/*
    * Copyright 2002-2014 the original author or authors.
    *
    * 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.springframework.expression.spel.standard;
  
  /**
   * Holder for a kind of token, the associated data and its position in the input data
   * stream (start/end).
   *
   * @author Andy Clement
   * @since 3.0
   */
  class Token {
  
  	TokenKind kind;
  
  	String data;
  
  	int startPos;  // index of first character
  
  	int endPos;  // index of char after the last character
  
  
  	/**
  	 * Constructor for use when there is no particular data for the token
  	 * (e.g. TRUE or '+')
  	 * @param startPos the exact start
  	 * @param endPos the index to the last character
  	 */
  	Token(TokenKind tokenKind, int startPos, int endPos) {
  		this.kind = tokenKind;
  		this.startPos = startPos;
  		this.endPos = endPos;
  	}
  
  	Token(TokenKind tokenKind, char[] tokenData, int startPos, int endPos) {
  		this(tokenKind, startPos, endPos);
  		this.data = new String(tokenData);
  	}
  
  
  	public TokenKind getKind() {
  		return this.kind;
  	}
  
  	@Override
  	public String toString() {
  		StringBuilder s = new StringBuilder();
  		s.append("[").append(this.kind.toString());
  		if (this.kind.hasPayload()) {
  			s.append(":").append(this.data);
  		}
  		s.append("]");
  		s.append("(").append(this.startPos).append(",").append(this.endPos).append(")");
  		return s.toString();
  	}
  
  	public boolean isIdentifier() {
  		return (this.kind == TokenKind.IDENTIFIER);
  	}
  
  	public boolean isNumericRelationalOperator() {
  		return (this.kind == TokenKind.GT || this.kind == TokenKind.GE || this.kind == TokenKind.LT ||
  				this.kind == TokenKind.LE || this.kind==TokenKind.EQ || this.kind==TokenKind.NE);
  	}
  
  	public String stringValue() {
  		return this.data;
  	}
  
  	public Token asInstanceOfToken() {
  		return new Token(TokenKind.INSTANCEOF, this.startPos, this.endPos);
  	}
  
  	public Token asMatchesToken() {
  		return new Token(TokenKind.MATCHES, this.startPos, this.endPos);
  	}
  
  	public Token asBetweenToken() {
  		return new Token(TokenKind.BETWEEN, this.startPos, this.endPos);
  	}
  
  }