/*
    * Copyright (C) 2011 the original author or authors.
    *
    * 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.
   */
  
  package org.codehaus.gmavenplus.mojo;
  
  import org.apache.maven.plugins.annotations.Parameter;
  import org.codehaus.gmavenplus.groovyworkarounds.DotGroovyFile;
  import org.codehaus.gmavenplus.model.IncludeClasspath;
  import org.codehaus.gmavenplus.model.internal.Version;
  import org.codehaus.gmavenplus.util.FileUtils;
  
  import java.io.File;
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.net.MalformedURLException;
  import java.util.HashMap;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import static org.codehaus.gmavenplus.util.ReflectionUtils.findConstructor;
  import static org.codehaus.gmavenplus.util.ReflectionUtils.findMethod;
  import static org.codehaus.gmavenplus.util.ReflectionUtils.invokeConstructor;
  import static org.codehaus.gmavenplus.util.ReflectionUtils.invokeMethod;
  
  
  /**
   * The base generate stubs mojo, which all generate stubs mojos extend.
   *
   * @author Keegan Witt
   * @since 1.0-beta-1
   */
  public abstract class AbstractGenerateStubsMojo extends AbstractGroovyStubSourcesMojo {
  
      /**
       * Groovy 5.0.0-alpha-1 version.
       */
      protected static final Version GROOVY_5_0_0_ALPHA1 = new Version(5, 0, 0, "alpha-1");
  
      /**
       * Groovy 4.0.11 version.
       */
      protected static final Version GROOVY_4_0_21 = new Version(4, 0, 21);
  
      /**
       * Groovy 4.0.11 version.
       */
      protected static final Version GROOVY_4_0_16 = new Version(4, 0, 16);
  
      /**
       * Groovy 4.0.11 version.
       */
      protected static final Version GROOVY_4_0_11 = new Version(4, 0, 11);
  
      /**
       * Groovy 4.0.6 version.
       */
      protected static final Version GROOVY_4_0_6 = new Version(4, 0, 6);
  
      /**
       * Groovy 4.0.2 version.
       */
      protected static final Version GROOVY_4_0_2 = new Version(4, 0, 2);
  
      /**
       * Groovy 4.0.0 beta-1 version.
       */
      protected static final Version GROOVY_4_0_0_BETA1 = new Version(4, 0, 0, "beta-1");
  
      /**
       * Groovy 4.0.0 alpha-3 version.
       */
      protected static final Version GROOVY_4_0_0_ALPHA3 = new Version(4, 0, 0, "alpha-3");
  
      /**
       * Groovy 4.0.0 alpha-1 version.
       */
      protected static final Version GROOVY_4_0_0_ALPHA1 = new Version(4, 0, 0, "alpha-1");
  
      /**
       * Groovy 3.0.8 version.
       */
      protected static final Version GROOVY_3_0_8 = new Version(3, 0, 8);
  
      /**
      * Groovy 3.0.6 version.
      */
     protected static final Version GROOVY_3_0_6 = new Version(3, 0, 6);
 
     /**
      * Groovy 3.0.3 version.
      */
     protected static final Version GROOVY_3_0_3 = new Version(3, 0, 3);
 
     /**
      * Groovy 3.0.0 beta-2 version.
      */
     protected static final Version GROOVY_3_0_0_BETA2 = new Version(3, 0, 0, "beta-2");
 
     /**
      * Groovy 3.0.0 beta-1 version.
      */
     protected static final Version GROOVY_3_0_0_BETA1 = new Version(3, 0, 0, "beta-1");
 
     /**
      * Groovy 3.0.0 alpha-4 version.
      */
     protected static final Version GROOVY_3_0_0_ALPHA4 = new Version(3, 0, 0, "alpha-4");
 
     /**
      * Groovy 3.0.0 alpha-2 version.
      */
     protected static final Version GROOVY_3_0_0_ALPHA2 = new Version(3, 0, 0, "alpha-2");
 
     /**
      * Groovy 3.0.0 alpha-1 version.
      */
     protected static final Version GROOVY_3_0_0_ALPHA1 = new Version(3, 0, 0, "alpha-1");
 
     /**
      * Groovy 2.6.0 alpha-4 version.
      */
     protected static final Version GROOVY_2_6_0_ALPHA4 = new Version(2, 6, 0, "alpha-4");
 
     /**
      * Groovy 2.6.0 alpha-1 version.
      */
     protected static final Version GROOVY_2_6_0_ALPHA1 = new Version(2, 6, 0, "alpha-1");
 
     /**
      * Groovy 2.5.7 version.
      */
     protected static final Version GROOVY_2_5_7 = new Version(2, 5, 7);
 
     /**
      * Groovy 2.5.3 version.
      */
     protected static final Version GROOVY_2_5_3 = new Version(2, 5, 3);
 
     /**
      * Groovy 2.3.3 version.
      */
     protected static final Version GROOVY_2_3_3 = new Version(2, 3, 3);
 
     /**
      * Groovy 2.1.3 version.
      */
     protected static final Version GROOVY_2_1_3 = new Version(2, 1, 3);
 
     /**
      * Groovy 2.9.0 beta-1 version.
      */
     protected static final Version GROOVY_1_9_0_BETA1 = new Version(1, 9, 0, "beta-1");
 
     /**
      * Groovy 1.9.0 beta-3 version.
      */
     protected static final Version GROOVY_1_9_0_BETA3 = new Version(1, 9, 0, "beta-3");
 
     /**
      * Groovy 1.8.2 version.
      */
     protected static final Version GROOVY_1_8_2 = new Version(1, 8, 2);
 
     /**
      * Groovy 1.8.3 version.
      */
     protected static final Version GROOVY_1_8_3 = new Version(1, 8, 3);
 
     /**
      * The encoding of source files.
      */
     @Parameter(defaultValue = "${project.build.sourceEncoding}")
     protected String sourceEncoding;
 
     /**
      * The Groovy compiler bytecode compatibility. One of
      * <ul>
      *   <li>1.4 (or 4)</li>
      *   <li>1.5 (or 5)</li>
      *   <li>1.6 (or 6)</li>
      *   <li>1.7 (or 7)</li>
      *   <li>1.8 (or 8)</li>
      *   <li>9 (or 1.9)</li>
      *   <li>10</li>
      *   <li>11</li>
      *   <li>12</li>
      *   <li>13</li>
      *   <li>14</li>
      *   <li>15</li>
      *   <li>16</li>
      *   <li>17</li>
      *   <li>18</li>
      *   <li>19</li>
      *   <li>20</li>
      *   <li>21</li>
      *   <li>22</li>
      *   <li>23</li>
      * </ul>
      * Using 1.6 (or 6) or 1.7 (or 7) requires Groovy &gt;= 2.1.3.
      * Using 1.8 (or 8) requires Groovy &gt;= 2.3.3.
      * Using 9 (or 1.9) requires Groovy &gt;= 2.5.3, or Groovy &gt;= 2.6.0 alpha 4, or Groovy &gt;= 3.0.0 alpha 2.
      * Using 9 (or 1.9) with invokedynamic requires Groovy &gt;= 2.5.3, or Groovy &gt;= 3.0.0 alpha 2, but not any 2.6 versions.
      * Using 10, 11, or 12 requires Groovy &gt;= 2.5.3, or Groovy &gt;= 3.0.0 alpha 4, but not any 2.6 versions.
      * Using 13 requires Groovy &gt;= 2.5.7, or Groovy &gt;= 3.0.0-beta-1, but not any 2.6 versions.
      * Using 14 requires Groovy &gt;= 3.0.0 beta-2.
      * Using 15 requires Groovy &gt;= 3.0.3.
      * Using 16 requires Groovy &gt;= 3.0.6.
      * Using 17 requires Groovy &gt;= 3.0.8 or Groovy &gt; 4.0.0-alpha-3.
      * Using 18 requires Groovy &gt; 4.0.0-beta-1.
      * Using 19 requires Groovy &gt; 4.0.2.
      * Using 20 requires Groovy &gt; 4.0.6.
      * Using 21 requires Groovy &gt; 4.0.11.
      * Using 22 requires Groovy &gt; 4.0.16.
      * Using 23 requires Groovy &gt; 4.0.21.
      *
      * @since 1.0-beta-3
      */
     @Parameter(property = "maven.compiler.target", defaultValue = "1.8")
     protected String targetBytecode;
 
     /**
      * Whether to check that the version of Groovy used is able to use the requested <code>targetBytecode</code>.
      *
      * @since 1.9.0
      */
     @Parameter(property = "skipBytecodeCheck", defaultValue = "false")
     protected boolean skipBytecodeCheck;
 
     /**
      * Whether Groovy compiler should be set to debug.
      */
     @Parameter(defaultValue = "false")
     protected boolean debug;
 
     /**
      * Whether Groovy compiler should be set to verbose.
      */
     @Parameter(defaultValue = "false")
     protected boolean verbose;
 
     /**
      * Groovy compiler warning level. Should be one of:
      * <dl>
      *   <dt>0</dt>
      *     <dd>None</dd>
      *   <dt>1</dt>
      *     <dd>Likely Errors</dd>
      *   <dt>2</dt>
      *     <dd>Possible Errors</dd>
      *   <dt>3</dt>
      *     <dd>Paranoia</dd>
      * </dl>
      */
     @Parameter(defaultValue = "1")
     protected int warningLevel;
 
     /**
      * Groovy compiler error tolerance (the number of non-fatal errors (per unit) that should be tolerated before compilation is aborted).
      */
     @Parameter(defaultValue = "0")
     protected int tolerance;
 
     /**
      * What classpath to include. One of
      * <ul>
      *   <li>PROJECT_ONLY</li>
      *   <li>PROJECT_AND_PLUGIN</li>
      *   <li>PLUGIN_ONLY</li>
      * </ul>
      * Uses the same scope as the required dependency resolution of this mojo. Use only if you know what you're doing.
      *
      * @since 1.8.0
      */
     @Parameter(defaultValue = "PROJECT_ONLY")
     protected IncludeClasspath includeClasspath;
 
     /**
      * Performs the stub generation on the specified source files.
      *
      * @param stubSources     the sources to perform stub generation on
      * @param classpath       The classpath to use for compilation
      * @param outputDirectory the directory to write the stub files to
      * @throws ClassNotFoundException    when a class needed for stub generation cannot be found
      * @throws InstantiationException    when a class needed for stub generation cannot be instantiated
      * @throws IllegalAccessException    when a method needed for stub generation cannot be accessed
      * @throws InvocationTargetException when a reflection invocation needed for stub generation cannot be completed
      * @throws MalformedURLException     when a classpath element provides a malformed URL
      */
     protected synchronized void doStubGeneration(final Set<File> stubSources, final List<?> classpath, final File outputDirectory) throws ClassNotFoundException, InvocationTargetException, IllegalAccessException, InstantiationException, MalformedURLException {
         if (stubSources == null || stubSources.isEmpty()) {
             getLog().info("No sources specified for stub generation. Skipping.");
             return;
         }
 
         setupClassWrangler(classpath, includeClasspath);
 
         logPluginClasspath();
         classWrangler.logGroovyVersion(mojoExecution.getMojoDescriptor().getGoal());
 
         if (!groovyVersionSupportsAction()) {
             getLog().error("Your Groovy version (" + classWrangler.getGroovyVersionString() + ") doesn't support stub generation. The minimum version of Groovy required is " + minGroovyVersion + ". Skipping stub generation.");
             return;
         }
 
         if (!skipBytecodeCheck) {
             verifyGroovyVersionSupportsTargetBytecode();
         }
 
         // get classes we need with reflection
         Class<?> compilerConfigurationClass = classWrangler.getClass("org.codehaus.groovy.control.CompilerConfiguration");
         Class<?> javaStubCompilationUnitClass = classWrangler.getClass("org.codehaus.groovy.tools.javac.JavaStubCompilationUnit");
         Class<?> groovyClassLoaderClass = classWrangler.getClass("groovy.lang.GroovyClassLoader");
 
         // setup stub generation options
         Object compilerConfiguration = setupCompilerConfiguration(outputDirectory, compilerConfigurationClass);
         Object groovyClassLoader = invokeConstructor(findConstructor(groovyClassLoaderClass, ClassLoader.class, compilerConfigurationClass), classWrangler.getClassLoader(), compilerConfiguration);
         Object javaStubCompilationUnit = invokeConstructor(findConstructor(javaStubCompilationUnitClass, compilerConfigurationClass, groovyClassLoaderClass, File.class), compilerConfiguration, groovyClassLoader, outputDirectory);
 
         // add Groovy sources
         addGroovySources(stubSources, compilerConfigurationClass, javaStubCompilationUnitClass, compilerConfiguration, javaStubCompilationUnit);
 
         // generate the stubs
         invokeMethod(findMethod(javaStubCompilationUnitClass, "compile"), javaStubCompilationUnit);
     }
 
     /**
      * Sets up the CompilerConfiguration to use for stub generation.
      *
      * @param outputDirectory            the directory to write the stub files to
      * @param compilerConfigurationClass the CompilerConfiguration class
      * @return the CompilerConfiguration to use for stub generation
      * @throws InstantiationException    when a class needed for stub generation cannot be instantiated
      * @throws IllegalAccessException    when a method needed for stub generation cannot be accessed
      * @throws InvocationTargetException when a reflection invocation needed for stub generation cannot be completed
      */
     protected Object setupCompilerConfiguration(final File outputDirectory, final Class<?> compilerConfigurationClass) throws InvocationTargetException, IllegalAccessException, InstantiationException {
         Object compilerConfiguration = invokeConstructor(findConstructor(compilerConfigurationClass));
         invokeMethod(findMethod(compilerConfigurationClass, "setDebug", boolean.class), compilerConfiguration, debug);
         invokeMethod(findMethod(compilerConfigurationClass, "setVerbose", boolean.class), compilerConfiguration, verbose);
         invokeMethod(findMethod(compilerConfigurationClass, "setWarningLevel", int.class), compilerConfiguration, warningLevel);
         invokeMethod(findMethod(compilerConfigurationClass, "setTolerance", int.class), compilerConfiguration, tolerance);
         invokeMethod(findMethod(compilerConfigurationClass, "setTargetBytecode", String.class), compilerConfiguration, translateJavacTargetToTargetBytecode(targetBytecode));
         if (sourceEncoding != null) {
             invokeMethod(findMethod(compilerConfigurationClass, "setSourceEncoding", String.class), compilerConfiguration, sourceEncoding);
         }
         Map<String, Object> options = new HashMap<>();
         options.put("stubDir", outputDirectory);
         options.put("keepStubs", Boolean.TRUE);
         invokeMethod(findMethod(compilerConfigurationClass, "setJointCompilationOptions", Map.class), compilerConfiguration, options);
 
         return compilerConfiguration;
     }
 
     /**
      * Adds the Groovy sources to the CompilationUnit.
      *
      * @param stubSources                  the sources to perform stub generation on
      * @param compilerConfigurationClass   the CompilerConfiguration class
      * @param javaStubCompilationUnitClass the JavaStubCompilationUnit class
      * @param compilerConfiguration        the CompilerConfiguration to use for stub generation
      * @param javaStubCompilationUnit      the JavaStubCompilationUnit to use for stub generation
      * @throws IllegalAccessException    when a method needed for stub generation cannot be accessed
      * @throws InvocationTargetException when a reflection invocation needed for stub generation cannot be completed
      */
     protected void addGroovySources(final Set<File> stubSources, final Class<?> compilerConfigurationClass, final Class<?> javaStubCompilationUnitClass, final Object compilerConfiguration, final Object javaStubCompilationUnit) throws InvocationTargetException, IllegalAccessException {
         Set<String> scriptExtensions = new HashSet<>();
         for (File stubSource : stubSources) {
             scriptExtensions.add(FileUtils.getFileExtension(stubSource));
         }
         getLog().debug("Detected Groovy file extensions: " + scriptExtensions + ".");
         if (supportsSettingExtensions()) {
             invokeMethod(findMethod(compilerConfigurationClass, "setScriptExtensions", Set.class), compilerConfiguration, scriptExtensions);
         }
         getLog().debug("Adding Groovy to generate stubs for:");
         Method addSource = findMethod(javaStubCompilationUnitClass, "addSource", File.class);
         for (File stubSource : stubSources) {
             getLog().debug("    " + stubSource);
             if (supportsSettingExtensions()) {
                 invokeMethod(addSource, javaStubCompilationUnit, stubSource);
             } else {
                 DotGroovyFile dotGroovyFile = new DotGroovyFile(stubSource).setScriptExtensions(scriptExtensions);
                 invokeMethod(addSource, javaStubCompilationUnit, dotGroovyFile);
             }
         }
     }
 
     /**
      * Determines whether the version of Groovy supports stub generation.
      *
      * @return <code>true</code> if the version of Groovy supports stub generation, <code>false</code> otherwise
      */
     protected boolean supportsSettingExtensions() {
         return groovyAtLeast(GROOVY_1_8_3) && (groovyOlderThan(GROOVY_1_9_0_BETA1) || groovyNewerThan(GROOVY_1_9_0_BETA3));
     }
 
     /**
      * Logs the stubs that have been generated.
      *
      * @param outputDirectory the output directory for the stubs
      */
     protected void logGeneratedStubs(File outputDirectory) {
         Set<File> stubs = getStubs(outputDirectory);
         getLog().info("Generated " + stubs.size() + " stub" + (stubs.size() != 1 ? "s" : "") + ".");
     }
 
     /**
      * This is a fix for <a href="http://jira.codehaus.org/browse/MGROOVY-187">...</a>
      * It modifies the dates of the created stubs to 1/1/1970, ensuring that the Java compiler will not overwrite perfectly
      * good compiled Groovy just because it has a newer source stub. Basically, this prevents the stubs from causing a
      * side effect with the Java compiler, but still allows stubs to work with JavaDoc.
      *
      * @param stubs the files on which to reset the modified date
      */
     protected void resetStubModifiedDates(final Set<File> stubs) {
         for (File stub : stubs) {
             boolean success = stub.setLastModified(0L);
             if (!success) {
                 getLog().warn("Unable to set modified time on stub " + stub.getAbsolutePath() + ".");
             }
         }
     }
 
     /**
      * Throws an exception if targetBytecode is not supported with this version of Groovy. That is, when Groovy added
      * the option to org.codehaus.groovy.control.CompilerConfiguration and used it in
      * org.codehaus.groovy.classgen.asm.WriterController.
      */
     protected void verifyGroovyVersionSupportsTargetBytecode() {
         if ("1.5".equals(targetBytecode) || "5".equals(targetBytecode) || "1.6".equals(targetBytecode) || "6".equals(targetBytecode) || "1.7".equals(targetBytecode) || "7".equals(targetBytecode) || "1.8".equals(targetBytecode) || "8".equals(targetBytecode) || "1.9".equals(targetBytecode) || "9".equals(targetBytecode) || "10".equals(targetBytecode)) {
             if (groovyNewerThan(GROOVY_5_0_0_ALPHA1)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " isn't accepted by Groovy " + GROOVY_5_0_0_ALPHA1 + " or newer.");
             }
         }
 
         if ("23".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_21)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_21 + " or newer.");
             }
         } else if ("22".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_16)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_16 + " or newer.");
             }
         } else if ("21".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_11)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_11 + " or newer.");
             }
         } else if ("20".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_6)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_6 + " or newer.");
             }
         } else if ("19".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_2)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_2 + " or newer.");
             }
         } else if ("18".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_4_0_0_BETA1)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_4_0_0_BETA1 + " or newer.");
             }
         } else if ("17".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_3_0_8) || (groovyAtLeast(GROOVY_4_0_0_ALPHA1) && groovyOlderThan(GROOVY_4_0_0_ALPHA3))) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_3_0_8 + "/" + GROOVY_4_0_0_ALPHA3 + " or newer.");
             }
         } else if ("16".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_3_0_6)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_3_0_6 + " or newer.");
             }
         } else if ("15".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_3_0_3)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_3_0_3 + " or newer.");
             }
         } else if ("14".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_3_0_0_BETA2)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_3_0_0_BETA2 + " or newer.");
             }
         } else if ("13".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_2_5_7) || (groovyAtLeast(GROOVY_2_6_0_ALPHA1) && groovyOlderThan(GROOVY_3_0_0_BETA1))) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_2_5_7 + "/" + GROOVY_3_0_0_BETA1 + " or newer. No 2.6 version is supported.");
             }
         } else if ("12".equals(targetBytecode) || "11".equals(targetBytecode) || "10".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_2_5_3) || (groovyAtLeast(GROOVY_2_6_0_ALPHA1) && groovyOlderThan(GROOVY_3_0_0_ALPHA4))) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_2_5_3 + "/" + GROOVY_3_0_0_ALPHA4 + " or newer. No 2.6 version is supported.");
             }
         } else if ("9".equals(targetBytecode) || "1.9".equals(targetBytecode)) {
             if (!isGroovyIndy() && (groovyOlderThan(GROOVY_2_5_3)
                     || (groovyAtLeast(GROOVY_2_6_0_ALPHA1) && groovyOlderThan(GROOVY_2_6_0_ALPHA4))
                     || (groovyAtLeast(GROOVY_3_0_0_ALPHA1) && groovyOlderThan(GROOVY_3_0_0_ALPHA2)))) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_2_5_3 + "/" + GROOVY_2_6_0_ALPHA4 + "/" + GROOVY_3_0_0_ALPHA2 + " or newer.");
             } else if (isGroovyIndy() && (groovyOlderThan(GROOVY_2_5_3) || (groovyAtLeast(GROOVY_2_6_0_ALPHA1) && groovyOlderThan(GROOVY_3_0_0_ALPHA4)))) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_2_5_3 + "/" + GROOVY_3_0_0_ALPHA4 + " or newer. No 2.6 version is supported.");
             }
         } else if ("8".equals(targetBytecode) || "1.8".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_2_3_3)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_2_3_3 + " or newer.");
             }
         } else if ("7".equals(targetBytecode) || "1.7".equals(targetBytecode) || "6".equals(targetBytecode) || "1.6".equals(targetBytecode)) {
             if (groovyOlderThan(GROOVY_2_1_3)) {
                 throw new IllegalArgumentException("Target bytecode " + targetBytecode + " requires Groovy " + GROOVY_2_1_3 + " or newer.");
             }
         } else if (!"5".equals(targetBytecode) && !"1.5".equals(targetBytecode) && !"4".equals(targetBytecode) && !"1.4".equals(targetBytecode)) {
             throw new IllegalArgumentException("Unrecognized target bytecode: '" + targetBytecode + "'. This check can be skipped with 'skipBytecodeCheck', but this may result in a different target bytecode being used.");
         }
     }
 
     protected static String translateJavacTargetToTargetBytecode(String targetBytecode) {
         Map<String, String> javacTargetToTargetBytecode = new HashMap<>();
         javacTargetToTargetBytecode.put("5", "1.5");
         javacTargetToTargetBytecode.put("6", "1.6");
         javacTargetToTargetBytecode.put("7", "1.7");
         javacTargetToTargetBytecode.put("8", "1.8");
         javacTargetToTargetBytecode.put("1.9", "9");
         return javacTargetToTargetBytecode.getOrDefault(targetBytecode, targetBytecode);
     }
 
 }