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. - copied and modified for use in jdt.core.manipulation
/*******************************************************************************
 * 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. - copied and modified for use in jdt.core.manipulation
 *******************************************************************************/
package org.eclipse.jdt.internal.corext.fix;

import java.util.ArrayList;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.CoreException;

import org.eclipse.text.edits.TextEditGroup;

import org.eclipse.jdt.core.dom.AST;
import org.eclipse.jdt.core.dom.ASTNode;
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.EnumConstantDeclaration;
import org.eclipse.jdt.core.dom.Modifier;
import org.eclipse.jdt.core.dom.TypeDeclaration;
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.refactoring.structure.CompilationUnitRewrite;
import org.eclipse.jdt.internal.corext.util.Messages;

import org.eclipse.jdt.internal.ui.text.correction.CorrectionMessages;
import org.eclipse.jdt.internal.ui.text.correction.IProblemLocationCore;

public class UnimplementedCodeFixCore extends CompilationUnitRewriteOperationsFixCore {

	public static final class MakeTypeAbstractOperation extends CompilationUnitRewriteOperation {

		private final TypeDeclaration fTypeDeclaration;

		public MakeTypeAbstractOperation(TypeDeclaration typeDeclaration) {
			fTypeDeclaration= typeDeclaration;
		}

		@Override
		public void rewriteAST(CompilationUnitRewrite cuRewrite, LinkedProposalModelCore linkedProposalPositions) throws CoreException {
			AST ast= cuRewrite.getAST();
			ASTRewrite rewrite= cuRewrite.getASTRewrite();
			Modifier newModifier= ast.newModifier(Modifier.ModifierKeyword.ABSTRACT_KEYWORD);
			TextEditGroup textEditGroup= createTextEditGroup(CorrectionMessages.UnimplementedCodeFix_TextEditGroup_label, cuRewrite);
			rewrite.getListRewrite(fTypeDeclaration, TypeDeclaration.MODIFIERS2_PROPERTY).insertLast(newModifier, textEditGroup);

			LinkedProposalPositionGroupCore group= new LinkedProposalPositionGroupCore("modifier"); //$NON-NLS-1$
			group.addPosition(rewrite.track(newModifier), !linkedProposalPositions.hasLinkedPositions());
			linkedProposalPositions.addPositionGroup(group);
		}
	}

	public static ICleanUpFixCore createCleanUp(CompilationUnit root, boolean addMissingMethod, boolean makeTypeAbstract, IProblemLocationCore[] problems) {
		Assert.isLegal(!addMissingMethod || !makeTypeAbstract);
		if (!addMissingMethod && !makeTypeAbstract)
			return null;

		if (problems.length == 0)
			return null;

		ArrayList<CompilationUnitRewriteOperation> operations= new ArrayList<>();

		for (IProblemLocationCore problem : problems) {
			if (addMissingMethod) {
				ASTNode typeNode= getSelectedTypeNode(root, problem);
				if (typeNode != null && !isTypeBindingNull(typeNode)) {
					operations.add(new AddUnimplementedMethodsOperation(typeNode));
				}
			} else {
				ASTNode typeNode= getSelectedTypeNode(root, problem);
				if (typeNode instanceof TypeDeclaration) {
					operations.add(new MakeTypeAbstractOperation((TypeDeclaration) typeNode));
				}
			}
		}

		if (operations.isEmpty())
			return null;

		String label;
		if (addMissingMethod) {
			label= CorrectionMessages.UnimplementedMethodsCorrectionProposal_description;
		} else {
			label= CorrectionMessages.UnimplementedCodeFix_MakeAbstractFix_label;
		}
		return new UnimplementedCodeFixCore(label, root, operations.toArray(new CompilationUnitRewriteOperation[operations.size()]));
	}

	public static IProposableFix createAddUnimplementedMethodsFix(final CompilationUnit root, IProblemLocationCore problem) {
		ASTNode typeNode= getSelectedTypeNode(root, problem);
		if (typeNode == null)
			return null;

		if (isTypeBindingNull(typeNode))
			return null;

		AddUnimplementedMethodsOperation operation= new AddUnimplementedMethodsOperation(typeNode);
		if (operation.getMethodsToImplement().length > 0) {
			return new UnimplementedCodeFixCore(CorrectionMessages.UnimplementedMethodsCorrectionProposal_description, root, new CompilationUnitRewriteOperation[] { operation });
		}
		return null;
	}

	public static UnimplementedCodeFixCore createMakeTypeAbstractFix(CompilationUnit root, IProblemLocationCore problem) {
		ASTNode typeNode= getSelectedTypeNode(root, problem);
		if (!(typeNode instanceof TypeDeclaration))
			return null;

		TypeDeclaration typeDeclaration= (TypeDeclaration) typeNode;
		MakeTypeAbstractOperation operation= new MakeTypeAbstractOperation(typeDeclaration);

		String label= Messages.format(CorrectionMessages.ModifierCorrectionSubProcessor_addabstract_description, BasicElementLabels.getJavaElementName(typeDeclaration.getName().getIdentifier()));
		return new UnimplementedCodeFixCore(label, root, new CompilationUnitRewriteOperation[] { operation });
	}

	public static ASTNode getSelectedTypeNode(CompilationUnit root, IProblemLocationCore problem) {
		ASTNode selectedNode= problem.getCoveringNode(root);
		if (selectedNode == null)
			return null;

		if (selectedNode.getNodeType() == ASTNode.ANONYMOUS_CLASS_DECLARATION) { // bug 200016
			selectedNode= selectedNode.getParent();
		}

		if (selectedNode.getLocationInParent() == EnumConstantDeclaration.NAME_PROPERTY) {
			selectedNode= selectedNode.getParent();
		}
		if (selectedNode.getNodeType() == ASTNode.SIMPLE_NAME && selectedNode.getParent() instanceof AbstractTypeDeclaration) {
			return selectedNode.getParent();
		} else if (selectedNode.getNodeType() == ASTNode.CLASS_INSTANCE_CREATION) {
			return ((ClassInstanceCreation) selectedNode).getAnonymousClassDeclaration();
		} else if (selectedNode.getNodeType() == ASTNode.ENUM_CONSTANT_DECLARATION) {
			EnumConstantDeclaration enumConst= (EnumConstantDeclaration) selectedNode;
			if (enumConst.getAnonymousClassDeclaration() != null)
				return enumConst.getAnonymousClassDeclaration();
			return enumConst;
		} else {
			return null;
		}
	}

	private static boolean isTypeBindingNull(ASTNode typeNode) {
		if (typeNode instanceof AbstractTypeDeclaration) {
			AbstractTypeDeclaration abstractTypeDeclaration= (AbstractTypeDeclaration) typeNode;
			if (abstractTypeDeclaration.resolveBinding() == null)
				return true;

			return false;
		} else if (typeNode instanceof AnonymousClassDeclaration) {
			AnonymousClassDeclaration anonymousClassDeclaration= (AnonymousClassDeclaration) typeNode;
			if (anonymousClassDeclaration.resolveBinding() == null)
				return true;

			return false;
		} else if (typeNode instanceof EnumConstantDeclaration) {
			return false;
		} else {
			return true;
		}
	}

	public UnimplementedCodeFixCore(String name, CompilationUnit compilationUnit, CompilationUnitRewriteOperation[] fixRewriteOperations) {
		super(name, compilationUnit, fixRewriteOperations);
	}
}