/*
    * This file is part of dependency-check-core.
    *
    * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
    *
   * 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.
   *
   * Copyright (c) 2012 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck.analyzer;
  
  import java.io.File;
  import java.util.HashSet;
  import java.util.Iterator;
  import java.util.ListIterator;
  import java.util.Set;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  import org.owasp.dependencycheck.Engine;
  import org.owasp.dependencycheck.analyzer.exception.AnalysisException;
  import org.owasp.dependencycheck.dependency.Dependency;
  import org.owasp.dependencycheck.dependency.Identifier;
  import org.owasp.dependencycheck.utils.DependencyVersion;
  import org.owasp.dependencycheck.utils.DependencyVersionUtil;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * <p>
   * This analyzer ensures dependencies that should be grouped together, to remove excess noise from the report, are grouped. An
   * example would be Spring, Spring Beans, Spring MVC, etc. If they are all for the same version and have the same relative path
   * then these should be grouped into a single dependency under the core/main library.</p>
   * <p>
   * Note, this grouping only works on dependencies with identified CVE entries</p>
   *
   * @author Jeremy Long
   */
  public class DependencyBundlingAnalyzer extends AbstractAnalyzer implements Analyzer {
  
      /**
       * The Logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(DependencyBundlingAnalyzer.class);
  
      //<editor-fold defaultstate="collapsed" desc="Constants and Member Variables">
      /**
       * A pattern for obtaining the first part of a filename.
       */
      private static final Pattern STARTING_TEXT_PATTERN = Pattern.compile("^[a-zA-Z0-9]*");
      /**
       * a flag indicating if this analyzer has run. This analyzer only runs once.
       */
      private boolean analyzed = false;
      //</editor-fold>
      //<editor-fold defaultstate="collapsed" desc="All standard implementation details of Analyzer">
      /**
       * The name of the analyzer.
       */
      private static final String ANALYZER_NAME = "Dependency Bundling Analyzer";
      /**
       * The phase that this analyzer is intended to run in.
       */
      private static final AnalysisPhase ANALYSIS_PHASE = AnalysisPhase.PRE_FINDING_ANALYSIS;
  
      /**
       * Returns the name of the analyzer.
       *
       * @return the name of the analyzer.
       */
      @Override
      public String getName() {
          return ANALYZER_NAME;
      }
  
      /**
       * Returns the phase that the analyzer is intended to run in.
       *
       * @return the phase that the analyzer is intended to run in.
       */
      @Override
      public AnalysisPhase getAnalysisPhase() {
          return ANALYSIS_PHASE;
      }
      //</editor-fold>
  
      /**
       * Analyzes a set of dependencies. If they have been found to have the same base path and the same set of identifiers they are
       * likely related. The related dependencies are bundled into a single reportable item.
       *
       * @param ignore this analyzer ignores the dependency being analyzed
       * @param engine the engine that is scanning the dependencies
      * @throws AnalysisException is thrown if there is an error reading the JAR file.
      */
     @Override
     public void analyze(Dependency ignore, Engine engine) throws AnalysisException {
         if (!analyzed) {
             analyzed = true;
             final Set<Dependency> dependenciesToRemove = new HashSet<Dependency>();
             final ListIterator<Dependency> mainIterator = engine.getDependencies().listIterator();
             //for (Dependency nextDependency : engine.getDependencies()) {
             while (mainIterator.hasNext()) {
                 final Dependency dependency = mainIterator.next();
                 if (mainIterator.hasNext() && !dependenciesToRemove.contains(dependency)) {
                     final ListIterator<Dependency> subIterator = engine.getDependencies().listIterator(mainIterator.nextIndex());
                     while (subIterator.hasNext()) {
                         final Dependency nextDependency = subIterator.next();
                         if (hashesMatch(dependency, nextDependency) && !containedInWar(dependency.getFilePath())
                                 && !containedInWar(nextDependency.getFilePath())) {
                             if (firstPathIsShortest(dependency.getFilePath(), nextDependency.getFilePath())) {
                                 mergeDependencies(dependency, nextDependency, dependenciesToRemove);
                             } else {
                                 mergeDependencies(nextDependency, dependency, dependenciesToRemove);
                                 break; //since we merged into the next dependency - skip forward to the next in mainIterator
                             }
                         } else if (isShadedJar(dependency, nextDependency)) {
                             if (dependency.getFileName().toLowerCase().endsWith("pom.xml")) {
                                 mergeDependencies(nextDependency, dependency, dependenciesToRemove);
                                 nextDependency.getRelatedDependencies().remove(dependency);
                                 break;
                             } else {
                                 mergeDependencies(dependency, nextDependency, dependenciesToRemove);
                                 dependency.getRelatedDependencies().remove(nextDependency);
                             }
                         } else if (cpeIdentifiersMatch(dependency, nextDependency)
                                 && hasSameBasePath(dependency, nextDependency)
                                 && fileNameMatch(dependency, nextDependency)) {
                             if (isCore(dependency, nextDependency)) {
                                 mergeDependencies(dependency, nextDependency, dependenciesToRemove);
                             } else {
                                 mergeDependencies(nextDependency, dependency, dependenciesToRemove);
                                 break; //since we merged into the next dependency - skip forward to the next in mainIterator
                             }
                         }
                     }
                 }
             }
             //removing dependencies here as ensuring correctness and avoiding ConcurrentUpdateExceptions
             // was difficult because of the inner iterator.
             engine.getDependencies().removeAll(dependenciesToRemove);
         }
     }
 
     /**
      * Adds the relatedDependency to the dependency's related dependencies.
      *
      * @param dependency the main dependency
      * @param relatedDependency a collection of dependencies to be removed from the main analysis loop, this is the source of
      * dependencies to remove
      * @param dependenciesToRemove a collection of dependencies that will be removed from the main analysis loop, this function
      * adds to this collection
      */
     private void mergeDependencies(final Dependency dependency, final Dependency relatedDependency, final Set<Dependency> dependenciesToRemove) {
         dependency.addRelatedDependency(relatedDependency);
         final Iterator<Dependency> i = relatedDependency.getRelatedDependencies().iterator();
         while (i.hasNext()) {
             dependency.addRelatedDependency(i.next());
             i.remove();
         }
         if (dependency.getSha1sum().equals(relatedDependency.getSha1sum())) {
             dependency.addAllProjectReferences(relatedDependency.getProjectReferences());
         }
         dependenciesToRemove.add(relatedDependency);
     }
 
     /**
      * Attempts to trim a maven repo to a common base path. This is typically [drive]\[repo_location]\repository\[path1]\[path2].
      *
      * @param path the path to trim
      * @return a string representing the base path.
      */
     private String getBaseRepoPath(final String path) {
         int pos = path.indexOf("repository" + File.separator) + 11;
         if (pos < 0) {
             return path;
         }
         int tmp = path.indexOf(File.separator, pos);
         if (tmp <= 0) {
             return path;
         }
         if (tmp > 0) {
             pos = tmp + 1;
         }
         tmp = path.indexOf(File.separator, pos);
         if (tmp > 0) {
             pos = tmp + 1;
         }
         return path.substring(0, pos);
     }
 
     /**
      * Returns true if the file names (and version if it exists) of the two dependencies are sufficiently similar.
      *
      * @param dependency1 a dependency2 to compare
      * @param dependency2 a dependency2 to compare
      * @return true if the identifiers in the two supplied dependencies are equal
      */
     private boolean fileNameMatch(Dependency dependency1, Dependency dependency2) {
         if (dependency1 == null || dependency1.getFileName() == null
                 || dependency2 == null || dependency2.getFileName() == null) {
             return false;
         }
         final String fileName1 = dependency1.getActualFile().getName();
         final String fileName2 = dependency2.getActualFile().getName();
 
         //version check
         final DependencyVersion version1 = DependencyVersionUtil.parseVersion(fileName1);
         final DependencyVersion version2 = DependencyVersionUtil.parseVersion(fileName2);
         if (version1 != null && version2 != null) {
             if (!version1.equals(version2)) {
                 return false;
             }
         }
 
         //filename check
         final Matcher match1 = STARTING_TEXT_PATTERN.matcher(fileName1);
         final Matcher match2 = STARTING_TEXT_PATTERN.matcher(fileName2);
         if (match1.find() && match2.find()) {
             return match1.group().equals(match2.group());
         }
 
         return false;
     }
 
     /**
      * Returns true if the CPE identifiers in the two supplied dependencies are equal.
      *
      * @param dependency1 a dependency2 to compare
      * @param dependency2 a dependency2 to compare
      * @return true if the identifiers in the two supplied dependencies are equal
      */
     private boolean cpeIdentifiersMatch(Dependency dependency1, Dependency dependency2) {
         if (dependency1 == null || dependency1.getIdentifiers() == null
                 || dependency2 == null || dependency2.getIdentifiers() == null) {
             return false;
         }
         boolean matches = false;
         int cpeCount1 = 0;
         int cpeCount2 = 0;
         for (Identifier i : dependency1.getIdentifiers()) {
             if ("cpe".equals(i.getType())) {
                 cpeCount1 += 1;
             }
         }
         for (Identifier i : dependency2.getIdentifiers()) {
             if ("cpe".equals(i.getType())) {
                 cpeCount2 += 1;
             }
         }
         if (cpeCount1 > 0 && cpeCount1 == cpeCount2) {
             for (Identifier i : dependency1.getIdentifiers()) {
                 if ("cpe".equals(i.getType())) {
                     matches |= dependency2.getIdentifiers().contains(i);
                     if (!matches) {
                         break;
                     }
                 }
             }
         }
         LOGGER.debug("IdentifiersMatch={} ({}, {})", matches, dependency1.getFileName(), dependency2.getFileName());
         return matches;
     }
 
     /**
      * Determines if the two dependencies have the same base path.
      *
      * @param dependency1 a Dependency object
      * @param dependency2 a Dependency object
      * @return true if the base paths of the dependencies are identical
      */
     private boolean hasSameBasePath(Dependency dependency1, Dependency dependency2) {
         if (dependency1 == null || dependency2 == null) {
             return false;
         }
         final File lFile = new File(dependency1.getFilePath());
         String left = lFile.getParent();
         final File rFile = new File(dependency2.getFilePath());
         String right = rFile.getParent();
         if (left == null) {
             return right == null;
         }
         if (left.equalsIgnoreCase(right)) {
             return true;
         }
         if (left.matches(".*[/\\\\]repository[/\\\\].*") && right.matches(".*[/\\\\]repository[/\\\\].*")) {
             left = getBaseRepoPath(left);
             right = getBaseRepoPath(right);
         }
         if (left.equalsIgnoreCase(right)) {
             return true;
         }
         //new code
         for (Dependency child : dependency2.getRelatedDependencies()) {
             if (hasSameBasePath(dependency1, child)) {
                 return true;
             }
         }
         return false;
     }
 
     /**
      * This is likely a very broken attempt at determining if the 'left' dependency is the 'core' library in comparison to the
      * 'right' library.
      *
      * @param left the dependency to test
      * @param right the dependency to test against
      * @return a boolean indicating whether or not the left dependency should be considered the "core" version.
      */
     boolean isCore(Dependency left, Dependency right) {
         final String leftName = left.getFileName().toLowerCase();
         final String rightName = right.getFileName().toLowerCase();
 
         final boolean returnVal;
         if (!rightName.matches(".*\\.(tar|tgz|gz|zip|ear|war).+") && leftName.matches(".*\\.(tar|tgz|gz|zip|ear|war).+")
                 || rightName.contains("core") && !leftName.contains("core")
                 || rightName.contains("kernel") && !leftName.contains("kernel")) {
             returnVal = false;
         } else if (rightName.matches(".*\\.(tar|tgz|gz|zip|ear|war).+") && !leftName.matches(".*\\.(tar|tgz|gz|zip|ear|war).+")
                 || !rightName.contains("core") && leftName.contains("core")
                 || !rightName.contains("kernel") && leftName.contains("kernel")) {
             returnVal = true;
 //        } else if (leftName.matches(".*struts2\\-core.*") && rightName.matches(".*xwork\\-core.*")) {
 //            returnVal = true;
 //        } else if (rightName.matches(".*struts2\\-core.*") && leftName.matches(".*xwork\\-core.*")) {
 //            returnVal = false;
         } else {
             /*
              * considered splitting the names up and comparing the components,
              * but decided that the file name length should be sufficient as the
              * "core" component, if this follows a normal naming protocol should
              * be shorter:
              * axis2-saaj-1.4.1.jar
              * axis2-1.4.1.jar       <-----
              * axis2-kernel-1.4.1.jar
              */
             returnVal = leftName.length() <= rightName.length();
         }
         LOGGER.debug("IsCore={} ({}, {})", returnVal, left.getFileName(), right.getFileName());
         return returnVal;
     }
 
     /**
      * Compares the SHA1 hashes of two dependencies to determine if they are equal.
      *
      * @param dependency1 a dependency object to compare
      * @param dependency2 a dependency object to compare
      * @return true if the sha1 hashes of the two dependencies match; otherwise false
      */
     private boolean hashesMatch(Dependency dependency1, Dependency dependency2) {
         if (dependency1 == null || dependency2 == null || dependency1.getSha1sum() == null || dependency2.getSha1sum() == null) {
             return false;
         }
         return dependency1.getSha1sum().equals(dependency2.getSha1sum());
     }
 
     /**
      * Determines if the jar is shaded and the created pom.xml identified the same CPE as the jar - if so, the pom.xml dependency
      * should be removed.
      *
      * @param dependency a dependency to check
      * @param nextDependency another dependency to check
      * @return true if on of the dependencies is a pom.xml and the identifiers between the two collections match; otherwise false
      */
     private boolean isShadedJar(Dependency dependency, Dependency nextDependency) {
         final String mainName = dependency.getFileName().toLowerCase();
         final String nextName = nextDependency.getFileName().toLowerCase();
         if (mainName.endsWith(".jar") && nextName.endsWith("pom.xml")) {
             return dependency.getIdentifiers().containsAll(nextDependency.getIdentifiers());
         } else if (nextName.endsWith(".jar") && mainName.endsWith("pom.xml")) {
             return nextDependency.getIdentifiers().containsAll(dependency.getIdentifiers());
         }
         return false;
     }
 
     /**
      * Determines which path is shortest; if path lengths are equal then we use compareTo of the string method to determine if the
      * first path is smaller.
      *
      * @param left the first path to compare
      * @param right the second path to compare
      * @return <code>true</code> if the leftPath is the shortest; otherwise <code>false</code>
      */
     protected boolean firstPathIsShortest(String left, String right) {
         final String leftPath = left.replace('\\', '/');
         final String rightPath = right.replace('\\', '/');
 
         final int leftCount = countChar(leftPath, '/');
         final int rightCount = countChar(rightPath, '/');
         if (leftCount == rightCount) {
             return leftPath.compareTo(rightPath) <= 0;
         } else {
             return leftCount < rightCount;
         }
     }
 
     /**
      * Counts the number of times the character is present in the string.
      *
      * @param string the string to count the characters in
      * @param c the character to count
      * @return the number of times the character is present in the string
      */
     private int countChar(String string, char c) {
         int count = 0;
         final int max = string.length();
         for (int i = 0; i < max; i++) {
             if (c == string.charAt(i)) {
                 count++;
             }
         }
         return count;
     }
 
     /**
      * Checks if the given file path is contained within a war or ear file.
      *
      * @param filePath the file path to check
      * @return true if the path contains '.war\' or '.ear\'.
      */
     private boolean containedInWar(String filePath) {
         return filePath == null ? false : filePath.matches(".*\\.(ear|war)[\\\\/].*");
     }
 }