/*******************************************************************************
 * Copyright (c) 2001, 2007 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 * IBM Corporation - initial API and implementation
 *******************************************************************************/
package org.eclipse.wst.validation.internal;

import java.lang.reflect.InvocationTargetException;
import java.util.logging.Level;

import org.eclipse.core.resources.IMarker;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.Preferences;
import org.eclipse.jem.util.logger.LogEntry;
import org.eclipse.jem.util.logger.proxy.Logger;
import org.eclipse.wst.validation.internal.plugin.ValidationPlugin;


/**
 * Only the validation framework can use this class.
 */
public final class ConfigurationManager implements ConfigurationConstants {
	private static ConfigurationManager inst = null;

	private ConfigurationManager() {
		//Default constructor
	}

	public static ConfigurationManager getManager() {
		if (inst == null) {
			inst = new ConfigurationManager();
		}
		return inst;
	}

	/**
	 * Given a validation marker, return the fully-qualified class name of the validator who owns
	 * the message. If the validator cannot be found or if the marker is not a validation marker,
	 * return null.
	 */
	public String getValidator(IMarker marker) {
		if (marker == null) {
			return null;
		}

		try {
			if (!marker.getType().equals(VALIDATION_MARKER)) {
				return null;
			}

			Object attrib = marker.getAttribute(VALIDATION_MARKER_OWNER);
			if (attrib == null) {
				// owner not set
				return null;
			}
			return attrib.toString();
		} catch (CoreException exc) {
			Logger logger = ValidationPlugin.getPlugin().getMsgLogger();
			if (logger.isLoggingLevel(Level.SEVERE)) {
				LogEntry entry = ValidationPlugin.getLogEntry();
				entry.setSourceIdentifier("InternalPreferenceManager.getValidator(IMarker)"); //$NON-NLS-1$
				entry.setTargetException(exc);
				logger.write(Level.SEVERE, entry);
			}
			return null;
		}
	}

	/**
	 * Return true if the given marker is a validation marker. Otherwise return false.
	 */
	public boolean isValidationMarker(IMarker marker) {
		if (marker == null) {
			return false;
		}

		try {
			return marker.getType().equals(VALIDATION_MARKER);
		} catch (CoreException exc) {
			Logger logger = ValidationPlugin.getPlugin().getMsgLogger();
			if (logger.isLoggingLevel(Level.SEVERE)) {
				LogEntry entry = ValidationPlugin.getLogEntry();
				entry.setSourceIdentifier("InternalPreferenceManager.isValidationMarker(IMarker)"); //$NON-NLS-1$
				entry.setTargetException(exc);
				logger.write(Level.SEVERE, entry);
			}
			return false;
		}
	}

	/**
	 * This method is for use by the TVT Validation plugin ONLY!!! No code should access the
	 * validation markers in the list directly except for the validation framework and the TVT
	 * Validation plugin.
	 */
	public void removeAllValidationMarkers(IProject project) {
		if ((project == null) || (!project.isOpen())) {
			return;
		}

		try {
			project.deleteMarkers(VALIDATION_MARKER, false, DEPTH_INFINITE); // false means only
			// consider VALIDATION_MARKER, not variants of VALIDATION_MARKER. 
			//Since addTask only adds VALIDATION_MARKER, we don't need to consider its subtypes.
		} catch (CoreException exc) {
			// Couldn't retrieve the markers from the resource for some reason...
			Logger logger = ValidationPlugin.getPlugin().getMsgLogger();
			if (logger.isLoggingLevel(Level.SEVERE)) {
				LogEntry entry = ValidationPlugin.getLogEntry();
				entry.setSourceIdentifier("WorkbenchMonitor.removeAllValidationMarkers(IProject)"); //$NON-NLS-1$
				entry.setTargetException(exc);
				logger.write(Level.SEVERE, entry);
			}
		}
	}

	/**
	 * This method returns the global preferences for the workspace.
	 */
	public GlobalConfiguration getGlobalConfiguration() throws InvocationTargetException {
		IWorkspaceRoot root = ValidationConfiguration.getRoot();
		GlobalConfiguration gp = null;
		try {
			gp = (GlobalConfiguration) root.getSessionProperty(USER_PREFERENCE);
			if (gp == null) {
				gp = new GlobalConfiguration(root);
				Preferences prefs = ValidationPlugin.getPlugin().getPluginPreferences();
				if( prefs != null ){
					prefs.addPropertyChangeListener(gp);
				}
				
				gp.getVersion(); // initialize the configuration's version attribute
				gp.load(); // initialize this instance from the stored values
				gp.passivate(); // store this instance as a property on the IResource
			}
			return gp;
		} catch (CoreException exc) {
			throw new InvocationTargetException(exc, ResourceHandler.getExternalizedMessage(ResourceConstants.VBF_EXC_RETRIEVE, new String[]{root.getName()}));
		}
	}

	public ProjectConfiguration getProjectConfiguration(IProject project) throws InvocationTargetException {
		ProjectConfiguration prjp = null;
		try {
			prjp = (ProjectConfiguration) project.getSessionProperty(USER_PREFERENCE);
			if (prjp == null || !prjp.getResource().exists()) {
				prjp = new ProjectConfiguration(project);
				prjp.getVersion(); // initialize the configuration's version attribute
				prjp.load(); // initialize this instance from the stored values
				prjp.passivate(); // store this instance as a property on the IResource
			}
			return prjp;
		} catch (CoreException exc) {
			throw new InvocationTargetException(exc, ResourceHandler.getExternalizedMessage(ResourceConstants.VBF_EXC_RETRIEVE, new String[]{project.getName()}));
		}
	}

	public ProjectConfiguration getProjectConfigurationWithoutMigrate(IProject project) throws InvocationTargetException {
		ProjectConfiguration prjp = null;
		try {
			prjp = (ProjectConfiguration) project.getSessionProperty(USER_PREFERENCE);
			if (prjp == null || !prjp.getResource().exists()) {
				prjp = new ProjectConfiguration(project);
				prjp.getVersion(); // initialize the configuration's version attribute
				prjp.load(); // initialize this instance from the stored values
				prjp.passivate(); // store this instance as a property on the IResource
			}
			return prjp;
		} catch (CoreException exc) {
			throw new InvocationTargetException(exc, ResourceHandler.getExternalizedMessage(ResourceConstants.VBF_EXC_RETRIEVE, new String[]{project.getName()}));
		}
	}


	/**
	 * The nature of the project has changed; update the enabled validators on the project.
	 */
	public void resetProjectNature(IProject project) throws InvocationTargetException {
		resetProjectNature(getProjectConfiguration(project));
	}

	/**
	 * When a project has been created for the first time, its natures may not have been complete at
	 * the time that this Preference was recreated. Call this method to recalculate the vmds.
	 */
	protected void resetProjectNature(ProjectConfiguration prjp) throws InvocationTargetException {
		prjp.resetProjectNature();
	}

	public void closing(IProject project) {
		try {
			if (isMigrated(project)) {
				ProjectConfiguration prjp = ConfigurationManager.getManager().getProjectConfiguration(project);
				if(!prjp.useGlobalPreference())
					prjp.store();
			}
		} catch (InvocationTargetException exc) {
			Logger logger = ValidationPlugin.getPlugin().getMsgLogger();
			if (logger.isLoggingLevel(Level.SEVERE)) {
				LogEntry entry = ValidationPlugin.getLogEntry();
				entry.setSourceIdentifier("InternalPreferenceManager::closing(" + project.getName() + ")"); //$NON-NLS-1$ //$NON-NLS-2$
				entry.setTargetException(exc);
				logger.write(Level.SEVERE, entry);

				if (exc.getTargetException() != null) {
					entry.setTargetException(exc);
					logger.write(Level.SEVERE, entry);
				}
			}
		}
	}

	public void deleting(IProject project) {
	}

	public void opening(IProject project) {
		// Do not load or migrate the project in this method; let the getConfiguration(IProject)
		// method do that. Do not load the project before it's necessary.
	}

	/**
	 * Return true if the global preferences are at the current level of metadata, false otherwise.
	 */
	public boolean isGlobalMigrated() throws InvocationTargetException {
		IWorkspaceRoot root = ValidationConfiguration.getRoot();
		if (root == null) {
			return false;
		}

		try {
			GlobalConfiguration gp = (GlobalConfiguration) root.getSessionProperty(USER_PREFERENCE);
			if (gp != null) {
				return gp.isVersionCurrent();
			}

			String serializedPrjp = root.getPersistentProperty(USER_PREFERENCE);
			if (serializedPrjp != null) {
				gp = new GlobalConfiguration(root);
				gp.getVersion(); // initialize the configuration's version attribute
				return gp.isVersionCurrent();
			}
		} catch (CoreException exc) {
			throw new InvocationTargetException(exc, ResourceHandler.getExternalizedMessage(ResourceConstants.VBF_EXC_RETRIEVE, new String[]{root.getName()}));
		}

		return false;
	}

	/**
	 * Return true if the given project has the current level of metadata, false otherwise.
	 */
	public boolean isMigrated(IProject project) throws InvocationTargetException {
		if (project == null) {
			return false;
		}
		try {
			if (project.isAccessible()) {
				ProjectConfiguration prjp = (ProjectConfiguration) project.getSessionProperty(USER_PREFERENCE);
				if (prjp != null) {
					return prjp.isVersionCurrent();
				}
				String serializedPrjp = project.getPersistentProperty(USER_PREFERENCE);
				if (serializedPrjp != null) {
					prjp = new ProjectConfiguration(project);
					prjp.getVersion(); // initialize the configuration's
					// version attribute
					return prjp.isVersionCurrent();
				}
			}
		} catch (CoreException exc) {
			throw new InvocationTargetException(exc, ResourceHandler.getExternalizedMessage(ResourceConstants.VBF_EXC_RETRIEVE, new String[]{project.getName()}));
		}
		return false;
	}

}