/*******************************************************************************
 * Copyright (c) 2005 BEA Systems, Inc. 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:
 *    Daniel R. Somerfield - initial API and implementation
 *******************************************************************************/
package org.eclipse.jst.server.core.internal.cactus;

import java.util.Arrays;
import java.util.Iterator;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.runtime.IAdaptable;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.IType;
import org.eclipse.jdt.core.ITypeHierarchy;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.core.Signature;
import org.eclipse.jst.server.core.internal.Trace;
import org.eclipse.wst.server.core.IModule;
import org.eclipse.wst.server.core.IModuleArtifact;
import org.eclipse.wst.server.core.ServerUtil;
import org.eclipse.wst.server.core.model.ModuleArtifactAdapterDelegate;
/**
 *
 */
public class CactusModuleArtifactAdapterDelegate extends ModuleArtifactAdapterDelegate {
	private static final String SERVLET_TEST_CASE_TYPE = "org.apache.cactus.ServletTestCase";

	private static final String SUITE_METHOD = "suite";

	private static final String TEST_CLASS_NAME = "junit.framework.Test";

	public IModuleArtifact getModuleArtifact(Object obj) {
		String methodName = "";
		if (obj instanceof IMethod) {
			IMethod method = (IMethod) obj;
			methodName = method.getElementName();
			obj = method.getCompilationUnit();
		}
		if (obj instanceof IAdaptable) {
			IResource resource = (IResource) ((IAdaptable) obj).getAdapter(IResource.class);
			String testClassName = getClassNameForType(resource);
			if (testClassName != null) {
				String projectName = resource.getProject().getName();
				return new WebTestableResource(getModule(resource.getProject()), false,
						projectName, testClassName, methodName);
			}
		}
		return null;
	}

	private static String getClassNameForType(IResource resource) {
		if (resource == null)
			return null;
		
		if (!"java".equals(resource.getFileExtension()) && !"class".equals(resource.getFileExtension()))
			return null;
		
		try {
			IProject project = resource.getProject();
			IPath path = resource.getFullPath();
			if (path == null || !project.hasNature(JavaCore.NATURE_ID))
				return null;
			
			IJavaProject javaProject = (IJavaProject) project.getNature(JavaCore.NATURE_ID);
			if (!javaProject.isOpen())
				javaProject.open(new NullProgressMonitor());
			
			// output location may not be on classpath
			IPath outputPath = javaProject.getOutputLocation();
			if (outputPath != null
					&& "class".equals(path.getFileExtension()) && outputPath.isPrefixOf(path)) { //$NON-NLS-1$
				int count = outputPath.segmentCount();
				path = path.removeFirstSegments(count);
			}
			
			// remove initial part of classpath
			IClasspathEntry[] classPathEntry = javaProject.getResolvedClasspath(true);
			if (classPathEntry != null) {
				int size = classPathEntry.length;
				for (int i = 0; i < size; i++) {
					IPath classPath = classPathEntry[i].getPath();
					if (classPath.isPrefixOf(path)) {
						int count = classPath.segmentCount();
						path = path.removeFirstSegments(count);
						i += size;
					}
				}
			}
			
			// get java element
			IJavaElement javaElement = javaProject.findElement(path);
			IType[] types = getTypes(javaElement);
			if (types != null) {
				int size2 = types.length;
				for (int i = 0; i < size2; i++) {
					if (hasSuperclass(types[i]) || hasSuiteMethod(types[i]))
						return types[i].getFullyQualifiedName();
				}
			}
			return null;
		} catch (Exception e) {
			Trace.trace(Trace.WARNING, "Unexpected exception: " + e);
			return null;
		}
	}

	private static boolean hasSuiteMethod(IType type) throws JavaModelException {
		IMethod[] methods = type.getMethods();
		int size = methods.length;
		for (int i = 0; i < size; i++) {
			IMethod method = methods[i];
			if (method.getParameterNames().length == 0 && method.getElementName().equals(SUITE_METHOD)) {
				String returnType = getFullyQualifiedTypeForMangledType(method.getReturnType(), type);
				if (TEST_CLASS_NAME.equals(returnType))
					return true;
			}
		}
		return false;
	}

	private static IType[] getTypes(IJavaElement element) {
		try {
			if (element.getElementType() != IJavaElement.COMPILATION_UNIT)
				return null;
			return ((ICompilationUnit) element).getAllTypes();
		} catch (Exception e) {
			return null;
		}
	}

	private static boolean hasSuperclass(IType type) {
		try {
			ITypeHierarchy hierarchy = type.newSupertypeHierarchy(null);
			IType[] superClasses = hierarchy.getAllSuperclasses(type);
			int size = superClasses.length;
			for (int i = 0; i < size; i++) {
				if (SERVLET_TEST_CASE_TYPE.equals(superClasses[i].getFullyQualifiedName())) //$NON-NLS-1$
					return true;
			}
			return false;
		} catch (Exception e) {
			return false;
		}
	}

	protected static IModule getModule(IProject project) {
		IModule deployable = null;
		Iterator iterator = Arrays.asList(ServerUtil.getModules("jst.web")).iterator();
		while (iterator.hasNext()) {
			Object next = iterator.next();
			if (next instanceof IModule) {
				deployable = (IModule) next;
				if (deployable.getProject().equals(project))
					return deployable;
			}
		}
		return null;
	}

	private static String getFullyQualifiedTypeForMangledType(String type,
			IType declaringType) throws JavaModelException {
		type = Signature.toString(type);
		return getFullyQualifiedTypeForType(type, declaringType);
	}

	private static String getFullyQualifiedTypeForType(String type, IType declaringType)
			throws JavaModelException {
		String[][] resolvedTypes = declaringType.resolveType(type);
		// Are there legit cases where this would not be the case? We might need to check
		// for this and bomb out if the type cannot be unambigiously resolved
		if (resolvedTypes.length != 1)
			Trace.trace(Trace.WARNING, "The type cannot be unambigiously resolved. Need to handle this case");
		String[] resolvedType = resolvedTypes[0];
		StringBuffer buffer = new StringBuffer();
		for (int i = 0; i < resolvedType.length - 1; i++) {
			buffer.append(resolvedType[i]);
			buffer.append('.');
		}

		buffer.append(resolvedType[resolvedType.length - 1]);

		return buffer.toString();
	}
}