/*
    * The contents of this file are subject to the terms of the Common Development and
    * Distribution License (the License). You may not use this file except in compliance with the
    * License.
    *
    * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
    * specific language governing permission and limitations under the License.
    *
    * When distributing Covered Software, include this CDDL Header Notice in each file and include
   * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
   * Header, with the fields enclosed by brackets [] replaced by your own identifying
   * information: "Portions Copyrighted [year] [name of copyright owner]".
   *
   *      Copyright 2011-2013 ForgeRock AS.
   *      Portions Copyright 2017 Wren Security.
   */
  package org.forgerock.i18n.maven;
  
  import com.google.common.xml.XmlEscapers;
  import java.io.BufferedReader;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.PrintWriter;
  import java.nio.charset.Charset;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.Calendar;
  import java.util.List;
  import java.util.Map;
  import java.util.Properties;
  import java.util.TreeMap;
  import java.util.UnknownFormatConversionException;
  import java.util.regex.Matcher;
  import java.util.regex.Pattern;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugins.annotations.Parameter;
  import org.apache.maven.project.MavenProject;
  
  /**
   * Abstract Mojo implementation for generating message source files from a one
   * or more property files.
   */
  abstract class AbstractGenerateMessagesMojo extends AbstractMojo {
      /**
       * A message file descriptor passed in from the POM configuration.
       */
      static final class MessageFile {
          /**
           * The name of the message property file to be processed.
           */
          private final String name;
  
          /**
           * Creates a new message file.
           *
           * @param name
           *            The name of the message file relative to the resource
           *            directory.
           */
          MessageFile(final String name) {
              this.name = name;
          }
  
          /**
           * {@inheritDoc}
           */
          @Override
          public String toString() {
              return name;
          }
  
          /**
           * Returns the class name (without package) which will contain the
           * generated message descriptors.
           *
           * @return The class name (without package) which will contain the
           *         generated message descriptors.
           */
          String getClassName() {
              final StringBuilder builder = new StringBuilder();
              final String shortName = getShortName();
              boolean upperCaseNextChar = true;
              for (final char c : shortName.toCharArray()) {
                  if (c == '_' || c == '-') {
                      upperCaseNextChar = true;
                      continue;
                  }
  
                  if (upperCaseNextChar) {
                      builder.append(Character.toUpperCase(c));
                      upperCaseNextChar = false;
                  } else {
                      builder.append(c);
                  }
              }
             builder.append("Messages");
             return builder.toString();
         }
 
         /**
          * The name of the message file relative to the resource directory.
          *
          * @return The name of the message file relative to the resource
          *         directory.
          */
         String getName() {
             return name;
         }
 
         /**
          * Returns a {@code File} representing the full path to the output Java
          * file.
          *
          * @param outputDirectory
          *            The target directory.
          * @return A {@code File} representing the full path to the output Java
          *         file.
          */
         File getOutputFile(final File outputDirectory) {
             final int lastSlash = name.lastIndexOf('/');
             final String parentPath = name.substring(0, lastSlash);
             final String path = parentPath.replace('/', File.separatorChar)
                     + File.separator + getClassName() + ".java";
             return new File(outputDirectory, path);
         }
 
         /**
          * Returns the name of the package containing the message file.
          *
          * @return The name of the package containing the message file.
          */
         String getPackageName() {
             final int lastSlash = name.lastIndexOf('/');
             final String parentPath = name.substring(0, lastSlash);
             return parentPath.replace('/', '.');
         }
 
         /**
          * The resource bundle name.
          *
          * @return The resource bundle name.
          */
         String getResourceBundleName() {
             return getPackageName() + "." + getShortName();
         }
 
         /**
          * Returns a {@code File} representing the full path to this message
          * file.
          *
          * @param resourceDirectory
          *            The resource directory.
          * @return A {@code File} representing the full path to this message
          *         file.
          */
         File getResourceFile(final File resourceDirectory) {
             final String path = name.replace('/', File.separatorChar);
             return new File(resourceDirectory, path);
         }
 
         /**
          * Returns the name of the message file with the package name and
          * trailing ".properties" suffix stripped.
          *
          * @return The name of the message file with the package name and
          *         trailing ".properties" suffix stripped.
          */
         String getShortName() {
             final int lastSlash = name.lastIndexOf('/');
             final String fileName = name.substring(lastSlash + 1);
             final int lastDot = fileName.lastIndexOf('.');
             return fileName.substring(0, lastDot);
         }
 
     }
 
     /**
      * Representation of a format specifier (for example %s).
      */
     private static final class FormatSpecifier {
 
         private final String[] sa;
 
         /**
          * Creates a new specifier.
          *
          * @param sa
          *            Specifier components.
          */
         FormatSpecifier(final String[] sa) {
             this.sa = sa;
         }
 
         /**
          * Returns a java class associated with a particular formatter based on
          * the conversion type of the specifier.
          *
          * @return Class for representing the type of argument used as a
          *         replacement for this specifier.
          */
         Class<?> getSimpleConversionClass() {
             Class<?> c = null;
             final String sa4 = sa[4] != null ? sa[4].toLowerCase() : null;
             final String sa5 = sa[5] != null ? sa[5].toLowerCase() : null;
             if ("t".equals(sa4)) {
                 c = Calendar.class;
             } else if ("b".equals(sa5)) {
                 c = Boolean.class;
             } else if ("h".equals(sa5) /* Hashcode */) {
                 c = Object.class;
             } else if ("s".equals(sa5)) {
                 c = Object.class; /* Conversion using toString() */
             } else if ("c".equals(sa5)) {
                 c = Character.class;
             } else if ("d".equals(sa5) || "o".equals(sa5) || "x".equals(sa5)
                     || "e".equals(sa5) || "f".equals(sa5) || "g".equals(sa5)
                     || "a".equals(sa5)) {
                 c = Number.class;
             } else if ("n".equals(sa5) || "%".equals(sa5)) {
                 // ignore literals
             }
             return c;
         }
 
         /**
          * Returns {@code true} if this specifier uses argument indexes (for
          * example 2$).
          *
          * @return boolean {@code true} if this specifier uses argument indexes.
          */
         boolean specifiesArgumentIndex() {
             return this.sa[0] != null;
         }
 
     }
 
     /**
      * Represents a message to be written into the messages files.
      */
     private static final class MessageDescriptorDeclaration {
 
         private final MessagePropertyKey key;
         private final String formatString;
         private final List<FormatSpecifier> specifiers;
         private final List<Class<?>> classTypes;
         private String[] constructorArgs;
 
         /**
          * Creates a parameterized instance.
          *
          * @param key
          *            The message key.
          * @param formatString
          *            The message format string.
          */
         MessageDescriptorDeclaration(final MessagePropertyKey key,
                 final String formatString) {
             this.key = key;
             this.formatString = formatString;
             this.specifiers = parse(formatString);
             this.classTypes = new ArrayList<Class<?>>();
             for (final FormatSpecifier f : specifiers) {
                 final Class<?> c = f.getSimpleConversionClass();
                 if (c != null) {
                     classTypes.add(c);
                 }
             }
         }
 
         /**
          * {@inheritDoc}
          */
         @Override
         public String toString() {
             final StringBuilder sb = new StringBuilder();
             sb.append(getComment());
             sb.append(indent(1));
             sb.append("public static final ");
             sb.append(getDescriptorClassDeclaration());
             sb.append(" ");
             sb.append(key.getName());
             sb.append(" =");
             sb.append(EOL);
             sb.append(indent(5));
             sb.append("new ");
             sb.append(getDescriptorClassDeclaration());
             sb.append("(");
             if (constructorArgs != null) {
                 for (int i = 0; i < constructorArgs.length; i++) {
                     sb.append(constructorArgs[i]);
                     if (i < constructorArgs.length - 1) {
                         sb.append(", ");
                     }
                 }
             }
             sb.append(");");
             return sb.toString();
         }
 
         /**
          * Returns a string representing the message type class' variable
          * information (for example '<String,Integer>') that is based on the
          * type of arguments specified by the specifiers in this message.
          *
          * @return String representing the message type class parameters.
          */
         String getClassTypeVariables() {
             final StringBuilder sb = new StringBuilder();
             if (classTypes.size() > 0) {
                 sb.append("<");
                 for (int i = 0; i < classTypes.size(); i++) {
                     final Class<?> c = classTypes.get(i);
                     if (c != null) {
                         sb.append(getShortClassName(c));
                         if (i < classTypes.size() - 1) {
                             sb.append(", ");
                         }
                     }
                 }
                 sb.append(">");
             }
             return sb.toString();
         }
 
         /**
          * Returns the javadoc comments that will appear above the messages
          * declaration in the messages file.
          *
          * @return The javadoc comments that will appear above the messages
          *         declaration in the messages file.
          */
         String getComment() {
             final StringBuilder sb = new StringBuilder();
             sb.append(indent(1)).append("/**").append(EOL);
             sb.append(indent(1)).append(" * ").append("<code>").append(EOL);
 
             // Unwrapped so that you can search through the descriptor
             // file for a message and not have to worry about line breaks
             final String ws = XmlEscapers.xmlContentEscaper().escape(formatString); // wrapText(formatString, 70);
 
             final String[] sa = ws.split(EOL);
             for (final String s : sa) {
                 sb.append(indent(1)).append(" * ").append(s).append(EOL);
             }
 
             sb.append(indent(1)).append(" * ").append("</code>").append(EOL);
             sb.append(indent(1)).append(" */").append(EOL);
             return sb.toString();
         }
 
         /**
          * Returns the name of the Java class that will be used to represent
          * this message's type.
          *
          * @return The name of the Java class that will be used to represent
          *         this message's type.
          */
         String getDescriptorClassDeclaration() {
             final StringBuilder sb = new StringBuilder();
             if (useGenericMessageTypeClass()) {
                 sb.append("LocalizableMessageDescriptor");
                 sb.append(".");
                 sb.append(DESCRIPTOR_CLASS_BASE_NAME);
                 sb.append("N");
             } else {
                 sb.append("LocalizableMessageDescriptor");
                 sb.append(".");
                 sb.append(DESCRIPTOR_CLASS_BASE_NAME);
                 sb.append(classTypes.size());
                 sb.append(getClassTypeVariables());
             }
             return sb.toString();
         }
 
         /**
          * Sets the arguments that will be supplied in the declaration of the
          * message.
          *
          * @param s
          *            The array of string arguments that will be passed in the
          *            constructor.
          */
         void setConstructorArguments(final String... s) {
             this.constructorArgs = s;
         }
 
         private void checkText(final String s) {
             int idx = s.indexOf('%');
             // If there are any '%' in the given string, we got a bad format
             // specifier.
             if (idx != -1) {
                 final char c = (idx > s.length() - 2 ? '%' : s.charAt(idx + 1));
                 throw new UnknownFormatConversionException(String.valueOf(c));
             }
         }
 
         private String getShortClassName(final Class<?> c) {
             String name;
             final String fqName = c.getName();
             final int i = fqName.lastIndexOf('.');
             if (i > 0) {
                 name = fqName.substring(i + 1);
             } else {
                 name = fqName;
             }
             return name;
         }
 
         private String indent(final int indent) {
             final char[] blankArray = new char[4 * indent];
             Arrays.fill(blankArray, ' ');
             return new String(blankArray);
         }
 
         /**
          * Returns a list of format specifiers contained in the provided format
          * string.
          *
          * @param s
          *            The format string.
          * @return The list of format specifiers.
          */
         private List<FormatSpecifier> parse(final String s) {
             final List<FormatSpecifier> sl = new ArrayList<FormatSpecifier>();
             final Matcher m = SPECIFIER_PATTERN.matcher(s);
             int i = 0;
             while (i < s.length()) {
                 if (m.find(i)) {
                     // Anything between the start of the string and the
                     // beginning of the format specifier is either fixed text or contains
                     // an invalid format string.
                     if (m.start() != i) {
                         // Make sure we didn't miss any invalid format
                         // specifiers
                         checkText(s.substring(i, m.start()));
 
                         // Assume previous characters were fixed text
                         // al.add(new FixedString(s.substring(i, m.start())));
                     }
 
                     // Expect 6 groups in regular expression
                     final String[] sa = new String[6];
                     for (int j = 0; j < m.groupCount(); j++) {
                         sa[j] = m.group(j + 1);
                     }
                     sl.add(new FormatSpecifier(sa));
                     i = m.end();
                 } else {
                     // No more valid format specifiers. Check for possible
                     // invalid format specifiers.
                     checkText(s.substring(i));
 
                     // The rest of the string is fixed text
                     // al.add(new FixedString(s.substring(i)));
                     break;
                 }
             }
             return sl;
         }
 
         /**
          * Indicates whether the generic message type class should be used. In
          * general this is when a format specifier is more complicated than we
          * support or when the number of arguments exceeds the number of
          * specific message type classes (MessageType0, MessageType1 ...) that
          * are defined.
          *
          * @return boolean {@code true} if the generic message type class should
          *         be used.
          */
         private boolean useGenericMessageTypeClass() {
             if (specifiers.size() > DESCRIPTOR_MAX_ARG_HANDLER) {
                 return true;
             } else {
                 for (final FormatSpecifier s : specifiers) {
                     if (s.specifiesArgumentIndex()) {
                         return true;
                     }
                 }
             }
             return false;
         }
 
     }
 
     /**
      * Indicates whether or not message files should be regenerated even if they
      * are already up to date.
      */
     @Parameter(defaultValue="false", required=true)
     private boolean force;
 
     /**
      * The list of files we want to transfer, relative to the resource
      * directory.
      */
     @Parameter(required=true)
     private String[] messageFiles;
 
     /**
      * The current Maven project.
      */
     @Parameter(defaultValue="${project}", readonly=true, required=true)
     private MavenProject project;
 
     /**
      * The base name of the specific argument handling subclasses defined below.
      * The class names consist of the base name followed by a number indicating
      * the number of arguments that they handle when creating messages or the
      * letter "N" meaning any number of arguments.
      */
     private static final String DESCRIPTOR_CLASS_BASE_NAME = "Arg";
 
     /**
      * The maximum number of arguments that can be handled by a specific
      * subclass. If you define more subclasses be sure to increment this number
      * appropriately.
      */
     private static final int DESCRIPTOR_MAX_ARG_HANDLER = 11;
 
     private static final String SPECIFIER_REGEX =
             "%(\\d+\\$)?([-#+ 0,(\\<]*)?(\\d+)?(\\.\\d+)?([tT])?([a-zA-Z%])";
 
     private static final Pattern SPECIFIER_PATTERN = Pattern
             .compile(SPECIFIER_REGEX);
 
     /**
      * The end-of-line character for this platform.
      */
     private static final String EOL = System.getProperty("line.separator");
 
     /**
      * The UTF-8 character set used for encoding/decoding files.
      */
     private static final Charset UTF_8 = Charset.forName("UTF-8");
 
     /**
      * {@inheritDoc}
      */
     @Override
     public final void execute() throws MojoExecutionException {
         final File resourceDirectory = getResourceDirectory();
 
         if (!resourceDirectory.exists()) {
             throw new MojoExecutionException("Source directory "
                     + resourceDirectory.getPath() + " does not exist");
         } else if (!resourceDirectory.isDirectory()) {
             throw new MojoExecutionException("Source directory "
                     + resourceDirectory.getPath() + " is not a directory");
         }
 
         final File targetDirectory = getTargetDirectory();
 
         if (!targetDirectory.exists()) {
             if (targetDirectory.mkdirs()) {
                 getLog().info(
                         "Created message output directory: "
                                 + targetDirectory.getPath());
             } else {
                 throw new MojoExecutionException(
                         "Unable to create message output directory: "
                                 + targetDirectory.getPath());
             }
         } else if (!targetDirectory.isDirectory()) {
             throw new MojoExecutionException("Output directory "
                     + targetDirectory.getPath() + " is not a directory");
         }
 
         if (project != null) {
             getLog().info(
                     "Adding source directory: " + targetDirectory.getPath());
             addNewSourceDirectory(targetDirectory);
         }
 
         for (final String messageFile : messageFiles) {
             processMessageFile(new MessageFile(messageFile));
         }
     }
 
     /**
      * Adds the generated source directory to the compilation path.
      *
      * @param targetDirectory
      *            The source directory to be added.
      */
     abstract void addNewSourceDirectory(final File targetDirectory);
 
     /**
      * Returns the resource directory containing the message files.
      *
      * @return The resource directory containing the message files.
      */
     abstract File getResourceDirectory();
 
     /**
      * Returns the target directory in which the source files should be
      * generated.
      *
      * @return The target directory in which the source files should be
      *         generated.
      */
     abstract File getTargetDirectory();
 
     /*
      * Returns the message Java stub file from this plugin's resources.
      */
     private InputStream getStubFile() throws MojoExecutionException {
         return getClass().getResourceAsStream("Messages.java.stub");
     }
 
     private void processMessageFile(final MessageFile messageFile) throws MojoExecutionException {
         final File resourceDirectory = getResourceDirectory();
         final File targetDirectory = getTargetDirectory();
 
         final File sourceFile = messageFile.getResourceFile(resourceDirectory);
         final File outputFile = messageFile.getOutputFile(targetDirectory);
 
         // Decide whether to generate messages based on modification
         // times and print status messages.
         if (!sourceFile.exists()) {
             throw new MojoExecutionException("Message file "
                     + messageFile.getName() + " does not exist");
         }
 
         if (outputFile.exists()) {
             if (force || sourceFile.lastModified() > outputFile.lastModified()) {
                 if (!outputFile.delete()) {
                     throw new MojoExecutionException(
                             "Unable to continue because the old message file "
                                     + messageFile.getName()
                                     + " could not be deleted");
                 }
 
                 getLog().info(
                         "Regenerating " + outputFile.getName() + " from "
                                 + sourceFile.getName());
             } else {
                 getLog().info(outputFile.getName() + " is up to date");
                 return;
             }
         } else {
             final File packageDirectory = outputFile.getParentFile();
             if (!packageDirectory.exists()) {
                 if (!packageDirectory.mkdirs()) {
                     throw new MojoExecutionException(
                             "Unable to create message output directory: "
                                     + packageDirectory.getPath());
                 }
             }
             getLog().info(
                     "Generating " + outputFile.getName() + " from "
                             + sourceFile.getName());
         }
 
         BufferedReader stubReader = null;
         PrintWriter outputWriter = null;
 
         try {
             stubReader = new BufferedReader(new InputStreamReader(
                     getStubFile(), UTF_8));
             outputWriter = new PrintWriter(outputFile, "UTF-8");
 
             final Properties properties = new Properties();
             final FileInputStream propertiesFile = new FileInputStream(
                     sourceFile);
             try {
                 properties.load(propertiesFile);
             } finally {
                 try {
                     propertiesFile.close();
                 } catch (Exception ignored) {
                     // Ignore.
                 }
             }
 
             for (String stubLine = stubReader.readLine(); stubLine != null; stubLine = stubReader
                     .readLine()) {
                 if (stubLine.contains("${MESSAGES}")) {
                     final Map<MessagePropertyKey, String> propertyMap =
                             new TreeMap<MessagePropertyKey, String>();
 
                     for (final Map.Entry<Object, Object> property : properties
                             .entrySet()) {
                         final String propKey = property.getKey().toString();
                         final MessagePropertyKey key = MessagePropertyKey
                                 .valueOf(propKey);
                         propertyMap.put(key, property.getValue().toString());
                     }
 
                     int usesOfGenericDescriptor = 0;
 
                     for (final Map.Entry<MessagePropertyKey, String> property : propertyMap
                             .entrySet()) {
                         final MessageDescriptorDeclaration message =
                                 new MessageDescriptorDeclaration(property.getKey(),
                                         property.getValue());
 
                         message.setConstructorArguments(
                                 messageFile.getClassName() + ".class",
                                 "RESOURCE",
                                 quote(property.getKey().toString()),
                                 String.valueOf(property.getKey().getOrdinal()));
                         outputWriter.println(message.toString());
                         outputWriter.println();
 
                         // Keep track of when we use the generic descriptor so
                         // that we can report it later
                         if (message.useGenericMessageTypeClass()) {
                             usesOfGenericDescriptor++;
                         }
                     }
 
                     getLog().debug(
                             "  Generated " + propertyMap.size()
                                     + " LocalizableMessage");
                     getLog().debug(
                             "  Number of LocalizableMessageDescriptor.ArgN: "
                                     + usesOfGenericDescriptor);
                 } else {
                     stubLine = stubLine.replace("${PACKAGE}",
                             messageFile.getPackageName());
                     stubLine = stubLine.replace("${CLASS_NAME}",
                             messageFile.getClassName());
                     stubLine = stubLine.replace("${FILE_NAME}",
                             messageFile.getName());
                     stubLine = stubLine.replace("${RESOURCE_BUNDLE_NAME}",
                             messageFile.getResourceBundleName());
                     outputWriter.println(stubLine);
                 }
             }
         } catch (final IOException e) {
             // Don't leave a malformed file laying around. Delete it so it will
             // be forced to be regenerated.
             if (outputFile.exists()) {
                 outputFile.deleteOnExit();
             }
             throw new MojoExecutionException(
                     "An IO error occurred while generating the message file: "
                             + e);
         } finally {
             if (stubReader != null) {
                 try {
                     stubReader.close();
                 } catch (final Exception e) {
                     // Ignore.
                 }
             }
 
             if (outputWriter != null) {
                 try {
                     outputWriter.close();
                 } catch (final Exception e) {
                     // Ignore.
                 }
             }
         }
 
     }
 
     private String quote(final String s) {
         return new StringBuilder().append("\"").append(s).append("\"")
                 .toString();
     }
 
     /**
      * Returns the Maven project associated with this Mojo.
      *
      * @return The Maven project associated with this Mojo.
      */
     protected MavenProject getMavenProject() {
         return project;
     }
 }