Copyright (c) 2019 IBM Corporation and others.
This program and the accompanying materials
are made available under the terms of the Eclipse Public License 2.0
which accompanies this distribution, and is available at
https://www.eclipse.org/legal/epl-2.0/
SPDX-License-Identifier: EPL-2.0
Contributors:
    IBM Corporation - initial API and implementation
    Red Hat Inc. - created based on PotentialProgrammingProblemsFix
/*******************************************************************************
 * Copyright (c) 2019 IBM Corporation and others.
 *
 * This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License 2.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Red Hat Inc. - created based on PotentialProgrammingProblemsFix
 *******************************************************************************/
package org.eclipse.jdt.internal.corext.fix;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashSet;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import java.util.Random;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.NullProgressMonitor;
import org.eclipse.core.runtime.OperationCanceledException;
import org.eclipse.core.runtime.SubProgressMonitor;

import org.eclipse.core.resources.IncrementalProjectBuilder;

import org.eclipse.ltk.core.refactoring.RefactoringStatus;

import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IField;
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.JavaModelException;
import org.eclipse.jdt.core.compiler.IProblem;
import org.eclipse.jdt.core.dom.ASTNode;
import org.eclipse.jdt.core.dom.ASTParser;
import org.eclipse.jdt.core.dom.AbstractTypeDeclaration;
import org.eclipse.jdt.core.dom.AnonymousClassDeclaration;
import org.eclipse.jdt.core.dom.ClassInstanceCreation;
import org.eclipse.jdt.core.dom.CompilationUnit;
import org.eclipse.jdt.core.dom.IBinding;
import org.eclipse.jdt.core.dom.ITypeBinding;
import org.eclipse.jdt.core.dom.Name;
import org.eclipse.jdt.core.dom.NameQualifiedType;
import org.eclipse.jdt.core.dom.ParameterizedType;
import org.eclipse.jdt.core.dom.QualifiedName;
import org.eclipse.jdt.core.dom.QualifiedType;
import org.eclipse.jdt.core.dom.SimpleName;
import org.eclipse.jdt.core.dom.SimpleType;
import org.eclipse.jdt.core.dom.Type;
import org.eclipse.jdt.core.dom.VariableDeclarationFragment;
import org.eclipse.jdt.core.dom.rewrite.ASTRewrite;
import org.eclipse.jdt.core.manipulation.ICleanUpFixCore;

import org.eclipse.jdt.internal.core.manipulation.util.BasicElementLabels;
import org.eclipse.jdt.internal.corext.dom.IASTSharedValues;
import org.eclipse.jdt.internal.corext.refactoring.util.JavaStatusContext;
import org.eclipse.jdt.internal.corext.util.Messages;

import org.eclipse.jdt.internal.ui.text.correction.IProblemLocationCore;
import org.eclipse.jdt.internal.ui.text.correction.ProblemLocationCore;
import org.eclipse.jdt.internal.ui.text.correction.SerialVersionHashOperationCore;


public class PotentialProgrammingProblemsFixCore extends CompilationUnitRewriteOperationsFixCore {

	
Name of the serializable class /** Name of the serializable class */
	private static final String SERIALIZABLE_NAME= "java.io.Serializable"; //$NON-NLS-1$

	
The name of the serial version field /** The name of the serial version field */
	private static final String NAME_FIELD= "serialVersionUID"; //$NON-NLS-1$

	public interface ISerialVersionFixContext {
		public RefactoringStatus initialize(IProgressMonitor monitor) throws CoreException;
		public Long getSerialVersionId(ITypeBinding binding);
	}

	public static class SerialVersionHashContext implements ISerialVersionFixContext {

		private final IJavaProject fProject;
		private final ICompilationUnit[] fCompilationUnits;
		private final Hashtable<String, Long> fIdsTable;

		public SerialVersionHashContext(IJavaProject project, ICompilationUnit[] compilationUnits) {
			fProject= project;
			fCompilationUnits= compilationUnits;
			fIdsTable= new Hashtable<>();
        }

		@Override
		public RefactoringStatus initialize(IProgressMonitor monitor) throws CoreException {
			if (monitor == null)
				monitor= new NullProgressMonitor();

			RefactoringStatus result;
			try {
				monitor.beginTask("", 10); //$NON-NLS-1$

				IType[] types= findTypesWithMissingUID(fProject, fCompilationUnits, new SubProgressMonitor(monitor, 1));
				if (types.length == 0)
					return new RefactoringStatus();

				fProject.getProject().build(IncrementalProjectBuilder.INCREMENTAL_BUILD, new SubProgressMonitor(monitor, 60));
				if (monitor.isCanceled())
					throw new OperationCanceledException();

				result= new RefactoringStatus();
				ASTParser parser= ASTParser.newParser(IASTSharedValues.SHARED_AST_LEVEL);
				parser.setProject(fProject);
				IBinding[] bindings= parser.createBindings(types, new SubProgressMonitor(monitor, 1));
				for (int i= 0; i < bindings.length; i++) {
					IBinding curr= bindings[i];
					if (curr instanceof ITypeBinding) {
						ITypeBinding typeBinding= (ITypeBinding) curr;
						try {
							Long id= SerialVersionHashOperationCore.calculateSerialVersionId(typeBinding, new SubProgressMonitor(monitor, 1));
							if (id != null) {
								setSerialVersionId(typeBinding, id);
							} else {
							   	result.addWarning(Messages.format(FixMessages.PotentialProgrammingProblemsFix_calculatingUIDFailed_unknown, BasicElementLabels.getJavaElementName(typeBinding.getName())));
							}
						} catch (IOException e) {
						   	result.addWarning(Messages.format(FixMessages.PotentialProgrammingProblemsFix_calculatingUIDFailed_exception, new String[] { BasicElementLabels.getJavaElementName(typeBinding.getName()), e.getLocalizedMessage()}), JavaStatusContext.create(types[i]));
				        } catch (CoreException e) {
						   	result.addWarning(Messages.format(FixMessages.PotentialProgrammingProblemsFix_calculatingUIDFailed_exception, new String[] { BasicElementLabels.getJavaElementName(typeBinding.getName()), e.getLocalizedMessage()}), JavaStatusContext.create(types[i]));
				        }
					}
				}
			} finally {
				monitor.done();
			}
			return result;
		}

		@Override
		public Long getSerialVersionId(ITypeBinding binding) {
			return fIdsTable.get(binding.getKey());
		}

		protected void setSerialVersionId(ITypeBinding binding, Long id) {
			fIdsTable.put(binding.getKey(), id);
		}

		private IType[] findTypesWithMissingUID(IJavaProject project, ICompilationUnit[] compilationUnits, IProgressMonitor monitor) throws CoreException {
			try {
				monitor.beginTask("", compilationUnits.length); //$NON-NLS-1$

				IType serializable= project.findType(SERIALIZABLE_NAME);

				List<IType> types= new ArrayList<>();

				if (compilationUnits.length > 500) {
					//500 is a guess. Building the type hierarchy on serializable is very expensive
					//depending on how many subtypes exit in the project.

					HashSet<ICompilationUnit> cus= new HashSet<>();
					cus.addAll(Arrays.asList(compilationUnits));

					monitor.subTask(Messages.format(FixMessages.Java50Fix_SerialVersion_CalculateHierarchy_description, SERIALIZABLE_NAME));
					ITypeHierarchy hierarchy1= serializable.newTypeHierarchy(project, new SubProgressMonitor(monitor, compilationUnits.length));
					IType[] allSubtypes1= hierarchy1.getAllSubtypes(serializable);
					addTypes(allSubtypes1, cus, types);
				} else {
					monitor.subTask(FixMessages.Java50Fix_InitializeSerialVersionId_subtask_description);
                    for (int i= 0; i < compilationUnits.length; i++) {
                    	collectChildrenWithMissingSerialVersionId(compilationUnits[i].getChildren(), serializable, types);
                    	if (monitor.isCanceled())
                    		throw new OperationCanceledException();
                    	monitor.worked(1);
                    }
				}

				return types.toArray(new IType[types.size()]);
			} finally {
				monitor.done();
			}
		}

		private void addTypes(IType[] allSubtypes, HashSet<ICompilationUnit> cus, List<IType> types) throws JavaModelException {
			for (int i= 0; i < allSubtypes.length; i++) {
				IType type= allSubtypes[i];

				IField field= type.getField(NAME_FIELD);
				if (!field.exists()) {
					if (type.isClass() && cus.contains(type.getCompilationUnit())){
						types.add(type);
					}
				}
			}
		}

		private void collectChildrenWithMissingSerialVersionId(IJavaElement[] children, IType serializable, List<IType> result) throws JavaModelException {
			for (int i= 0; i < children.length; i++) {
				IJavaElement child= children[i];
				if (child instanceof IType) {
					IType type= (IType)child;

					if (type.isClass()) {
    					IField field= type.getField(NAME_FIELD);
    					if (!field.exists()) {
    						ITypeHierarchy hierarchy= type.newSupertypeHierarchy(new NullProgressMonitor());
    						IType[] interfaces= hierarchy.getAllSuperInterfaces(type);
    						for (int j= 0; j < interfaces.length; j++) {
    							if (interfaces[j].equals(serializable)) {
    								result.add(type);
    								break;
    							}
    						}
						}
					}

					collectChildrenWithMissingSerialVersionId(type.getChildren(), serializable, result);
				} else if (child instanceof IMethod) {
					collectChildrenWithMissingSerialVersionId(((IMethod)child).getChildren(), serializable, result);
				} else if (child instanceof IField) {
					collectChildrenWithMissingSerialVersionId(((IField)child).getChildren(), serializable, result);
				}
			}
		}
	}

	public static class SerialVersionHashBatchOperation extends AbstractSerialVersionOperationCore {

		private final ISerialVersionFixContext fContext;

		protected SerialVersionHashBatchOperation(ICompilationUnit unit, ASTNode[] node, ISerialVersionFixContext context) {
			super(unit, node);
			fContext= context;
		}

		@Override
		protected boolean addInitializer(VariableDeclarationFragment fragment, ASTNode declarationNode) {
			ITypeBinding typeBinding= getTypeBinding(declarationNode);
			if (typeBinding == null)
				return false;

			Long id= fContext.getSerialVersionId(typeBinding);
			if (id == null)
				return false;

			fragment.setInitializer(fragment.getAST().newNumberLiteral(id.toString() + LONG_SUFFIX));
			return true;
		}

		@Override
		protected void addLinkedPositions(ASTRewrite rewrite, VariableDeclarationFragment fragment, LinkedProposalModelCore positionGroups) {}

	}

	private static ISerialVersionFixContext fCurrentContext;

	public static IProposableFix[] createMissingSerialVersionFixes(CompilationUnit compilationUnit, IProblemLocationCore problem) {
		if (problem.getProblemId() != IProblem.MissingSerialVersion)
			return null;

		final ICompilationUnit unit= (ICompilationUnit)compilationUnit.getJavaElement();
		if (unit == null)
			return null;

		final SimpleName simpleName= getSelectedName(compilationUnit, problem);
		if (simpleName == null)
			return null;

		ASTNode declaringNode= getDeclarationNode(simpleName);
		if (declaringNode == null)
			return null;

		SerialVersionDefaultOperationCore defop= new SerialVersionDefaultOperationCore(unit, new ASTNode[] {declaringNode});
		IProposableFix fix1= new PotentialProgrammingProblemsFixCore(FixMessages.Java50Fix_SerialVersion_default_description, compilationUnit, new CompilationUnitRewriteOperation[] {defop});

		SerialVersionHashOperationCore hashop= new SerialVersionHashOperationCore(unit, new ASTNode[] {declaringNode});
		IProposableFix fix2= new PotentialProgrammingProblemsFixCore(FixMessages.Java50Fix_SerialVersion_hash_description, compilationUnit, new CompilationUnitRewriteOperation[] {hashop});

		return new IProposableFix[] {fix1, fix2};
	}

	public static RefactoringStatus checkPreConditions(IJavaProject project, ICompilationUnit[] compilationUnits, IProgressMonitor monitor,
			boolean calculatedId,
			boolean defaultId,
			boolean randomId) throws CoreException {

		if (defaultId) {
			fCurrentContext= new ISerialVersionFixContext() {
				@Override
				public Long getSerialVersionId(ITypeBinding binding) {
					return Long.valueOf(1);
				}
				@Override
				public RefactoringStatus initialize(IProgressMonitor pm) throws CoreException {
	                return new RefactoringStatus();
                }
			};
			return fCurrentContext.initialize(monitor);
		} else if (randomId) {
			fCurrentContext= new ISerialVersionFixContext() {
				private Random rng;
				@Override
				public Long getSerialVersionId(ITypeBinding binding) {
					return Long.valueOf(rng.nextLong());
				}
				@Override
				public RefactoringStatus initialize(IProgressMonitor pm) throws CoreException {
					rng= new Random((new Date()).getTime());
	                return new RefactoringStatus();
                }
			};
			return fCurrentContext.initialize(monitor);
		} else if (calculatedId) {
			fCurrentContext= new SerialVersionHashContext(project, compilationUnits);
			return fCurrentContext.initialize(monitor);
		} else {
			return new RefactoringStatus();
		}
    }

	public static RefactoringStatus checkPostConditions(IProgressMonitor monitor) {
		if (monitor != null)
			monitor.done();

		fCurrentContext= null;
	    return new RefactoringStatus();
    }

	public static ICleanUpFixCore createCleanUp(CompilationUnit compilationUnit, boolean addSerialVersionIds) {

		IProblem[] problems= compilationUnit.getProblems();
		IProblemLocationCore[] locations= new IProblemLocationCore[problems.length];
		for (int i= 0; i < problems.length; i++) {
			locations[i]= new ProblemLocationCore(problems[i]);
		}
		return createCleanUp(compilationUnit, locations, addSerialVersionIds);
	}

	public static ICleanUpFixCore createCleanUp(CompilationUnit compilationUnit, IProblemLocationCore[] problems, boolean addSerialVersionIds) {
		if (addSerialVersionIds) {

			final ICompilationUnit unit= (ICompilationUnit)compilationUnit.getJavaElement();
			if (unit == null)
				return null;

			List<ASTNode> declarationNodes= new ArrayList<>();
			for (int i= 0; i < problems.length; i++) {
				if (problems[i].getProblemId() == IProblem.MissingSerialVersion) {
					final SimpleName simpleName= getSelectedName(compilationUnit, problems[i]);
					if (simpleName != null) {
						ASTNode declarationNode= getDeclarationNode(simpleName);
						if (declarationNode != null) {
							declarationNodes.add(declarationNode);
						}
					}
				}
			}
			if (declarationNodes.size() == 0)
				return null;

			for (Iterator<ASTNode> iter= declarationNodes.iterator(); iter.hasNext();) {
	            ASTNode declarationNode= iter.next();
	            ITypeBinding binding= getTypeBinding(declarationNode);
	            if (fCurrentContext.getSerialVersionId(binding) != null) {
	            	SerialVersionHashBatchOperation op= new SerialVersionHashBatchOperation(unit, declarationNodes.toArray(new ASTNode[declarationNodes.size()]), fCurrentContext);
	    			return new PotentialProgrammingProblemsFixCore(FixMessages.PotentialProgrammingProblemsFix_add_id_change_name, compilationUnit, new CompilationUnitRewriteOperation[] {op});
	            }
            }
		}
		return null;
	}

	public static SimpleName getSelectedName(CompilationUnit compilationUnit, IProblemLocationCore problem) {
		final ASTNode selection= problem.getCoveredNode(compilationUnit);
		if (selection == null)
			return null;

		Name name= null;
		if (selection instanceof SimpleType) {
			name= ((SimpleType) selection).getName();
		} else if (selection instanceof NameQualifiedType) {
			name= ((NameQualifiedType) selection).getName();
		} else if (selection instanceof QualifiedType) {
			name= ((QualifiedType) selection).getName();
		} else if (selection instanceof ParameterizedType) {
			final ParameterizedType type= (ParameterizedType) selection;
			final Type raw= type.getType();
			if (raw instanceof SimpleType)
				name= ((SimpleType) raw).getName();
			else if (raw instanceof NameQualifiedType)
				name= ((NameQualifiedType) raw).getName();
			else if (raw instanceof QualifiedType)
				name= ((QualifiedType) raw).getName();
		} else if (selection instanceof Name) {
			name= (Name) selection;
		}
		if (name == null)
			return null;

		if (name.isSimpleName()) {
			return (SimpleName)name;
		} else {
			return ((QualifiedName)name).getName();
		}
	}

	
Returns the declaration node for the originally selected node.
Params:
name – the name of the node
Returns:
the declaration node/**
	 * Returns the declaration node for the originally selected node.
	 * @param name the name of the node
	 *
	 * @return the declaration node
	 */
	public static ASTNode getDeclarationNode(SimpleName name) {
		ASTNode parent= name.getParent();
		if (!(parent instanceof AbstractTypeDeclaration)) {

			parent= parent.getParent();
			if (parent instanceof ParameterizedType || parent instanceof Type)
				parent= parent.getParent();
			if (parent instanceof ClassInstanceCreation) {

				final ClassInstanceCreation creation= (ClassInstanceCreation) parent;
				parent= creation.getAnonymousClassDeclaration();
			}
		}
		return parent;
	}

	
Returns the type binding of the class declaration node.
Params:
parent – the node to get the type for
Returns:
the type binding/**
	 * Returns the type binding of the class declaration node.
	 *
	 * @param parent the node to get the type for
	 * @return the type binding
	 */
	public static ITypeBinding getTypeBinding(final ASTNode parent) {
		if (parent instanceof AbstractTypeDeclaration) {
			final AbstractTypeDeclaration declaration= (AbstractTypeDeclaration) parent;
			return declaration.resolveBinding();
		} else if (parent instanceof AnonymousClassDeclaration) {
			final AnonymousClassDeclaration declaration= (AnonymousClassDeclaration) parent;
			return declaration.resolveBinding();
		} else if (parent instanceof ParameterizedType) {
			final ParameterizedType type= (ParameterizedType) parent;
			return type.resolveBinding();
		}
		return null;
	}

	protected PotentialProgrammingProblemsFixCore(String name, CompilationUnit compilationUnit, CompilationUnitRewriteOperation[] fixRewriteOperations) {
		super(name, compilationUnit, fixRewriteOperations);
	}
}