/**
 * DoubletsGUI.java
 * Boston University CAS CS 112 HW7
 * By Ian Denhardt and Leo Reyzin
 */

import java.awt.*;
import java.awt.event.*;
import java.io.IOException;
import java.util.*;
import javax.swing.*;



public class DoubletsGUI extends JFrame{

	WordGraph g;
	int numWords;
	int maxLength;
	
	public DoubletsGUI() {
		Container contentPane = getContentPane();
		contentPane.setLayout(new BoxLayout(contentPane, BoxLayout.X_AXIS));

		// Create a text area for error messages & info
		JTextArea errorAndProgressMessage = new JTextArea();
		errorAndProgressMessage.setEditable(false);
		// add scroll bar to the error window
		JScrollPane scroll1 = new JScrollPane(errorAndProgressMessage);
		scroll1.setPreferredSize(new Dimension(400, 700));
		// create the button to open the file
		JButton openButton = new JButton("Click to select a dictionary file");
		openButton.addActionListener(new OpenListener(errorAndProgressMessage));
		// Add the two to a panel
		JPanel openFilePanel = new JPanel();
		openFilePanel.setLayout(new BoxLayout(openFilePanel, BoxLayout.Y_AXIS));
		openFilePanel.add(scroll1);
		openFilePanel.add(openButton);

		contentPane.add(openFilePanel);
		
		// add some gray space
		contentPane.add(new JLabel("   "));

		// Create a text area for output
		JTextArea output = new JTextArea();
		output.setEditable(false);
		// add scroll a bar to the output window
		JScrollPane scroll2 = new JScrollPane(output);
		scroll2.setPreferredSize(new Dimension(400, 700));

		// create a first word panel, with input area and button
		JPanel firstWordPanel = new JPanel();
		firstWordPanel.setLayout(new BoxLayout(firstWordPanel, BoxLayout.X_AXIS));

		JLabel beforeFirstWordText = new JLabel("Word1: ");
		firstWordPanel.add(beforeFirstWordText);
		JTextField firstWordInput = new JTextField();
		firstWordPanel.add(firstWordInput);

		JButton listNeighborsButton = new JButton("List Neighbors");
		listNeighborsButton.addActionListener(new ListNeighborsListener(firstWordInput, output));
		firstWordPanel.add(listNeighborsButton);	

		// create a second word panel, with input area and button
		JPanel secondWordPanel = new JPanel();
		secondWordPanel.setLayout(new BoxLayout(secondWordPanel, BoxLayout.X_AXIS));

		JLabel beforeSecondWordText = new JLabel("Word2: ");
		secondWordPanel.add(beforeSecondWordText);
		JTextField secondWordInput = new JTextField();
		secondWordPanel.add(secondWordInput);

		JButton ConnectButton = new JButton("Find a chain");
		ConnectButton.addActionListener(new ConnectListener(firstWordInput, secondWordInput, output));
		secondWordPanel.add(ConnectButton);	

		// add the two panels and the output window to a new panel
		JPanel workPanel = new JPanel();
		workPanel.setLayout(new BoxLayout(workPanel, BoxLayout.Y_AXIS));
		workPanel.add(scroll2);
		workPanel.add(firstWordPanel);
		workPanel.add(secondWordPanel);
		contentPane.add(workPanel);	
	}

	public static void main(String[] args) {
		DoubletsGUI frame = new DoubletsGUI();
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		frame.setSize(900,800);
		frame.setVisible(true);
	}

	// This class is in charge of opening the file
	private class OpenListener implements ActionListener {
		private JTextArea out;

		// constructor: keeps track of where the information message (opened/failed) is to be displayed
		public OpenListener(JTextArea out) {
			this.out = out;
		}

		private boolean firstPass(Scanner fileScanner) {
			if (!fileScanner.hasNext()) {
				out.append("File is empty.\n");
				return false;
			}
			numWords=1;
			String prev = fileScanner.next();
			maxLength = prev.length();
			String cur;
			while (fileScanner.hasNext()) {				
				cur = fileScanner.next();
				numWords++;
				if (cur.length()>maxLength)
					maxLength = cur.length();
				if (cur.toLowerCase().compareTo(prev.toLowerCase())<=0) {
					out.append("Not in alphabetical order: " + cur.toLowerCase() + " preceeds " + prev.toLowerCase()+"!\n");
					return false;
				}
			}
			return true;
		}

		private void buildGraph (Scanner fileScanner) {
			final int HOW_OFTEN_TO_PRINT = 10000, HOW_OFTEN_NEW_LINE = 50000;
			
			// read the file into the graph
			g = new WordGraph (numWords);
			int wordsRead = 0;
			out.append("Words read so far: ");
			while (fileScanner.hasNext()) {
				g.addVertex(fileScanner.next().toLowerCase());
				// print the number of words processed every once in a while, to show progress
				if (++wordsRead % HOW_OFTEN_TO_PRINT == 0) {
					out.append(wordsRead+" ");
					if (wordsRead % HOW_OFTEN_NEW_LINE == 0)
						out.append("\n");
					out.paintImmediately(out.getVisibleRect());
				}
			}
			if (wordsRead % HOW_OFTEN_NEW_LINE !=0)
				out.append("\n");
		}
		
		private void printStats() {
			int [] maxDegree = new int [maxLength+1];
			WordGraph.Vertex[] highestDegreeVertex = new WordGraph.Vertex [maxLength+1];
			for (WordGraph.Vertex v : g) {
				int len = v.toString().length();
				int degree = v.getDegree();
				if (degree > maxDegree[len]) {
					maxDegree[len] = degree;
					highestDegreeVertex[len] = v;
				}
			}
			
			for (int i = 1; i<=maxLength; i++)
				if (maxDegree[i]>0)
					out.append("Highest-degree word of length " + i + ": " + highestDegreeVertex[i] + " (degree " + maxDegree[i]+ ").\n" );
		}
		
		// is invoked when file is chosen; processes the file or displays a failure message
		public void actionPerformed(ActionEvent e) {
			JFileChooser chooser = new JFileChooser();
			int option = chooser.showOpenDialog(null);
			Scanner fileScanner;

			if(option == JFileChooser.APPROVE_OPTION) {
				try {
					fileScanner = new Scanner(chooser.getSelectedFile());
				}
				catch (IOException exc) {
					out.append("Unable to open file because of the following error: \""+exc.getMessage()+"\"");
					return;
				}

				// Do the first pass through the file to get the number of words, check alphabetical order, get max length
				out.append("Opened file: " + chooser.getSelectedFile().getName()+"\n");
				if (firstPass(fileScanner) == false)
					return;
				out.append("Words in the file: "+numWords+".  Maximum length of a word: " + maxLength + ".\nProcessing file...\n");

				// Do the second pass through the file to build the graph
				try {					
					fileScanner = new Scanner(chooser.getSelectedFile());
				}
				catch (IOException exc) {
					out.append("Unable to open file because of the following error: \""+exc.getMessage()+"\"");
					return;
				}
				buildGraph(fileScanner);
				printStats();
			}
		}
	}

	// This class is in charge of processing requests to list neighbors of a word 
	private class ListNeighborsListener implements ActionListener {
		private JTextField word;
		private JTextArea out;

		public ListNeighborsListener(JTextField word, JTextArea out) {
			this.word = word;
			this.out = out;
		}

		public void actionPerformed(ActionEvent e) {
			if (g == null) {
				out.append("Please select a file first!\n");
				return;
			}
			WordGraph.Vertex v = g.find(word.getText());
			if (v == null) {
				out.append(word.getText()+ ": word not in the dictionary.\n");
				return;
			}
			LinkedList<WordGraph.Vertex> neighbors = v.getNeighbors();
			
			out.append(word.getText()+" has " + neighbors.size() + " neighbors:\n" );
			for (WordGraph.Vertex u : neighbors)
				out.append(u+"\n");
			out.paintImmediately(out.getVisibleRect());
//			out.append(Double.toString(g.Centrality(v)));
		}
	}

	// This class is in charge of processing requests to find a chain
	private class ConnectListener implements ActionListener {
		private JTextField beginWord, endWord;
		private JTextArea out;

		public ConnectListener(JTextField beginWord, JTextField endWord, JTextArea out) {
			this.beginWord = beginWord;
			this.endWord = endWord;
			this.out = out;
		}

		public void actionPerformed(ActionEvent e) {
			if (g == null) {
				out.append("Please select a file first!\n");
				return;
			}
			String beginText = beginWord.getText();
			WordGraph.Vertex begin = g.find(beginText);
			if (begin == null) {
				out.append(beginText+ ": word not in the dictionary.\n");
				return;
			}

			String endText = endWord.getText();
			WordGraph.Vertex end = g.find(endText);
			if (end == null) {
				out.append(endText + ": word not in the dictionary.\n");
				return;
			}

			Stack<WordGraph.Vertex> path = g.bfs(begin, end);
			if (path == null) {
				out.append("There is no chain between " + beginText + " and " + endText + ".\n");
			}
			else {
				out.append("The chain from " + beginText + " to " + endText + " is of length " + (path.size()-1) + ":\n");
				while (!path.isEmpty()) 
					out.append(path.pop()+"\n");
			}
		}
	}

}