const { E10SUtils } = ChromeUtils.importESModule(
  "resource://gre/modules/E10SUtils.sys.mjs"
);

const HISTORY = [
  { url: httpURL("dummy_page.html") },
  { url: fileURL("dummy_page.html") },
  { url: httpURL("dummy_page.html") },
];

function reversed(list) {
  let copy = list.slice();
  copy.reverse();
  return copy;
}

function butLast(list) {
  return list.slice(0, -1);
}

async function runTest() {
  await BrowserTestUtils.withNewTab({ gBrowser }, async function(aBrowser) {
    // Perform initial load of each URL in the history.
    let count = 0;
    let index = -1;
    for (let { url } of HISTORY) {
      BrowserTestUtils.loadURI(aBrowser, url);

      await BrowserTestUtils.browserLoaded(aBrowser, false, loaded => {
        return (
          Services.io.newURI(loaded).scheme == Services.io.newURI(url).scheme
        );
      });

      count++;
      index++;
      await SpecialPowers.spawn(
        aBrowser,
        [{ count, index, url }],
        async function({ count, index, url }) {
          docShell.QueryInterface(Ci.nsIWebNavigation);

          is(
            docShell.sessionHistory.count,
            count,
            "Initial Navigation Count Match"
          );
          is(
            docShell.sessionHistory.index,
            index,
            "Initial Navigation Index Match"
          );

          let real = Services.io.newURI(content.location.href);
          let expect = Services.io.newURI(url);
          is(real.scheme, expect.scheme, "Initial Navigation URL Scheme");
        }
      );
    }

    // Go back to the first entry.
    for (let { url } of reversed(HISTORY).slice(1)) {
      SpecialPowers.spawn(aBrowser, [], () => {
        content.history.back();
      });
      await BrowserTestUtils.browserLoaded(aBrowser, false, loaded => {
        return (
          Services.io.newURI(loaded).scheme == Services.io.newURI(url).scheme
        );
      });

      index--;
      await SpecialPowers.spawn(
        aBrowser,
        [{ count, index, url }],
        async function({ count, index, url }) {
          docShell.QueryInterface(Ci.nsIWebNavigation);

          is(docShell.sessionHistory.count, count, "Go Back Count Match");
          is(docShell.sessionHistory.index, index, "Go Back Index Match");

          let real = Services.io.newURI(content.location.href);
          let expect = Services.io.newURI(url);
          is(real.scheme, expect.scheme, "Go Back URL Scheme");
        }
      );
    }

    // Go forward to the last entry.
    for (let { url } of HISTORY.slice(1)) {
      SpecialPowers.spawn(aBrowser, [], () => {
        content.history.forward();
      });
      await BrowserTestUtils.browserLoaded(aBrowser, false, loaded => {
        return (
          Services.io.newURI(loaded).scheme == Services.io.newURI(url).scheme
        );
      });

      index++;
      await SpecialPowers.spawn(
        aBrowser,
        [{ count, index, url }],
        async function({ count, index, url }) {
          docShell.QueryInterface(Ci.nsIWebNavigation);

          is(docShell.sessionHistory.count, count, "Go Forward Count Match");
          is(docShell.sessionHistory.index, index, "Go Forward Index Match");

          let real = Services.io.newURI(content.location.href);
          let expect = Services.io.newURI(url);
          is(real.scheme, expect.scheme, "Go Forward URL Scheme");
        }
      );
    }
  });
}

add_task(runTest);