'use strict';

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

/**
 * Initialize a new `Block` with an optional `node`.
 *
 * @param {Node} node
 * @api public
 */

var Block = module.exports = function Block(node){
  this.nodes = [];
  if (node) this.push(node);
};

// Inherit from `Node`.
Block.prototype = Object.create(Node.prototype);
Block.prototype.constructor = Block;

Block.prototype.type = 'Block';

/**
 * Block flag.
 */

Block.prototype.isBlock = true;

/**
 * Replace the nodes in `other` with the nodes
 * in `this` block.
 *
 * @param {Block} other
 * @api private
 */

Block.prototype.replace = function(other){
  other.nodes = this.nodes;
};

/**
 * Pust the given `node`.
 *
 * @param {Node} node
 * @return {Number}
 * @api public
 */

Block.prototype.push = function(node){
  return this.nodes.push(node);
};

/**
 * Check if this block is empty.
 *
 * @return {Boolean}
 * @api public
 */

Block.prototype.isEmpty = function(){
  return 0 == this.nodes.length;
};

/**
 * Unshift the given `node`.
 *
 * @param {Node} node
 * @return {Number}
 * @api public
 */

Block.prototype.unshift = function(node){
  return this.nodes.unshift(node);
};

/**
 * Return the "last" block, or the first `yield` node.
 *
 * @return {Block}
 * @api private
 */

Block.prototype.includeBlock = function(){
  var ret = this
    , node;

  for (var i = 0, len = this.nodes.length; i < len; ++i) {
    node = this.nodes[i];
    if (node.yield) return node;
    else if (node.textOnly) continue;
    else if (node.includeBlock) ret = node.includeBlock();
    else if (node.block && !node.block.isEmpty()) ret = node.block.includeBlock();
    if (ret.yield) return ret;
  }

  return ret;
};

/**
 * Return a clone of this block.
 *
 * @return {Block}
 * @api private
 */

Block.prototype.clone = function(){
  var clone = new Block;
  for (var i = 0, len = this.nodes.length; i < len; ++i) {
    clone.push(this.nodes[i].clone());
  }
  return clone;
};
