//Author: ^-^ Veerle ^-^
import java.io.*;
import java.util.Vector;

public class currencyConverter2R //Class for reading the instruction txt file and creating the conversion matrix and currencies list
{
	
	private float[][] conversionMatrix; //2D grid to store the conversion rates in
	private Vector vecCurrencies = new Vector(); //Vectors are arrays that can grow in size
	private BufferedReader readFile;
	private String strError = ""; //If there is an error, this message will be passed
	private boolean isError = false, noFile = false; //Error flags
	
	public currencyConverter2R ()
	{
	}
	
	public Vector getCurrencies ()
	{
		return vecCurrencies;
	}
	
	public float[][] getConversionMatrix ()
	{
		return conversionMatrix;
	}
	
	public boolean isError ()
	{
		return isError;
	}
	
	public String getErrorMsg ()
	{
		return strError;
	}
	
	public boolean noFile ()
	{
		return noFile;
	}
	
	private void reset () //Resets the flags and currency list
	{
		
		isError = false;
		noFile = false;		
		vecCurrencies.clear();
		
	}
	
	public void read () //Method that is called by the main programme
	{
		
		reset();
	
		try //Tries the following code, if an error occurs it is catched
		{
			readFile = new BufferedReader(new FileReader("currencyConverter2Instructions.txt"));
		}
		catch (IOException errorMsg) //If an error occured, this code executes
		{			
			
			isError = true;
			noFile = true;
			strError = "Error: Unable to find \"currencyConverter2Instructions.txt\"";
			
		}
		
		if (!isError) //If there was not an error with opening the file
		{
			readCurrencies();
		}
		
	}
	
	private void readCurrencies ()
	{
		
		String strBuffer = ""; //Stores the current line
		boolean isReadingCurrencies = false; //Flag for if currently reading currencies
		boolean hasReadCurrencies = false; //Flag for if currencies have all been read
		boolean isReadingRates = false; //Flag for if currently reading rates
		boolean hasReadRates = false; //Flag for if rates have all been read
		int column = 0, row = 0; //Row and column of the conversion matrix
		
		try
		{
			
			while ((strBuffer = readFile.readLine()) != null) //Keep looping until end of file
			{
				
				if (strBuffer.length() == 0) //If empty line
				{
					continue;
				}
				else if (strBuffer.charAt(0) == '/') //If a comment line
				{
					continue;
				}
				
				if (strBuffer.charAt(0) == '#') //Start of section
				{
					
					if (!hasReadCurrencies) //If haven't already read currencies
					{
						isReadingCurrencies = true; //Start reading currencies
					}
					else 
					{
						isReadingRates = true; //Start reading rates
					}
					
					continue;
					
				}
				else if (strBuffer.charAt(0) == '~') //End of section
				{
					
					if (!hasReadCurrencies)
					{
						
						hasReadCurrencies = true; //Finish reading currencies
						isReadingCurrencies = false;
						
						int numberCurrencies = vecCurrencies.size();
						conversionMatrix = new float[numberCurrencies][numberCurrencies]; //Create the conversion matrix with row/column = number currencies
						
					}
					else
					{
						
						hasReadRates = true;
						isReadingRates = false;
						
					}
					
					continue;
					
				}					
				
				if (isReadingCurrencies)
				{
					vecCurrencies.addElement(strBuffer);			
				}
				else if (isReadingRates)
				{
					
					int startIndex = strBuffer.indexOf('('); //Gets the char index number of the first time "(" is found
					int endIndex = strBuffer.indexOf(')');
					String strRate = strBuffer.substring(startIndex + 1, endIndex); //Creates a new string containing the conversion rate that is bordered by ( and )
					
					if (column >= vecCurrencies.size()) //Starts a new row when the column number is gt or eq to the number of currencies
					{
						
						column = 0;
						row++;
						
					}

					conversionMatrix[row][column] = Float.parseFloat(strRate); //Convert the current string conversion rate into a float, and put it into the conversion matrix
					column++;		
					
				}
			
			}
			
			readFile.close(); //Closes the file
			
		}
		catch (IOException errorMsg)
		{
				
			isError = true;		
			strError = "Error reading the file, check the synax of \"currencyConverter2Instructions.txt\"";			
			
		}
		
	}
	
}