/*******************************************************************************
 * Copyright (c) 2004, 2013 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
 *******************************************************************************/
package org.eclipse.ant.internal.ui.datatransfer;

import java.io.File;
import java.text.MessageFormat;

import org.apache.tools.ant.BuildException;
import org.apache.tools.ant.taskdefs.Javac;
import org.eclipse.ant.internal.ui.AntUIPlugin;
import org.eclipse.core.resources.IContainer;
import org.eclipse.core.resources.IFolder;
import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IProjectDescription;
import org.eclipse.core.resources.IResource;
import org.eclipse.core.resources.IWorkspaceRoot;
import org.eclipse.core.resources.ResourcesPlugin;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.IProgressMonitor;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.core.runtime.Path;
import org.eclipse.core.runtime.Status;
import org.eclipse.jdt.core.IClasspathEntry;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IPackageFragmentRoot;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.launching.JavaRuntime;

public class ProjectCreator {

	public IJavaProject createJavaProjectFromJavacNode(String projectName, Javac javacTask, IProgressMonitor monitor) throws CoreException {
		try {
			IJavaProject javaProject = createJavaProject(projectName, monitor);

			File destDir = javacTask.getDestdir();
			String destDirName = destDir == null ? null : destDir.getName();
			org.apache.tools.ant.types.Path sourceDirs = javacTask.getSrcdir();
			createSourceDirectories(destDir, destDirName, sourceDirs, javaProject, monitor);

			// add rt.jar
			addVariableEntry(javaProject, new Path(JavaRuntime.JRELIB_VARIABLE), new Path(JavaRuntime.JRESRC_VARIABLE), new Path(JavaRuntime.JRESRCROOT_VARIABLE), monitor);

			setClasspath(javacTask, javaProject, monitor);

			javaProject.getProject().refreshLocal(IResource.DEPTH_INFINITE, monitor);
			return javaProject;
		}
		catch (BuildException be) {
			IStatus status = new Status(IStatus.ERROR, AntUIPlugin.PI_ANTUI, IStatus.OK, be.getLocalizedMessage(), be);
			throw new CoreException(status);
		}
	}

	private void setClasspath(Javac javacTask, IJavaProject javaProject, IProgressMonitor monitor) throws CoreException {
		try {
			org.apache.tools.ant.types.Path classpath = javacTask.getClasspath();
			if (classpath == null) {
				return;
			}
			for (String cp : classpath.list()) {
				File classpathEntry = new File(cp);
				if (classpathEntry.isFile()) {
					addLibrary(javaProject, new Path(classpathEntry.getAbsolutePath()), monitor);
				} else {
					addContainer(javaProject, new Path(classpathEntry.getAbsolutePath()), monitor);
				}
			}
		}
		catch (BuildException be) {
			IStatus status = new Status(IStatus.ERROR, AntUIPlugin.PI_ANTUI, IStatus.OK, MessageFormat.format(DataTransferMessages.ProjectCreator_0, new Object[] {
					be.getLocalizedMessage() }), be);
			throw new CoreException(status);
		}
	}

	private void createSourceDirectories(File destDir, String destDirName, org.apache.tools.ant.types.Path sourceDirs, IJavaProject javaProject, IProgressMonitor monitor) throws CoreException {
		for (String srcDir : sourceDirs.list()) {
			File srcDirectory = new File(srcDir);
			String srcDirectoryName = srcDirectory.getName();
			String destDirPath = destDir == null ? srcDir : destDir.getAbsolutePath();
			if (destDirName == null) {
				destDirName = srcDirectoryName;
			}
			addSourceContainer(javaProject, srcDirectoryName, srcDir, destDirName, destDirPath, monitor);
		}
	}

	private IJavaProject createJavaProject(String projectName, IProgressMonitor monitor) throws CoreException {
		IWorkspaceRoot root = ResourcesPlugin.getWorkspace().getRoot();
		IProject project = root.getProject(projectName);
		if (!project.exists()) {
			project.create(monitor);
		} else {
			project.refreshLocal(IResource.DEPTH_INFINITE, monitor);
		}

		if (!project.isOpen()) {
			project.open(monitor);
		}

		if (!project.hasNature(JavaCore.NATURE_ID)) {
			addNatureToProject(project, JavaCore.NATURE_ID, monitor);
		}

		IJavaProject jproject = JavaCore.create(project);

		jproject.setRawClasspath(new IClasspathEntry[0], monitor);

		return jproject;
	}

	private void addNatureToProject(IProject proj, String natureId, IProgressMonitor monitor) throws CoreException {
		IProjectDescription description = proj.getDescription();
		String[] prevNatures = description.getNatureIds();
		String[] newNatures = new String[prevNatures.length + 1];
		System.arraycopy(prevNatures, 0, newNatures, 0, prevNatures.length);
		newNatures[prevNatures.length] = natureId;
		description.setNatureIds(newNatures);
		proj.setDescription(description, monitor);
	}

	/**
	 * Adds a source container to a IJavaProject.
	 */
	private void addSourceContainer(IJavaProject jproject, String srcName, String srcPath, String outputName, String outputPath, IProgressMonitor monitor) throws CoreException {
		IProject project = jproject.getProject();
		IContainer container = null;
		if (srcName == null || srcName.length() == 0) {
			container = project;
		} else {
			IFolder folder = project.getFolder(srcName);
			if (!folder.exists()) {
				folder.createLink(new Path(srcPath), IResource.ALLOW_MISSING_LOCAL, monitor);
			}
			container = folder;
		}
		IPackageFragmentRoot root = jproject.getPackageFragmentRoot(container);

		IPath output = null;
		if (outputName != null) {
			IFolder outputFolder = project.getFolder(outputName);
			if (!outputFolder.exists()) {
				outputFolder.createLink(new Path(outputPath), IResource.ALLOW_MISSING_LOCAL, monitor);
			}
			output = outputFolder.getFullPath();
		}

		IClasspathEntry cpe = JavaCore.newSourceEntry(root.getPath(), new IPath[0], output);

		addToClasspath(jproject, cpe, monitor);
	}

	private void addToClasspath(IJavaProject jproject, IClasspathEntry cpe, IProgressMonitor monitor) throws JavaModelException {
		IClasspathEntry[] oldEntries = jproject.getRawClasspath();
		for (IClasspathEntry oldEntry : oldEntries) {
			if (oldEntry.equals(cpe)) {
				return;
			}
		}
		int nEntries = oldEntries.length;
		IClasspathEntry[] newEntries = new IClasspathEntry[nEntries + 1];
		System.arraycopy(oldEntries, 0, newEntries, 0, nEntries);
		newEntries[nEntries] = cpe;
		jproject.setRawClasspath(newEntries, monitor);
	}

	/**
	 * Adds a variable entry with source attachment to a IJavaProject if the path can be resolved.
	 */
	private void addVariableEntry(IJavaProject jproject, IPath path, IPath sourceAttachPath, IPath sourceAttachRoot, IProgressMonitor monitor) throws JavaModelException {
		IClasspathEntry cpe = JavaCore.newVariableEntry(path, sourceAttachPath, sourceAttachRoot);
		addToClasspath(jproject, cpe, monitor);
	}

	/**
	 * Adds a library entry to an IJavaProject.
	 */
	private void addLibrary(IJavaProject jproject, IPath path, IProgressMonitor monitor) throws JavaModelException {
		IClasspathEntry cpe = JavaCore.newLibraryEntry(path, null, null);
		addToClasspath(jproject, cpe, monitor);
	}

	/**
	 * Adds a container entry to an IJavaProject.
	 */
	private void addContainer(IJavaProject jproject, IPath path, IProgressMonitor monitor) throws CoreException {
		IClasspathEntry cpe = JavaCore.newContainerEntry(path);
		addToClasspath(jproject, cpe, monitor);
		IProject project = jproject.getProject();
		IFolder folder = project.getFolder(path.lastSegment());
		if (!folder.exists()) {
			folder.createLink(path, IResource.ALLOW_MISSING_LOCAL, monitor);
		}
	}
}