001/*
002 *  Copyright 2018 Anyware Services
003 *
004 *  Licensed under the Apache License, Version 2.0 (the "License");
005 *  you may not use this file except in compliance with the License.
006 *  You may obtain a copy of the License at
007 *
008 *      http://www.apache.org/licenses/LICENSE-2.0
009 *
010 *  Unless required by applicable law or agreed to in writing, software
011 *  distributed under the License is distributed on an "AS IS" BASIS,
012 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 *  See the License for the specific language governing permissions and
014 *  limitations under the License.
015 */
016package org.ametys.plugins.core.ui.resources.css.sass;
017
018import java.util.ArrayList;
019import java.util.Arrays;
020import java.util.HashSet;
021import java.util.LinkedHashSet;
022import java.util.List;
023import java.util.Map;
024import java.util.Objects;
025import java.util.Set;
026import java.util.concurrent.ConcurrentHashMap;
027import java.util.function.Consumer;
028import java.util.stream.Collectors;
029
030import org.apache.avalon.framework.service.ServiceException;
031import org.apache.avalon.framework.service.ServiceManager;
032import org.apache.avalon.framework.service.Serviceable;
033import org.apache.commons.lang3.StringUtils;
034import org.apache.commons.lang3.tuple.Pair;
035import org.apache.excalibur.source.Source;
036import org.apache.excalibur.source.SourceResolver;
037
038import org.ametys.plugins.core.ui.minimize.HashCache.UriData;
039import org.ametys.plugins.core.ui.resources.ResourceDependenciesList;
040import org.ametys.plugins.core.ui.resources.css.sass.SassImportHelper.SassImportInfo;
041import org.ametys.plugins.core.ui.util.RequestAttributesHelper;
042import org.ametys.runtime.plugin.component.AbstractLogEnabled;
043
044/**
045 * Dependencies list for sass files compiled into css
046 * Uncompiled sass files don't depend on anything and are managed by the DefaultResourceDependenciesList
047 */
048public class SassDependenciesList extends AbstractLogEnabled implements ResourceDependenciesList, Serviceable
049{
050    /** List of sass extensions */
051    protected static final String[] __SASS_EXTENSION = new String[] {".scss", ".sass"};
052    
053    /** RequestAttributesHelper */
054    protected RequestAttributesHelper _requestAttributesHelper;
055
056    /** The source resolver */
057    protected SourceResolver _sourceResolver;
058
059    /** The Sass import helper */
060    protected SassImportHelper _sassImportHelper;
061
062    /* Dependencies cache */
063    private Map<String, Pair<List<String>, Long>> _dependenciesCache = new ConcurrentHashMap<>();
064
065    @Override
066    public void service(ServiceManager manager) throws ServiceException
067    {
068        _sourceResolver = (SourceResolver) manager.lookup(SourceResolver.ROLE);
069        _requestAttributesHelper = (RequestAttributesHelper) manager.lookup(RequestAttributesHelper.ROLE);
070        _sassImportHelper = (SassImportHelper) manager.lookup(SassImportHelper.ROLE);
071    }
072    
073    @Override
074    public boolean isSupported(String uri)
075    {
076        if (StringUtils.endsWith(uri, ".css"))
077        {
078            return getSassImportInfo(uri) != null;
079        }
080
081        return false;
082    }
083
084    @Override
085    public int getPriority()
086    {
087        return 200;
088    }
089
090    @Override
091    public Set<UriData> getDependenciesList(String uri, Map<String, String> data)
092    {
093        SassImportInfo fileSource = null;
094        
095        try
096        {
097            fileSource = getSassImportInfo(uri);
098            
099            if (fileSource != null)
100            {
101                String media = data.getOrDefault("media", null);
102                return getDependenciesList(uri, media, fileSource.getSource(), fileSource.getLastModified(), true);
103            }
104        }
105        finally 
106        {
107            if (fileSource != null)
108            {
109                _sourceResolver.release(fileSource.getSource());
110            }
111        }
112        
113        return new HashSet<>();
114    }
115    
116    /**
117     * Get the Sass import informations from the URI
118     * @param uri The URI
119     * @return The information
120     */
121    protected SassImportInfo getSassImportInfo(String uri)
122    {
123        String uriWithoutExtension = StringUtils.removeEnd(uri, ".css");
124        return _sassImportHelper.findExistingImportSource(Arrays.stream(__SASS_EXTENSION).map(ext -> uriWithoutExtension + ext).collect(Collectors.toList()));
125    }
126
127    private Set<UriData> getDependenciesList(SassImportInfo sassImportInfo, String media)
128    {
129        return getDependenciesList(sassImportInfo, media, false);
130    }
131
132    private Set<UriData> getDependenciesList(SassImportInfo sassImportInfo, String media, boolean firstLevel)
133    {
134        return getDependenciesList(sassImportInfo.getUri(), media, sassImportInfo.getSource(), sassImportInfo.getLastModified(), firstLevel);
135    }
136    
137    private Set<UriData> getDependenciesList(String uri, String media, Source source, long lastModified, boolean firstLevel)
138    {
139        Set<UriData> dependencies = new LinkedHashSet<>();
140        UriData fileInfos = new UriData(uri, firstLevel);
141        fileInfos.setLastModified(lastModified);
142        fileInfos.setMedia(media);
143        dependencies.add(fileInfos);
144        
145        Pair<List<String>, Long> dependencyFromCache = _dependenciesCache.get(uri);
146
147        if (dependencyFromCache == null || dependencyFromCache.getRight() != lastModified)
148        {
149            // cache is outdated
150            List<String> dependenciesCache = new ArrayList<>();
151            
152            Consumer<UriData> addDependencyToCache = cssDependency -> 
153            {
154                if (!dependenciesCache.contains(cssDependency.getUri()))
155                {
156                    dependenciesCache.add(cssDependency.getUri());
157                    dependencies.add(cssDependency);
158                }
159            };
160            
161            _sassImportHelper.getDependenciesList(source).values()
162                    .stream()
163                    .map(sassImport -> getDependenciesList(sassImport, media))
164                    .flatMap(Set::stream)
165                    .forEach(addDependencyToCache);
166            
167            _dependenciesCache.put(uri, Pair.of(dependenciesCache, lastModified));
168        }
169        else
170        {
171            // cache is up to date, lookup dependencies of each entry from the cache to build the full list
172            dependencyFromCache.getLeft()
173                    .stream()
174                    .map(uriFromCache -> _sassImportHelper.getImportSource(uriFromCache))
175                    .filter(Objects::nonNull)
176                    .map(sassImport -> getDependenciesList(sassImport, media))
177                    .forEach(subDependencies -> dependencies.addAll(subDependencies));
178        }
179        
180        return dependencies;
181    }
182}