package com.google.gwt.sample.stockwatcher.client;

import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.event.dom.client.ClickEvent;
import com.google.gwt.event.dom.client.ClickHandler;
import com.google.gwt.event.dom.client.KeyCodes;
import com.google.gwt.event.dom.client.KeyPressEvent;
import com.google.gwt.event.dom.client.KeyPressHandler;
import com.google.gwt.i18n.client.DateTimeFormat;
import com.google.gwt.i18n.client.NumberFormat;
import com.google.gwt.user.client.Window;
import com.google.gwt.user.client.ui.Button;
import com.google.gwt.user.client.ui.FlexTable;
import com.google.gwt.user.client.ui.HorizontalPanel;
import com.google.gwt.user.client.ui.Label;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.TextBox;
import com.google.gwt.user.client.ui.VerticalPanel;
import java.util.ArrayList;
import com.google.gwt.user.client.Timer;
import com.google.gwt.user.client.Random;
import com.google.gwt.i18n.client.NumberFormat;
import java.util.Date;

public class StockWatcher implements EntryPoint {
	private static final int REFRESH_INTERVAL = 5000; //ms
	private VerticalPanel mainPanel = new VerticalPanel();
	private FlexTable stocksFlexTable = new FlexTable();
	private HorizontalPanel addPanel = new HorizontalPanel();
	private TextBox newSymbolTextBox = new TextBox();
	private Button addStockButton = new Button("Add");
	private Label lastUpdatedLabel = new Label();
	private ArrayList<String> stocks = new ArrayList<String>();
	
	/**
	 *Entry  point method
	 */
	
	public void onModuleLoad() {
		// TODO Create table for stock data.
		stocksFlexTable.setText(0,0,"Symbol");
		stocksFlexTable.setText(0,1,"Price");
		stocksFlexTable.setText(0,2,"Change");
		stocksFlexTable.setText(0,3,"Remove");
		// TODO Assemble Add Stock Panel.
		addPanel.add(newSymbolTextBox);
		addPanel.add(addStockButton);
		// TODO Assemble Main panel.
		mainPanel.add(stocksFlexTable);
		mainPanel.add(addPanel);
		mainPanel.add(lastUpdatedLabel);
		// TODO Associate the Main panel with the HTML host page.
		RootPanel.get("stockList").add(mainPanel);
		// TODO Move cursor focus to the input box.
		newSymbolTextBox.setFocus(true);
		
		//Setup timer to refresh list automatically.
		Timer refreshTimer = new Timer() {
			@Override
			public void run() {
				refreshWatchList();
			}
		};
		refreshTimer.scheduleRepeating(REFRESH_INTERVAL);
		
		//Listen for mouse events on the Add button.
		addStockButton.addClickHandler(new ClickHandler(){
			public void onClick(ClickEvent event) {
				addStock();
			}
		});
		//Listen for keyboard events in the input box.
		newSymbolTextBox.addKeyPressHandler(new KeyPressHandler() {
			public void onKeyPress(KeyPressEvent event) {
				if (event.getCharCode() == KeyCodes.KEY_ENTER){
					addStock();
				}
			}
		});
		
	}
	/**
	 * Add Stock to FlexTable. Executed when the user clicks the addStockButton or
	 * presses enter in the newSymbolTextBox.
	 */
	private void addStock() {
		// TODO Auto-generated method stub
		final String symbol = newSymbolTextBox.getText().toUpperCase().trim();
		newSymbolTextBox.setFocus(true);
		
		//Stock code must be between 1 and 10 chars that are numbers, letters, or dots.
		if (!symbol.matches("^[0-9A-Z\\.]{1,10}$")){
			Window.alert("'" + symbol + "' is not a valid symbol.");
			newSymbolTextBox.selectAll();
			return;
		} 
		
		newSymbolTextBox.setText("");
			// TODO Don't add the stock if it's already in the table.
		if  (stocks.contains(symbol))
			return;
			// TODO Add the stock to the table.
		int row = stocksFlexTable.getRowCount();
		stocks.add(symbol);
		stocksFlexTable.setText(row, 0, symbol);
			// TODO Add a button to remove this stock from the table.
		Button removeStockButton = new Button("x");
		removeStockButton.addClickHandler(new ClickHandler(){
			public void onClick(ClickEvent event) {
				int removedIndex = stocks.indexOf(symbol);
				stocks.remove(removedIndex);
				stocksFlexTable.removeRow(removedIndex + 1);
			}
		});
		stocksFlexTable.setWidget(row, 3, removeStockButton);
			// TODO Get the stock price.
		refreshWatchList();
		
		}
	/*
	 * Generate random stock price.
	 */
	 private void refreshWatchList() {
		    final double MAX_PRICE = 100.0; // $100.00
		    final double MAX_PRICE_CHANGE = 0.02; // +/- 2%

		    StockPrice[] prices = new StockPrice[stocks.size()];
		    for (int i = 0; i < stocks.size(); i++) {
		      double price = Random.nextDouble() * MAX_PRICE;
		      double change = price * MAX_PRICE_CHANGE
		          * (Random.nextDouble() * 2.0 - 1.0);

		      prices[i] = new StockPrice(stocks.get(i), price, change);
		    }

		    updateTable(prices);
		  }
	  /**
	   * Update the Price and Change fields all the rows in the stock table.
	   *
	   * @param prices Stock data for all rows.
	   */
	  private void updateTable(StockPrice[] prices) {
	    for (int i = 0; i < prices.length; i++) {
	      updateTable(prices[i]);
	    }
	    //Display timestamp showing last refresh.
	    lastUpdatedLabel.setText("Last update : "
	    		+ DateTimeFormat.getMediumDateTimeFormat().format( new Date()));

	  }
			 /**
			   * Update a single row in the stock table.
			   *
			   * @param price Stock data for a single row.
			   */
			  private void updateTable(StockPrice price) {
			    // Make sure the stock is still in the stock table.
			    if (!stocks.contains(price.getSymbol())) {
			      return;
			    }

			    int row = stocks.indexOf(price.getSymbol()) + 1;

			    // Format the data in the Price and Change fields.
			    String priceText = NumberFormat.getFormat("#,##0.00").format(
			        price.getPrice());
			    NumberFormat changeFormat = NumberFormat.getFormat("+#,##0.00;-#,##0.00");
			    String changeText = changeFormat.format(price.getChange());
			    String changePercentText = changeFormat.format(price.getChangePercent());

			    // Populate the Price and Change fields with new data.
			    stocksFlexTable.setText(row, 1, priceText);
			    stocksFlexTable.setText(row, 2, changeText + " (" + changePercentText
			        + "%)");
			  }
		
		}