core/org.eclipse.statet.rj.server/src/org/eclipse/statet/rj/server/util/RJContext.java

/*=============================================================================#
 # Copyright (c) 2013, 2018 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.rj.server.util;

import static org.eclipse.statet.rj.server.util.ServerUtils.RJ_SERVER_ID;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Properties;
import java.util.regex.Pattern;

import org.eclipse.statet.jcommons.collections.ImCollections;
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.rj.RjInitFailedException;
import org.eclipse.statet.rj.RjInvalidConfigurationException;


@NonNullByDefault
public class RJContext {
	
	
	public static final String RJ_BUNDLE_PATH_PROPERTY_KEY= "org.eclipse.statet.rj.Path"; //$NON-NLS-1$
	public static final String RJ_SERVER_CLASS_PATH_PROPERTY_KEY= "org.eclipse.statet.rj.server.ClassPath.urls"; //$NON-NLS-1$
	
	public static final String RJ_PATH_SEPARATOR= ":,:"; //$NON-NLS-1$
	private static final Pattern RJ_PATH_SEPARATOR_PATTERN= Pattern.compile(RJ_PATH_SEPARATOR, Pattern.LITERAL);
	
	protected static final String LOCALHOST_POLICY_FILENAME= "localhost.policy"; //$NON-NLS-1$
	
	
	public static PathEntryProvider detectRJLibPaths() throws RjInitFailedException {
		List<Path> expliciteBaseDirectories= null;
		
		final String path= System.getProperty(RJ_BUNDLE_PATH_PROPERTY_KEY);
		if (path != null) {
			expliciteBaseDirectories= new ArrayList<>();
			final String[] directories= RJ_PATH_SEPARATOR_PATTERN.split(path);
			for (final String pathString : directories) {
				expliciteBaseDirectories.add(Paths.get(pathString));
			}
		}
		
		return PathEntryProvider.detectLibPaths(RJContext.class, expliciteBaseDirectories);
	}
	
	
	private ImList<PathEntryProvider> libPathEntryProviders;
	
	
	public RJContext(final PathEntryProvider pathEntryProvider,
			final PathEntryProvider ... pathEntryProviderAdditionals) {
		this.libPathEntryProviders= ImCollections.addElement(
				ImCollections.newList(pathEntryProviderAdditionals),
				0, pathEntryProvider);
	}
	
	
	protected RJContext() {
	}
	
	
	public List<PathEntry> searchRJLibs(final List<String> libIds)
			throws RjInvalidConfigurationException {
		final List<? extends PathEntry> candidates= getRJLibCandidates();
		
		final ArrayList<PathEntry> resolved= new ArrayList<>(libIds.size());
		StringBuilder sb= null;
		
		Collections.sort(candidates);
		for (final String libId : libIds) {
			final PathEntry entry= searchLib(candidates, libId);
			if (entry == null) {
				if (sb == null) {
					sb= new StringBuilder("Missing RJ library ");
				}
				else {
					sb.append(", "); //$NON-NLS-1$
				}
				sb.append('\'');
				sb.append(libId);
				sb.append('\'');
			}
			else {
				resolved.add(entry);
			}
		}
		if (sb != null) {
			sb.append('.');
			throw new RjInvalidConfigurationException(sb.toString());
		}
		return resolved;
	}
	
	protected List<? extends PathEntry> getRJLibCandidates() throws RjInvalidConfigurationException {
		final List<PathEntry> pathsEntries= new ArrayList<>();
		for (final PathEntryProvider provider : this.libPathEntryProviders) {
			provider.getEntries(pathsEntries);
		}
		return pathsEntries;
	}
	
	protected @Nullable PathEntry searchLib(final List<? extends PathEntry> files, final String bundleId) {
		for (final PathEntry entry : files) {
			if (entry.bundleId.equals(bundleId)) {
				return entry;
			}
		}
		return null;
	}
	
	
	public String getServerPolicyFilePath() throws RjInvalidConfigurationException {
		final URL resource= RJContext.class.getClassLoader().getResource(LOCALHOST_POLICY_FILENAME);
		if (resource != null) {
			resource.toString();
		}
		try {
			final PathEntry lib= searchRJLibs(ImCollections.newList(RJ_SERVER_ID)).get(0);
			final Path policyPath= lib.getResourcePath(LOCALHOST_POLICY_FILENAME);
			if (policyPath != null && Files.isRegularFile(policyPath)) {
				return policyPath.toUri().toString();
			}
			else {
				final String s= lib.getUrlString();
				if (s.endsWith("/")) { //$NON-NLS-1$
					return s + LOCALHOST_POLICY_FILENAME;
				}
			}
			throw new UnsupportedOperationException(String.format("PathEntry= '%1$s'", lib));
		}
		catch (final Exception e) {
			throw new RjInvalidConfigurationException("Failed find server policy file.", e);
		}
	}
	
	
	protected String getPropertiesDirPath() {
		return System.getProperty("user.dir");
	}
	
	protected @Nullable InputStream getInputStream(final String path) throws IOException {
		final File file= new File(path);
		if (!file.exists()) {
			return null;
		}
		return new FileInputStream(file);
	}
	
	protected OutputStream getOutputStream(final String path) throws IOException {
		final File file= new File(path);
		return new FileOutputStream(file, false);
	}
	
	public @Nullable Properties loadProperties(final String name) throws IOException {
		if (name == null) {
			throw new NullPointerException("name");
		}
		final String path= getPropertiesDirPath() + '/' + name + ".properties"; //$NON-NLS-1$
		final InputStream in= getInputStream(path);
		if (in == null) {
			return null;
		}
		
		final Properties properties= new Properties();
		try {
			properties.load(in);
		}
		finally {
			if (in != null) {
				try {
					in.close();
				}
				catch (final IOException e) {}
			}
		}
		
		return properties;
	}
	
	public void saveProperties(final String name, final Properties properties) throws IOException {
		if (name == null) {
			throw new NullPointerException("name");
		}
		if (properties == null) {
			throw new NullPointerException("properties");
		}
		final String path= getPropertiesDirPath() + '/' + name + ".properties"; //$NON-NLS-1$
		final OutputStream out= getOutputStream(path);
		
		try {
			properties.store(out, null);
		}
		finally {
			if (out != null) {
				try {
					out.close();
				}
				catch (final IOException e) {}
			}
		}
	}
	
}