/* Any copyright is dedicated to the Public Domain.
 http://creativecommons.org/publicdomain/zero/1.0/ */

"use strict";

requestLongerTimeout(2);

// Test different kinds of drag and drop node re-ordering.

const TEST_URL = URL_ROOT + "doc_markup_dragdrop.html";

add_task(function* () {
  let {inspector} = yield openInspectorForURL(TEST_URL);
  let ids;

  info("Expand #test node");
  let parentFront = yield getNodeFront("#test", inspector);
  yield inspector.markup.expandNode(parentFront);
  yield waitForMultipleChildrenUpdates(inspector);

  info("Scroll #test into view");
  let parentContainer = yield getContainerForNodeFront(parentFront, inspector);
  parentContainer.elt.scrollIntoView(true);

  info("Test putting an element back at its original place");
  yield dragElementToOriginalLocation("#firstChild", inspector);
  ids = yield getChildrenIDsOf(parentFront, inspector);
  is(ids[0], "firstChild",
     "#firstChild is still the first child of #test");
  is(ids[1], "middleChild",
     "#middleChild is still the second child of #test");

  info("Testing switching elements inside their parent");
  yield moveElementDown("#firstChild", "#middleChild", inspector);
  ids = yield getChildrenIDsOf(parentFront, inspector);
  is(ids[0], "middleChild",
     "#firstChild is now the second child of #test");
  is(ids[1], "firstChild",
     "#middleChild is now the first child of #test");

  info("Testing switching elements with a last child");
  yield moveElementDown("#firstChild", "#lastChild", inspector);
  ids = yield getChildrenIDsOf(parentFront, inspector);
  is(ids[1], "lastChild",
     "#lastChild is now the second child of #test");
  is(ids[2], "firstChild",
     "#firstChild is now the last child of #test");

  info("Testing appending element to a parent");
  yield moveElementDown("#before", "#test", inspector);
  ids = yield getChildrenIDsOf(parentFront, inspector);
  is(ids.length, 4,
     "New element appended to #test");
  is(ids[0], "before",
     "New element is appended at the right place (currently first child)");

  info("Testing moving element to after it's parent");
  yield moveElementDown("#firstChild", "#test", inspector);
  ids = yield getChildrenIDsOf(parentFront, inspector);
  is(ids.length, 3,
     "#firstChild is no longer #test's child");
  let siblingFront = yield inspector.walker.nextSibling(parentFront);
  is(siblingFront.id, "firstChild",
     "#firstChild is now #test's nextElementSibling");
});

function* dragElementToOriginalLocation(selector, inspector) {
  info("Picking up and putting back down " + selector);

  function onMutation() {
    ok(false, "Mutation received from dragging a node back to its location");
  }
  inspector.on("markupmutation", onMutation);
  yield simulateNodeDragAndDrop(inspector, selector, 0, 0);

  // Wait a bit to make sure the event never fires.
  // This doesn't need to catch *all* cases, since the mutation
  // will cause failure later in the test when it checks element ordering.
  yield wait(500);
  inspector.off("markupmutation", onMutation);
}

function* moveElementDown(selector, next, inspector) {
  info("Switching " + selector + " with " + next);

  let container = yield getContainerForSelector(next, inspector);
  let height = container.tagLine.getBoundingClientRect().height;

  let onMutated = inspector.once("markupmutation");
  let uiUpdate = inspector.once("inspector-updated");

  yield simulateNodeDragAndDrop(inspector, selector, 0, Math.round(height) + 2);

  let mutations = yield onMutated;
  yield uiUpdate;

  is(mutations.length, 2, "2 mutations were received");
}

function* getChildrenIDsOf(parentFront, {walker}) {
  let {nodes} = yield walker.children(parentFront);
  // Filter out non-element nodes since children also returns pseudo-elements.
  return nodes.filter(node => {
    return !node.isPseudoElement;
  }).map(node => {
    return node.id;
  });
}