/*
    * 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.commons.configuration2.tree;
  
  import org.apache.commons.lang3.builder.EqualsBuilder;
  import org.apache.commons.lang3.builder.HashCodeBuilder;
  import org.apache.commons.lang3.builder.ToStringBuilder;
  
  /**
   * <p>
   * A class representing the various symbols that are supported in keys recognized by {@link DefaultExpressionEngine}.
   * </p>
   * <p>
   * An instance of this class is associated with each instance of {@code DefaultExpressionEngine}. It determines which
   * concrete symbols are used to define elements like separators, attributes, etc. within a configuration key.
   * </p>
   * <p>
   * Instances are created using the nested {@code Builder} class. They are immutable and can be shared between arbitrary
   * components.
   * </p>
   *
   * @since 2.0
   */
  public final class DefaultExpressionEngineSymbols {
      /**
       * A builder class for creating instances of {@code DefaultExpressionEngineSymbols}.
       */
      public static class Builder {
          /** Stores the property delimiter. */
          private String propertyDelimiter;
  
          /** Stores the escaped property delimiter. */
          private String escapedDelimiter;
  
          /** Stores the attribute start marker. */
          private String attributeStart;
  
          /** Stores the attribute end marker. */
          private String attributeEnd;
  
          /** Stores the index start marker. */
          private String indexStart;
  
          /** Stores the index end marker. */
          private String indexEnd;
  
          /**
           * Creates a new, uninitialized instance of {@code Builder}. All symbols are undefined.
           */
          public Builder() {
          }
  
          /**
           * Creates a new instance of {@code Builder} whose properties are initialized from the passed in
           * {@code DefaultExpressionEngineSymbols} object. This is useful if symbols are to be created which are similar to the
           * passed in instance.
           *
           * @param c the {@code DefaultExpressionEngineSymbols} object serving as starting point for this builder
           */
          public Builder(final DefaultExpressionEngineSymbols c) {
              propertyDelimiter = c.getPropertyDelimiter();
              escapedDelimiter = c.getEscapedDelimiter();
              indexStart = c.getIndexStart();
              indexEnd = c.getIndexEnd();
              attributeStart = c.getAttributeStart();
              attributeEnd = c.getAttributeEnd();
          }
  
          /**
           * Creates the {@code DefaultExpressionEngineSymbols} instance based on the properties set for this builder object. This
           * method does not change the state of this builder. So it is possible to change properties and create another
           * {@code DefaultExpressionEngineSymbols} instance.
           *
           * @return the newly created {@code DefaultExpressionEngineSymbols} instance
           */
          public DefaultExpressionEngineSymbols create() {
              return new DefaultExpressionEngineSymbols(this);
          }
  
          /**
           * Sets the string representing the end marker of an attribute in a property key.
           *
           * @param attributeEnd the attribute end marker
           * @return a reference to this object for method chaining
           */
         public Builder setAttributeEnd(final String attributeEnd) {
             this.attributeEnd = attributeEnd;
             return this;
         }
 
         /**
          * Sets the string representing the start marker of an attribute in a property key. Attribute start and end marker are
          * used together to detect attributes in a property key.
          *
          * @param attributeStart the attribute start marker
          * @return a reference to this object for method chaining
          */
         public Builder setAttributeStart(final String attributeStart) {
             this.attributeStart = attributeStart;
             return this;
         }
 
         /**
          * Sets the string representing an escaped property delimiter. With this string a delimiter that belongs to the key of a
          * property can be escaped. If for instance &quot;.&quot; is used as property delimiter, you can set the escaped
          * delimiter to &quot;\.&quot; and can then escape the delimiter with a back slash.
          *
          * @param escapedDelimiter the escaped property delimiter
          * @return a reference to this object for method chaining
          */
         public Builder setEscapedDelimiter(final String escapedDelimiter) {
             this.escapedDelimiter = escapedDelimiter;
             return this;
         }
 
         /**
          * Sets the string representing the end of an index in a property key.
          *
          * @param indexEnd the index end
          * @return a reference to this object for method chaining
          */
         public Builder setIndexEnd(final String indexEnd) {
             this.indexEnd = indexEnd;
             return this;
         }
 
         /**
          * Sets the string representing the start of an index in a property key. Index start and end marker are used together to
          * detect indices in a property key.
          *
          * @param is the index start
          * @return a reference to this object for method chaining
          */
         public Builder setIndexStart(final String is) {
             this.indexStart = is;
             return this;
         }
 
         /**
          * Sets the string representing a delimiter for properties.
          *
          * @param propertyDelimiter the property delimiter
          * @return a reference to this object for method chaining
          */
         public Builder setPropertyDelimiter(final String propertyDelimiter) {
             this.propertyDelimiter = propertyDelimiter;
             return this;
         }
     }
 
     /** Constant for the default property delimiter. */
     public static final String DEFAULT_PROPERTY_DELIMITER = ".";
 
     /** Constant for the default escaped property delimiter. */
     public static final String DEFAULT_ESCAPED_DELIMITER = DEFAULT_PROPERTY_DELIMITER + DEFAULT_PROPERTY_DELIMITER;
 
     /** Constant for the default attribute start marker. */
     public static final String DEFAULT_ATTRIBUTE_START = "[@";
 
     /** Constant for the default attribute end marker. */
     public static final String DEFAULT_ATTRIBUTE_END = "]";
 
     /** Constant for the default index start marker. */
     public static final String DEFAULT_INDEX_START = "(";
 
     /** Constant for the default index end marker. */
     public static final String DEFAULT_INDEX_END = ")";
 
     /**
      * An instance with default symbols. This instance is used by the default instance of {@code DefaultExpressionEngine}.
      */
     public static final DefaultExpressionEngineSymbols DEFAULT_SYMBOLS = createDefaultSmybols();
 
     /**
      * Creates the {@code DefaultExpressionEngineSymbols} object with default symbols.
      *
      * @return the default symbols instance
      */
     private static DefaultExpressionEngineSymbols createDefaultSmybols() {
         return new Builder().setPropertyDelimiter(DEFAULT_PROPERTY_DELIMITER).setEscapedDelimiter(DEFAULT_ESCAPED_DELIMITER).setIndexStart(DEFAULT_INDEX_START)
             .setIndexEnd(DEFAULT_INDEX_END).setAttributeStart(DEFAULT_ATTRIBUTE_START).setAttributeEnd(DEFAULT_ATTRIBUTE_END).create();
     }
 
     /** Stores the property delimiter. */
     private final String propertyDelimiter;
 
     /** Stores the escaped property delimiter. */
     private final String escapedDelimiter;
 
     /** Stores the attribute start marker. */
     private final String attributeStart;
 
     /** Stores the attribute end marker. */
     private final String attributeEnd;
 
     /** Stores the index start marker. */
     private final String indexStart;
 
     /** Stores the index end marker. */
     private final String indexEnd;
 
     /**
      * Creates a new instance of {@code DefaultExpressionEngineSymbols}.
      *
      * @param b the builder for defining the properties of this instance
      */
     private DefaultExpressionEngineSymbols(final Builder b) {
         propertyDelimiter = b.propertyDelimiter;
         escapedDelimiter = b.escapedDelimiter;
         indexStart = b.indexStart;
         indexEnd = b.indexEnd;
         attributeStart = b.attributeStart;
         attributeEnd = b.attributeEnd;
     }
 
     /**
      * Compares this object with another one. Two instances of {@code DefaultExpressionEngineSymbols} are considered equal
      * if all of their properties are equal.
      *
      * @param obj the object to compare to
      * @return a flag whether these objects are equal
      */
     @Override
     public boolean equals(final Object obj) {
         if (this == obj) {
             return true;
         }
         if (!(obj instanceof DefaultExpressionEngineSymbols)) {
             return false;
         }
 
         final DefaultExpressionEngineSymbols c = (DefaultExpressionEngineSymbols) obj;
         return new EqualsBuilder().append(getPropertyDelimiter(), c.getPropertyDelimiter()).append(getEscapedDelimiter(), c.getEscapedDelimiter())
             .append(getIndexStart(), c.getIndexStart()).append(getIndexEnd(), c.getIndexEnd()).append(getAttributeStart(), c.getAttributeStart())
             .append(getAttributeEnd(), c.getAttributeEnd()).isEquals();
     }
 
     /**
      * Gets the string representing an attribute end marker.
      *
      * @return the attribute end marker
      */
     public String getAttributeEnd() {
         return attributeEnd;
     }
 
     /**
      * Gets the string representing an attribute start marker.
      *
      * @return the attribute start marker
      */
     public String getAttributeStart() {
         return attributeStart;
     }
 
     /**
      * Gets the string representing an escaped property delimiter.
      *
      * @return the escaped property delimiter
      */
     public String getEscapedDelimiter() {
         return escapedDelimiter;
     }
 
     /**
      * Gets the string representing the end of an index in a property key.
      *
      * @return the index end marker
      */
     public String getIndexEnd() {
         return indexEnd;
     }
 
     /**
      * Gets the string representing the start of an index in a property key.
      *
      * @return the index start marker
      */
     public String getIndexStart() {
         return indexStart;
     }
 
     /**
      * Gets the string used as delimiter in property keys.
      *
      * @return the property delimiter
      */
     public String getPropertyDelimiter() {
         return propertyDelimiter;
     }
 
     /**
      * Returns a hash code for this object.
      *
      * @return a hash code
      */
     @Override
     public int hashCode() {
         return new HashCodeBuilder().append(getPropertyDelimiter()).append(getEscapedDelimiter()).append(getIndexStart()).append(getIndexEnd())
             .append(getAttributeStart()).append(getAttributeEnd()).toHashCode();
     }
 
     /**
      * Returns a string representation for this object. This string contains the values of all properties.
      *
      * @return a string for this object
      */
     @Override
     public String toString() {
         return new ToStringBuilder(this).append("propertyDelimiter", getPropertyDelimiter()).append("escapedDelimiter", getEscapedDelimiter())
             .append("indexStart", getIndexStart()).append("indexEnd", getIndexEnd()).append("attributeStart", getAttributeStart())
             .append("attributeEnd", getAttributeEnd()).toString();
     }
 }