/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.rat.help;
  
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.io.Writer;
  import java.lang.reflect.InvocationTargetException;
  import java.util.Collection;
  import java.util.Comparator;
  import java.util.Map;
  import java.util.SortedSet;
  import java.util.TreeSet;
  import java.util.UUID;
  
  import org.apache.commons.cli.HelpFormatter;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.rat.ConfigurationException;
  import org.apache.rat.ReportConfiguration;
  import org.apache.rat.analysis.IHeaderMatcher;
  import org.apache.rat.config.parameters.ComponentType;
  import org.apache.rat.config.parameters.Description;
  import org.apache.rat.config.parameters.DescriptionBuilder;
  import org.apache.rat.configuration.MatcherBuilderTracker;
  import org.apache.rat.configuration.builders.AbstractBuilder;
  import org.apache.rat.license.ILicense;
  import org.apache.rat.license.ILicenseFamily;
  import org.apache.rat.license.LicenseSetFactory.LicenseFilter;
  
  import static java.lang.String.format;
  
  /**
   * Generates text based documentation for Licenses, LicenceFamilies, and Matchers.
   * Utilizes the same command line as the CLI based Report client so that additional licenses, etc. can be added.
   */
  public final class Licenses extends AbstractHelp {
      /** The report configuration to extract licenses from */
      private final ReportConfiguration config;
      /** The licenses in the report config */
      private final SortedSet<ILicense> licenses;
      /** The formatter */
      private final HelpFormatter formatter;
      /** The writer to write to */
      private final PrintWriter printWriter;
  
      /**
       * Constructor
       * @param config The configuration that contains the license information.
       * @param writer the writer to write the report to.
       */
      public Licenses(final ReportConfiguration config, final Writer writer) {
          this.config = config;
          this.licenses = config.getLicenses(LicenseFilter.ALL);
          printWriter = new PrintWriter(writer);
          formatter = HelpFormatter.builder().setShowDeprecated(false).setPrintWriter(printWriter).get();
      }
  
      /**
       * Prints the text indented and wrapped.
       * @param indent the number of spaces to indent.
       * @param text the text to write.
       */
      void print(final int indent, final String text) {
          int leftMargin = indent * HELP_PADDING;
          int tabStop = leftMargin + (HELP_PADDING / 2);
          formatter.printWrapped(printWriter, HELP_WIDTH, tabStop, createPadding(leftMargin) + text);
      }
  
      /**
       * Print the help text with the version information.
       * @throws IOException on output error.
       */
      public void printHelp() throws IOException {
          print(0, format("Listing of licenses for %s", versionInfo));
          output();
      }
  
      /**
       * Output the License information without the version information.
       * @throws IOException on error.
       */
      public void output() throws IOException {
  
         print(0, header("LICENSES"));
 
         if (licenses.isEmpty()) {
             print(0, "No licenses defined");
         } else {
             Description licenseDescription = DescriptionBuilder.build(licenses.first());
             Collection<Description> licenseParams = licenseDescription.filterChildren(d -> d.getType() == ComponentType.PARAMETER);
 
             print(0, format("Licenses have the following properties:%n"));
 
             for (Description param : licenseParams) {
                 print(1, format("%s: %s%n", param.getCommonName(), param.getDescription()));
             }
 
             print(0, format("%nThe defined licenses are:%n"));
             for (ILicense l : licenses) {
                 print(0, System.lineSeparator());
                 printObject(0, l);
             }
         }
         print(0, header("DEFINED MATCHERS"));
         SortedSet<Description> matchers = new TreeSet<>(Comparator.comparing(Description::getCommonName));
         for (Class<? extends AbstractBuilder> mClazz : MatcherBuilderTracker.instance().getClasses()) {
             try {
                 AbstractBuilder builder = mClazz.getConstructor().newInstance();
                 matchers.add(builder.getDescription());
             } catch (NoSuchMethodException | SecurityException | InstantiationException | IllegalAccessException
                      | IllegalArgumentException | InvocationTargetException e) {
                 throw new ConfigurationException(
                         format("Can not instantiate matcher builder  %s ", mClazz.getName()), e);
             }
         }
         for (Description description : matchers) {
             print(0, format("%n%s: %s%n", description.getCommonName(), description.getDescription()));
             for (Description child : description.getChildren().values()) {
                 if (IHeaderMatcher.class.isAssignableFrom(child.getChildType())) {
                     if (child.isCollection()) {
                         print(2, "Encloses multiple matchers");
                     } else {
                         print(2, "Wraps a single matcher");
                     }
                 } else {
                     print(1, format("%s: %s%s", child.getCommonName(), child.isRequired() ? "(required) " : "", child.getDescription()));
                 }
             }
         }
 
         print(0, header("DEFINED FAMILIES"));
         for (ILicenseFamily family : config.getLicenseFamilies(LicenseFilter.ALL)) {
             print(1, format("%s - %s%n", family.getFamilyCategory(), family.getFamilyName()));
         }
         printWriter.flush();
     }
 
     /**
      * Print the description of an object.
      * @param indent the number of spaces to indent the print.
      * @param object the object to print.
      * @throws IOException on output error.
      */
     private void printObject(final int indent, final Object object) throws IOException {
         if (object == null) {
             return;
         }
         Description description = DescriptionBuilder.build(object);
         if (description == null) {
             print(indent, format("Unknown Object of class: %s%n", object.getClass().getName()));
         } else {
             print(indent, format("%s (%s)%n", description.getCommonName(), description.getDescription()));
             printChildren(indent + 1, object, description.getChildren());
         }
     }
 
     /**
      * Returns {@code true} if the string is a UUID.
      * @param s the string to check.
      * @return {@code true} if the string is a UUID.
      */
     private boolean isUUID(final String s) {
         try {
             UUID.fromString(s);
             return true;
         } catch (IllegalArgumentException expected) {
            return false;
         }
     }
 
     /**
      * Print the information for the children.
      * @param indent the number of spaces to indent.
      * @param parent the parent object.
      * @param children the children of the parent.
      * @throws IOException on write error.
      */
     private void printChildren(final int indent, final Object parent, final Map<String, Description> children) throws IOException {
         for (Description d : children.values()) {
             switch (d.getType()) {
                 case PARAMETER:
                     if (d.isCollection()) {
                         print(indent, format("%s: %n", d.getCommonName()));
                         try {
                             Collection<?> result = (Collection<?>) d.getter(parent.getClass()).invoke(parent);
                             for (Object o : result) {
                                 printObject(indent + 1, o);
                             }
                             return;
                         } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
                             throw new RuntimeException(e);
                         }
                     }
                     if (IHeaderMatcher.class.isAssignableFrom(d.getChildType())) {
                         print(indent, format("%s: %n", d.getCommonName()));
                         // is a matcher.
                         try {
                             Object matcher = d.getter(parent.getClass()).invoke(parent);
                             printObject(indent + 1, matcher);
                         } catch (InvocationTargetException | IllegalAccessException | NoSuchMethodException e) {
                             throw new RuntimeException(e);
                         }
                     } else {
                         String txt = StringUtils.defaultIfBlank(d.getParamValue(parent), "").replaceAll("\\s{2,}", " ");
                         if (!txt.isEmpty() && !(d.getCommonName().equals("id") && isUUID(txt))) {
                                print(indent, format("%s: %s%n", d.getCommonName(), txt.replaceAll("\\s{2,}", " ")));
                         }
                     }
                     break;
                 case BUILD_PARAMETER:
                 case LICENSE:
                     // do nothing
                     break;
                 case MATCHER:
                     printChildren(indent + 1, parent, d.getChildren());
                     break;
             }
         }
     }
 }