var forEachEls = require("./foreach-els")

var defaultSwitches = require("./switches")

module.exports = function(switches, switchesOptions, selectors, fromEl, toEl, options) {
  var switchesQueue = []

  selectors.forEach(function(selector) {
    var newEls = fromEl.querySelectorAll(selector)
    var oldEls = toEl.querySelectorAll(selector)
    if (this.log) {
      this.log("Pjax switch", selector, newEls, oldEls)
    }
    if (newEls.length !== oldEls.length) {
      throw "DOM doesn’t look the same on new loaded page: ’" + selector + "’ - new " + newEls.length + ", old " + oldEls.length
    }

    forEachEls(newEls, function(newEl, i) {
      var oldEl = oldEls[i]
      if (this.log) {
        this.log("newEl", newEl, "oldEl", oldEl)
      }

      var callback = (switches[selector]) ?
        switches[selector].bind(this, oldEl, newEl, options, switchesOptions[selector]) :
        defaultSwitches.outerHTML.bind(this, oldEl, newEl, options)

      switchesQueue.push(callback)
    }, this)
  }, this)

  this.state.numPendingSwitches = switchesQueue.length

  switchesQueue.forEach(function(queuedSwitch) {
    queuedSwitch()
  })
}