
/*!
 * Stylus - Ident
 * Copyright(c) 2010 LearnBoost <dev@learnboost.com>
 * MIT Licensed
 */

/**
 * Module dependencies.
 */

var Node = require('./node')
  , nodes = require('./');

/**
 * Initialize a new `Ident` by `name` with the given `val` node.
 *
 * @param {String} name
 * @param {Node} val
 * @api public
 */

var Ident = module.exports = function Ident(name, val){
  Node.call(this);
  this.name = name;
  this.string = name;
  this.val = val || nodes.null;
};

/**
 * Check if the variable has a value.
 *
 * @return {Boolean}
 * @api public
 */

Ident.prototype.__defineGetter__('isEmpty', function(){
  return undefined == this.val;
});

/**
 * Return hash.
 *
 * @return {String}
 * @api public
 */

Ident.prototype.__defineGetter__('hash', function(){
  return this.name;
});

/**
 * Inherit from `Node.prototype`.
 */

Ident.prototype.__proto__ = Node.prototype;

/**
 * Return a clone of this node.
 * 
 * @return {Node}
 * @api public
 */

Ident.prototype.clone = function(){
  var clone = new Ident(this.name, this.val.clone());
  clone.lineno = this.lineno;
  clone.filename = this.filename;
  clone.property = this.property;
  return clone;
};

/**
 * Return <name>.
 *
 * @return {String}
 * @api public
 */

Ident.prototype.toString = function(){
  return this.name;
};

/**
 * Coerce `other` to an ident.
 *
 * @param {Node} other
 * @return {String}
 * @api public
 */

Ident.prototype.coerce = function(other){
  switch (other.nodeName) {
    case 'ident':
    case 'string':
    case 'literal':
      return new Ident(other.string);
    default:
      return Node.prototype.coerce.call(this, other);
  }
};

/**
 * Operate on `right` with the given `op`.
 *
 * @param {String} op
 * @param {Node} right
 * @return {Node}
 * @api public
 */

Ident.prototype.operate = function(op, right){
  var val = right.first;
  switch (op) {
    case '-':
      if ('unit' == val.nodeName) {
        var expr = new nodes.Expression;
        val = val.clone();
        val.val = -val.val;
        expr.push(this);
        expr.push(val);
        return expr;
      }
    case '+':
      return new nodes.Ident(this.string + this.coerce(val).string);
  }
  return Node.prototype.operate.call(this, op, right);
};
