/*
    * Copyright (c) 2002-2026 Gargoyle Software Inc.
    *
    * 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
    * https://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.htmlunit;
  
  import java.io.BufferedReader;
  import java.io.IOException;
  import java.io.PrintStream;
  import java.io.PrintWriter;
  import java.io.StringReader;
  import java.io.StringWriter;
  import java.util.StringTokenizer;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.htmlunit.corejs.javascript.EcmaError;
  import org.htmlunit.corejs.javascript.JavaScriptException;
  import org.htmlunit.corejs.javascript.RhinoException;
  import org.htmlunit.corejs.javascript.WrappedException;
  import org.htmlunit.html.HtmlPage;
  
  /**
   * An exception that will be thrown if an error occurs during the processing of
   * a script.
   *
   * @author Mike Bowler
   * @author Marc Guillemot
   * @author Frank Danek
   * @author Ronald Brill
   */
  public class ScriptException extends RuntimeException {
  
      /** Logging support. */
      private static final Log LOG = LogFactory.getLog(ScriptException.class);
  
      private final String scriptSourceCode_;
      private final HtmlPage page_;
  
      /**
       * Creates an instance.
       * @param page the page in which the script causing this exception was executed
       * @param throwable the exception that was thrown from the script engine
       * @param scriptSourceCode the code that was being executed when this exception
       *        was thrown. This may be null if the exception was not caused by execution
       *        of JavaScript.
       */
      public ScriptException(final HtmlPage page, final Throwable throwable,
              final String scriptSourceCode) {
          super(getMessageFrom(throwable), throwable);
          scriptSourceCode_ = scriptSourceCode;
          page_ = page;
      }
  
      private static String getMessageFrom(final Throwable throwable) {
          if (throwable == null) {
              return "null";
          }
          return throwable.getMessage();
      }
  
      /**
       * Creates an instance.
       * @param page the page in which the script causing this exception was executed
       * @param throwable the exception that was thrown from the script engine
       */
      public ScriptException(final HtmlPage page, final Throwable throwable) {
          this(page, throwable, null);
      }
  
      /**
       * Prints the stack trace to System.out. If this exception contains another
       * exception then the stack traces for both will be printed.
       */
      @Override
      public void printStackTrace() {
          printStackTrace(System.out);
      }
  
      /**
       * Prints the stack trace. If this exception contains another exception then
       * the stack traces for both will be printed.
       *
       * @param writer Where the stack trace will be written
       */
      @Override
      public void printStackTrace(final PrintWriter writer) {
          writer.write(createPrintableStackTrace());
      }
 
     /**
      * Prints the stack trace. If this exception contains another exception then
      * the stack traces for both will be printed.
      *
      * @param stream Where the stack trace will be written
      */
     @Override
     public void printStackTrace(final PrintStream stream) {
         stream.print(createPrintableStackTrace());
     }
 
     private String createPrintableStackTrace() {
         final StringWriter stringWriter = new StringWriter();
         final PrintWriter printWriter = new PrintWriter(stringWriter);
 
         printWriter.println("======= EXCEPTION START ========");
 
         if (getCause() != null) {
             if (getCause() instanceof EcmaError ecmaError) {
                 printWriter.print("EcmaError: ");
                 printWriter.print("lineNumber=[");
                 printWriter.print(ecmaError.lineNumber());
                 printWriter.print("] column=[");
                 printWriter.print(ecmaError.columnNumber());
                 printWriter.print("] lineSource=[");
                 printWriter.print(getFailingLine());
                 printWriter.print("] name=[");
                 printWriter.print(ecmaError.getName());
                 printWriter.print("] sourceName=[");
                 printWriter.print(ecmaError.sourceName());
                 printWriter.print("] message=[");
                 printWriter.print(ecmaError.getMessage());
                 printWriter.print("]");
                 printWriter.println();
             }
             else {
                 printWriter.println("Exception class=[" + getCause().getClass().getName() + "]");
             }
         }
 
         super.printStackTrace(printWriter);
         if (getCause() instanceof JavaScriptException) {
             final Object value = ((JavaScriptException) getCause()).getValue();
 
             printWriter.print("JavaScriptException value = ");
             if (value instanceof Throwable throwable) {
                 throwable.printStackTrace(printWriter);
             }
             else {
                 printWriter.println(value);
             }
         }
         else if (getCause() instanceof WrappedException wrappedException) {
             printWriter.print("WrappedException: ");
             wrappedException.printStackTrace(printWriter);
 
             final Throwable innerException = wrappedException.getWrappedException();
             if (innerException == null) {
                 printWriter.println("Inside wrapped exception: null");
             }
             else {
                 printWriter.println("Inside wrapped exception:");
                 innerException.printStackTrace(printWriter);
             }
         }
         else if (getCause() != null) {
             printWriter.println("Enclosed exception: ");
             getCause().printStackTrace(printWriter);
         }
 
         if (scriptSourceCode_ != null && !scriptSourceCode_.isEmpty()) {
             printWriter.println("== CALLING JAVASCRIPT ==");
             printWriter.println(scriptSourceCode_);
         }
         printWriter.println("======= EXCEPTION END ========");
 
         return stringWriter.toString();
     }
 
     /**
      * Returns the source code line that failed.
      * @return the source code line that failed
      */
     public String getScriptSourceCode() {
         return scriptSourceCode_;
     }
 
     /**
      * Returns the line of source that was being executed when this exception was
      * thrown.
      *
      * @return the line of source or an empty string if the exception was not thrown
      *         due to the execution of a script.
      */
     public String getFailingLine() {
         final int lineNumber = getFailingLineNumber();
         if (lineNumber == -1 || scriptSourceCode_ == null) {
             return "<no source>";
         }
 
         try (BufferedReader reader = new BufferedReader(new StringReader(scriptSourceCode_))) {
             for (int i = 0; i < lineNumber - 1; i++) {
                 reader.readLine();
             }
             return reader.readLine();
         }
         catch (final IOException e) {
             // Theoretically impossible
             LOG.error("Reading scriptSourceCode failed.", e);
         }
 
         return "";
     }
 
     /**
      * Returns the line number of the source that was executing at the time of the exception.
      *
      * @return the line number or -1 if the exception was not thrown due to the
      *         execution of a script.
      */
     public int getFailingLineNumber() {
         if (getCause() instanceof RhinoException cause) {
             return cause.lineNumber();
         }
 
         return -1;
     }
 
     /**
      * Returns the column number of the source that was executing at the time of the exception.
      *
      * @return the column number or -1 if the exception was not thrown due to the
      *         execution of a script.
      */
     public int getFailingColumnNumber() {
         if (getCause() instanceof RhinoException cause) {
             return cause.columnNumber();
         }
 
         return -1;
     }
 
     /**
      * Gets the HTML page in which the script error occurred.<br>
      * Caution: this page may be only partially parsed if the exception occurred in a script
      * executed at parsing time.
      * @return the page
      */
     public HtmlPage getPage() {
         return page_;
     }
 
     /**
      * Prints the script stack trace.
      * This represents only the script calls.
      * @param writer where the stack trace will be written
      */
     public void printScriptStackTrace(final PrintWriter writer) {
         final StringWriter stringWriter = new StringWriter();
         final PrintWriter printWriter = new PrintWriter(stringWriter);
 
         getCause().printStackTrace(printWriter);
 
         writer.print(getCause().getMessage());
         final StringTokenizer st = new StringTokenizer(stringWriter.toString(), "\r\n");
         while (st.hasMoreTokens()) {
             final String line = st.nextToken();
             if (line.contains("at script")) {
                 writer.println();
                 writer.print(line.replaceFirst("at script\\.?", "at "));
             }
         }
     }
 
 }