// ***************************************************************************************************************************
// * 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.juneau.config.internal;

import static org.apache.juneau.internal.CollectionUtils.*;
import static org.apache.juneau.internal.StringUtils.*;

import java.io.*;
import java.util.*;

import org.apache.juneau.internal.*;

/**
 * Represents a single entry in a configuration.
 * 
 * This is a read-only object.
 */
public class ConfigEntry {
   final String rawLine;
   final String key, value, comment;
   final String modifiers;
   final List<String> preLines;
   
   static final ConfigEntry NULL = new ConfigEntry(null, null, null, null, null);
   
   private final static AsciiSet MOD_CHARS = AsciiSet.create("#$%&*+^@~");

   ConfigEntry(String line, List<String> preLines) {
      this.rawLine = line;
      int i = line.indexOf('=');
      String key = line.substring(0, i).trim();
      
      int modIndex = key.length();
      for (int j = key.length()-1; j > 0; j--) 
         if (MOD_CHARS.contains(key.charAt(j)))
            modIndex--;

      this.modifiers = key.substring(modIndex);
      this.key = key.substring(0, modIndex);
      
      line = line.substring(i+1);
   
      i = line.indexOf('#');
      if (i != -1) {
         String[] l2 = StringUtils.split(line, '#', 2);
         line = l2[0];
         if (l2.length == 2)
            this.comment = l2[1].trim();
         else
            this.comment = null;
      } else {
         this.comment = null;
      }
   
      this.value = StringUtils.replaceUnicodeSequences(line.trim());

      this.preLines = immutableList(preLines);
   }
   
   ConfigEntry(String key, String value, String modifiers, String comment, List<String> preLines) {
      this.rawLine = null;
      this.key = key;
      this.value = value;
      this.comment = comment;
      this.modifiers = modifiers;
      this.preLines = immutableList(preLines);
   }
   
   /**
    * Returns the raw value of this entry.
    * 
    * @return The raw value of this entry.
    */
   public String getValue() {
      return value;
   }
   
   /**
    * Returns the same-line comment of this entry.
    * 
    * @return The same-line comment of this entry.
    */
   public String getComment() {
      return comment;
   }

   /**
    * Returns the pre-lines of this entry.
    * 
    * @return The pre-lines of this entry as an unmodifiable list.
    */
   public List<String> getPreLines() {
      return preLines;
   }

   /**
    * Returns whether this entry has the specified modifier.
    * 
    * @param m The modifier character.
    * @return <jk>true</jk> if this entry is encoded.
    */
   public boolean hasModifier(char m) {
      return modifiers.indexOf(m) != -1;
   }

   /**
    * Returns the modifiers for this entry.
    * 
    * @return The modifiers for this entry, or an empty string if it has no modifiers.
    */
   public String getModifiers() {
      return modifiers;
   }
   
   Writer writeTo(Writer w) throws IOException {
      if (value == null)
         return w;
      for (String pl : preLines)
         w.append(pl).append('\n');
      if (rawLine != null) {
         for (int i = 0; i < rawLine.length(); i++) {
            char c = rawLine.charAt(i);
            if (c == '\n')
               w.append('\n').append('\t');
            else if (c != '\r') 
               w.append(c);
         }
         w.append('\n');
      } else {
         w.append(key);
         if (modifiers != null)
            w.append(modifiers);
         w.append(" = ");
         
         String val = value;
         for (int i = 0; i < val.length(); i++) {
            char c = val.charAt(i);
            if (c == '\n')
               w.append('\n').append('\t');
            else if (c != '\r') {
               if (REPLACE_CHARS.contains(c) || (Character.isISOControl(c) && ! (c == '\n' || c == '\r' || c == '\t'))) {
                  w.append(StringUtils.unicodeSequence(c));
               } else {
                  w.append(c);
               }
            }
         }
            
         if (! isEmpty(comment)) 
            w.append(" # ").append(comment);
         
         w.append('\n');
      }
      return w;
   }
   
   private static final AsciiSet REPLACE_CHARS = AsciiSet.create("\\#");
}