/*=============================================================================#
 # Copyright (c) 2005, 2020 Stephan Wahlbrink and others.
 # 
 # This program and the accompanying materials are made available under the
 # terms of the Eclipse Public License 2.0 which is available at
 # https://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
 # which is available at https://www.apache.org/licenses/LICENSE-2.0.
 # 
 # SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
 # 
 # Contributors:
 #     Stephan Wahlbrink <sw@wahlbrink.eu> - initial API and implementation
 #=============================================================================*/

package org.eclipse.statet.internal.r.core;

import org.eclipse.core.resources.IProject;
import org.eclipse.core.resources.IProjectDescription;
import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IPath;
import org.eclipse.core.runtime.Path;

import org.eclipse.statet.jcommons.collections.ImCollections;
import org.eclipse.statet.jcommons.collections.ImIdentitySet;
import org.eclipse.statet.jcommons.collections.ImList;
import org.eclipse.statet.jcommons.lang.NonNullByDefault;
import org.eclipse.statet.jcommons.lang.Nullable;

import org.eclipse.statet.ecommons.preferences.PreferencesManageListener;
import org.eclipse.statet.ecommons.preferences.core.PreferenceAccess;
import org.eclipse.statet.ecommons.preferences.core.PreferenceSetService;
import org.eclipse.statet.ecommons.resources.core.AbstractProjectNature;
import org.eclipse.statet.ecommons.resources.core.BuildUtils;
import org.eclipse.statet.ecommons.resources.core.ProjectUtils;

import org.eclipse.statet.ltk.buildpaths.core.IBuildpathElement;
import org.eclipse.statet.r.core.RCodeStyleSettings;
import org.eclipse.statet.r.core.RCore;
import org.eclipse.statet.r.core.RProject;
import org.eclipse.statet.r.core.RProjects;
import org.eclipse.statet.r.core.renv.IREnvManager;
import org.eclipse.statet.rj.renv.core.REnv;
import org.eclipse.statet.rj.renv.core.REnvUtils;


@NonNullByDefault
public class RProjectNature extends AbstractProjectNature implements RProject, PreferenceSetService.ChangeListener {
	
	
	public static final String OLD_QUALIFIER= "de.walware.r.core/RProjectBuild"; //$NON-NLS-1$
	
	public static final String RPKG_ROOT_FOLDER_PATH_KEY= "RPkgRootFolder.path"; //$NON-NLS-1$
	public static final String RENV_CODE_KEY= "REnv.code"; //$NON-NLS-1$
	
	
	private static final ImIdentitySet<String> PREF_QUALIFIERS= ImCollections.newIdentitySet(
			IREnvManager.PREF_QUALIFIER,
			BUILD_PREF_QUALIFIER );
	
	
	public static @Nullable RProjectNature getRProject(final @Nullable IProject project) {
		try {
			return (project != null) ? (RProjectNature) project.getNature(RProjects.R_NATURE_ID) : null;
		}
		catch (final CoreException e) {
			RCorePlugin.log(e.getStatus());
			return null;
		}
	}
	
	
	private @Nullable String rPkgName;
	
	private PreferencesManageListener preferenceListener;
	
	private RCodeStyleSettings rCodeStyle;
	
	private @Nullable REnv rEnv;
	
	private RBuildpathPrefs rBuildpathPrefs;
	private ImList<IBuildpathElement> rRawBuildpath;
	
	
	@SuppressWarnings("null")
	public RProjectNature() {
		super();
	}
	
	
	@Override
	public void setProject(final IProject project) {
		super.setProject(project);
		
		addPreferenceSetListener(this, PREF_QUALIFIERS);
		
		updateREnv();
		
		this.rCodeStyle= new RCodeStyleSettings(1);
		this.preferenceListener= new PreferencesManageListener(this.rCodeStyle, getPrefs(),
				RCodeStyleSettings.ALL_GROUP_IDS );
		
		this.rBuildpathPrefs= new RBuildpathPrefs(getProjectContext(), BUILD_PREF_QUALIFIER,
				getProject() );
		updateBuildpath();
		
		this.rPkgName= RCorePlugin.getInstance().getRModelManager().getIndex()
				.getPkgName(project.getName());
		
		RCorePlugin.getInstance().getResourceTracker().register(project, this);
	}
	
	@Override
	public void dispose() {
		RCorePlugin.getInstance().getResourceTracker().unregister(getProject());
		
		super.dispose();
		
		if (this.preferenceListener != null) {
			this.preferenceListener.dispose();
			this.preferenceListener= null;
		}
		
		this.rEnv= null;
	}
	
	@Override
	public void deconfigure() throws CoreException {
		dispose();
		super.deconfigure();
	}
	
	@Override
	public void addBuilders() throws CoreException {
		final IProject project= getProject();
		final IProjectDescription description= project.getDescription();
		boolean changed= false;
		changed|= ProjectUtils.addBuilder(description, RSupportBuilder.ID);
		
		if (changed) {
			project.setDescription(description, null);
		}
	}
	
	@Override
	public void removeBuilders() throws CoreException {
		final IProject project= getProject();
		final IProjectDescription description= project.getDescription();
		boolean changed= false;
		changed|= ProjectUtils.removeBuilder(description, RSupportBuilder.ID);
		
		if (changed) {
			project.setDescription(description, null);
		}
	}
	
	
	@Override
	public void preferenceChanged(final PreferenceSetService.ChangeEvent event) {
		boolean clean= false;
		
		if (event.contains(IREnvManager.PREF_QUALIFIER)
				|| event.contains(RProject.RENV_CODE_PREF) ) {
			updateREnv();
		}
		if (event.contains(RProject.BUILD_PREF_QUALIFIER, RBuildpathPrefs.STAMP_KEY)) {
			updateBuildpath();
			clean= true;
		}
		if (event.contains(RProject.PKG_BASE_FOLDER_PATH_PREF)) {
			clean= true;
		}
		
		if (clean) {
			BuildUtils.getCleanJob(getProject(), false).schedule();
		}
	}
	
	private void updateREnv() {
		final IREnvManager rEnvManager= RCore.getREnvManager();
		final String s= getProjectValue(RProject.RENV_CODE_PREF);
		this.rEnv= (s != null) ? REnvUtils.decode(s, rEnvManager) : rEnvManager.getDefault();
	}
	
	private void updateBuildpath() {
		final ImList<IBuildpathElement> rawBuildpath= this.rBuildpathPrefs.load();
		synchronized (this) {
			this.rRawBuildpath= rawBuildpath;
		}
	}
	
	@Override
	public PreferenceAccess getPrefs() {
		return this;
	}
	
	@Override
	public @Nullable REnv getREnv() {
		return this.rEnv;
	}
	
	@Override
	public RCodeStyleSettings getRCodeStyle() {
		return this.rCodeStyle;
	}
	
	@Override
	public @Nullable IPath getPkgRootPath() {
		final IProject project= getProject();
		try {
			if (project.hasNature(RProjects.R_PKG_NATURE_ID)) {
				final IPath projectPath= getProject().getFullPath();
				final String s= getPreferenceValue(RProject.PKG_BASE_FOLDER_PATH_PREF);
				if (s != null) {
					return projectPath.append(Path.fromPortableString(s));
				}
				return projectPath;
			}
		}
		catch (final CoreException e) {
		}
		return null;
	}
	
	
	@Override
	public ImList<IBuildpathElement> getRawBuildpath() {
		return this.rRawBuildpath;
	}
	
	
	@Override
	public @Nullable String getPkgName() {
		return this.rPkgName;
	}
	
	/**
	 * Called by project builder
	 * 
	 * @param pkgName
	 */
	public void updateRPkgConfig(final @Nullable String pkgName) {
		final boolean changed= (pkgName != null) != (this.rPkgName != null);
		this.rPkgName= pkgName;
		
		if (changed) {
//			checkPackageNature();
		}
	}
	
	public void saveBuildpath(final ImList<IBuildpathElement> rawBuildpath) {
		if (getRawBuildpath().equals(rawBuildpath)) {
			return;
		}
		this.rBuildpathPrefs.save(rawBuildpath, true);
	}
	
}