/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements. See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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.apache.logging.log4j.core.layout;
  
  import java.io.IOException;
  import java.io.Writer;
  import java.nio.charset.Charset;
  import java.util.LinkedHashMap;
  import java.util.Map;
  
  import org.apache.logging.log4j.core.LogEvent;
  import org.apache.logging.log4j.core.config.Configuration;
  import org.apache.logging.log4j.core.config.plugins.PluginBuilderAttribute;
  import org.apache.logging.log4j.core.config.plugins.PluginElement;
  import org.apache.logging.log4j.core.impl.MutableLogEvent;
  import org.apache.logging.log4j.core.jackson.XmlConstants;
  import org.apache.logging.log4j.core.lookup.StrSubstitutor;
  import org.apache.logging.log4j.core.util.KeyValuePair;
  import org.apache.logging.log4j.core.util.StringBuilderWriter;
  import org.apache.logging.log4j.util.Strings;
  
  import com.fasterxml.jackson.annotation.JsonAnyGetter;
  import com.fasterxml.jackson.annotation.JsonRootName;
  import com.fasterxml.jackson.annotation.JsonUnwrapped;
  import com.fasterxml.jackson.core.JsonGenerationException;
  import com.fasterxml.jackson.databind.JsonMappingException;
  import com.fasterxml.jackson.databind.ObjectWriter;
  import com.fasterxml.jackson.dataformat.xml.annotation.JacksonXmlRootElement;
  
  abstract class AbstractJacksonLayout extends AbstractStringLayout {
  
      protected static final String DEFAULT_EOL = "\r\n";
      protected static final String COMPACT_EOL = Strings.EMPTY;
  
      public static abstract class Builder<B extends Builder<B>> extends AbstractStringLayout.Builder<B> {
  
          @PluginBuilderAttribute
          private boolean eventEol;
  
          @PluginBuilderAttribute
          private boolean compact;
  
          @PluginBuilderAttribute
          private boolean complete;
  
          @PluginBuilderAttribute
          private boolean locationInfo;
  
          @PluginBuilderAttribute
          private boolean properties;
  
          @PluginBuilderAttribute
          private boolean includeStacktrace = true;
  
          @PluginBuilderAttribute
          private boolean stacktraceAsString = false;
  
          @PluginBuilderAttribute
          private boolean includeNullDelimiter = false;
  
          @PluginElement("AdditionalField")
          private KeyValuePair[] additionalFields;
  
          protected String toStringOrNull(final byte[] header) {
              return header == null ? null : new String(header, Charset.defaultCharset());
          }
  
          public boolean getEventEol() {
              return eventEol;
          }
  
          public boolean isCompact() {
              return compact;
          }
  
          public boolean isComplete() {
              return complete;
          }
  
          public boolean isLocationInfo() {
              return locationInfo;
          }
  
          public boolean isProperties() {
              return properties;
         }
 
         /**
          * If "true", includes the stacktrace of any Throwable in the generated data, defaults to "true".
          * @return If "true", includes the stacktrace of any Throwable in the generated data, defaults to "true".
          */
         public boolean isIncludeStacktrace() {
             return includeStacktrace;
         }
 
         public boolean isStacktraceAsString() {
             return stacktraceAsString;
         }
 
         public boolean isIncludeNullDelimiter() { return includeNullDelimiter; }
 
         public KeyValuePair[] getAdditionalFields() {
             return additionalFields;
         }
 
         public B setEventEol(final boolean eventEol) {
             this.eventEol = eventEol;
             return asBuilder();
         }
 
         public B setCompact(final boolean compact) {
             this.compact = compact;
             return asBuilder();
         }
 
         public B setComplete(final boolean complete) {
             this.complete = complete;
             return asBuilder();
         }
 
         public B setLocationInfo(final boolean locationInfo) {
             this.locationInfo = locationInfo;
             return asBuilder();
         }
 
         public B setProperties(final boolean properties) {
             this.properties = properties;
             return asBuilder();
         }
 
         /**
          * If "true", includes the stacktrace of any Throwable in the generated JSON, defaults to "true".
          * @param includeStacktrace If "true", includes the stacktrace of any Throwable in the generated JSON, defaults to "true".
          * @return this builder
          */
         public B setIncludeStacktrace(final boolean includeStacktrace) {
             this.includeStacktrace = includeStacktrace;
             return asBuilder();
         }
 
         /**
          * Whether to format the stacktrace as a string, and not a nested object (optional, defaults to false).
          *
          * @return this builder
          */
         public B setStacktraceAsString(final boolean stacktraceAsString) {
             this.stacktraceAsString = stacktraceAsString;
             return asBuilder();
         }
 
         /**
          * Whether to include NULL byte as delimiter after each event (optional, default to false).
          *
          * @return this builder
          */
         public B setIncludeNullDelimiter(final boolean includeNullDelimiter) {
             this.includeNullDelimiter = includeNullDelimiter;
             return asBuilder();
         }
 
         /**
          * Additional fields to set on each log event.
          *
          * @return this builder
          */
         public B setAdditionalFields(KeyValuePair[] additionalFields) {
             this.additionalFields = additionalFields;
             return asBuilder();
         }
     }
 
     protected final String eol;
     protected final ObjectWriter objectWriter;
     protected final boolean compact;
     protected final boolean complete;
     protected final boolean includeNullDelimiter;
     protected final ResolvableKeyValuePair[] additionalFields;
 
     @Deprecated
     protected AbstractJacksonLayout(final Configuration config, final ObjectWriter objectWriter, final Charset charset,
             final boolean compact, final boolean complete, final boolean eventEol, final Serializer headerSerializer,
             final Serializer footerSerializer) {
         this(config, objectWriter, charset, compact, complete, eventEol, headerSerializer, footerSerializer, false);
     }
 
     @Deprecated
     protected AbstractJacksonLayout(final Configuration config, final ObjectWriter objectWriter, final Charset charset,
             final boolean compact, final boolean complete, final boolean eventEol, final Serializer headerSerializer,
             final Serializer footerSerializer, final boolean includeNullDelimiter) {
         this(config, objectWriter, charset, compact, complete, eventEol, headerSerializer, footerSerializer, includeNullDelimiter, null);
     }
 
     protected AbstractJacksonLayout(final Configuration config, final ObjectWriter objectWriter, final Charset charset,
             final boolean compact, final boolean complete, final boolean eventEol, final Serializer headerSerializer,
             final Serializer footerSerializer, final boolean includeNullDelimiter,
             final KeyValuePair[] additionalFields) {
         super(config, charset, headerSerializer, footerSerializer);
         this.objectWriter = objectWriter;
         this.compact = compact;
         this.complete = complete;
         this.eol = compact && !eventEol ? COMPACT_EOL : DEFAULT_EOL;
         this.includeNullDelimiter = includeNullDelimiter;
         this.additionalFields = prepareAdditionalFields(config, additionalFields);
     }
 
     protected static boolean valueNeedsLookup(final String value) {
         return value != null && value.contains("${");
     }
 
     private static ResolvableKeyValuePair[] prepareAdditionalFields(final Configuration config, final KeyValuePair[] additionalFields) {
         if (additionalFields == null || additionalFields.length == 0) {
             // No fields set
             return new ResolvableKeyValuePair[0];
         }
 
         // Convert to specific class which already determines whether values needs lookup during serialization
         final ResolvableKeyValuePair[] resolvableFields = new ResolvableKeyValuePair[additionalFields.length];
 
         for (int i = 0; i < additionalFields.length; i++) {
             ResolvableKeyValuePair resolvable = resolvableFields[i] = new ResolvableKeyValuePair(additionalFields[i]);
 
             // Validate
             if (config == null && resolvable.valueNeedsLookup) {
                 throw new IllegalArgumentException("configuration needs to be set when there are additional fields with variables");
             }
         }
 
         return resolvableFields;
     }
 
     /**
      * Formats a {@link org.apache.logging.log4j.core.LogEvent}.
      *
      * @param event The LogEvent.
      * @return The XML representation of the LogEvent.
      */
     @Override
     public String toSerializable(final LogEvent event) {
         final StringBuilderWriter writer = new StringBuilderWriter();
         try {
             toSerializable(event, writer);
             return writer.toString();
         } catch (final IOException e) {
             // Should this be an ISE or IAE?
             LOGGER.error(e);
             return Strings.EMPTY;
         }
     }
 
     private static LogEvent convertMutableToLog4jEvent(final LogEvent event) {
         // TODO Jackson-based layouts have certain filters set up for Log4jLogEvent.
         // TODO Need to set up the same filters for MutableLogEvent but don't know how...
         // This is a workaround.
         return event instanceof MutableLogEvent
                 ? ((MutableLogEvent) event).createMemento()
                 : event;
     }
 
     protected Object wrapLogEvent(final LogEvent event) {
         if (additionalFields.length > 0) {
             // Construct map for serialization - note that we are intentionally using original LogEvent
             Map<String, String> additionalFieldsMap = resolveAdditionalFields(event);
             // This class combines LogEvent with AdditionalFields during serialization
             return new LogEventWithAdditionalFields(event, additionalFieldsMap);
         } else {
             // No additional fields, return original object
             return event;
         }
     }
 
     private Map<String, String> resolveAdditionalFields(LogEvent logEvent) {
         // Note: LinkedHashMap retains order
         final Map<String, String> additionalFieldsMap = new LinkedHashMap<>(additionalFields.length);
         final StrSubstitutor strSubstitutor = configuration.getStrSubstitutor();
 
         // Go over each field
         for (ResolvableKeyValuePair pair : additionalFields) {
             if (pair.valueNeedsLookup) {
                 // Resolve value
                 additionalFieldsMap.put(pair.key, strSubstitutor.replace(logEvent, pair.value));
             } else {
                 // Plain text value
                 additionalFieldsMap.put(pair.key, pair.value);
             }
         }
 
         return additionalFieldsMap;
     }
 
     public void toSerializable(final LogEvent event, final Writer writer)
             throws JsonGenerationException, JsonMappingException, IOException {
         objectWriter.writeValue(writer, wrapLogEvent(convertMutableToLog4jEvent(event)));
         writer.write(eol);
         if (includeNullDelimiter) {
             writer.write('\0');
         }
         markEvent();
     }
 
     @JsonRootName(XmlConstants.ELT_EVENT)
     @JacksonXmlRootElement(namespace = XmlConstants.XML_NAMESPACE, localName = XmlConstants.ELT_EVENT)
     public static class LogEventWithAdditionalFields {
 
         private final Object logEvent;
         private final Map<String, String> additionalFields;
 
         public LogEventWithAdditionalFields(Object logEvent, Map<String, String> additionalFields) {
             this.logEvent = logEvent;
             this.additionalFields = additionalFields;
         }
 
         @JsonUnwrapped
         public Object getLogEvent() {
             return logEvent;
         }
 
         @JsonAnyGetter
         @SuppressWarnings("unused")
         public Map<String, String> getAdditionalFields() {
             return additionalFields;
         }
     }
 
     protected static class ResolvableKeyValuePair {
 
         final String key;
         final String value;
         final boolean valueNeedsLookup;
 
         ResolvableKeyValuePair(KeyValuePair pair) {
             this.key = pair.getKey();
             this.value = pair.getValue();
             this.valueNeedsLookup = AbstractJacksonLayout.valueNeedsLookup(this.value);
         }
     }
 }