/*
    * Copyright 2012-2025 CodeLibs Project and the Others.
    *
    * 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.
   */
  package org.codelibs.fess.timer;
  
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.util.Arrays;
  import java.util.function.Supplier;
  
  import org.apache.commons.io.output.ByteArrayOutputStream;
  import org.apache.commons.text.StringEscapeUtils;
  import org.codelibs.core.timer.TimeoutTarget;
  import org.codelibs.fess.Constants;
  import org.codelibs.fess.helper.SystemHelper;
  import org.codelibs.fess.taglib.FessFunctions;
  import org.codelibs.fess.util.ComponentUtil;
  
  /**
   * Abstract base class for monitor targets that implement timeout functionality.
   */
  public abstract class MonitorTarget implements TimeoutTarget {
  
      /**
       * Default constructor.
       */
      public MonitorTarget() {
          // Default constructor
      }
  
      /**
       * Appends a key-value pair to the buffer in JSON format.
       *
       * @param buf the string buffer to append to
       * @param key the key name
       * @param supplier the value supplier
       * @return the updated buffer
       */
      protected StringBuilder append(final StringBuilder buf, final String key, final Supplier<Object> supplier) {
          final StringBuilder tempBuf = new StringBuilder();
          tempBuf.append('"').append(key).append("\":");
          try {
              final Object value = supplier.get();
              if (value == null) {
                  tempBuf.append("null");
              } else if (value instanceof Integer || value instanceof Long) {
                  tempBuf.append(value);
              } else if (value instanceof Short) {
                  tempBuf.append(((Short) value).shortValue());
              } else if (value instanceof double[]) {
                  tempBuf.append(Arrays.toString((double[]) value));
              } else {
                  tempBuf.append('"').append(StringEscapeUtils.escapeJson(value.toString())).append('"');
              }
          } catch (final Exception e) {
              tempBuf.append("null");
          }
          buf.append(tempBuf.toString());
          return buf;
      }
  
      /**
       * Appends a timestamp to the buffer.
       *
       * @param buf the string buffer to append to
       * @return the updated buffer
       */
      protected StringBuilder appendTimestamp(final StringBuilder buf) {
          final SystemHelper systemHelper = ComponentUtil.getSystemHelper();
          append(buf, "timestamp", () -> FessFunctions.formatDate(systemHelper.getCurrentTime()));
          return buf;
      }
  
      /**
       * Appends exception information to the buffer.
       *
       * @param buf the string buffer to append to
       * @param exception the exception to append
       * @return the updated buffer
       */
      protected StringBuilder appendException(final StringBuilder buf, final Exception exception) {
          try (ByteArrayOutputStream baos = new ByteArrayOutputStream();
                  PrintWriter writer = new PrintWriter(baos, false, Constants.CHARSET_UTF_8)) {
              exception.printStackTrace(writer);
              writer.flush();
              append(buf, "exception", () -> StringEscapeUtils.escapeJson(new String(baos.toByteArray(), Constants.CHARSET_UTF_8)));
          } catch (final IOException e) {
             append(buf, "exception", () -> StringEscapeUtils.escapeJson(e.getMessage()));
         }
         return buf;
     }
 }