/*******************************************************************************
 * Copyright (c) 2007 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse 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.jst.jsp.core.internal.util;

import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;
import org.eclipse.jst.jsp.core.internal.Logger;
import org.eclipse.wst.common.componentcore.ComponentCore;
import org.eclipse.wst.common.componentcore.ModuleCoreNature;
import org.eclipse.wst.common.componentcore.resources.IVirtualComponent;
import org.eclipse.wst.common.componentcore.resources.IVirtualFile;
import org.eclipse.wst.common.componentcore.resources.IVirtualResource;
import org.eclipse.wst.common.project.facet.core.IFacetedProject;
import org.eclipse.wst.common.project.facet.core.IProjectFacet;
import org.eclipse.wst.common.project.facet.core.ProjectFacetsManager;

/**
 * Wrapper class for all Facet-related calls. If the Facet or ModuleCore
 * bundles are not available, this class will not load, or if it does, its
 * methods will cause NoClassDefFoundErrors. This allows us to
 * compartmentalize the dependencies.
 * 
 */
final class FacetModuleCoreSupportDelegate {
	private static final String SLASH = "/";

	/**
	 * Copied to avoid unneeded extra dependency (plus it's unclear why the
	 * value is in that plug-in).
	 * 
	 * @see org.eclipse.wst.common.componentcore.internal.util.IModuleConstants.JST_WEB_MODULE
	 */
	private final static String JST_WEB_MODULE = "jst.web"; //$NON-NLS-1$

	/**
	 * @param project
	 * @return -1 if the project does not have the JST Web facet, the version
	 *         number of it otherwise
	 * @throws CoreException
	 */
	static float getDynamicWebProjectVersion(IProject project) {
		// In the absence of any facet information, assume the highest level
		float version = 2.5f;
		try {
			IFacetedProject faceted = ProjectFacetsManager.create(project);
			if (faceted != null && ProjectFacetsManager.isProjectFacetDefined(JST_WEB_MODULE)) {
				IProjectFacet webModuleFacet = ProjectFacetsManager.getProjectFacet(JST_WEB_MODULE);
				if (faceted.hasProjectFacet(webModuleFacet)) {
					version = Float.parseFloat(faceted.getInstalledVersion(webModuleFacet).getVersionString());
				}
			}
		}
		catch (NumberFormatException e) {
			Logger.logException(e);
		}
		catch (CoreException e) {
			Logger.logException(e);
		}
		return version;
	}

	/**
	 * @param path -
	 *            the full path to a resource within the workspace
	 * @return - the runtime path of the resource if one exists, null
	 *         otherwise
	 */
	static IPath getRuntimePath(IPath path) {
		IProject project = ResourcesPlugin.getWorkspace().getRoot().getProject(path.segment(0));

		if (!ModuleCoreNature.isFlexibleProject(project))
			return null;

		IVirtualResource[] virtualResources = ComponentCore.createResources(ResourcesPlugin.getWorkspace().getRoot().getFile(path));
		if (virtualResources != null && virtualResources.length > 0) {
			return virtualResources[0].getRuntimePath();
		}
		return null;
	}

	/**
	 * @param project
	 * @return the IPath to the "root" of the web contents
	 */
	static IPath getWebContentRootPath(IProject project) {
		if (!ModuleCoreNature.isFlexibleProject(project))
			return null;

		IPath path = null;
		IVirtualComponent component = ComponentCore.createComponent(project);
		if (component != null && component.exists()) {
			path = component.getRootFolder().getWorkspaceRelativePath();
		}
		return path;
	}

	/**
	 * @param project
	 * @return
	 * @throws CoreException
	 */
	static boolean isDynamicWebProject(IProject project) {
		try {
			if (ProjectFacetsManager.isProjectFacetDefined(JST_WEB_MODULE)) {
				IFacetedProject faceted = ProjectFacetsManager.create(project);
				IProjectFacet webModuleFacet = ProjectFacetsManager.getProjectFacet(JST_WEB_MODULE);
				if (faceted != null && faceted.hasProjectFacet(webModuleFacet)) {
					return true;
				}
			}
		}
		catch (CoreException e) {
			Logger.logException(e);
		}
		return false;
	}

	/**
	 * @param basePath -
	 *            the full path to a resource within the workspace
	 * @param reference -
	 *            the reference string to resolve
	 * @return - the full path within the workspace that corresponds to the
	 *         given reference according to the virtual pathing support
	 */
	static IPath resolve(IPath basePath, String reference) {
		if (reference == null || basePath == null || basePath.segmentCount() == 0)
			return null;

		IProject project = ResourcesPlugin.getWorkspace().getRoot().getProject(basePath.segment(0));

		if (!ModuleCoreNature.isFlexibleProject(project))
			return null;

		if (basePath.segmentCount() > 1) {
			IFile baseFile = ResourcesPlugin.getWorkspace().getRoot().getFile(basePath);
			IVirtualResource[] virtualResources = ComponentCore.createResources(baseFile);
			for (int i = 0; i < virtualResources.length; i++) {
				IPath baseRuntimePath = virtualResources[i].getRuntimePath();
				IPath referenceRuntimePath = null;
				if (reference.startsWith(SLASH)) {
					referenceRuntimePath = new Path(reference);
				}
				else {
					referenceRuntimePath = baseRuntimePath.removeLastSegments(1).append(reference);
				}
				IVirtualFile virtualFile = ComponentCore.createFile(project, referenceRuntimePath);
				if (virtualFile != null && virtualFile.exists()) {
					IFile[] underlyingFiles = virtualFile.getUnderlyingFiles();
					for (int j = 0; j < underlyingFiles.length; j++) {
						if (underlyingFiles[j].getProject().equals(project) && underlyingFiles[j].exists()) {
							return underlyingFiles[j].getFullPath();
						}

					}
				}
			}
		}
		else {
			IVirtualFile virtualFile = ComponentCore.createFile(project, new Path(reference));
			if (virtualFile != null && virtualFile.exists()) {
				return virtualFile.getUnderlyingFile().getFullPath();
			}
		}
		return null;
	}
}