/*
    * 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) 2016 Jeremy Long. All Rights Reserved.
   */
  package org.owasp.dependencycheck.exception;
  
  import java.io.PrintStream;
  import java.io.PrintWriter;
  import java.util.ArrayList;
  import java.util.List;
  import javax.annotation.concurrent.NotThreadSafe;
  
  /**
   * A collection of several exceptions.
   *
   * @author Jeremy Long
   */
  @NotThreadSafe
  public class ExceptionCollection extends Exception {
  
      /**
       * The serial version UID for serialization.
       */
      private static final long serialVersionUID = -3032674811026089923L;
  
      /**
       * The default exception message.
       */
      private static final String MSG = "One or more exceptions occurred during analysis:";
      /**
       * A collection of exceptions.
       */
      private final List<Throwable> exceptions;
      /**
       * Flag indicating if a fatal exception occurred that would prevent the
       * attempt at completing the analysis even if exceptions occurred.
       */
      private boolean fatal = false;
  
      /**
       * Instantiates a new exception collection.
       *
       * @param exceptions a list of exceptions
       */
      public ExceptionCollection(List<Throwable> exceptions) {
          super(MSG);
          this.exceptions = exceptions;
      }
  
      /**
       * Instantiates a new exception collection.
       *
       * @param exceptions a list of exceptions
       * @param fatal indicates if any of the exceptions that occurred is fatal -
       * meaning that no analysis was performed.
       */
      public ExceptionCollection(List<Throwable> exceptions, boolean fatal) {
          super(MSG);
          this.exceptions = exceptions;
          this.fatal = fatal;
      }
  
      /**
       * Instantiates a new exception collection.
       *
       * @param exception a list of exceptions
       * @param fatal indicates if the exception that occurred is fatal - meaning
       * that no analysis was performed.
       */
      public ExceptionCollection(Throwable exception, boolean fatal) {
          super(MSG);
          if (exception instanceof ExceptionCollection) {
              final ExceptionCollection other = ((ExceptionCollection) exception);
              this.exceptions = other.getExceptions();
              this.fatal = other.isFatal();
          } else {
              this.exceptions = new ArrayList<>();
              this.exceptions.add(exception);
              this.fatal = fatal;
          }
      }
  
      /**
       * Instantiates a new exception collection.
       *
       * @param exception a list of exceptions
      */
     public ExceptionCollection(Throwable exception) {
         super(MSG);
         if (exception instanceof ExceptionCollection) {
             final ExceptionCollection other = ((ExceptionCollection) exception);
             this.exceptions = other.getExceptions();
             this.fatal = other.isFatal();
         } else {
             this.exceptions = new ArrayList<>();
             this.exceptions.add(exception);
             this.fatal = false;
         }
     }
 
     /**
      * Instantiates a new exception collection.
      */
     public ExceptionCollection() {
         super(MSG);
         this.exceptions = new ArrayList<>();
     }
 
     /**
      * Get the value of exceptions.
      *
      * @return the value of exceptions
      */
     public List<Throwable> getExceptions() {
         return exceptions;
     }
 
     /**
      * Adds an exception to the collection.
      *
      * @param ex the exception to add
      */
     public void addException(Throwable ex) {
         if (ex instanceof ExceptionCollection) {
             this.exceptions.addAll(((ExceptionCollection) ex).getExceptions());
         }
         this.exceptions.add(ex);
     }
 
     /**
      * Adds an exception to the collection.
      *
      * @param ex the exception to add
      * @param fatal flag indicating if this is a fatal error
      */
     public void addException(Throwable ex, boolean fatal) {
         addException(ex);
         this.fatal = fatal;
     }
 
     /**
      * Get the value of fatal.
      *
      * @return the value of fatal
      */
     public boolean isFatal() {
         return fatal;
     }
 
     /**
      * Set the value of fatal.
      *
      * @param fatal new value of fatal
      */
     public void setFatal(boolean fatal) {
         this.fatal = fatal;
     }
 
     /**
      * Prints the stack trace.
      *
      * @param s the writer to print to
      */
     @Override
     public void printStackTrace(PrintWriter s) {
         s.println(MSG);
         super.printStackTrace(s);
         this.exceptions.forEach((t) -> {
             s.println("Next Exception:");
             t.printStackTrace(s);
         });
     }
 
     /**
      * Prints the stack trace.
      *
      * @param s the stream to write the stack trace to
      */
     @Override
     public void printStackTrace(PrintStream s) {
         s.println(MSG);
         super.printStackTrace(s);
         this.exceptions.forEach((t) -> {
             s.println("Next Exception:");
             t.printStackTrace(s);
         });
     }
 
     /**
      * Returns the error message, including the message from all contained
      * exceptions.
      *
      * @return the error message
      */
     @Override
     public String getMessage() {
         final StringBuilder sb = new StringBuilder(MSG);
 
         this.exceptions.forEach((t) -> sb.append("\n\t")
                 .append(t.getClass().getSimpleName())
                 .append(": ")
                 .append(ExceptionCollection.nestedCauseList(t)));
         return sb.toString();
     }
 
     private static StringBuilder nestedCauseList(Throwable t) {
         final StringBuilder sb = new StringBuilder().append(t.getMessage());
         Throwable nestedCause = t.getCause();
         while (nestedCause != null) {
             sb.append("\n\t\tcaused by ").append(nestedCause.getClass().getSimpleName()).append(": ").append(nestedCause.getMessage());
             nestedCause = nestedCause.getCause();
         }
         return sb;
     }
 }