package com.quantum;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileWriter;
import java.io.IOException;
import java.net.URL;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;

import com.quantum.model.BookmarkCollection;
import com.quantum.util.xml.XMLHelper;
import com.quantum.view.subset.SubsetContentProvider;

import org.eclipse.core.resources.ISaveContext;
import org.eclipse.core.resources.ISaveParticipant;
import org.eclipse.core.resources.ISavedState;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IPluginDescriptor;
import org.eclipse.core.runtime.Path;
import org.eclipse.jface.preference.IPreferenceStore;
import org.eclipse.jface.preference.PreferenceConverter;
import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.dnd.Clipboard;
import org.eclipse.swt.graphics.FontData;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.RGB;
import org.eclipse.ui.IViewPart;
import org.eclipse.ui.IWorkbench;
import org.eclipse.ui.IWorkbenchPage;
import org.eclipse.ui.IWorkbenchPart;
import org.eclipse.ui.IWorkbenchWindow;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.plugin.AbstractUIPlugin;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.xml.sax.SAXException;

/**
 * @author root
 * Main class of the quantum plugin, sets defaults, saves and recovers state.
 */
public class QuantumPlugin extends AbstractUIPlugin {
     
	private static QuantumPlugin plugin;
	private Clipboard sysClip;

	
	public QuantumPlugin(IPluginDescriptor descriptor) {
		super(descriptor);
		plugin = this;
	}

	public static QuantumPlugin getDefault() {
		return plugin;
	}
	/**
	 * Reads the Quantum Plugin state from a file. The file has been created with writeImportantState
	 * @param target
	 */
	protected void readStateFrom(File target) {
		String fileName = target.getName();
		if (!fileName.endsWith(Messages.getString("QuantumPlugin.saveFileExtension"))){ //$NON-NLS-1$
            try {
    			// It's the 2.0 format for preferences
    			BookmarkCollection.getInstance().load(target);
            } catch (IOException e) {
                e.printStackTrace();
            }
		} else {
			//It's the 2.1 format for preferences and subsets
			FileInputStream source = null;
			try {
				source = new FileInputStream(target);
			} catch (FileNotFoundException e1) {
				e1.printStackTrace();
				return;
			}
			DocumentBuilderFactory factory = DocumentBuilderFactory.newInstance();
			DocumentBuilder parser;
			try {
				parser = factory.newDocumentBuilder();
                Document doc = parser.parse(source);

                Element root = doc.getDocumentElement();
                BookmarkCollection.getInstance().importXML(root);
                BookmarkCollection.getInstance().setChanged(false);
                SubsetContentProvider.getInstance().importXML(root);

			} catch (ParserConfigurationException e) {
				e.printStackTrace();
			} catch (SAXException e) {
				e.printStackTrace();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}		
	}

	/* (non-Javadoc)
	 * @see org.eclipse.core.runtime.Plugin#startup()
	 */
	public void startup() throws CoreException {
		super.startup();
		ISaveParticipant saveParticipant = new QuantumSaveParticipant();
		ISavedState lastState =
			ResourcesPlugin.getWorkspace().addSaveParticipant(
				this,
				saveParticipant);
		if (lastState != null) {
    		IPath location = lastState.lookup(new Path(Messages.getString("QuantumPlugin.saveDir"))); //$NON-NLS-1$
    		if (location != null) {
        		// the plugin instance should read any important state from the file. 
        		File f = getStateLocation().append(location).toFile();
        		readStateFrom(f);
        		
            }
        }
        sysClip = new Clipboard(null);
 	}

	/* (non-Javadoc)
	 * @see org.eclipse.core.runtime.Plugin#shutdown()
	 */
	public void shutdown() throws CoreException {
		super.shutdown();
		sysClip.dispose();
	}

	/**
	 * Write the bookmarks and subsets to a file, saving them for next use of the quantum plugin
	 * @param target
	 */
	protected void writeImportantState(File target) {
        try {
            Document document = XMLHelper.createEmptyDocument();
            
    		Element root = (Element) document.appendChild(
                document.createElement(Messages.getString("ExportXMLAction.SavedData"))); //$NON-NLS-1$
    		
    		BookmarkCollection.getInstance().exportXML(root);
    		SubsetContentProvider.getInstance().exportXML(root);

            FileWriter writer =  new FileWriter(target);
            try {
                XMLHelper.createDOMSerializer(writer).serialize(document);
    		} finally {
    			writer.close();
    		}
        } catch (ParserConfigurationException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
	}
	
	/**
	 *  Gets an image descriptof from a file in the icons directory 
	 * @param name of the file to get
	 * @return ImageDescriptor or null if not found
	 */
	public static ImageDescriptor getImageDescriptor(String name) {
		ImageDescriptor descriptor = null;
		try {
			URL installURL =
				QuantumPlugin.getDefault().getDescriptor().getInstallURL();
			URL url = new URL(installURL, Messages.getString("QuantumPlugin.iconsDir") + name); //$NON-NLS-1$
			descriptor = ImageDescriptor.createFromURL(url);
		} catch (Exception e) {
			e.printStackTrace();
		}
		return descriptor;
	}
	public static Image getImage(String name) {
        ImageDescriptor imageDescriptor = getImageDescriptor(name);
		return imageDescriptor == null ? null : imageDescriptor.createImage();
	}

	protected void initializeDefaultPluginPreferences() {
		RGB BACKGROUND = new RGB(255, 255, 255);
		RGB COMMENT = new RGB(88, 148, 64);
		RGB KEYWORD = new RGB(126, 0, 75);
		RGB STRING = new RGB(0, 0, 255);
		RGB NUMERIC = new RGB(255, 0, 0);
		RGB DEFAULT = new RGB(0, 0, 0);
		IPreferenceStore store = getPreferenceStore();
		PreferenceConverter.setDefault(store,
			"quantum.background.color", BACKGROUND); //$NON-NLS-1$
		PreferenceConverter.setDefault(store,
			"quantum.text.color", DEFAULT); //$NON-NLS-1$
		PreferenceConverter.setDefault(store,
			"quantum.keyword.color", KEYWORD); //$NON-NLS-1$
		PreferenceConverter.setDefault(store,
			"quantum.comment.color", COMMENT); //$NON-NLS-1$
		PreferenceConverter.setDefault(store,
			"quantum.string.color", STRING); //$NON-NLS-1$
		PreferenceConverter.setDefault(store,
			"quantum.numeric.color", NUMERIC); //$NON-NLS-1$
		getPreferenceStore().setDefault("quantum.text.bold", false); //$NON-NLS-1$
		getPreferenceStore().setDefault("quantum.keyword.bold", true); //$NON-NLS-1$
		getPreferenceStore().setDefault("quantum.string.bold", false); //$NON-NLS-1$
		getPreferenceStore().setDefault("quantum.comment.bold", false); //$NON-NLS-1$
		getPreferenceStore().setDefault("quantum.numeric.bold", false); //$NON-NLS-1$
		PreferenceConverter.setDefault(getPreferenceStore(), "quantum.font", (FontData) null); //$NON-NLS-1$
        getPreferenceStore().setDefault("com.quantum.model.Bookmark.queryHistorySize", 20); //$NON-NLS-1$
	}
	// Returns the active page
	public IWorkbenchPage getActivePage()
	{
		IWorkbench workbench = getWorkbench();
		IWorkbenchWindow window = workbench.getActiveWorkbenchWindow();
		if (window == null)	return null;
		IWorkbenchPage page = window.getActivePage();
		return page;
	}
	/**
	 * returns a view in the active page, creating it if needed
	 * @param view, the name of the view (e.g com.quantum.view.tableview)
	 * @return true if successful, false if not
	 */
	public IViewPart getView(String view)
	{
		IViewPart tableView = null;
		try {
			IWorkbenchPage page = QuantumPlugin.getDefault().getActivePage();
			tableView =  page.findView(view);
			if (tableView == null){
				// showView will give focus to the created view, we don't want that
				// so we save the active part
				IWorkbenchPart part = page.getActivePart();
				tableView = page.showView(view);
				// and return the focus to it
				page.activate(part);
			}
		} catch (PartInitException e) {
			e.printStackTrace();
		}
		return tableView;
	}



	class QuantumSaveParticipant implements ISaveParticipant {
		/**
		* @see org.eclipse.core.resources.ISaveParticipant#doneSaving(ISaveContext)
		*/
		public void doneSaving(ISaveContext context) {
		}
		/**
		 * @see org.eclipse.core.resources.ISaveParticipant#prepareToSave(ISaveContext)
		 */
		public void prepareToSave(ISaveContext context) throws CoreException {
		}

		/**
		 * @see org.eclipse.core.resources.ISaveParticipant#rollback(ISaveContext)
		 */
		public void rollback(ISaveContext context) {
		}

		/**
		 * @see org.eclipse.core.resources.ISaveParticipant#saving(ISaveContext)
		 */
		public void saving(ISaveContext context) throws CoreException {
			switch (context.getKind()) {
				case ISaveContext.FULL_SAVE :
					QuantumPlugin quantumPluginInstance = QuantumPlugin.getDefault();
					// save the plug in state 
					if (BookmarkCollection.getInstance().isAnythingChanged()
						|| SubsetContentProvider.getInstance().hasChanged()) {

						int saveNumber = context.getSaveNumber();
						String saveFileName = Messages.getString("QuantumPlugin.saveDir") + "-" + Integer.toString(saveNumber) + Messages.getString("QuantumPlugin.saveFileExtension"); //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
						File f = quantumPluginInstance.getStateLocation().append(saveFileName).toFile();

						// if we fail to write, an exception is thrown and we do not update the path 
						quantumPluginInstance.writeImportantState(f);

						context.map(new Path(Messages.getString("QuantumPlugin.saveDir")), new Path(saveFileName)); //$NON-NLS-1$
						context.needSaveNumber();

					} else {
						System.out.println("Not saving unchanged bookmarks"); //$NON-NLS-1$
					}
					break;
				case ISaveContext.PROJECT_SAVE :
					// get the project related to this save operation 
					//IProject project = context.getProject(); 
					// save its information, if necessary 
					break;
				case ISaveContext.SNAPSHOT :
					// This operation needs to be really fast because 
					// snapshots can be requested frequently by the 
					// workspace. 
					break;
			}
		}
	}
	/**
	 * @return
	 */
	public Clipboard getSysClip() {
		return sysClip;
	}
}