/*******************************************************************************
 * Copyright (c) 2000, 2005 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.jdt.internal.junit.util;

import java.lang.reflect.InvocationTargetException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Status;
import org.eclipse.core.runtime.SubProgressMonitor;

import org.eclipse.core.resources.IResource;

import org.eclipse.jface.operation.IRunnableContext;
import org.eclipse.jface.operation.IRunnableWithProgress;

import org.eclipse.ui.IFileEditorInput;
import org.eclipse.ui.PlatformUI;

import org.eclipse.jdt.core.Flags;
import org.eclipse.jdt.core.IClassFile;
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.IPackageFragmentRoot;
import org.eclipse.jdt.core.IRegion;
import org.eclipse.jdt.core.ISourceReference;
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.jdt.core.search.IJavaSearchConstants;
import org.eclipse.jdt.core.search.IJavaSearchScope;
import org.eclipse.jdt.core.search.SearchEngine;
import org.eclipse.jdt.core.search.SearchMatch;
import org.eclipse.jdt.core.search.SearchParticipant;
import org.eclipse.jdt.core.search.SearchPattern;
import org.eclipse.jdt.core.search.SearchRequestor;

import org.eclipse.jdt.launching.IJavaLaunchConfigurationConstants;

import org.eclipse.jdt.internal.junit.ui.JUnitMessages;
import org.eclipse.jdt.internal.junit.ui.JUnitPlugin;

/**
 * Custom Search engine for suite() methods
 */
public class TestSearchEngine {

	private static class JUnitSearchResultCollector extends SearchRequestor {
		List fList;
		Set fFailed= new HashSet();
		Set fMatches= new HashSet();
		
		public JUnitSearchResultCollector(List list) {
			fList= list;
		}
		
		public void acceptSearchMatch(SearchMatch match) throws CoreException {
			Object enclosingElement= match.getElement();
			if (!(enclosingElement instanceof IMethod)) 
				return;
			
			IMethod method= (IMethod)enclosingElement;		
			
			IType declaringType= method.getDeclaringType();
			if (fMatches.contains(declaringType) || fFailed.contains(declaringType))
				return;
			if (!hasSuiteMethod(declaringType) && !isTestType(declaringType)) {
				fFailed.add(declaringType);
				return;
			}
			fMatches.add(declaringType);
		}
		
		public void endReporting() {
			fList.addAll(fMatches);
		}
	}
	
	private List searchMethod(IProgressMonitor pm, final IJavaSearchScope scope) throws CoreException {
		final List typesFound= new ArrayList(200);	
		searchMethod(typesFound, scope, pm);
		return typesFound;	
	}

	private List searchMethod(final List v, IJavaSearchScope scope, final IProgressMonitor progressMonitor) throws CoreException {		
		SearchRequestor requestor= new JUnitSearchResultCollector(v);
		int matchRule= SearchPattern.R_EXACT_MATCH | SearchPattern.R_CASE_SENSITIVE | SearchPattern.R_ERASURE_MATCH;
		SearchPattern suitePattern= SearchPattern.createPattern("suite() Test", IJavaSearchConstants.METHOD, IJavaSearchConstants.DECLARATIONS, matchRule); //$NON-NLS-1$
		SearchParticipant[] participants= new SearchParticipant[] {SearchEngine.getDefaultSearchParticipant()};
		new SearchEngine().search(suitePattern, participants, scope, requestor, progressMonitor); 
		return v;
	}
	
	public static IType[] findTests(IRunnableContext context, final Object[] elements) throws InvocationTargetException, InterruptedException {
		final Set result= new HashSet();
		
			if (elements.length > 0) {
				IRunnableWithProgress runnable= new IRunnableWithProgress() {
					public void run(IProgressMonitor pm) throws InterruptedException {
						doFindTests(elements, result, pm);
					}
				};
				context.run(true, true, runnable);			
			}
			return (IType[]) result.toArray(new IType[result.size()]) ;
	}

	public static IType[] findTests(final Object[] elements) throws InvocationTargetException, InterruptedException{
		final Set result= new HashSet();
	
		if (elements.length > 0) {
			IRunnableWithProgress runnable= new IRunnableWithProgress() {
				public void run(IProgressMonitor pm) throws InterruptedException {
					doFindTests(elements, result, pm);
				}
			};
			PlatformUI.getWorkbench().getProgressService().busyCursorWhile(runnable);			
		}
		return (IType[]) result.toArray(new IType[result.size()]) ;
	}
	
	public static void doFindTests(Object[] elements, Set result, IProgressMonitor pm) throws InterruptedException {
		int nElements= elements.length;
		pm.beginTask(JUnitMessages.TestSearchEngine_message_searching, nElements);  
		try {
			for (int i= 0; i < nElements; i++) {
				try {
					collectTypes(elements[i], new SubProgressMonitor(pm, 1), result);
				} catch (CoreException e) {
					JUnitPlugin.log(e.getStatus());
				}
				if (pm.isCanceled()) {
					throw new InterruptedException();
				}
			}
		} finally {
			pm.done();
		}
	}


	private static void collectTypes(Object element, IProgressMonitor pm, Set result) throws CoreException/*, InvocationTargetException*/ {
		pm.beginTask(JUnitMessages.TestSearchEngine_message_searching, 10);  
	    element= computeScope(element);
	    try {
			while((element instanceof ISourceReference) && !(element instanceof ICompilationUnit)) {
				if(element instanceof IType) {
					if (hasSuiteMethod((IType)element) || isTestType((IType)element)) {
						result.add(element);
						return;
					}
				}
				element= ((IJavaElement)element).getParent();
			}
			if (element instanceof ICompilationUnit) {
				ICompilationUnit cu= (ICompilationUnit)element;
				IType[] types= cu.getAllTypes();
	
				for (int i= 0; i < types.length; i++) {
					if (hasSuiteMethod(types[i])  || isTestType(types[i]))
						result.add(types[i]);
				}
			} 
			else if (element instanceof IJavaElement) {
			    List testCases= findTestCases((IJavaElement)element, new SubProgressMonitor(pm, 7));
				List suiteMethods= searchSuiteMethods(new SubProgressMonitor(pm, 3), (IJavaElement)element);			
				while (!suiteMethods.isEmpty()) {
					if (!testCases.contains(suiteMethods.get(0))) {
						testCases.add(suiteMethods.get(0));
					}
					suiteMethods.remove(0);
				}
				result.addAll(testCases);
			}
	    } finally {
	        pm.done();
	    }
	}
	
	private static List findTestCases(IJavaElement element, IProgressMonitor pm) throws JavaModelException {
		List found = new ArrayList();
		IJavaProject javaProject= element.getJavaProject();

		IType testCaseType = testCaseType(javaProject); 
		if (testCaseType == null)
			return found;
		
		IType[] subtypes= javaProject.newTypeHierarchy(testCaseType, getRegion(element), pm).getAllSubtypes(testCaseType);
			
		if (subtypes == null)
		    throw new JavaModelException(new CoreException(new Status(IStatus.ERROR, JUnitPlugin.PLUGIN_ID, IJavaLaunchConfigurationConstants.ERR_UNSPECIFIED_MAIN_TYPE, JUnitMessages.JUnitBaseLaunchConfiguration_error_notests, null))); 

		for (int i = 0; i < subtypes.length; i++) {
		    try {
		        if (hasValidModifiers(subtypes[i]))
		            found.add(subtypes[i]);
		    } catch (JavaModelException e) {
		        JUnitPlugin.log(e.getStatus());
		    }
		}
		return found;
	}

	private static IType testCaseType(IJavaProject javaProject) {
		try {
			return javaProject.findType("junit.framework.TestCase"); //$NON-NLS-1$
		} catch (JavaModelException e) {
			JUnitPlugin.log(e.getStatus());
			return null;
		} 
	}
	
	private static IRegion getRegion(IJavaElement element) throws JavaModelException{
		IRegion result= JavaCore.newRegion();
		if (element.getElementType() == IJavaElement.JAVA_PROJECT) {
			// for projects only add the contained source folders
			IPackageFragmentRoot[] roots= ((IJavaProject) element).getPackageFragmentRoots();
			for (int i= 0; i < roots.length; i++) {
				if (!roots[i].isExternal()) {
					result.add(roots[i]);
				}
			}
		} else {
			result.add(element);
		}
		return result;
	}

	private static Object computeScope(Object element) throws JavaModelException {
		if (element instanceof IFileEditorInput)
			element= ((IFileEditorInput)element).getFile();
		if (element instanceof IResource)
			element= JavaCore.create((IResource)element);
		if (element instanceof IClassFile) {
			IClassFile cf= (IClassFile)element;
			element= cf.getType();
		}
		return element;
	}
	
	private static List searchSuiteMethods(IProgressMonitor pm, IJavaElement element) throws CoreException {	
		// fix for bug 36449  JUnit should constrain tests to selected project [JUnit]
		IJavaSearchScope scope= SearchEngine.createJavaSearchScope(new IJavaElement[] { element },
				IJavaSearchScope.SOURCES);
		TestSearchEngine searchEngine= new TestSearchEngine(); 
		return searchEngine.searchMethod(pm, scope);
	}
		
	public static boolean hasSuiteMethod(IType type) throws JavaModelException {
		IMethod method= type.getMethod("suite", new String[0]); //$NON-NLS-1$
		if (method == null || !method.exists()) 
			return false;
		
		if (!Flags.isStatic(method.getFlags()) ||	
			!Flags.isPublic(method.getFlags()) ||			
			!Flags.isPublic(method.getDeclaringType().getFlags())) { 
			return false;
		}
		if (!Signature.getSimpleName(Signature.toString(method.getReturnType())).equals(JUnitPlugin.SIMPLE_TEST_INTERFACE_NAME)) {
			return false;
		}
		return true;
	}
	
	private static boolean isTestType(IType type) throws JavaModelException {
	    if (!hasValidModifiers(type))
		    return false;
		
		IType[] interfaces= type.newSupertypeHierarchy(null).getAllSuperInterfaces(type);
		for (int i= 0; i < interfaces.length; i++)
			if(interfaces[i].getFullyQualifiedName('.').equals(JUnitPlugin.TEST_INTERFACE_NAME))
				return true;
		return false;
	}
	
	private static boolean hasValidModifiers(IType type) throws JavaModelException {
		if (Flags.isAbstract(type.getFlags())) 
			return false;
		if (!Flags.isPublic(type.getFlags())) 
			return false;
		return true;
	}

	public static boolean isTestImplementor(IType type) throws JavaModelException {
		ITypeHierarchy typeHier= type.newSupertypeHierarchy(null);
		IType[] superInterfaces= typeHier.getAllInterfaces();
		for (int i= 0; i < superInterfaces.length; i++) {
			if (superInterfaces[i].getFullyQualifiedName('.').equals(JUnitPlugin.TEST_INTERFACE_NAME))
				return true;
		}
		return false;
	}

	public static boolean isTestOrTestSuite(IType type) throws JavaModelException {
		return hasSuiteMethod(type) || isTestType(type);
	}

	public static boolean hasTestCaseType(IJavaProject javaProject) {
		return testCaseType(javaProject) != null;
	}

}