/*******************************************************************************
 * Copyright (c) 2007, 2013 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.IContainer;
import org.eclipse.core.resources.IFile;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
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.IVirtualFolder;
import org.eclipse.wst.common.componentcore.resources.IVirtualReference;
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 META_INF_RESOURCES = "META-INF/resources/"; //$NON-NLS-1$
	private static final String SLASH = "/"; //$NON-NLS-1$

	/**
	 * 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 the version of the JST Web facet, a default otherwise
	 * @throws CoreException
	 */
	static float getDynamicWebProjectVersion(IProject project) {
		if (project == null)
			return FacetModuleCoreSupport.DEFAULT_SERVLET_VERSION;

		// In the absence of any facet information, assume the highest level
		float version = FacetModuleCoreSupport.DEFAULT_SERVLET_VERSION;
		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) {
		if (path == null)
			return null;

		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 (project == null)
			return null;

		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) {
		if (project == null)
			return false;
		
		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;
	}

	private static IPath resolveInReferenced(IProject project, IPath runtimeReference) {
		IVirtualReference[] references = ComponentCore.createComponent(project).getReferences();
		if (references != null) {
			for (int i = 0; i < references.length; i++) {
				IVirtualComponent referencedComponent = references[i].getReferencedComponent();
				if (referencedComponent == null)
					continue;
				IVirtualComponent component = referencedComponent.getComponent();
				if (component == null)
					continue;
				IVirtualFolder rootFolder = component.getRootFolder();
				if (rootFolder == null)
					continue;
				IPath referencedPathRoot = rootFolder.getWorkspaceRelativePath();
				/*
				 * See Servlet 3.0, section 4.6 ; this is the only referenced
				 * module/component type we support
				 */
				IPath resolved = referencedPathRoot.append(META_INF_RESOURCES).append(runtimeReference);
				if (resolved != null && component.getProject().findMember(resolved.removeFirstSegments(1)) != null)
					return resolved;
			}
		}
		return null;
	}

	/**
	 * @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) {
			IResource baseResource = ResourcesPlugin.getWorkspace().getRoot().findMember(basePath);
			if (baseResource != null) {
				IVirtualResource[] virtualResources = ComponentCore.createResources(baseResource);
				for (int i = 0; i < virtualResources.length; i++) {
					IPath referenceRuntimePath = null;
					if (reference.startsWith(SLASH)) {
						referenceRuntimePath = new Path(reference);
					}
					else {
						IPath baseRuntimePath = virtualResources[i].getRuntimePath();
						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].isAccessible()) {
								return underlyingFiles[j].getFullPath();
							}
						}
						if (underlyingFiles.length > 0) {
							return underlyingFiles[0].getFullPath();
						}
					}
					else {
						// http://bugs.eclipse.org/338751 
						IVirtualFolder virtualFolder = ComponentCore.createFolder(project, referenceRuntimePath);
						if (virtualFolder != null && virtualFolder.exists()) {
							IContainer[] underlyingFolders = virtualFolder.getUnderlyingFolders();
							for (int j = 0; j < underlyingFolders.length; j++) {
								if (underlyingFolders[j].isAccessible()) {
									return underlyingFolders[j].getFullPath();
								}
							}
							if (underlyingFolders.length > 0) {
								return underlyingFolders[0].getFullPath();
							}
						}
						else {
							// check assembled projects
							return resolveInReferenced(project, referenceRuntimePath);
						}
					}
				}
			}
		}
		else {
			IVirtualFile virtualFile = ComponentCore.createFile(project, new Path(reference));
			if (virtualFile != null && virtualFile.exists()) {
				return virtualFile.getUnderlyingFile().getFullPath();
			}
		}
		return null;
	}

	static IPath[] getAcceptableRootPaths(IProject project) {
		if (!ModuleCoreNature.isFlexibleProject(project)) {
			return new IPath[]{project.getFullPath()};
		}

		IPath[] paths = null;
		IVirtualFolder componentFolder = ComponentCore.createFolder(project, Path.ROOT);
		if (componentFolder != null && componentFolder.exists()) {
			IContainer[] workspaceFolders = componentFolder.getUnderlyingFolders();
			paths = new IPath[workspaceFolders.length];
			for (int i = 0; i < workspaceFolders.length; i++) {
				paths[i] = workspaceFolders[i].getFullPath();
			}
		}
		else {
			paths = new IPath[]{project.getFullPath()};
		}
		return paths;
	}

	static IPath getDefaultRoot(IProject project) {
		if (ModuleCoreNature.isFlexibleProject(project)) {
			IVirtualFolder componentFolder = ComponentCore.createFolder(project, Path.ROOT);
			if (componentFolder != null && componentFolder.exists()) {
				return componentFolder.getWorkspaceRelativePath();
			}
		}
		return null;
	}

	static IPath getRootContainerForPath(IProject project, IPath path) {
		if (ModuleCoreNature.isFlexibleProject(project)) {
			IVirtualFolder componentFolder = ComponentCore.createFolder(project, Path.ROOT);
			if (componentFolder != null && componentFolder.exists()) {
				IContainer[] workspaceFolders = componentFolder.getUnderlyingFolders();
				for (int i = 0; i < workspaceFolders.length; i++) {
					if (workspaceFolders[i].getFullPath().isPrefixOf(path)) {
						return workspaceFolders[i].getFullPath();
					}
				}
			}
		}
		return null;
	}
}