")){
                        //remove everything after the prefix
                        //of the line
                        lineText = lineText.substring(lineText.indexOf('s')+1, lineText.length());

                        //remove the extra spaces on
                        //the rest of the line
                        lineText = lineText.trim();
                        
                        //create a scanner and search
                        //remaining text for the int
                        Scanner s = new Scanner(lineText);
                        if(s.hasNextInt()){
                            //if int is found, count
                            //it as the number of rows
                            numRows = s.nextInt();
                        }else{
                            //else let user know number of rows
                            //was untraceable
                            System.err.println("number of rows" +
                                " cannot be found");
                        }
                    }
                    //if you have found the line
                    //containing the NODATA_value number
                    if (lineText.startsWith("NODATA_value")){
                        //remove everything after the prefix
                        //of the line
                        lineText = lineText.substring(lineText.indexOf('e')+1, lineText.length());

                        //remove the extra spaces on
                        //the rest of the line
                        lineText = lineText.trim();
                        
                        //create a scanner and search
                        //remaining text for an int
                        Scanner s = new Scanner(lineText);
                        if(s.hasNextInt()){
                            //if int is found, count
                            //it as the number of NODATA_value
                            noDataValue = s.nextInt();
                        }else{
                            //else let user know number of NODATA_value
                            //was untraceable
                            System.err.println("NODATA_value" +
                                " cannot be found");
                        }
                    }
                
                }
                //if you have searched through
                //the entire header
                if(line == HEADER_LENGTH){
                    //create array with found values
                    //to hold the elevations
                    numsFromFile = new Integer[numRows + 1][numCols + 1];
                }
                
                //if you are searching past
                //the header of the fild
                if(line > HEADER_LENGTH){ 
                    //create a scanner to search the lines
                    Scanner s = new Scanner(lineText);
                    //while there is an int
                    // to be looked at
                    while(s.hasNextInt()){
                        //add the int to the array
                        numsFromFile[line-7][intNum%numCols] = s.nextInt();
                        
                        //increase the counter
                        //of ints that have
                        //been located
                        intNum++;
                    }
                }   
            }
            //ensures the array was filled
            for(int j = 0; j< (numRows); j++){
                for(int i = 0; i< (numCols); i++){
                    if(numsFromFile[j][i]== null){
                        System.err.println("data received was incomplete");
                    }
                }
            }
            
            //Closes the file
            input.close();
        }catch (FileNotFoundException fnfex ){
            JOptionPane.showMessageDialog(null, 
                "Unable to find elevations file " + fileName, "Error",
                JOptionPane.ERROR_MESSAGE);
        }catch(IOException e){
            JOptionPane.showMessageDialog(null, 
                "Error Opening File", "Error",
                JOptionPane.ERROR_MESSAGE);
        }
        System.err.println("done");
    }

}//end