/*******************************************************************************
 * Copyright (c) 2007, 2008 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.corext.refactoring;

import org.eclipse.core.runtime.Assert;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;

import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.ResourcesPlugin;

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

import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IMethod;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.WorkingCopyOwner;

import org.eclipse.jdt.internal.corext.util.Messages;

import org.eclipse.jdt.ui.JavaElementLabels;

public class JavaRefactoringDescriptorUtil {
	/* TODO: share implementation with
	 * org.eclipse.jdt.internal.core.refactoring.descriptors.JavaRefactoringDescriptorUtil
	 */

	private JavaRefactoringDescriptorUtil(){}

	/**
	 * Predefined argument called <code>element&lt;Number&gt;</code>.
	 * <p>
	 * This argument should be used to describe the elements being refactored.
	 * The value of this argument does not necessarily have to uniquely identify
	 * the elements. However, it must be possible to uniquely identify the
	 * elements using the value of this argument in conjunction with the values
	 * of the other user-defined attributes.
	 * </p>
	 * <p>
	 * The element arguments are simply distinguished by appending a number to
	 * the argument name, e.g. element1. The indices of this argument are non
	 * zero-based.
	 * </p>
	 */
	public static final String ATTRIBUTE_ELEMENT= "element"; //$NON-NLS-1$

	/**
	 * Predefined argument called <code>input</code>.
	 * <p>
	 * This argument should be used to describe the element being refactored.
	 * The value of this argument does not necessarily have to uniquely identify
	 * the input element. However, it must be possible to uniquely identify the
	 * input element using the value of this argument in conjunction with the
	 * values of the other user-defined attributes.
	 * </p>
	 */
	public static final String ATTRIBUTE_INPUT= "input"; //$NON-NLS-1$

	/**
	 * Predefined argument called <code>name</code>.
	 * <p>
	 * This argument should be used to name the element being refactored. The
	 * value of this argument may be shown in the user interface.
	 * </p>
	 */
	public static final String ATTRIBUTE_NAME= "name"; //$NON-NLS-1$

	/**
	 * Predefined argument called <code>references</code>.
	 * <p>
	 * This argument should be used to describe whether references to the
	 * elements being refactored should be updated as well.
	 * </p>
	 */
	public static final String ATTRIBUTE_REFERENCES= "references"; //$NON-NLS-1$

	/**
	 * Predefined argument called <code>selection</code>.
	 * <p>
	 * This argument should be used to describe user input selections within a
	 * text file. The value of this argument has the format "offset length".
	 * </p>
	 */
	public static final String ATTRIBUTE_SELECTION= "selection"; //$NON-NLS-1$

	/**
	 * Converts the specified element to an input handle.
	 *
	 * @param project
	 *            the project, or <code>null</code> for the workspace
	 * @param element
	 *            the element
	 * @return a corresponding input handle
	 *         Note: if the given project is not the element's project, then the full handle is returned
	 */
	public static String elementToHandle(final String project, final IJavaElement element) {
		final String handle= element.getHandleIdentifier();
		if (project != null && ! (element instanceof IJavaProject)) {
			IJavaProject javaProject= element.getJavaProject();
			if (project.equals(javaProject.getElementName())) {
				final String id= javaProject.getHandleIdentifier();
				return handle.substring(id.length());
			}
		}
		return handle;
	}

	/**
	 * Converts an input handle back to the corresponding java element.
	 *
	 * @param project
	 *            the project, or <code>null</code> for the workspace
	 * @param handle
	 *            the input handle
	 * @return the corresponding java element, or <code>null</code> if no such
	 *         element exists
	 */
	public static IJavaElement handleToElement(final String project, final String handle) {
		return handleToElement(project, handle, true);
	}

	/**
	 * Converts an input handle back to the corresponding java element.
	 *
	 * @param project
	 *            the project, or <code>null</code> for the workspace
	 * @param handle
	 *            the input handle
	 * @param check
	 *            <code>true</code> to check for existence of the element,
	 *            <code>false</code> otherwise
	 * @return the corresponding java element, or <code>null</code> if no such
	 *         element exists
	 */
	public static IJavaElement handleToElement(final String project, final String handle, final boolean check) {
		return handleToElement(null, project, handle, check);
	}

	/**
	 * Converts an input handle back to the corresponding java element.
	 *
	 * @param owner
	 *            the working copy owner
	 * @param project
	 *            the project, or <code>null</code> for the workspace
	 * @param handle
	 *            the input handle
	 * @param check
	 *            <code>true</code> to check for existence of the element,
	 *            <code>false</code> otherwise
	 * @return the corresponding java element, or <code>null</code> if no such
	 *         element exists
	 */
	public static IJavaElement handleToElement(final WorkingCopyOwner owner, final String project, final String handle, final boolean check) {
		IJavaElement element= null;
		if (owner != null)
			element= JavaCore.create(handle, owner);
		else
			element= JavaCore.create(handle);
		if (element == null && project != null) {
			final IJavaProject javaProject= JavaCore.create(ResourcesPlugin.getWorkspace().getRoot()).getJavaProject(project);
			final String identifier= javaProject.getHandleIdentifier();
			if (owner != null)
				element= JavaCore.create(identifier + handle, owner);
			else
				element= JavaCore.create(identifier + handle);
		}
		if (check && element instanceof IMethod) {
			/*
			 * Resolve the method based on simple names of parameter types
			 * (to accommodate for different qualifications when refactoring is e.g.
			 * recorded in source but applied on binary method):
			 */
			final IMethod method= (IMethod) element;
			final IMethod[] methods= method.getDeclaringType().findMethods(method);
			if (methods != null && methods.length > 0)
				element= methods[0];
		}
		if (element != null && (!check || element.exists()))
			return element;
		return null;
	}

	/**
	 * Converts an input handle with the given prefix back to the corresponding
	 * resource.
	 *
	 * @param project
	 *            the project, or <code>null</code> for the workspace
	 * @param handle
	 *            the input handle
	 *
	 * @return the corresponding resource, or <code>null</code> if no such
	 *         resource exists.
	 *         Note: if the given handle is absolute, the project is not used to resolve.
	 */
	public static IResource handleToResource(final String project, final String handle) {
		final IWorkspaceRoot root= ResourcesPlugin.getWorkspace().getRoot();
		if ("".equals(handle)) //$NON-NLS-1$
			return null;
		final IPath path= Path.fromPortableString(handle);
		if (path == null)
			return null;
		if (project != null && !"".equals(project) && ! path.isAbsolute()) //$NON-NLS-1$
			return root.getProject(project).findMember(path);
		return root.findMember(path);
	}

	/**
	 * Converts the specified resource to an input handle.
	 *
	 * @param project
	 *            the project, or <code>null</code> for the workspace
	 * @param resource
	 *            the resource
	 *
	 * @return the input handle.
	 *         Note: if the given project is not the resource's project, then the full handle is returned.
	 */
	public static String resourceToHandle(final String project, final IResource resource) {
		if (project != null && !"".equals(project) && project.equals(resource.getProject().getName())) //$NON-NLS-1$
			return resource.getProjectRelativePath().toPortableString();
		return resource.getFullPath().toPortableString();
	}

	/**
	 * Creates a fatal error status telling that the input element does not
	 * exist.
	 *
	 * @param element
	 *            the input element, or <code>null</code>
	 * @param name
	 *            the name of the refactoring
	 * @param id
	 *            the id of the refactoring
	 * @return the refactoring status
	 */
	public static RefactoringStatus createInputFatalStatus(final Object element, final String name, final String id) {
		Assert.isNotNull(name);
		Assert.isNotNull(id);
		if (element != null)
			return RefactoringStatus.createFatalErrorStatus(Messages.format(RefactoringCoreMessages.InitializableRefactoring_input_not_exists, new String[] { JavaElementLabels.getTextLabel(element, JavaElementLabels.ALL_FULLY_QUALIFIED), name, id}));
		else
			return RefactoringStatus.createFatalErrorStatus(Messages.format(RefactoringCoreMessages.InitializableRefactoring_inputs_do_not_exist, new String[] { name, id}));
	}

	/**
	 * Creates a warning status telling that the input element does not exist.
	 *
	 * @param element
	 *            the input element, or <code>null</code>
	 * @param name
	 *            the name of the refactoring
	 * @param id
	 *            the id of the refactoring
	 * @return the refactoring status
	 */
	public static RefactoringStatus createInputWarningStatus(final Object element, final String name, final String id) {
		Assert.isNotNull(name);
		Assert.isNotNull(id);
		if (element != null)
			return RefactoringStatus.createWarningStatus(Messages.format(RefactoringCoreMessages.InitializableRefactoring_input_not_exists, new String[] { JavaElementLabels.getTextLabel(element, JavaElementLabels.ALL_FULLY_QUALIFIED), name, id}));
		else
			return RefactoringStatus.createWarningStatus(Messages.format(RefactoringCoreMessages.InitializableRefactoring_inputs_do_not_exist, new String[] { name, id}));
	}

}