var jsdom = require("mocha-jsdom");
var assert = require("assert");

/**
 * Automated tests for jQuery Once.
 */
describe("jQuery Once", function() {
  "use strict";

  /**
   * The global instance of jQuery.
   */
  var $;

  /**
   * Turn the Mocha test environment into a DOM environment with JSDom.
   */
  jsdom();

  /**
   * Before the tests initiate, load jQuery and jQuery Once.
   */
  before(function() {
    $ = require("jquery");
    require("../jquery.once.js");
  });

  /**
   * Before each test, reset the document body so that there is fresh data.
   */
  beforeEach(function() {
    // Build the body HTML.
    document.body.innerHTML = "<p>This is the <span>Test</span>.</p>";
  });

  it("should require ID to be a string", function () {
    // Expect it to throw an error.
    assert.throws(function() {
      $("span").once(function () {
        // Nothing.
      });
    });
  });

  it("properly executes .once('test2')", function () {
    // Create one once('test2') call.
    $("span").once("test2").data("test2", "foo");

    // Create another once('test2') call.
    $("span").once("test2").data("test2", "bar");

    // The data should result to the first once() call.
    var data = $("span").data("test2");
    assert.equal(data, "foo");
  });

  it("is called only once with an ID", function() {
    // Count the number of times once() was called.
    $("span").data("count", 0);

    // Create the once() callback.
    var callback = function() {
      // Increment the count variable stored in the data.
      $("span").data("count", $("span").data("count") + 1);
    };

    // Call once() a bunch of times.
    for (var i = 0; i < 10; i++) {
      $("span").once("count").each(callback);
    }

    // Verify that it was only called once.
    var count = $("span").data("count");
    assert.equal(count, 1, "It was called " + count + " times.");
  });

  it("is called only once without an ID", function() {
    // Count the number of times once() was called.
    $("span").data("once", 0);

    // Create the once() callback.
    var callback = function() {
      $("span").data("once", $("span").data("once") + 1);
    };

    // Call once() a bunch of times.
    for (var i = 0; i < 10; i++) {
      $("span").once().each(callback);
    }

    // Verify that it was only called once.
    var count = $("span").data("once");
    assert.equal(count, 1, "It was called " + count + " times.");
  });

  it("retrieves empty once data correctly", function() {
    // Verify that the element starts without the class.
    var hasData = $("span").data("jquery-once-test3");
    assert(!hasData, "Value not applied in the beginning.");

    // Create one once() call.
    $("span").once("test3");

    // Verify the data is applied.
    hasData = $("span").data("jquery-once-test3");
    assert(hasData, "The value is properly applied after once().");
  });

  it("calls removeOnce() correctly", function() {
    // Create one once() call.
    $("span").once("test4");

    // Verify the data is applied.
    var hasData = $("span").data("jquery-once-test4");
    assert(hasData, "The value is properly applied after once().");

    // Remove the once property.
    $("span").removeOnce("test4");
    hasData = $("span").data("jquery-once-test4");
    assert(!hasData, "The value is properly removed when called removeOnce().");
  });

  it("calls findOnce() correctly", function() {
    // Append an additional span to the end.
    document.body.innerHTML += "<p>This is the <span>Test 2</span>.</p>";

    // Create one once() call.
    $("span").once("test5").data("foo", "bar");

    // Find the once'd elements.
    $("span").findOnce("test5").each(function() {
      assert.equal($(this).data("foo"), "bar", "Found correct span data.");
    });
  });

});