/**
    * Copyright 2010-2012 The Kuali Foundation
    *
    * Licensed under the Educational Community License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    *
    * http://www.opensource.org/licenses/ecl2.php
    *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  package org.codehaus.mojo.license;
  
  import java.io.File;
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Comparator;
  import java.util.HashMap;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.Set;
  import java.util.SortedMap;
  import java.util.SortedSet;
  import java.util.TreeSet;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  
  import org.apache.commons.collections.CollectionUtils;
  import org.apache.commons.lang.StringUtils;
  import org.apache.maven.artifact.Artifact;
  import org.apache.maven.artifact.factory.ArtifactFactory;
  import org.apache.maven.artifact.repository.ArtifactRepository;
  import org.apache.maven.artifact.resolver.ArtifactNotFoundException;
  import org.apache.maven.artifact.resolver.ArtifactResolutionException;
  import org.apache.maven.artifact.resolver.ArtifactResolver;
  import org.apache.maven.model.License;
  import org.apache.maven.project.MavenProject;
  import org.apache.maven.project.MavenProjectBuilder;
  import org.apache.maven.project.MavenProjectHelper;
  import org.codehaus.mojo.license.model.LicenseMap;
  import org.codehaus.plexus.logging.AbstractLogEnabled;
  import org.codehaus.plexus.logging.Logger;
  
  /**
   * Default implementation of the third party tool.
   *
   * @author <a href="mailto:tchemit@codelutin.com">Tony Chemit</a>
   * @version $Id: DefaultThirdPartyTool.java 14410 2011-08-10 20:54:51Z tchemit $
   * @plexus.component role="org.codehaus.mojo.license.ThirdPartyTool" role-hint="default"
   */
  public class DefaultThirdPartyTool extends AbstractLogEnabled implements ThirdPartyTool {
  
      public static final String DESCRIPTOR_CLASSIFIER = "third-party";
  
      public static final String DESCRIPTOR_TYPE = "properties";
  
      // ----------------------------------------------------------------------
      // Components
      // ----------------------------------------------------------------------
  
      /**
       * The component that is used to resolve additional artifacts required.
       *
       * @plexus.requirement
       */
      private ArtifactResolver artifactResolver;
  
      /**
       * The component used for creating artifact instances.
       *
       * @plexus.requirement
       */
      private ArtifactFactory artifactFactory;
  
      /**
       * Project builder.
       *
       * @plexus.requirement
       */
      private MavenProjectBuilder mavenProjectBuilder;
  
      /**
       * Maven ProjectHelper.
       *
       * @plexus.requirement
       */
      private MavenProjectHelper projectHelper;
  
      /**
       * Maven project comparator.
       */
     private final Comparator<MavenProject> projectComparator = MojoHelper.newMavenProjectComparator();
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void attachThirdPartyDescriptor(MavenProject project, File file) {
 
         projectHelper.attachArtifact(project, DESCRIPTOR_TYPE, DESCRIPTOR_CLASSIFIER, file);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public SortedSet<MavenProject> getProjectsWithNoLicense(LicenseMap licenseMap, boolean doLog) {
 
         Logger log = getLogger();
 
         // get unsafe dependencies (says with no license)
         SortedSet<MavenProject> unsafeDependencies = licenseMap.get(LicenseMap.getUnknownLicenseMessage());
 
         if (doLog) {
             if (CollectionUtils.isEmpty(unsafeDependencies)) {
                 log.debug("There is no dependency with no license from poms.");
             } else {
                 log.debug("There is " + unsafeDependencies.size() + " dependencies with no license from poms : ");
                 for (MavenProject dep : unsafeDependencies) {
 
                     // no license found for the dependency
                     log.debug(" - " + MojoHelper.getArtifactId(dep.getArtifact()));
                 }
             }
         }
 
         return unsafeDependencies;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public SortedProperties loadThirdPartyDescriptorsForUnsafeMapping(String encoding,
             Collection<MavenProject> projects, SortedSet<MavenProject> unsafeDependencies, LicenseMap licenseMap,
             ArtifactRepository localRepository, List<ArtifactRepository> remoteRepositories)
             throws ThirdPartyToolException, IOException {
 
         SortedProperties result = new SortedProperties(encoding);
         Map<String, MavenProject> unsafeProjects = new HashMap<String, MavenProject>();
         for (MavenProject unsafeDependency : unsafeDependencies) {
             String id = MojoHelper.getArtifactId(unsafeDependency.getArtifact());
             unsafeProjects.put(id, unsafeDependency);
         }
 
         for (MavenProject mavenProject : projects) {
 
             if (CollectionUtils.isEmpty(unsafeDependencies)) {
 
                 // no more unsafe dependencies to find
                 break;
             }
 
             File thirdPartyDescriptor = resolvThirdPartyDescriptor(mavenProject, localRepository, remoteRepositories);
 
             if (thirdPartyDescriptor != null && thirdPartyDescriptor.exists() && thirdPartyDescriptor.length() > 0) {
 
                 if (getLogger().isInfoEnabled()) {
                     getLogger().info("Detects third party descriptor " + thirdPartyDescriptor);
                 }
 
                 // there is a third party file detected form the given dependency
                 SortedProperties unsafeMappings = new SortedProperties(encoding);
 
                 if (thirdPartyDescriptor.exists()) {
 
                     getLogger().debug("Load missing file " + thirdPartyDescriptor);
 
                     // load the missing file
                     unsafeMappings.load(thirdPartyDescriptor);
                 }
 
                 for (String id : unsafeProjects.keySet()) {
 
                     if (unsafeMappings.containsKey(id)) {
 
                         String license = (String) unsafeMappings.get(id);
                         if (StringUtils.isEmpty(license)) {
 
                             // empty license means not fill, skip it
                             continue;
                         }
 
                         // found a resolved unsafe dependency in the missing third party file
                         MavenProject resolvedProject = unsafeProjects.get(id);
                         unsafeDependencies.remove(resolvedProject);
 
                         // push back to
                         result.put(id, license.trim());
 
                         addLicense(licenseMap, resolvedProject, license);
                     }
                 }
             }
         }
         return result;
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public File resolvThirdPartyDescriptor(MavenProject project, ArtifactRepository localRepository,
             List<ArtifactRepository> repositories) throws ThirdPartyToolException {
         if (project == null) {
             throw new IllegalArgumentException("The parameter 'project' can not be null");
         }
         if (localRepository == null) {
             throw new IllegalArgumentException("The parameter 'localRepository' can not be null");
         }
         if (repositories == null) {
             throw new IllegalArgumentException("The parameter 'remoteArtifactRepositories' can not be null");
         }
 
         try {
             return resolveThirdPartyDescriptor(project, localRepository, repositories);
         } catch (ArtifactNotFoundException e) {
             getLogger().debug("ArtifactNotFoundException: Unable to locate third party descriptor: " + e);
             return null;
         } catch (ArtifactResolutionException e) {
             throw new ThirdPartyToolException("ArtifactResolutionException: Unable to locate third party descriptor: "
                     + e.getMessage(), e);
         } catch (IOException e) {
             throw new ThirdPartyToolException(
                     "IOException: Unable to locate third party descriptor: " + e.getMessage(), e);
         }
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void addLicense(LicenseMap licenseMap, MavenProject project, String licenseName) {
         License license = new License();
         license.setName(licenseName.trim());
         license.setUrl(licenseName.trim());
         addLicense(licenseMap, project, license);
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void addLicense(LicenseMap licenseMap, MavenProject project, License license) {
         addLicense(licenseMap, project, Arrays.asList(license));
     }
 
     /**
      * This does some cleanup, and basic safety checks on the license objects passed in<br>
      * 1 - Ignore system scoped dependencies<br>
      * 2 - If there are no licenses declared, use "Unknown License"<br>
      * 3 - If there is no name declared, but there is a url, use the url as a key<br>
      * 4 - If there is no name or url, use "Unknown License" as a key<br>
      */
     @Override
     public void addLicense(LicenseMap licenseMap, MavenProject project, List<?> licenses) {
 
         if (Artifact.SCOPE_SYSTEM.equals(project.getArtifact().getScope())) {
             // Do not deal with system scope dependencies
             return;
         }
 
         if (CollectionUtils.isEmpty(licenses)) {
             // No natively declared license was expressed in the pom for this dependency
             // Really funky use of "put"
             // This adds the dependency to the list of dependencies with an unknown license
             licenseMap.put(LicenseMap.getUnknownLicenseMessage(), project);
             return;
         }
 
         for (Object o : licenses) {
             String id = MojoHelper.getArtifactId(project.getArtifact());
             if (o == null) {
                 getLogger().warn("could not acquire a license for " + id);
                 continue;
             }
             License license = (License) o;
             String licenseKey = license.getName();
 
             // tchemit 2010-08-29 Ano #816 Check if the License object is well formed
             if (StringUtils.isEmpty(license.getName())) {
                 getLogger().debug("No license name defined for " + id);
                 licenseKey = license.getUrl();
             }
 
             if (StringUtils.isEmpty(licenseKey)) {
                 getLogger().debug("No license url defined for " + id);
                 licenseKey = LicenseMap.getUnknownLicenseMessage();
             }
 
             // Really funky use of "put"
             // This adds the dependency to the list of dependencies with this license
             licenseMap.put(licenseKey, project);
         }
     }
 
     /**
      * {@inheritDoc}
      */
     @Override
     public void mergeLicenses(LicenseMap licenseMap, String... licenses) {
         if (licenses.length == 0) {
             return;
         }
 
         String mainLicense = licenses[0].trim();
         SortedSet<MavenProject> mainSet = licenseMap.get(mainLicense);
         if (mainSet == null) {
             getLogger().debug("No license [" + mainLicense + "] found, will create it.");
             mainSet = new TreeSet<MavenProject>(projectComparator);
             licenseMap.put(mainLicense, mainSet);
         }
         int size = licenses.length;
         for (int i = 1; i < size; i++) {
             String license = licenses[i].trim();
             SortedSet<MavenProject> set = licenseMap.get(license);
             if (set == null) {
                 getLogger().debug("No license [" + license + "] found, skip this merge.");
                 continue;
             }
             getLogger().debug("Merge license [" + license + "] (" + set.size() + " depedencies).");
             mainSet.addAll(set);
             set.clear();
             licenseMap.remove(license);
         }
     }
 
     protected Properties getProperties(String encoding, File file) throws IOException {
         if (!file.exists()) {
             return new Properties();
         }
         // Load our properties file that maps Maven GAV's to a license
         SortedProperties properties = new SortedProperties(encoding);
         getLogger().debug("Loading " + file);
         properties.load(file);
         return properties;
     }
 
     protected void handleStuff(Properties customMappings, SortedMap<String, MavenProject> artifactCache) {
         // Store any custom mappings that are not used by this project
         List<String> unusedDependencies = new ArrayList<String>();
 
         // If the custom mapping file contains GAV entries with type+classifier, remove type+classifier
         // A simple GAV is enough to figure out appropriate licensing
         Map<String, String> migrateKeys = migrateCustomMappingKeys(customMappings.stringPropertyNames());
         for (String id : migrateKeys.keySet()) {
             String migratedId = migrateKeys.get(id);
 
             MavenProject project = artifactCache.get(migratedId);
             if (project == null) {
                 // Now we are sure this is an unused dependency
                 // Add this GAV as one that we don't care about for this project
                 unusedDependencies.add(id);
             } else {
                 if (!id.equals(migratedId)) {
 
                     // migrates id to migratedId
                     getLogger().info("Migrates [" + id + "] to [" + migratedId + "] in the custom mapping file.");
                     Object value = customMappings.get(id);
                     customMappings.remove(id);
                     customMappings.put(migratedId, value);
                 }
             }
         }
 
         if (!unusedDependencies.isEmpty()) {
             // there are some unused dependencies in the custom mappings file, remove them
             for (String id : unusedDependencies) {
                 getLogger().debug("dependency [" + id + "] does not exist in this project");
                 // Remove it from the custom mappings file since we don't care about it for this project
                 customMappings.remove(id);
             }
         }
 
     }
 
     protected void handleUnsafeDependencies(Set<MavenProject> deps, Properties mappings, LicenseMap licenseMap) {
         Iterator<MavenProject> itr = deps.iterator();
         while (itr.hasNext()) {
             MavenProject dep = itr.next();
             String license = getLicense(dep, mappings);
             if (!StringUtils.isBlank(license)) {
                 addLicense(licenseMap, dep, license);
                 itr.remove();
             } else {
                 getLogger().debug(MojoHelper.getArtifactName(dep) + " " + license);
             }
         }
     }
 
     protected String getLicense(MavenProject d, Properties mappings) {
         String groupId = d.getGroupId();
         String artifactId = d.getArtifactId();
         String version = d.getVersion();
 
         // Exact match
         String id1 = groupId + "--" + artifactId + "--" + version;
         // Match on groupId + artifactId
         String id2 = groupId + "--" + artifactId;
         // Match on groupId
         String id3 = groupId;
 
         String value1 = mappings.getProperty(id1);
         String value2 = mappings.getProperty(id2);
         String value3 = mappings.getProperty(id3);
 
         // Return the license, starting with the most specific, progressing to the least specific
         if (!StringUtils.isBlank(value1)) {
             return value1;
         } else if (!StringUtils.isBlank(value2)) {
             return value2;
         } else if (!StringUtils.isBlank(value3)) {
             return value3;
         } else {
             return null;
         }
     }
 
     /**
      *
      */
     @Override
     public SortedProperties loadUnsafeMapping(LicenseMap licenseMap, SortedMap<String, MavenProject> artifactCache,
             String encoding, File missingFile) throws IOException {
 
         // This is the list of dependencies with no declared license info in their pom's
         SortedSet<MavenProject> unsafeDependencies = licenseMap.get(LicenseMap.getUnknownLicenseMessage());
 
         // Load our properties file that maps Maven GAV's to a license
         Properties customMappings = getProperties(encoding, missingFile);
 
         // Update licenseMap with info from customMappings
         handleUnsafeDependencies(unsafeDependencies, customMappings, licenseMap);
 
         // Return customMappings
         return new SortedProperties(customMappings);
     }
 
     // ----------------------------------------------------------------------
     // Private methods
     // ----------------------------------------------------------------------
 
     /**
      * @param project
      *            not null
      * @param localRepository
      *            not null
      * @param repositories
      *            not null
      * @return the resolved site descriptor
      * @throws IOException
      *             if any
      * @throws ArtifactResolutionException
      *             if any
      * @throws ArtifactNotFoundException
      *             if any
      */
     private File resolveThirdPartyDescriptor(MavenProject project, ArtifactRepository localRepository,
             List<ArtifactRepository> repositories) throws IOException, ArtifactResolutionException,
             ArtifactNotFoundException {
         File result;
 
         // TODO: this is a bit crude - proper type, or proper handling as metadata rather than an artifact in 2.1?
         Artifact artifact = artifactFactory.createArtifactWithClassifier(project.getGroupId(), project.getArtifactId(),
                 project.getVersion(), DESCRIPTOR_TYPE, DESCRIPTOR_CLASSIFIER);
         try {
             artifactResolver.resolve(artifact, repositories, localRepository);
 
             result = artifact.getFile();
 
             // we use zero length files to avoid re-resolution (see below)
             if (result.length() == 0) {
                 getLogger().debug("Skipped third party descriptor");
             }
         } catch (ArtifactNotFoundException e) {
             getLogger().debug("Unable to locate third party files descriptor : " + e);
 
             // we can afford to write an empty descriptor here as we don't expect it to turn up later in the remote
             // repository, because the parent was already released (and snapshots are updated automatically if changed)
             result = new File(localRepository.getBasedir(), localRepository.pathOf(artifact));
 
             FileUtil.createNewFile(result);
         }
 
         return result;
     }
 
     private final Pattern GAV_PLUS_TYPE_PATTERN = Pattern.compile("(.+)--(.+)--(.+)--(.+)");
 
     private final Pattern GAV_PLUS_TYPE_AND_CLASSIFIER_PATTERN = Pattern.compile("(.+)--(.+)--(.+)--(.+)--(.+)");
 
     private Map<String, String> migrateCustomMappingKeys(Set<String> customMappingKeys) {
         Map<String, String> migrateKeys = new HashMap<String, String>();
         for (String id : customMappingKeys) {
             Matcher matcher;
             String newId = id;
             matcher = GAV_PLUS_TYPE_AND_CLASSIFIER_PATTERN.matcher(id);
             if (matcher.matches()) {
                 newId = matcher.group(1) + "--" + matcher.group(2) + "--" + matcher.group(3);
             } else {
                 matcher = GAV_PLUS_TYPE_PATTERN.matcher(id);
                 if (matcher.matches()) {
                     newId = matcher.group(1) + "--" + matcher.group(2) + "--" + matcher.group(3);
                 }
             }
             migrateKeys.put(id, newId);
         }
         return migrateKeys;
     }
 }