/*
===============================================================

Hi! Welcome to my little playground!

My name is Tobias Bogliolo. 'Open source' by default and always 'responsive',
I'm a publicist, visual designer and frontend developer based in Barcelona. 

Here you will find some of my personal experiments. Sometimes usefull,
sometimes simply for fun. You are free to use them for whatever you want 
but I would appreciate an attribution from my work. I hope you enjoy it.

===============================================================
*/
$(document).ready(function(){

  //Swipe speed:
  var tolerance = 100; //px.
  var speed = 650; //ms.

  //Elements:
  var interactiveElements = $('input, button, a');
  var itemsLength = $('.panel').length;
  var active = 1;

  //Background images:
  for (i=1; i<=itemsLength; i++){
    var $layer = $(".panel:nth-child("+i+")");
    var bgImg = $layer.attr("data-img");
    $layer.css({
      "background": "url("+bgImg+") no-repeat center / cover"
    });
  };

  //Transitions:
  setTimeout(function() {
    $(".panel").css({
      "transition": "cubic-bezier(.4,.95,.5,1.5) "+speed+"ms"
    });
  }, 200);

  //Presets:
  $(".panel:not(:first)").addClass("right");

  //Swipe:
  function swipeScreen() {
    $('.swipe').on('mousedown touchstart', function(e) {

      var touch = e.originalEvent.touches;
      var start = touch ? touch[0].pageX : e.pageX;
      var difference;

      $(this).on('mousemove touchmove', function(e) {
        var contact = e.originalEvent.touches,
        end = contact ? contact[0].pageX : e.pageX;
        difference = end-start;
      });

      //On touch end:
      $(window).one('mouseup touchend', function(e) {
        e.preventDefault();

        //Swipe right:
        if (active < itemsLength && difference < -tolerance) {
          $(".panel:nth-child("+active+")").addClass("left");
          $(".panel:nth-child("+(active+1)+")").removeClass("right");
          active += 1;
          btnDisable();
        };

        // Swipe left:
        if (active > 1 && difference > tolerance) {
          $(".panel:nth-child("+(active-1)+")").removeClass("left");
          $(".panel:nth-child("+active+")").addClass("right");
          active -= 1;
          btnDisable();
        };

        $('.swipe').off('mousemove touchmove');
      });

    });
  };
  swipeScreen();

  //Prevent swipe on interactive elements:
  interactiveElements.on('touchstart touchend touchup', function(e) {
    e.stopPropagation();
  });

  //Buttons:
  $(".btn-prev").click(function(){
    // Swipe left:
    if (active > 1) {
      $(".panel:nth-child("+(active-1)+")").removeClass("left");
      $(".panel:nth-child("+active+")").addClass("right");
      active -= 1;
      btnDisable();
    };
  });

  $(".btn-next").click(function(){
    //Swipe right:
    if (active < itemsLength) {
      $(".panel:nth-child("+active+")").addClass("left");
      $(".panel:nth-child("+(active+1)+")").removeClass("right");
      active += 1;
      btnDisable();
    };
  });

  function btnDisable() {
    if (active >= itemsLength) {
      $(".btn-next").prop("disabled", true);
      $(".btn-prev").prop("disabled", false);
    }
    else if (active <= 1) {
      $(".btn-prev").prop("disabled", true);
      $(".btn-next").prop("disabled", false);
    }
    else {
      $(".btn-prev, .btn-next").prop("disabled", false);
    };
  };

});