package org.simantics.utils.ui.widgets;

import java.io.File;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.jface.layout.GridDataFactory;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.layout.GridLayout;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Group;
import org.eclipse.swt.widgets.Text;

public abstract class FileOrDirectorySelectionWidget extends Composite{
	
	Text fileText;
	String filename[];
	
	private List<FileSelectionListener> listeners = new ArrayList<FileSelectionListener>();
	
	public FileOrDirectorySelectionWidget(Composite parent, String name,int style) {
		super(parent, style);
		this.setLayout(new GridLayout(1,false));
		GridDataFactory.fillDefaults().grab(true, false).align(SWT.FILL, SWT.TOP).applyTo(this);
		
		Group fileGroup = new Group(this, SWT.NONE);
		GridDataFactory.fillDefaults().grab(true, false).align(SWT.FILL, SWT.TOP).applyTo(fileGroup);
		
		fileGroup.setText(name);
		fileGroup.setLayout(new GridLayout(2, false));
		
		fileText = new Text(fileGroup, SWT.SINGLE|SWT.BORDER);
		GridData data = new GridData();
		data.grabExcessHorizontalSpace = true;
		data.horizontalAlignment = SWT.FILL;
		fileText.setLayoutData(data);
		
		Button browseButton = new Button(fileGroup, SWT.PUSH);
		browseButton.setText("Browse");
		data = new GridData();
		browseButton.setLayoutData(data);
		
		
				
		browseButton.addSelectionListener(new SelectionAdapter() {
			@Override
			public void widgetSelected(SelectionEvent e) {
				String[] name = openDialog();
				if (name != null) {
					setFilename(name,true);
				}
			}
		});
		
		fileText.addModifyListener(new ModifyListener() {
			
			@Override
			public void modifyText(ModifyEvent e) {
				String file = fileText.getText();
				String files[] = file.split(",");
				for (int i = 0; i < files.length; i++) {
					files[i] = files[i].trim();
				}
				setFilename(files, false);
				
			}
		});
	}
	
	protected abstract String[] openDialog();
	
	protected abstract boolean isValid(File file);
	
	protected void setFilename(String[] filename) {
		setFilename(filename, true);
	}
	
	protected void setFilename(String[] filename, boolean update) {
		String text = "";
		if (filename.length < 6) {
			for (String s : filename) {
				text += s + ",";
			}
			if (text.length() > 2)
				text = text.substring(0, text.length() - 1);
		} else {
			text = filename[0] + " and " + (filename.length -1) + " other files.";
		}
		
		if (update && !text.equals(fileText.getText()))
			fileText.setText(text);
		
		boolean accept = true;
		for (String s : filename){
			File file = new File(s);
			if (!isValid(file)) {
				accept = false;
				break;
			}
		}
		if (accept)
			this.filename = filename;
		else
			this.filename = null;
		
		for (FileSelectionListener l : listeners) {
			l.fileSelected(this, this.filename);
		}
	}
	
	public String[] getFilename() {
		return filename;
	}
	
	public void addListener(FileSelectionListener listener) {
		this.listeners.add(listener);
	}
	
	public void removeListener(FileSelectionListener listener) {
		this.listeners.remove(listener);
	}
	

}