package org.codehaus.plexus.compiler.eclipse;
   
   /**
    * The MIT License
    * <p>
    * Copyright (c) 2005, The Codehaus
    * <p>
    * Permission is hereby granted, free of charge, to any person obtaining a copy of
    * this software and associated documentation files (the "Software"), to deal in
   * the Software without restriction, including without limitation the rights to
   * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
   * of the Software, and to permit persons to whom the Software is furnished to do
   * so, subject to the following conditions:
   * <p>
   * The above copyright notice and this permission notice shall be included in all
   * copies or substantial portions of the Software.
   * <p>
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
   * SOFTWARE.
   */
  import javax.inject.Named;
  import javax.inject.Singleton;
  import javax.tools.Diagnostic;
  import javax.tools.DiagnosticListener;
  import javax.tools.JavaCompiler;
  import javax.tools.JavaFileObject;
  import javax.tools.StandardJavaFileManager;
  
  import java.io.File;
  import java.io.PrintWriter;
  import java.io.StringWriter;
  import java.nio.charset.Charset;
  import java.nio.charset.IllegalCharsetNameException;
  import java.nio.charset.UnsupportedCharsetException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Iterator;
  import java.util.List;
  import java.util.Locale;
  import java.util.Map.Entry;
  import java.util.ServiceLoader;
  
  import org.codehaus.plexus.compiler.AbstractCompiler;
  import org.codehaus.plexus.compiler.CompilerConfiguration;
  import org.codehaus.plexus.compiler.CompilerException;
  import org.codehaus.plexus.compiler.CompilerMessage;
  import org.codehaus.plexus.compiler.CompilerOutputStyle;
  import org.codehaus.plexus.compiler.CompilerResult;
  import org.codehaus.plexus.util.StringUtils;
  import org.eclipse.jdt.core.compiler.CompilationProgress;
  import org.eclipse.jdt.core.compiler.batch.BatchCompiler;
  
  /**
   *
   */
  @Named("eclipse")
  @Singleton
  public class EclipseJavaCompiler extends AbstractCompiler {
      public EclipseJavaCompiler() {
          super(CompilerOutputStyle.ONE_OUTPUT_FILE_PER_INPUT_FILE, ".java", ".class", null);
      }
  
      // ----------------------------------------------------------------------
      // Compiler Implementation
      // ----------------------------------------------------------------------
      boolean errorsAsWarnings = false;
  
      @Override
      public String getCompilerId() {
          return "eclipse";
      }
  
      @Override
      public CompilerResult performCompile(CompilerConfiguration config) throws CompilerException {
          List<String> args = new ArrayList<>();
          args.add("-noExit"); // Make sure ecj does not System.exit on us 8-/
  
          // Build settings from configuration
          if (config.isDebug()) {
              args.add("-preserveAllLocals");
              args.add("-g:lines,vars,source");
          } else {
              args.add("-g:lines,source");
          }
  
          String releaseVersion = decodeVersion(config.getReleaseVersion());
          // EcjFailureException: Failed to run the ecj compiler: option -source is not supported when --release is used
          if (releaseVersion != null) {
              args.add("--release");
              args.add(releaseVersion);
          } else {
              String sourceVersion = decodeVersion(config.getSourceVersion());
  
              if (sourceVersion != null) {
                 args.add("-source");
                 args.add(sourceVersion);
             }
 
             String targetVersion = decodeVersion(config.getTargetVersion());
 
             if (targetVersion != null) {
                 args.add("-target");
                 args.add(targetVersion);
             }
         }
 
         if (StringUtils.isNotEmpty(config.getSourceEncoding())) {
             args.add("-encoding");
             args.add(config.getSourceEncoding());
         }
 
         if (!config.isShowWarnings()) {
             args.add("-warn:none");
         } else {
             String warnings = config.getWarnings();
             StringBuilder warns =
                     StringUtils.isEmpty(warnings) ? new StringBuilder() : new StringBuilder(warnings).append(',');
 
             if (config.isShowDeprecation()) {
                 append(warns, "+deprecation");
             } else {
                 append(warns, "-deprecation");
             }
 
             // -- Make room for more warnings to be enabled/disabled
             args.add("-warn:" + warns);
         }
 
         if (config.isParameters()) {
             args.add("-parameters");
         }
 
         if (config.isFailOnWarning()) {
             args.add("-failOnWarning");
         }
 
         // Set Eclipse-specific options
         // compiler-specific extra options override anything else in the config object...
         this.errorsAsWarnings = processCustomArguments(config, args);
 
         // Output path
         args.add("-d");
         args.add(config.getOutputLocation());
 
         // -- classpath
         // must be done before annotation processors: https://bugs.eclipse.org/bugs/show_bug.cgi?id=573833
         List<String> classpathEntries = new ArrayList<>(config.getClasspathEntries());
         classpathEntries.add(config.getOutputLocation());
         args.add("-classpath");
         args.add(getPathString(classpathEntries));
 
         List<String> modulepathEntries = config.getModulepathEntries();
         if (modulepathEntries != null && !modulepathEntries.isEmpty()) {
             args.add("--module-path");
             args.add(getPathString(modulepathEntries));
         }
 
         // Annotation processors defined?
         // must be done after classpath: https://bugs.eclipse.org/bugs/show_bug.cgi?id=573833
         if (!isPreJava1_6(config)) {
             File generatedSourcesDir = config.getGeneratedSourcesDirectory();
             if (generatedSourcesDir != null) {
                 generatedSourcesDir.mkdirs();
 
                 // -- option to specify where annotation processor is to generate its output
                 args.add("-s");
                 args.add(generatedSourcesDir.getAbsolutePath());
             }
 
             // now add jdk 1.6 annotation processing related parameters
             String[] annotationProcessors = config.getAnnotationProcessors();
             List<String> processorPathEntries = config.getProcessorPathEntries();
             List<String> processorModulePathEntries = config.getProcessorModulePathEntries();
 
             if ((annotationProcessors != null && annotationProcessors.length > 0)
                     || (processorPathEntries != null && processorPathEntries.size() > 0)
                     || (processorModulePathEntries != null && processorModulePathEntries.size() > 0)) {
                 if (annotationProcessors != null && annotationProcessors.length > 0) {
                     args.add("-processor");
                     StringBuilder sb = new StringBuilder();
                     for (String ap : annotationProcessors) {
                         if (sb.length() > 0) {
                             sb.append(',');
                         }
                         sb.append(ap);
                     }
                     args.add(sb.toString());
                 }
 
                 if (processorPathEntries != null && processorPathEntries.size() > 0) {
                     if (isReplaceProcessorPath(config)) {
                         args.add("--processor-module-path");
                     } else {
                         args.add("-processorpath");
                     }
                     args.add(getPathString(processorPathEntries));
                 }
 
                 if (processorModulePathEntries != null && processorModulePathEntries.size() > 0) {
                     args.add("--processor-module-path");
                     args.add(getPathString(processorModulePathEntries));
                 }
 
                 if (config.getProc() != null) {
                     args.add("-proc:" + config.getProc());
                 }
             }
         }
 
         // Collect sources
         List<String> allSources = Arrays.asList(getSourceFiles(config));
         List<CompilerMessage> messageList = new ArrayList<>();
         if (allSources.isEmpty()) {
             // -- Nothing to do -> bail out
             return new CompilerResult(true, messageList);
         }
 
         allSources = resortSourcesToPutModuleInfoFirst(allSources);
 
         logCompiling(null, config);
 
         // Compile
         try {
             StringWriter sw = new StringWriter();
             PrintWriter devNull = new PrintWriter(sw);
             JavaCompiler compiler = getEcj();
             boolean success = false;
             if (compiler != null) {
                 getLog().debug("Using JSR-199 EclipseCompiler");
                 // ECJ JSR-199 compiles against the latest Java version it supports if no source
                 // version is given explicitly. BatchCompiler uses 1.3 as default. So check
                 // whether a source version is specified, and if not supply 1.3 explicitly.
                 if (!haveSourceOrReleaseArgument(args)) {
                     getLog().debug("ecj: no source level nor release specified, defaulting to Java 1.3");
                     args.add("-source");
                     args.add("1.3");
                 }
 
                 // Also check for the encoding. Could have been set via the CompilerConfig
                 // above, or also via the arguments explicitly. We need the charset for the
                 // StandardJavaFileManager below.
                 String encoding = null;
                 Iterator<String> allArgs = args.iterator();
                 while (encoding == null && allArgs.hasNext()) {
                     String option = allArgs.next();
                     if ("-encoding".equals(option) && allArgs.hasNext()) {
                         encoding = allArgs.next();
                     }
                 }
                 final Locale defaultLocale = Locale.getDefault();
                 final List<CompilerMessage> messages = messageList;
                 DiagnosticListener<? super JavaFileObject> messageCollector = new DiagnosticListener<JavaFileObject>() {
 
                     @Override
                     public void report(Diagnostic<? extends JavaFileObject> diagnostic) {
                         // Convert to Plexus' CompilerMessage and append to messageList
                         String fileName = "Unknown source";
                         try {
                             JavaFileObject file = diagnostic.getSource();
                             if (file != null) {
                                 fileName = file.getName();
                             }
                         } catch (NullPointerException e) {
                             // ECJ bug: diagnostic.getSource() may throw an NPE if there is no source
                         }
                         long startColumn = diagnostic.getColumnNumber();
                         // endColumn may be wrong if the endPosition is not on the same line.
                         long endColumn = startColumn + (diagnostic.getEndPosition() - diagnostic.getStartPosition());
                         CompilerMessage message = new CompilerMessage(
                                 fileName,
                                 convert(diagnostic.getKind()),
                                 (int) diagnostic.getLineNumber(),
                                 (int) startColumn,
                                 (int) diagnostic.getLineNumber(),
                                 (int) endColumn,
                                 diagnostic.getMessage(defaultLocale));
                         messages.add(message);
                     }
                 };
                 Charset charset = null;
                 if (encoding != null) {
                     encoding = encoding.trim();
                     try {
                         charset = Charset.forName(encoding);
                     } catch (IllegalCharsetNameException | UnsupportedCharsetException e) {
                         getLog().warn("ecj: invalid or unsupported character set '" + encoding + "', using default");
                         // charset remains null
                     }
                 }
                 if (charset == null) {
                     charset = Charset.defaultCharset();
                 }
                 if (getLog().isDebugEnabled()) {
                     getLog().debug("ecj: using character set " + charset.displayName());
                     getLog().debug("ecj command line: " + args);
                     getLog().debug("ecj input source files: " + allSources);
                 }
 
                 try (StandardJavaFileManager manager =
                         compiler.getStandardFileManager(messageCollector, defaultLocale, charset)) {
                     Iterable<? extends JavaFileObject> units = manager.getJavaFileObjectsFromStrings(allSources);
                     success =
                             Boolean.TRUE.equals(compiler.getTask(devNull, manager, messageCollector, args, null, units)
                                     .call());
                 } catch (RuntimeException e) {
                     throw new EcjFailureException(e.getLocalizedMessage());
                 }
                 getLog().debug(sw.toString());
             } else {
                 // Use the BatchCompiler and send all errors to xml temp file.
                 File errorF = null;
                 try {
                     errorF = File.createTempFile("ecjerr-", ".xml");
                     getLog().debug("Using legacy BatchCompiler; error file " + errorF);
 
                     args.add("-log");
                     args.add(errorF.toString());
                     args.addAll(allSources);
 
                     getLog().debug("ecj command line: " + args);
 
                     success = BatchCompiler.compile(
                             args.toArray(new String[args.size()]), devNull, devNull, new CompilationProgress() {
                                 @Override
                                 public void begin(int i) {}
 
                                 @Override
                                 public void done() {}
 
                                 @Override
                                 public boolean isCanceled() {
                                     return false;
                                 }
 
                                 @Override
                                 public void setTaskName(String s) {}
 
                                 @Override
                                 public void worked(int i, int i1) {}
                             });
                     getLog().debug(sw.toString());
 
                     if (errorF.length() < 80) {
                         throw new EcjFailureException(sw.toString());
                     }
                     messageList = new EcjResponseParser().parse(errorF, errorsAsWarnings);
                 } finally {
                     if (null != errorF) {
                         try {
                             errorF.delete();
                         } catch (Exception x) {
                         }
                     }
                 }
             }
             boolean hasError = false;
             for (CompilerMessage compilerMessage : messageList) {
                 if (compilerMessage.isError()) {
                     hasError = true;
                     break;
                 }
             }
             if (!hasError && !success && !errorsAsWarnings) {
                 CompilerMessage.Kind kind =
                         errorsAsWarnings ? CompilerMessage.Kind.WARNING : CompilerMessage.Kind.ERROR;
 
                 // -- Compiler reported failure but we do not seem to have one -> probable
                 // exception
                 CompilerMessage cm = new CompilerMessage(
                         "[ecj] The compiler reported an error but has not written it to its logging", kind);
                 messageList.add(cm);
                 hasError = true;
 
                 // -- Try to find the actual message by reporting the last 5 lines as a message
                 String stdout = getLastLines(sw.toString(), 5);
                 if (stdout.length() > 0) {
                     cm = new CompilerMessage("[ecj] The following line(s) might indicate the issue:\n" + stdout, kind);
                     messageList.add(cm);
                 }
             }
             return new CompilerResult(!hasError || errorsAsWarnings, messageList);
         } catch (EcjFailureException x) {
             throw x;
         } catch (Exception x) {
             throw new RuntimeException(x); // sigh
         }
     }
 
     private static final String OPT_REPLACE_PROCESSOR_PATH = "replaceProcessorPathWithProcessorModulePath";
     private static final String OPT_REPLACE_PROCESSOR_PATH_ = "-" + OPT_REPLACE_PROCESSOR_PATH;
 
     static boolean isReplaceProcessorPath(CompilerConfiguration config) {
         for (Entry<String, String> entry : config.getCustomCompilerArgumentsEntries()) {
             String opt = entry.getKey();
             if (opt.equals(OPT_REPLACE_PROCESSOR_PATH) || opt.equals(OPT_REPLACE_PROCESSOR_PATH_)) {
                 return true;
             }
         }
         return false;
     }
 
     static List<String> resortSourcesToPutModuleInfoFirst(List<String> allSources) {
         List<String> resorted = new ArrayList<>(allSources.size());
 
         for (String mi : allSources) {
             if (mi.endsWith("module-info.java")) {
                 resorted.add(mi);
             }
         }
 
         for (String nmi : allSources) {
             if (!nmi.endsWith("module-info.java")) {
                 resorted.add(nmi);
             }
         }
 
         return resorted;
     }
 
     static boolean processCustomArguments(CompilerConfiguration config, List<String> args) {
         boolean result = false;
 
         for (Entry<String, String> entry : config.getCustomCompilerArgumentsEntries()) {
             String opt = entry.getKey();
             String optionValue = entry.getValue();
 
             // handle errorsAsWarnings options
             if (opt.equals("errorsAsWarnings") || opt.equals("-errorsAsWarnings")) {
                 result = true;
                 continue;
             }
 
             if (opt.equals("-properties")) {
                 if (null != optionValue) {
                     File propFile = new File(optionValue);
                     if (!propFile.exists() || !propFile.isFile()) {
                         throw new IllegalArgumentException(
                                 "Properties file specified by -properties " + propFile + " does not exist");
                     }
                 }
             }
 
             // -- Write .class files even when error occur, but make sure methods with compile errors do abort when
             // called
             if (opt.equals("-proceedOnError")) {
                 // Generate a class file even with errors, but make methods with errors fail when called
                 args.add("-proceedOnError:Fatal");
                 continue;
             }
 
             if (!opt.equals(OPT_REPLACE_PROCESSOR_PATH) && !opt.equals(OPT_REPLACE_PROCESSOR_PATH_)) {
                 /*
                  * The compiler mojo makes quite a mess of passing arguments, depending on exactly WHICH
                  * way is used to pass them. The method method using <compilerArguments> uses the tag names
                  * of its contents to denote option names, and so the compiler mojo happily adds a '-' to
                  * all of the names there and adds them to the "custom compiler arguments" map as a
                  * name, value pair where the name always contains a single '-'. The Eclipse compiler (and
                  * javac too, btw) has options with two dashes (like --add-modules for java 9). These cannot
                  * be passed using a <compilerArguments> tag.
                  *
                  * The other method is to use <compilerArgs>, where each SINGLE argument needs to be passed
                  * using an <arg>xxxx</arg> tag. In there the xxx is not manipulated by the compiler mojo, so
                  * if it starts with a dash or more dashes these are perfectly preserved. But of course these
                  * single <arg> entries are not a pair. So the compiler mojo adds them as pairs of (xxxx, null).
                  *
                  * We use that knowledge here: if a pair has a null value then do not mess up the key but
                  * render it as a single value. This should ensure that something like:
                  * <compilerArgs>
                  *     <arg>--add-modules</arg>
                  *     <arg>java.se.ee</arg>
                  * </compilerArgs>
                  *
                  * is actually added to the command like as such.
                  *
                  * (btw: the above example will still give an error when using ecj <= 4.8M6:
                  *      invalid module name: java.se.ee
                  * but that seems to be a bug in ecj).
                  */
                 if (null == optionValue) {
                     // -- We have an option from compilerArgs: use the key as-is as a single option value
                     args.add(opt);
                 } else {
                     if (!opt.startsWith("-")) {
                         opt = "-" + opt;
                     }
                     args.add(opt);
                     args.add(optionValue);
                 }
             }
         }
         return result;
     }
 
     private static boolean haveSourceOrReleaseArgument(List<String> args) {
         Iterator<String> allArgs = args.iterator();
         while (allArgs.hasNext()) {
             String option = allArgs.next();
             if (("-source".equals(option) || "--release".equals(option)) && allArgs.hasNext()) {
                 return true;
             }
         }
         return false;
     }
 
     private JavaCompiler getEcj() {
         ServiceLoader<JavaCompiler> javaCompilerLoader =
                 ServiceLoader.load(JavaCompiler.class, BatchCompiler.class.getClassLoader());
         Class<?> c = null;
         try {
             c = Class.forName(
                     "org.eclipse.jdt.internal.compiler.tool.EclipseCompiler",
                     false,
                     BatchCompiler.class.getClassLoader());
         } catch (ClassNotFoundException e) {
             // Ignore
         }
         if (c != null) {
             for (JavaCompiler javaCompiler : javaCompilerLoader) {
                 if (c.isInstance(javaCompiler)) {
                     return javaCompiler;
                 }
             }
         }
         getLog().debug("Cannot find org.eclipse.jdt.internal.compiler.tool.EclipseCompiler");
         return null;
     }
 
     private CompilerMessage.Kind convert(Diagnostic.Kind kind) {
         if (kind == null) {
             return CompilerMessage.Kind.OTHER;
         }
         switch (kind) {
             case ERROR:
                 return errorsAsWarnings ? CompilerMessage.Kind.WARNING : CompilerMessage.Kind.ERROR;
             case WARNING:
                 return CompilerMessage.Kind.WARNING;
             case MANDATORY_WARNING:
                 return CompilerMessage.Kind.MANDATORY_WARNING;
             case NOTE:
                 return CompilerMessage.Kind.NOTE;
             case OTHER:
             default:
                 return CompilerMessage.Kind.OTHER;
         }
     }
 
     private String getLastLines(String text, int lines) {
         List<String> lineList = new ArrayList<>();
         text = text.replace("\r\n", "\n");
         text = text.replace("\r", "\n"); // make sure eoln is \n
 
         int index = text.length();
         while (index > 0) {
             int before = text.lastIndexOf('\n', index - 1);
 
             if (before + 1 < index) { // Non empty line?
                 lineList.add(text.substring(before + 1, index));
                 lines--;
                 if (lines <= 0) {
                     break;
                 }
             }
 
             index = before;
         }
 
         StringBuilder sb = new StringBuilder();
         for (int i = lineList.size() - 1; i >= 0; i--) {
             String s = lineList.get(i);
             sb.append(s);
             sb.append(System.getProperty("line.separator")); // 8-/
         }
         return sb.toString();
     }
 
     private static void append(StringBuilder warns, String s) {
         if (warns.length() > 0) {
             warns.append(',');
         }
         warns.append(s);
     }
 
     private boolean isPreJava1_6(CompilerConfiguration config) {
         String s = config.getSourceVersion();
         if (s == null) {
             // now return true, as the 1.6 version is not the default - 1.4 is.
             return true;
         }
         return s.startsWith("1.5")
                 || s.startsWith("1.4")
                 || s.startsWith("1.3")
                 || s.startsWith("1.2")
                 || s.startsWith("1.1")
                 || s.startsWith("1.0");
     }
 
     @Override
     public String[] createCommandLine(CompilerConfiguration config) throws CompilerException {
         return null;
     }
 
     @Override
     public boolean supportsIncrementalCompilation() {
         return true;
     }
 
     /**
      * Change any Maven Java version number to ECJ's version number. Do not check the validity
      * of the version: the compiler does that nicely, and this allows compiler updates without
      * changing the compiler plugin. This is important with the half year release cycle for Java.
      */
     private String decodeVersion(String versionSpec) {
         if (StringUtils.isEmpty(versionSpec)) {
             return null;
         }
 
         if (versionSpec.equals("1.9")) {
             getLog().warn("Version 9 should be specified as 9, not 1.9");
             return "9";
         }
         return versionSpec;
     }
 }