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

public class currencyConverter2W //Class for writing the currencies and conversion rates to a txt file
{
	
	private boolean isError = false;
	private String strError = "";
	private DecimalFormat decFormat = new DecimalFormat("#0.00");
	
	public currencyConverter2W ()
	{
	}
	
	public void createDefault () //Used if the file can't be found, creates a default file
	{
		
		Vector vecCurrencies = new Vector(); //Vector is an array that can grow
		vecCurrencies.addElement("Pound");
		vecCurrencies.addElement("Euro");
		vecCurrencies.addElement("Dollar");
		
		float[][] conversionMatrix = new float[3][3];
		
		conversionMatrix[0][0] = 1.00f; //Default conversion rates (probably wrong now)
		conversionMatrix[0][1] = 1.45f;
		conversionMatrix[0][2] = 1.74f;
		conversionMatrix[1][0] = 0.69f;
		conversionMatrix[1][1] = 1.00f;
		conversionMatrix[1][2] = 1.21f;
		conversionMatrix[2][0] = 0.57f;
		conversionMatrix[2][1] = 0.83f;
		conversionMatrix[2][2] = 1.00f;
		
		write(vecCurrencies, conversionMatrix);
		
	}
	
	private void addCurrentLine (String strBuffer, BufferedWriter writeFile) //Writes a line to the txt file
	{
		
		try //Attempts to execute the following code, if an error occurs it is caught
		{
			//Write the text, from index 0 (start) to the length of the current text
			writeFile.write(strBuffer, 0, strBuffer.length());
			writeFile.newLine(); //Creates a new line
			
		}
		catch (IOException e)
		{
			
			isError = true;
			strError = "Error writing to the file";
			
		}
		
	}
	
	public void write (Vector vecCurrencies, float[][] conversionMatrix) //Method called when data is to be written
	{
		
		isError = false;
		
		try
		{	
			
			BufferedWriter writeFile = new BufferedWriter(new FileWriter("currencyConverter2Instructions.txt"));			
			String strBuffer = "";
			
			for (int i = 0; i < 6; i++) //Repeat 6 times
			{
				
				switch (i) //Takes the variable i, and executes one of the following lines depending on the state of it
				{
					//Creates the header stuff
					case 0: strBuffer = "/Lines starting with / are comments, # is start of a section, ~ is end of a section";
							break;
					case 1: strBuffer = "/( is start of a field, ) is end of a field";
							break;
					case 2: strBuffer = "/Do not edit this file!!!!!!!!!!!!!!!! The programme can make all modifications itself";
							break;
					case 3: //Line 3 or 4 both share the same
					case 4:	strBuffer = "/";
							break;
					case 5: strBuffer = "#supported currencies";
							break;
							
				}
				
				addCurrentLine(strBuffer, writeFile); //Write the current line to the txt file
				
			}
			
			for (int i = 0; i < vecCurrencies.size(); i++) //Repeat for how many currencies
			{
				
				strBuffer = vecCurrencies.elementAt(i).toString(); //Get each element in turn and convert it into a string				
				addCurrentLine(strBuffer, writeFile);
								
			}
			
			for (int i = 0; i < 4; i++) //Repeat 4 times
			{
				
				switch (i)
				{
					
					case 0: strBuffer = "~end of supported currencies";
							break;
					case 1:
					case 2: strBuffer = "/";
							break;
					case 3: strBuffer = "#conversions";
							break;
				
				}
				
				addCurrentLine(strBuffer, writeFile);
				
			}
			
			for (int row = 0; row < vecCurrencies.size(); row++) //write the conversion rates
			{
				
				for (int column = 0; column < vecCurrencies.size(); column++)
				{
					//Outputs in the format sourceCurrency to desCurrency (conversionRate)
					strBuffer = "" + vecCurrencies.elementAt(row) + " to " + vecCurrencies.elementAt(column) + " (" + decFormat.format(conversionMatrix[row][column]) + ")";
					addCurrentLine(strBuffer, writeFile);
					
				}
				
			}
			
			strBuffer = "~end of conversion";
			addCurrentLine(strBuffer, writeFile);
			
			writeFile.close(); //Closes the file
			
		}
		catch (IOException e)
		{
			
			isError = true;
			strError = "Error opening file to write to";
			
		}		
			
	}
	
	public boolean isError ()
	{
		return isError;
	}
	
	public String getErrorMsg ()
	{
		return strError;
	}
	
}