var config = require('../config')

/**
 * Check if a node is in the document.
 *
 * @param {Node} node
 * @return {Boolean}
 */

var doc =
  typeof document !== 'undefined' &&
  document.documentElement

exports.inDoc = function (node) {
  return doc && doc.contains(node)
}

/**
 * Extract an attribute from a node.
 *
 * @param {Node} node
 * @param {String} attr
 */

exports.attr = function (node, attr) {
  attr = config.prefix + attr
  var val = node.getAttribute(attr)
  if (val !== null) {
    node.removeAttribute(attr)
  }
  return val
}

/**
 * Insert el before target
 *
 * @param {Element} el
 * @param {Element} target 
 */

exports.before = function (el, target) {
  target.parentNode.insertBefore(el, target)
}

/**
 * Insert el after target
 *
 * @param {Element} el
 * @param {Element} target 
 */

exports.after = function (el, target) {
  if (target.nextSibling) {
    exports.before(el, target.nextSibling)
  } else {
    target.parentNode.appendChild(el)
  }
}

/**
 * Remove el from DOM
 *
 * @param {Element} el
 */

exports.remove = function (el) {
  el.parentNode.removeChild(el)
}

/**
 * Prepend el to target
 *
 * @param {Element} el
 * @param {Element} target 
 */

exports.prepend = function (el, target) {
  if (target.firstChild) {
    exports.before(el, target.firstChild)
  } else {
    target.appendChild(el)
  }
}

/**
 * Replace target with el
 *
 * @param {Element} target
 * @param {Element} el
 */

exports.replace = function (target, el) {
  var parent = target.parentNode
  parent.insertBefore(el, target)
  parent.removeChild(target)
}

/**
 * Copy attributes from one element to another.
 *
 * @param {Element} from
 * @param {Element} to
 */

exports.copyAttributes = function (from, to) {
  if (from.hasAttributes()) {
    var attrs = from.attributes
    for (var i = 0, l = attrs.length; i < l; i++) {
      var attr = attrs[i]
      to.setAttribute(attr.name, attr.value)
    }
  }
}

/**
 * Add event listener shorthand.
 *
 * @param {Element} el
 * @param {String} event
 * @param {Function} cb
 */

exports.on = function (el, event, cb) {
  el.addEventListener(event, cb)
}

/**
 * Remove event listener shorthand.
 *
 * @param {Element} el
 * @param {String} event
 * @param {Function} cb
 */

exports.off = function (el, event, cb) {
  el.removeEventListener(event, cb)
}