/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.pattern;
  
  import ch.qos.logback.classic.spi.IThrowableProxy;
  import ch.qos.logback.classic.spi.ThrowableProxyUtil;
  import ch.qos.logback.core.CoreConstants;
  
  /**
   * @author Tomasz Nurkiewicz
   * @since 0.9.30
   */
  public class RootCauseFirstThrowableProxyConverter extends ExtendedThrowableProxyConverter {
  
      @Override
      protected String throwableProxyToString(IThrowableProxy tp) {
          StringBuilder buf = new StringBuilder(BUILDER_CAPACITY);
          recursiveAppendRootCauseFirst(buf, null, ThrowableProxyUtil.REGULAR_EXCEPTION_INDENT, tp);
          return buf.toString();
      }
  
      protected void recursiveAppendRootCauseFirst(StringBuilder sb, String prefix, int indent, IThrowableProxy tp) {
          if (tp.getCause() != null) {
              recursiveAppendRootCauseFirst(sb, prefix, indent, tp.getCause());
              prefix = null; // to avoid adding it more than once
          }
          ThrowableProxyUtil.indent(sb, indent - 1);
          if (prefix != null) {
              sb.append(prefix);
          }
          ThrowableProxyUtil.subjoinFirstLineRootCauseFirst(sb, tp);
          sb.append(CoreConstants.LINE_SEPARATOR);
          subjoinSTEPArray(sb, indent, tp);
          IThrowableProxy[] suppressed = tp.getSuppressed();
          if (suppressed != null) {
              for (IThrowableProxy current : suppressed) {
                  recursiveAppendRootCauseFirst(sb, CoreConstants.SUPPRESSED,
                          indent + ThrowableProxyUtil.SUPPRESSED_EXCEPTION_INDENT, current);
              }
          }
      }
  }