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

public class currencyConverter2E extends JFrame implements ActionListener //Setup frame, allowing you to edit the currencies
{
	
	private final int maxCurrenciesSupported = 50;
	private final String storedPassword = "pcfy"; //Password for saving changes
	
	private currencyConverter2R readObject; //Read the txt file
	private currencyConverter2W writeObject; //Write to the txt file
	private currencyConverter2T conversionTable; //Display the conversion table
	
	private Vector vecCurrencies;
	private String[] backupCurrencies = new String[maxCurrenciesSupported]; //Stores a string array of all the currencies since the last save
	private int backupCurrenciesAmount; //Amount of currencies since last time saved
	private DecimalFormat decFormat = new DecimalFormat("#.00");
	private JButton cmdSave, cmdClose, cmdAddCurrency, cmdRemoveCurrency, cmdRenameCurrency;
	private JScrollPane scrollTable;
	private JLabel lblInstructions, lblDummy;
	private JPanel panRoot, panButtonArea, panButtonRow1, panButtonRow2, panNorthArea;
	
	private Color clrBackgrounds = new Color(75,141,221); //Light white
	private Color clrForegrounds = new Color(0,0,0); //Black
	
	private boolean changesMade = false; //Flag for if the combo box models need updating or not
	private boolean isPasswordCorrect = false; //Flag for if a correct password has been entered
	private boolean currenciesAlreadyRead = false; //Flag for if the currencies have already been read
	private float[][] conversionMatrix; //2D grid of all the conversions
	
	public currencyConverter2E (String title) //Sets up the frame
	{
		
		this.setTitle(title);
		this.setResizable(false);
		this.setLayout(new BorderLayout());
		this.setSize(new Dimension(550, 250));
		
		writeObject = new currencyConverter2W();
		readObject = new currencyConverter2R();
		conversionTable = new currencyConverter2T();
		
		cmdSave = new JButton("Save");
		cmdClose = new JButton("Close");
		cmdAddCurrency = new JButton("Add Currency");
		cmdRemoveCurrency = new JButton("Remove Currency");
		cmdRenameCurrency = new JButton("Rename Currency");
		
		cmdSave.addActionListener(this);
		cmdClose.addActionListener(this);
		cmdAddCurrency.addActionListener(this);
		cmdRemoveCurrency.addActionListener(this);
		cmdRenameCurrency.addActionListener(this);
		
		lblDummy = new JLabel("");
		lblInstructions = new JLabel("Change the conversion rates in the table and click save to apply changes", JLabel.CENTER);
		
		panRoot = new JPanel(new BorderLayout());
		panButtonArea = new JPanel(new BorderLayout());
		panNorthArea = new JPanel(new BorderLayout());
		panButtonRow1 = new JPanel();
		panButtonRow2 = new JPanel();
		
		//Sets up the scroll pane with the V and Hz scroll bars always showing, with the conversion table inside the pane
		scrollTable = new JScrollPane(conversionTable, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
		
		
		this.add(panRoot, BorderLayout.CENTER);
			panRoot.add(panNorthArea, BorderLayout.NORTH);
				panNorthArea.add(lblInstructions, BorderLayout.NORTH);
				panNorthArea.add(scrollTable, BorderLayout.SOUTH);
			panRoot.add(panButtonArea, BorderLayout.SOUTH);
				panButtonArea.add(panButtonRow1, BorderLayout.NORTH);
					panButtonRow1.add(cmdSave);
					panButtonRow1.add(cmdClose);					
				panButtonArea.add(panButtonRow2, BorderLayout.SOUTH);
					panButtonRow2.add(cmdAddCurrency);
					panButtonRow2.add(cmdRenameCurrency);
					panButtonRow2.add(cmdRemoveCurrency);				
			
		panRoot.setBackground(clrBackgrounds);
		panButtonArea.setBackground(clrBackgrounds);
		panButtonRow1.setBackground(clrBackgrounds);
		panButtonRow2.setBackground(clrBackgrounds);
		panNorthArea.setBackground(clrBackgrounds);
		scrollTable.setBackground(clrBackgrounds);
		
		lblInstructions.setForeground(clrForegrounds);
		
		lblInstructions.setBorder(BorderFactory.createEmptyBorder(3,1,3,1));
		panButtonRow2.setBorder(BorderFactory.createEmptyBorder(1,1,3,1));
		scrollTable.setBorder(BorderFactory.createEmptyBorder(3,5,3,5));				
		
	}	
	
	public void checkPassword () //Requires a correct password to make changes
	{
		
		if (!isPasswordCorrect) //If the correct password hasn't been entered yet
		{
			//Show the dialogue box and get the password they type in
			String enteredPassword = "default value";
			enteredPassword = JOptionPane.showInputDialog(null, "Enter Password (password is pcfy)", "Password", JOptionPane.QUESTION_MESSAGE);
			
			if (enteredPassword != null)
			{

				if (enteredPassword.equalsIgnoreCase(storedPassword)) //If password is correct
				{
				
					JOptionPane.showMessageDialog(null, "Password is correct, you may save changes", "Correct Password", JOptionPane.INFORMATION_MESSAGE);
					isPasswordCorrect = true;
				
				}
				else
				{			
					JOptionPane.showMessageDialog(null, "Password is incorrect, enter the correct password to save changes", "Incorrect Password", JOptionPane.WARNING_MESSAGE);
				}
			
			}
			
		}
		
	}
	
	public void resetCurrencies () //Tells the read object to read the currencies and conversions
	{
		
		if (!currenciesAlreadyRead) //If they have not already been read
		{
				
			readObject.read(); //Tells the read object to read
			
			if (readObject.isError()) //If an error occured
			{
				
				if (readObject.noFile()) //If no file exist
				{
								
					writeObject.createDefault(); //Create the default file
					readObject.read(); //Read again
					
				}
				else
				{
					System.out.print(readObject.getErrorMsg());
				}
				
			}
	
			conversionMatrix = readObject.getConversionMatrix(); //Gets the conversion matrix
			vecCurrencies = readObject.getCurrencies(); //Gets the currencies
			backupCurrenciesAmount = vecCurrencies.size(); //Sets the backup amount of how many currencies exist
			
			for (int i = 0; i < backupCurrenciesAmount; i++)
			{
				backupCurrencies[i] = vecCurrencies.elementAt(i).toString(); //Sets the backup currencies list
			}
				
			conversionTable.updateTable(vecCurrencies, conversionMatrix, false); //Show the table of conversion rates (but don't require a save)
			currenciesAlreadyRead = true; //Stops the programme unnessarrily reading the file again
			
		}
		
		changesMade = false; //Turn of the flag saying combo boxes should be updated
		
	}
	
	private void saveChanges () //Tells the write object to write the currencies and conversions
	{
		
		checkPassword();
		
		if (isPasswordCorrect)
		{
			
			conversionMatrix = conversionTable.getConversionMatrix(); //Gets the running conversion table		
			writeObject.write(vecCurrencies, conversionMatrix); //Writes the file
			
			if (writeObject.isError()) //If error occured
			{
				JOptionPane.showMessageDialog(null, "Error saving file", "Error saving file", JOptionPane.ERROR_MESSAGE);
			}
			else
			{
				
				JOptionPane.showMessageDialog(null, "Save was sucessfull", "Saved", JOptionPane.INFORMATION_MESSAGE);				
				changesMade = true; //Turn on the flag to reset combo boxes
				conversionTable.saved(); //Tell converion table to turn of the flag requiring a save
				
				if (vecCurrencies.size() != backupCurrenciesAmount) //If the size has changed (add/remove currency)
				{
					
					backupCurrenciesAmount = vecCurrencies.size(); //Change backup size
					
					for (int i = 0; i < maxCurrenciesSupported; i++) //Remove all the backup currencies
					{
						backupCurrencies[i] = "";
					}
					
					for (int i = 0; i < backupCurrenciesAmount; i++) //Add the new currencies
					{
						backupCurrencies[i] = vecCurrencies.elementAt(i).toString();
					}
					
				}
												
			}
		
		}
				
	}
	
	private void addCurrency () //Method for adding a currency
	{
		
		String currencyName = "default Value"; 
		currencyName = JOptionPane.showInputDialog(null, "Enter Currency Name", "Add Currency", JOptionPane.QUESTION_MESSAGE);

		if (currencyName != null)
		{
			
			int currencyExists = checkCurrencyExists(currencyName); //Check if the currency name already exists

		
			if (currencyExists != -1) //-1 is used if the currency name doesn't exist
			{
				JOptionPane.showMessageDialog(null, "Error, currency name is already used","Error", JOptionPane.ERROR_MESSAGE);
			}
			else
			{
				//Creates a new conversion matrix one row/column size bigger
				float[][] newConversionMatrix = new float[vecCurrencies.size() + 1][vecCurrencies.size() + 1];
	
				
				vecCurrencies.addElement(currencyName); //Add the new currency
				
				for (int row = 0; row < vecCurrencies.size(); row++)
				{
					
					for (int column = 0; column < vecCurrencies.size(); column++)
					{
						
						if ((vecCurrencies.size() - 1) == row) //If last row
						{
							newConversionMatrix[row][column] = 1.00f; //Default value which the user can change
						}
						else
						{
							
							if ((vecCurrencies.size() - 1) == column) //If last column
							{
								newConversionMatrix[row][column] = 1.00f;
							}
							else
							{
								newConversionMatrix[row][column] = conversionMatrix[row][column];
							}
							
						}
						
					}
					
				}
				
				conversionMatrix = newConversionMatrix;
				conversionTable.updateTable (vecCurrencies, conversionMatrix, true); //Update the conversion table the user sees, and turn on the flag requiring a save
				
			}
			
		}
	
	}
	
	private int checkCurrencyExists (String name) //Checks if a currency name already exists
	{
		
		for (int i = 0; i < vecCurrencies.size(); i++)
		{

			if (name.equalsIgnoreCase(vecCurrencies.elementAt(i).toString()))
			{
				return i; //Returns the index number where it was found (useful for removing and renaming the currency)
				
			}
			
		}
		
		return -1; //Returns -1 if the currency name was not found
		
	}		
	
	private void removeCurrency () //Method for removing a currency
	{
		
		String currencyName = "default value";
		currencyName = JOptionPane.showInputDialog(null, "Enter Currency Name", "Remove Currency", JOptionPane.QUESTION_MESSAGE);
		
		if (currencyName != null)
		{
			
			int currencyIndex = checkCurrencyExists(currencyName);
			
			if (currencyIndex != -1) //If the currency name exists
			{
				
				int selectedValue = JOptionPane.showConfirmDialog(null, "Are you sure you want to remove " + currencyName + "?", "Remove Currency?", JOptionPane.YES_NO_OPTION);
					
				if (selectedValue == JOptionPane.YES_OPTION) //If user confirms the delete
				{					
					//makes a new conversion matrix with a row/column size reduced
					float[][] newConversionMatrix = new float[vecCurrencies.size() - 1][vecCurrencies.size() - 1];
					int newRow = 0, newColumn = 0; //These are the new column/rows
					
					for (int row = 0; row < vecCurrencies.size(); row++)
					{
						
						if (row != currencyIndex) //If the row number doesn't eq the index at which the currency name was found
						{
	
							for (int column = 0; column < vecCurrencies.size(); column++)
							{
								
								if (column != currencyIndex) //If the column number doesn't eq the index at which the currency name was found
								{
									//Insert the currency into the new conversion matrix with the new row/column addresses
									newConversionMatrix[newRow][newColumn] = conversionMatrix[row][column];
									newColumn++;
									
								}
								
							}
							
							newRow++; //Only increases if the index didn't match
													
						}
						
						newColumn = 0;
						
					}
					
					vecCurrencies.removeElementAt(currencyIndex); //Removes the currency from the vector
					
					conversionMatrix = newConversionMatrix;
					conversionTable.updateTable(vecCurrencies, conversionMatrix, true); //Updates the table for the user to see, and turns on the flag requiring a save
					
				}
					
			}
			else
			{
				JOptionPane.showMessageDialog(null, "Unreconised Currency " + currencyName, "Error", JOptionPane.ERROR_MESSAGE);
			}
		
		}
		
	}
	
	private void renameCurrency () //Method for renaming a currency
	{
		
		String currencyName = "";
		currencyName = JOptionPane.showInputDialog(null, "Enter Existing Currency Name", "Rename Currency", JOptionPane.QUESTION_MESSAGE);
		
		if (currencyName != null)
		{
			
			int currencyIndex = checkCurrencyExists(currencyName);
			
			if (currencyIndex != -1) //If currency exists
			{
				
				String newName = JOptionPane.showInputDialog(null, "Enter the new Currency Name", "Rename Currency", JOptionPane.QUESTION_MESSAGE);
				int newCurrencyIndex = checkCurrencyExists(currencyName);
				
				if (newCurrencyIndex == -1) //If new currency name doesn't exist
				{
									
					vecCurrencies.setElementAt(newName, currencyIndex); //Make the change
					conversionTable.updateTable(vecCurrencies, conversionMatrix, true); //Updates the table for the user to see, and turns on the flag requring a save
					
				}
				else
				{
					JOptionPane.showMessageDialog(null, "Currency Name already exists " + currencyName, "Error", JOptionPane.ERROR_MESSAGE);
				}
				
			}
			else
			{
				JOptionPane.showMessageDialog(null, "Unreconised Currency " + currencyName, "Error", JOptionPane.ERROR_MESSAGE);
			}
		
		}
		
	}				
	
	public boolean hasChangesBeenMade () //Method for finding if changes have been made
	{
		return changesMade;
	}
	
	public float getRate (int source, int des) //Gets an indvidual conversion
	{
		return conversionMatrix[source][des];
	}
	
	public DefaultComboBoxModel getModel () //Gets a model to be used with a combo box
	{
		
		DefaultComboBoxModel cmenu = new DefaultComboBoxModel(vecCurrencies);
		return cmenu;
		
	}
	
	public boolean isError ()
	{
		return readObject.isError();
	}
	
	public String getErrorMsg ()
	{
		return readObject.getErrorMsg();
	}
	
	public void actionPerformed (ActionEvent e)
	{
		
		if (e.getSource() == cmdSave)
		{
			saveChanges();
		}
		else if (e.getSource() == cmdClose)
		{			
			
			if (conversionTable.changesMade()) //If changes have been made
			{
				
				int selectedValue = JOptionPane.showConfirmDialog(null, "Do you wish to Save changes?", "Save changes?", JOptionPane.YES_NO_OPTION);
				//Ask the user if they want to save changes
				if (selectedValue == JOptionPane.YES_OPTION) //If they answer yes
				{
					
					saveChanges(); //Save changes (asks for a password first if not already entered)
					
					if (isPasswordCorrect) //If the password is correct
					{
						this.setVisible(false);						
					}
					//If the password is not correct, don't close the frame since the user might have entered the wrong password by mistake
						
				}
				else //If not changing
				{
					
					conversionMatrix = conversionTable.getDefault(); //Resets the default
					
					if (vecCurrencies.size() != backupCurrenciesAmount) //If the size has changed
					{
						
						vecCurrencies.clear(); //Clear everything
											
						for (int i = 0; i < backupCurrenciesAmount; i++) //Reset the vector list
						{
							vecCurrencies.addElement(backupCurrencies[i]);
						}
						
					}
					
					conversionTable.updateTable(vecCurrencies, conversionMatrix, false); //Update the conversion table for the user to see, but don't require a save
					this.setVisible(false);
					
				}
			
			}
			else
			{
				this.setVisible(false);
			}						
			
		}
		else if (e.getSource() == cmdAddCurrency)
		{
			
			if (vecCurrencies.size() < maxCurrenciesSupported) //If cap has not been reached
			{
				
				checkPassword();
			
				if (isPasswordCorrect)
				{
					addCurrency();
				}
				
			}
			else
			{
				JOptionPane.showMessageDialog(null, "To many currencies, max " + maxCurrenciesSupported + " allowed", "Overflow", JOptionPane.ERROR_MESSAGE);
			}
			
		}
		else if (e.getSource() == cmdRemoveCurrency)
		{
				
			checkPassword();
			
			if (isPasswordCorrect)
			{
				removeCurrency();
			}
			
		}
		else if (e.getSource() == cmdRenameCurrency)
		{
			
			checkPassword();
			
			if (isPasswordCorrect)
			{
				renameCurrency();
			}
			
		}
		
	}
	
}