//Author: ^-^ Veerle ^-^
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Vector;
import java.text.DecimalFormat;

public class currencyConverter2T extends JPanel //Table showing the conversion rates
{
	
	private currencyConverter2K currencyKeyListener = new currencyConverter2K();
	private boolean requireSave = false; //When an obvious change is made (like adding/renaming/removing a currency) this is true
	private final int maxCurrenciesSupported = 50;
	private float[][] backupConversionMatrix; //Stores the last saved conversion matrix so it can be restored
	private JLabel lblDummy; //Dummy label for the NW corner
	private JLabel[] lblCurrencies = new JLabel[maxCurrenciesSupported];
	private JLabel[] lblHeaderCurrencies = new JLabel[maxCurrenciesSupported];
	private JTextField[][] txtRate = new JTextField[maxCurrenciesSupported][maxCurrenciesSupported]; //Creates the max size labels and txt fields
	private GridLayout conversionGrid;
	private DecimalFormat decFormat = new DecimalFormat("#0.00");
	private Color clrBackgrounds = new Color(75,141,221); //Blue
	private Color clrForegrounds = new Color(255,255,255); //White
	
	public currencyConverter2T ()
	{
		
		for (int i = 0; i < maxCurrenciesSupported; i++)
		{
			
			lblCurrencies[i] = new JLabel("", JLabel.CENTER);
			//Headers are used since you can not add the same component twice to containers
			lblHeaderCurrencies[i] = new JLabel("", JLabel.CENTER);
			
			lblCurrencies[i].setForeground(clrForegrounds);
			lblHeaderCurrencies[i].setForeground(clrForegrounds);
			
			for (int p = 0; p < maxCurrenciesSupported; p++)
			{
								
				txtRate[i][p] = new JTextField("", 3);
				txtRate[i][p].addKeyListener(currencyKeyListener);
				
			}
			
		}
		
		lblDummy = new JLabel("");
		lblDummy.setForeground(clrForegrounds);
		
		conversionGrid = new GridLayout(1,1,2,2);
		
		this.setLayout(conversionGrid);		
		this.add(lblDummy);			
		this.setBackground(clrBackgrounds);
		
	}
	
	public boolean changesMade () //Checks if any changes have been made
	{
		
		if (requireSave) //If obvious change like add/remove/rename a currency
		{
			return true;
		}
		else //If not obvious change, compares the values in the grid to the backup conversion matrix
		{			
			
			for (int row = 0; row < (conversionGrid.getRows() - 1); row++)
			{
			
				for (int column = 0; column < (conversionGrid.getColumns() - 1); column++)
				{
					
					if (Float.parseFloat(txtRate[row][column].getText()) != backupConversionMatrix[row][column])
					{
						return true; //If a change has been made
					}
					
				}
				
			}
			
		}
		
		return false; //If no changes were found
		
	}
	
	public void saved () //Turns of the flag requiring a save once a sucessfull save has been made
	{
		requireSave = false;
	}			
	
	public float[][] getDefault () //Gets the backup conversion matrix so it can be restored
	{
		return backupConversionMatrix;
	}		
	
	public void updateTable (Vector vecCurrencies, float[][] conversionMatrix, boolean changeMade) //Updates the table that the user sees
	{
		
		if (changeMade) //If updating without saving
		{			
			requireSave = true;
		}
		else //If first time, or sucessfull save, sets the backup conversion matrix to the new one
		{
			
			requireSave = false;
			backupConversionMatrix = conversionMatrix;			
			
		}

		//removes everything from the grid
		for (int row = 0; row < conversionGrid.getRows(); row++)
		{
			
			for (int column = 0; column < conversionGrid.getColumns(); column++)
			{
				
				if (row == 0)
				{

					if (column == 0)
					{
						this.remove(lblDummy);
					}
					else
					{
						this.remove(lblHeaderCurrencies[column - 1]);
					}
					
				}
				else
				{
					
					if (column == 0)
					{
						this.remove(lblCurrencies[row - 1]);
					}
					else
					{
						this.remove(txtRate[row - 1][column - 1]);
					}
					
				}
				
			}
			
		}

		//Number of currencies + 1 for the row/column headers
		conversionGrid.setRows(vecCurrencies.size() + 1);
		conversionGrid.setColumns(vecCurrencies.size() + 1);
		
		//Sets up the required labels and txt boxes
		for (int index = 0; index < vecCurrencies.size(); index++)
		{
			//Sets the captions of the labels to the currencies they represent
			lblCurrencies[index].setText(vecCurrencies.elementAt(index).toString());
			lblHeaderCurrencies[index].setText(vecCurrencies.elementAt(index).toString());
			
			for (int column = 0; column < vecCurrencies.size(); column++)
			{
				//Sets the text in the txt field to the conversion rate it is representing
				txtRate[index][column].setText("" + decFormat.format(conversionMatrix[index][column]));
			}
			
		}

		//adds them to the grid		
		for (int row = 0; row < conversionGrid.getRows(); row++)
		{
			
			for (int column = 0; column < conversionGrid.getColumns(); column++)
			{
				
				if (row == 0) //If first row (header row)
				{
					
					if (column == 0)
					{
						this.add(lblDummy);
					}
					else
					{
						this.add(lblHeaderCurrencies[column - 1]);
					}
					
				}
				else
				{
					
					if (column == 0) //If first column (header column)
					{
						this.add(lblCurrencies[row - 1]);
					}
					else
					{
						this.add(txtRate[row - 1][column - 1]);
					}
					
				}
				
			}
			
		}
		
		revalidate(); //If you change items in a panel you need to revalidate it so it repaints
		
	}
	
	public float[][] getConversionMatrix () //Gets all the values in the grid and puts them in a conversionMatrix to be written to the file
	{
		
		int numCurrencies = conversionGrid.getRows() - 1;
		
		float[][] conversionMatrix = new float[numCurrencies][numCurrencies];
		
		for (int row = 0; row < numCurrencies; row++)
		{
			
			for (int column = 0; column < numCurrencies; column++)
			{
				conversionMatrix[row][column] = Float.parseFloat(txtRate[row][column].getText());
			}
			
		}
		
		backupConversionMatrix = conversionMatrix; //Since you are saving the file, the backup now equals the saved conversion matrix
		
		return conversionMatrix;
		
	}
	
}