/*
    * 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.reporting;
  
  import com.fasterxml.jackson.core.JsonFactory;
  import com.fasterxml.jackson.core.JsonGenerator;
  import com.fasterxml.jackson.core.JsonParser;
  import edu.umd.cs.findbugs.annotations.SuppressFBWarnings;
  import org.apache.commons.io.FilenameUtils;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.commons.text.WordUtils;
  import org.apache.velocity.VelocityContext;
  import org.apache.velocity.app.VelocityEngine;
  import org.apache.velocity.context.Context;
  import org.owasp.dependencycheck.analyzer.Analyzer;
  import org.owasp.dependencycheck.data.nvdcve.DatabaseProperties;
  import org.owasp.dependencycheck.dependency.Dependency;
  import org.owasp.dependencycheck.dependency.EvidenceType;
  import org.owasp.dependencycheck.exception.ExceptionCollection;
  import org.owasp.dependencycheck.exception.ReportException;
  import org.owasp.dependencycheck.utils.Checksum;
  import org.owasp.dependencycheck.utils.FileUtils;
  import org.owasp.dependencycheck.utils.Settings;
  import org.owasp.dependencycheck.utils.XmlUtils;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  
  import javax.annotation.concurrent.NotThreadSafe;
  import javax.xml.XMLConstants;
  import javax.xml.parsers.ParserConfigurationException;
  import javax.xml.transform.OutputKeys;
  import javax.xml.transform.Transformer;
  import javax.xml.transform.TransformerConfigurationException;
  import javax.xml.transform.TransformerException;
  import javax.xml.transform.TransformerFactory;
  import javax.xml.transform.sax.SAXSource;
  import javax.xml.transform.sax.SAXTransformerFactory;
  import javax.xml.transform.stream.StreamResult;
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.io.InputStreamReader;
  import java.io.OutputStream;
  import java.io.OutputStreamWriter;
  import java.nio.charset.StandardCharsets;
  import java.nio.file.Files;
  import java.time.ZonedDateTime;
  import java.time.format.DateTimeFormatter;
  import java.util.List;
  
  /**
   * The ReportGenerator is used to, as the name implies, generate reports.
   * Internally the generator uses the Velocity Templating Engine. The
   * ReportGenerator exposes a list of Dependencies to the template when
   * generating the report.
   *
   * @author Jeremy Long
   */
  @NotThreadSafe
  public class ReportGenerator {
  
      /**
       * The logger.
       */
      private static final Logger LOGGER = LoggerFactory.getLogger(ReportGenerator.class);
  
      /**
       * An enumeration of the report formats.
       */
      public enum Format {
  
          /**
           * Generate all reports.
           */
          ALL,
          /**
           * Generate XML report.
           */
          XML,
         /**
          * Generate HTML report.
          */
         HTML,
         /**
          * Generate JSON report.
          */
         JSON,
         /**
          * Generate CSV report.
          */
         CSV,
         /**
          * Generate Sarif report.
          */
         SARIF,
         /**
          * Generate HTML report without script or non-vulnerable libraries for
          * Jenkins.
          */
         JENKINS,
         /**
          * Generate JUNIT report.
          */
         JUNIT,
         /**
          * Generate Report in GitLab dependency check format.
          *
          * @see <a href="https://gitlab.com/gitlab-org/security-products/security-report-schemas/-/blob/master/dist/dependency-scanning-report-format.json">format definition</a>
          * @see <a href="https://docs.gitlab.com/ee/development/integrations/secure.html">additional explanations on the format</a>
          */
         GITLAB
     }
 
     /**
      * The Velocity Engine.
      */
     private final VelocityEngine velocityEngine;
     /**
      * The Velocity Engine Context.
      */
     private final Context context;
     /**
      * The configured settings.
      */
     private final Settings settings;
 
     //CSOFF: ParameterNumber
     //CSOFF: LineLength
 
     /**
      * Constructs a new ReportGenerator.
      *
      * @param applicationName the application name being analyzed
      * @param dependencies the list of dependencies
      * @param analyzers the list of analyzers used
      * @param properties the database properties (containing timestamps of the
      * NVD CVE data)
      * @param settings a reference to the database settings
      * @param exceptions a collection of exceptions that may have occurred
      * during the analysis
      * @since 5.1.0
      */
     public ReportGenerator(String applicationName, List<Dependency> dependencies, List<Analyzer> analyzers,
                            DatabaseProperties properties, Settings settings, ExceptionCollection exceptions) {
         this(applicationName, null, null, null, dependencies, analyzers, properties, settings, exceptions);
     }
 
     /**
      * Constructs a new ReportGenerator.
      *
      * @param applicationName the application name being analyzed
      * @param groupID the group id of the project being analyzed
      * @param artifactID the application id of the project being analyzed
      * @param version the application version of the project being analyzed
      * @param dependencies the list of dependencies
      * @param analyzers the list of analyzers used
      * @param properties the database properties (containing timestamps of the
      * NVD CVE data)
      * @param settings a reference to the database settings
      * @param exceptions a collection of exceptions that may have occurred
      * during the analysis
      * @since 5.1.0
      */
     public ReportGenerator(String applicationName, String groupID, String artifactID, String version,
                            List<Dependency> dependencies, List<Analyzer> analyzers, DatabaseProperties properties,
                            Settings settings, ExceptionCollection exceptions) {
         this.settings = settings;
         velocityEngine = createVelocityEngine();
         velocityEngine.init();
         context = createContext(applicationName, dependencies, analyzers, properties, groupID,
                 artifactID, version, exceptions);
     }
 
     /**
      * Constructs the velocity context used to generate the dependency-check
      * reports.
      *
      * @param applicationName the application name being analyzed
      * @param groupID the group id of the project being analyzed
      * @param artifactID the application id of the project being analyzed
      * @param version the application version of the project being analyzed
      * @param dependencies the list of dependencies
      * @param analyzers the list of analyzers used
      * @param properties the database properties (containing timestamps of the
      * NVD CVE data)
      * @param exceptions a collection of exceptions that may have occurred
      * during the analysis
      * @return the velocity context
      */
     @SuppressWarnings("JavaTimeDefaultTimeZone")
     private VelocityContext createContext(String applicationName, List<Dependency> dependencies,
                                           List<Analyzer> analyzers, DatabaseProperties properties, String groupID,
                                           String artifactID, String version, ExceptionCollection exceptions) {
 
         final ZonedDateTime dt = ZonedDateTime.now();
         final String scanDate = DateTimeFormatter.RFC_1123_DATE_TIME.format(dt);
         final String scanDateXML = DateTimeFormatter.ISO_INSTANT.format(dt);
         final String scanDateJunit = DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(dt);
         final String scanDateGitLab = DateTimeFormatter.ISO_LOCAL_DATE_TIME.format(dt.withNano(0));
 
         // Remember to update type definitions at templates/velocity_implicit.vm
         final VelocityContext ctxt = new VelocityContext();
         ctxt.put("applicationName", applicationName);
         dependencies.sort(Dependency.NAME_COMPARATOR);
         ctxt.put("dependencies", dependencies);
         ctxt.put("analyzers", analyzers);
         ctxt.put("properties", properties);
         ctxt.put("scanDate", scanDate);
         ctxt.put("scanDateXML", scanDateXML);
         ctxt.put("scanDateJunit", scanDateJunit);
         ctxt.put("scanDateGitLab", scanDateGitLab);
         ctxt.put("enc", new EscapeTool());
         ctxt.put("rpt", new ReportTool());
         ctxt.put("checksum", Checksum.class);
         ctxt.put("WordUtils", new WordUtils());
         ctxt.put("StringUtils", new StringUtils());
         ctxt.put("VENDOR", EvidenceType.VENDOR);
         ctxt.put("PRODUCT", EvidenceType.PRODUCT);
         ctxt.put("VERSION", EvidenceType.VERSION);
         ctxt.put("version", settings.getString(Settings.KEYS.APPLICATION_VERSION, "Unknown"));
         ctxt.put("settings", settings);
         if (version != null) {
             ctxt.put("applicationVersion", version);
         }
         if (artifactID != null) {
             ctxt.put("artifactID", artifactID);
         }
         if (groupID != null) {
             ctxt.put("groupID", groupID);
         }
         if (exceptions != null) {
             ctxt.put("exceptions", exceptions.getExceptions());
         }
         return ctxt;
     }
     //CSON: ParameterNumber
     //CSON: LineLength
 
     /**
      * Creates a new Velocity Engine.
      *
      * @return a velocity engine
      */
     private VelocityEngine createVelocityEngine() {
         return new VelocityEngine();
     }
 
     /**
      * Writes the dependency-check report to the given output location.
      *
      * @param outputLocation the path where the reports should be written
      * @param format the format the report should be written in (a valid member
      * of {@link Format}) or even the path to a custom velocity template
      * (either fully qualified or the template name on the class path).
      * @throws ReportException is thrown if there is an error creating out the
      * reports
      */
     public void write(String outputLocation, String format) throws ReportException {
         Format reportFormat = null;
         try {
             reportFormat = Format.valueOf(format.toUpperCase());
         } catch (IllegalArgumentException ex) {
             LOGGER.trace("ignore this exception", ex);
         }
 
         if (reportFormat != null) {
             write(outputLocation, reportFormat);
         } else {
             File out = getReportFile(outputLocation, null);
             if (out.isDirectory()) {
                 out = new File(out, FilenameUtils.getBaseName(format));
                 LOGGER.warn("Writing non-standard VSL output to a directory using template name as file name.");
             }
             LOGGER.info("Writing custom report to: {}", out.getAbsolutePath());
             processTemplate(format, out);
         }
 
     }
 
     /**
      * Writes the dependency-check report(s).
      *
      * @param outputLocation the path where the reports should be written
      * @param format the format the report should be written in (see
      * {@link Format})
      * @throws ReportException is thrown if there is an error creating out the
      * reports
      */
     public void write(String outputLocation, Format format) throws ReportException {
         if (format == Format.ALL) {
             for (Format f : Format.values()) {
                 if (f != Format.ALL) {
                     write(outputLocation, f);
                 }
             }
         } else {
             final File out = getReportFile(outputLocation, format);
             final String templateName = format.toString().toLowerCase() + "Report";
             LOGGER.info("Writing {} report to: {}", format, out.getAbsolutePath());
             processTemplate(templateName, out);
             if (settings.getBoolean(Settings.KEYS.PRETTY_PRINT, false)) {
                 if (format == Format.JSON || format == Format.SARIF) {
                     pretifyJson(out.getPath());
                 } else if (format == Format.XML || format == Format.JUNIT) {
                     pretifyXml(out.getPath());
                 }
             }
         }
     }
 
     /**
      * Determines the report file name based on the give output location and
      * format. If the output location contains a full file name that has the
      * correct extension for the given report type then the output location is
      * returned. However, if the output location is a directory, this method
      * will generate the correct name for the given output format.
      *
      * @param outputLocation the specified output location
      * @param format the report format
      * @return the report File
      */
     public static File getReportFile(String outputLocation, Format format) {
         File outFile = new File(outputLocation);
         if (outFile.getParentFile() == null) {
             outFile = new File(".", outputLocation);
         }
         final String pathToCheck = outputLocation.toLowerCase();
         if (format == Format.XML && !pathToCheck.endsWith(".xml")) {
             return new File(outFile, "dependency-check-report.xml");
         }
         if (format == Format.HTML && !pathToCheck.endsWith(".html") && !pathToCheck.endsWith(".htm")) {
             return new File(outFile, "dependency-check-report.html");
         }
         if (format == Format.JENKINS && !pathToCheck.endsWith(".html") && !pathToCheck.endsWith(".htm")) {
             return new File(outFile, "dependency-check-jenkins.html");
         }
         if (format == Format.JSON && !pathToCheck.endsWith(".json")) {
             return new File(outFile, "dependency-check-report.json");
         }
         if (format == Format.CSV && !pathToCheck.endsWith(".csv")) {
             return new File(outFile, "dependency-check-report.csv");
         }
         if (format == Format.JUNIT && !pathToCheck.endsWith(".xml")) {
             return new File(outFile, "dependency-check-junit.xml");
         }
         if (format == Format.SARIF && !pathToCheck.endsWith(".sarif")) {
             return new File(outFile, "dependency-check-report.sarif");
         }
         if (format == Format.GITLAB && !pathToCheck.endsWith(".json")) {
             return new File(outFile, "dependency-check-gitlab.json");
         }
         return outFile;
     }
 
     /**
      * Generates a report from a given Velocity Template. The template name
      * provided can be the name of a template contained in the jar file, such as
      * 'XmlReport' or 'HtmlReport', or the template name can be the path to a
      * template file.
      *
      * @param template the name of the template to load
      * @param file the output file to write the report to
      * @throws ReportException is thrown when the report cannot be generated
      */
     @SuppressFBWarnings(justification = "try with resources will clean up the output stream", value = {"OBL_UNSATISFIED_OBLIGATION"})
     protected void processTemplate(String template, File file) throws ReportException {
         ensureParentDirectoryExists(file);
         try (OutputStream output = new FileOutputStream(file)) {
             processTemplate(template, output);
         } catch (IOException ex) {
             throw new ReportException(String.format("Unable to write to file: %s", file), ex);
         }
     }
 
     /**
      * Generates a report from a given Velocity Template. The template name
      * provided can be the name of a template contained in the jar file, such as
      * 'XmlReport' or 'HtmlReport', or the template name can be the path to a
      * template file.
      *
      * @param templateName the name of the template to load
      * @param outputStream the OutputStream to write the report to
      * @throws ReportException is thrown when an exception occurs
      */
     protected void processTemplate(String templateName, OutputStream outputStream) throws ReportException {
         try {
             String logTag;
             InputStream input;
             final File f = new File(templateName);
             if (f.isFile()) {
                 logTag = templateName;
                 input = new FileInputStream(f);
             } else {
                 logTag = "templates/" + templateName + ".vsl";
                 input = FileUtils.getResourceAsStream(logTag);
             }
 
             try (InputStreamReader reader = new InputStreamReader(input, StandardCharsets.UTF_8);
                  OutputStreamWriter writer = new OutputStreamWriter(outputStream, StandardCharsets.UTF_8)) {
                 if (!velocityEngine.evaluate(context, writer, logTag, reader)) {
                     throw new ReportException("Failed to convert the template into html.");
                 }
                 writer.flush();
             }
         } catch (FileNotFoundException ex) {
             throw new ReportException("Unable to locate template file: " + templateName, ex);
         } catch (IOException ex) {
             throw new ReportException("Unable to write the report", ex);
         }
     }
 
     /**
      * Validates that the given file's parent directory exists. If the directory
      * does not exist an attempt to create the necessary path is made; if that
      * fails a ReportException will be raised.
      *
      * @param file the file or directory directory
      * @throws ReportException thrown if the parent directory does not exist and
      * cannot be created
      */
     private void ensureParentDirectoryExists(File file) throws ReportException {
         if (!file.getParentFile().exists()) {
             final boolean created = file.getParentFile().mkdirs();
             if (!created) {
                 final String msg = String.format("Unable to create directory '%s'.", file.getParentFile().getAbsolutePath());
                 throw new ReportException(msg);
             }
         }
     }
 
     /**
      * Reformats the given XML file.
      *
      * @param path the path to the XML file to be reformatted
      */
     private void pretifyXml(String path) {
         final String outputPath = path + ".pretty";
         final File in = new File(path);
         final File out = new File(outputPath);
         try (OutputStream os = new FileOutputStream(out)) {
             final TransformerFactory transformerFactory = SAXTransformerFactory.newInstance();
             transformerFactory.setFeature(XMLConstants.FEATURE_SECURE_PROCESSING, true);
             final Transformer transformer = transformerFactory.newTransformer();
             transformer.setOutputProperty(OutputKeys.ENCODING, StandardCharsets.UTF_8.name());
             transformer.setOutputProperty(OutputKeys.INDENT, "yes");
             transformer.setOutputProperty("{http://xml.apache.org/xslt}indent-amount", "2");
 
             final SAXSource saxs = new SAXSource(XmlUtils.buildSecureXmlReader(), new InputSource(path));
             transformer.transform(saxs, new StreamResult(new OutputStreamWriter(os, StandardCharsets.UTF_8)));
         } catch (ParserConfigurationException | TransformerConfigurationException ex) {
             LOGGER.debug("Configuration exception when pretty printing", ex);
             LOGGER.error("Unable to generate pretty report, caused by: {}", ex.getMessage());
         } catch (TransformerException | SAXException | IOException ex) {
             LOGGER.debug("Malformed XML?", ex);
             LOGGER.error("Unable to generate pretty report, caused by: {}", ex.getMessage());
         }
         replaceWithPrettified(out, in);
     }
 
     /**
      * Reformats the given JSON file.
      *
      * @param pathToJson the path to the JSON file to be reformatted
      * @throws ReportException thrown if the given JSON file is malformed
      */
     private void pretifyJson(String pathToJson) throws ReportException {
         LOGGER.debug("pretify json: {}", pathToJson);
         final String outputPath = pathToJson + ".pretty";
         final File in = new File(pathToJson);
         final File out = new File(outputPath);
 
         final JsonFactory factory = new JsonFactory();
 
         try (InputStream is = new FileInputStream(in); OutputStream os = new FileOutputStream(out)) {
 
             final JsonParser parser = factory.createParser(is);
             final JsonGenerator generator = factory.createGenerator(os);
 
             generator.useDefaultPrettyPrinter();
 
             while (parser.nextToken() != null) {
                 generator.copyCurrentEvent(parser);
             }
             generator.flush();
         } catch (IOException ex) {
             LOGGER.debug("Malformed JSON?", ex);
             throw new ReportException("Unable to generate json report", ex);
         }
         replaceWithPrettified(out, in);
     }
 
     private void replaceWithPrettified(File prettified, File original) {
         if (prettified.isFile() && original.isFile() && original.delete()) {
             try {
                 Thread.sleep(1000);
                 Files.move(prettified.toPath(), original.toPath());
             } catch (IOException ex) {
                 LOGGER.error("Unable to generate pretty report, caused by: {}", ex.getMessage());
             } catch (InterruptedException ex) {
                 Thread.currentThread().interrupt();
                 LOGGER.error("Unable to generate pretty report, caused by: {}", ex.getMessage());
             }
         }
     }
 
 }