/* Any copyright is dedicated to the Public Domain.
 * http://creativecommons.org/publicdomain/zero/1.0/ */
/* eslint-disable mozilla/no-arbitrary-setTimeout */

/**
 * Testing search suggestions from SearchSuggestionController.jsm.
 */

"use strict";

const { AppConstants } = ChromeUtils.importESModule(
  "resource://gre/modules/AppConstants.sys.mjs"
);
const { FormHistory } = ChromeUtils.importESModule(
  "resource://gre/modules/FormHistory.sys.mjs"
);
const { SearchSuggestionController } = ChromeUtils.importESModule(
  "resource://gre/modules/SearchSuggestionController.sys.mjs"
);
const { PromiseUtils } = ChromeUtils.importESModule(
  "resource://gre/modules/PromiseUtils.sys.mjs"
);
const { TelemetryTestUtils } = ChromeUtils.importESModule(
  "resource://testing-common/TelemetryTestUtils.sys.mjs"
);

const ENGINE_NAME = "other";
const SEARCH_TELEMETRY_LATENCY = "SEARCH_SUGGESTIONS_LATENCY_MS";

// We must make sure the FormHistoryStartup component is
// initialized in order for it to respond to FormHistory
// requests from nsFormAutoComplete.js.
var formHistoryStartup = Cc[
  "@mozilla.org/satchel/form-history-startup;1"
].getService(Ci.nsIObserver);
formHistoryStartup.observe(null, "profile-after-change", null);

var getEngine, postEngine, unresolvableEngine, alternateJSONEngine;

add_task(async function setup() {
  Services.prefs.setBoolPref("browser.search.suggest.enabled", true);
  // These tests intentionally test broken connections.
  consoleAllowList = consoleAllowList.concat([
    "Non-200 status or empty HTTP response: 404",
    "Non-200 status or empty HTTP response: 500",
    "Unexpected response, searchString does not match remote response",
    "HTTP request timeout",
    "HTTP error",
  ]);

  let server = useHttpServer();
  server.registerContentType("sjs", "sjs");

  await AddonTestUtils.promiseStartupManager();

  registerCleanupFunction(async () => {
    // Remove added form history entries
    await updateSearchHistory("remove", null);
    Services.prefs.clearUserPref("browser.search.suggest.enabled");
  });
});

add_task(async function add_test_engines() {
  let getEngineData = {
    baseURL: gDataUrl,
    name: "GET suggestion engine",
    method: "GET",
  };

  let postEngineData = {
    baseURL: gDataUrl,
    name: "POST suggestion engine",
    method: "POST",
  };

  let unresolvableEngineData = {
    baseURL: "http://example.invalid/",
    name: "Offline suggestion engine",
    method: "GET",
  };

  let alternateJSONSuggestEngineData = {
    baseURL: gDataUrl,
    name: "Alternative JSON suggestion type",
    method: "GET",
    alternativeJSONType: true,
  };

  getEngine = await SearchTestUtils.promiseNewSearchEngine({
    url: `${gDataUrl}engineMaker.sjs?${JSON.stringify(getEngineData)}`,
  });
  postEngine = await SearchTestUtils.promiseNewSearchEngine({
    url: `${gDataUrl}engineMaker.sjs?${JSON.stringify(postEngineData)}`,
  });
  unresolvableEngine = await SearchTestUtils.promiseNewSearchEngine({
    url: `${gDataUrl}engineMaker.sjs?${JSON.stringify(unresolvableEngineData)}`,
  });
  alternateJSONEngine = await SearchTestUtils.promiseNewSearchEngine({
    url: `${gDataUrl}engineMaker.sjs?${JSON.stringify(
      alternateJSONSuggestEngineData
    )}`,
  });
});

// Begin tests

add_task(async function simple_no_result_promise() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("no remote", false, getEngine);
  Assert.equal(result.term, "no remote");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 0);

  assertLatencyHistogram(histogram, true);
});

add_task(async function simple_remote_no_local_result() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("mo", false, getEngine);
  Assert.equal(result.term, "mo");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[0].value, "Mozilla");
  Assert.equal(result.remote[1].value, "modern");
  Assert.equal(result.remote[2].value, "mom");

  assertLatencyHistogram(histogram, true);
});

add_task(async function simple_remote_no_local_result_telemetry() {
  Services.telemetry.clearScalars();

  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  await controller.fetch("mo", false, getEngine);

  let scalars = {};
  const key = "browser.search.data_transferred";

  await TestUtils.waitForCondition(() => {
    scalars =
      Services.telemetry.getSnapshotForKeyedScalars("main", false).parent || {};
    return key in scalars;
  }, "should have the expected keyed scalars");

  const scalar = scalars[key];
  Assert.ok(`sggt-${ENGINE_NAME}` in scalar, "correct telemetry category");
  Assert.notEqual(scalar[`sggt-${ENGINE_NAME}`], 0, "bandwidth logged");

  assertLatencyHistogram(histogram, true);
});

add_task(async function simple_remote_no_local_result_alternative_type() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("mo", false, alternateJSONEngine);
  Assert.equal(result.term, "mo");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[0].value, "Mozilla");
  Assert.equal(result.remote[1].value, "modern");
  Assert.equal(result.remote[2].value, "mom");
});

add_task(async function remote_term_case_mismatch() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("Query Case Mismatch", false, getEngine);
  Assert.equal(result.term, "Query Case Mismatch");
  Assert.equal(result.remote.length, 1);
  Assert.equal(result.remote[0].value, "Query Case Mismatch");
});

add_task(async function simple_local_no_remote_result() {
  await updateSearchHistory("bump", "no remote entries");

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("no remote", false, getEngine);
  Assert.equal(result.term, "no remote");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "no remote entries");
  Assert.equal(result.remote.length, 0);

  await updateSearchHistory("remove", "no remote entries");
});

add_task(async function simple_non_ascii() {
  await updateSearchHistory("bump", "I ❤️ XUL");

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("I ❤️", false, getEngine);
  Assert.equal(result.term, "I ❤️");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "I ❤️ XUL");
  Assert.equal(result.remote.length, 1);
  Assert.equal(result.remote[0].value, "I ❤️ Mozilla");
});

add_task(async function both_local_remote_result_dedupe() {
  await updateSearchHistory("bump", "Mozilla");

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("mo", false, getEngine);
  Assert.equal(result.term, "mo");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "Mozilla");
  Assert.equal(result.remote.length, 2);
  Assert.equal(result.remote[0].value, "modern");
  Assert.equal(result.remote[1].value, "mom");
});

add_task(async function POST_both_local_remote_result_dedupe() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("mo", false, postEngine);
  Assert.equal(result.term, "mo");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "Mozilla");
  Assert.equal(result.remote.length, 2);
  Assert.equal(result.remote[0].value, "modern");
  Assert.equal(result.remote[1].value, "mom");
});

add_task(async function both_local_remote_result_dedupe2() {
  await updateSearchHistory("bump", "mom");

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("mo", false, getEngine);
  Assert.equal(result.term, "mo");
  Assert.equal(result.local.length, 2);
  Assert.equal(result.local[0].value, "mom");
  Assert.equal(result.local[1].value, "Mozilla");
  Assert.equal(result.remote.length, 1);
  Assert.equal(result.remote[0].value, "modern");
});

add_task(async function both_local_remote_result_dedupe3() {
  // All of the server entries also exist locally
  await updateSearchHistory("bump", "modern");

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("mo", false, getEngine);
  Assert.equal(result.term, "mo");
  Assert.equal(result.local.length, 3);
  Assert.equal(result.local[0].value, "modern");
  Assert.equal(result.local[1].value, "mom");
  Assert.equal(result.local[2].value, "Mozilla");
  Assert.equal(result.remote.length, 0);
});

add_task(async function valid_tail_results() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("tail query", false, getEngine);
  Assert.equal(result.term, "tail query");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[0].value, "tail query normal");
  Assert.ok(!result.remote[0].matchPrefix);
  Assert.ok(!result.remote[0].tail);
  Assert.equal(result.remote[1].value, "tail query tail 1");
  Assert.equal(result.remote[1].matchPrefix, "… ");
  Assert.equal(result.remote[1].tail, "tail 1");
  Assert.equal(result.remote[2].value, "tail query tail 2");
  Assert.equal(result.remote[2].matchPrefix, "… ");
  Assert.equal(result.remote[2].tail, "tail 2");
});

add_task(async function alt_tail_results() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("tailalt query", false, getEngine);
  Assert.equal(result.term, "tailalt query");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[0].value, "tailalt query normal");
  Assert.ok(!result.remote[0].matchPrefix);
  Assert.ok(!result.remote[0].tail);
  Assert.equal(result.remote[1].value, "tailalt query tail 1");
  Assert.equal(result.remote[1].matchPrefix, "… ");
  Assert.equal(result.remote[1].tail, "tail 1");
  Assert.equal(result.remote[2].value, "tailalt query tail 2");
  Assert.equal(result.remote[2].matchPrefix, "… ");
  Assert.equal(result.remote[2].tail, "tail 2");
});

add_task(async function invalid_tail_results() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("tailjunk query", false, getEngine);
  Assert.equal(result.term, "tailjunk query");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[0].value, "tailjunk query normal");
  Assert.ok(!result.remote[0].matchPrefix);
  Assert.ok(!result.remote[0].tail);
  Assert.equal(result.remote[1].value, "tailjunk query tail 1");
  Assert.ok(!result.remote[1].matchPrefix);
  Assert.ok(!result.remote[1].tail);
  Assert.equal(result.remote[2].value, "tailjunk query tail 2");
  Assert.ok(!result.remote[2].matchPrefix);
  Assert.ok(!result.remote[2].tail);
});

add_task(async function too_few_tail_results() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("tailjunk few query", false, getEngine);
  Assert.equal(result.term, "tailjunk few query");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[0].value, "tailjunk few query normal");
  Assert.ok(!result.remote[0].matchPrefix);
  Assert.ok(!result.remote[0].tail);
  Assert.equal(result.remote[1].value, "tailjunk few query tail 1");
  Assert.ok(!result.remote[1].matchPrefix);
  Assert.ok(!result.remote[1].tail);
  Assert.equal(result.remote[2].value, "tailjunk few query tail 2");
  Assert.ok(!result.remote[2].matchPrefix);
  Assert.ok(!result.remote[2].tail);
});

add_task(async function empty_rich_results() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("richempty query", false, getEngine);
  Assert.equal(result.term, "richempty query");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[0].value, "richempty query normal");
  Assert.ok(!result.remote[0].matchPrefix);
  Assert.ok(!result.remote[0].tail);
  Assert.equal(result.remote[1].value, "richempty query tail 1");
  Assert.ok(!result.remote[1].matchPrefix);
  Assert.ok(!result.remote[1].tail);
  Assert.equal(result.remote[2].value, "richempty query tail 2");
  Assert.ok(!result.remote[2].matchPrefix);
  Assert.ok(!result.remote[2].tail);
});

add_task(async function tail_offset_index() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("tail tail 1 t", false, getEngine);
  Assert.equal(result.term, "tail tail 1 t");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 3);
  Assert.equal(result.remote[1].value, "tail tail 1 t tail 1");
  Assert.equal(result.remote[1].matchPrefix, "… ");
  Assert.equal(result.remote[1].tail, "tail 1");
  Assert.equal(result.remote[1].tailOffsetIndex, 14);
});

add_task(async function fetch_twice_in_a_row() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  // Two entries since the first will match the first fetch but not the second.
  await updateSearchHistory("bump", "delay local");
  await updateSearchHistory("bump", "delayed local");

  let controller = new SearchSuggestionController();
  let resultPromise1 = controller.fetch("delay", false, getEngine);

  // A second fetch while the server is still waiting to return results leads to an abort.
  let resultPromise2 = controller.fetch("delayed ", false, getEngine);
  await resultPromise1.then(results => Assert.equal(null, results));

  let result = await resultPromise2;
  Assert.equal(result.term, "delayed ");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "delayed local");
  Assert.equal(result.remote.length, 1);
  Assert.equal(result.remote[0].value, "delayed ");

  // Only the second fetch's latency should be recorded since the first fetch
  // was aborted and latencies for aborted fetches are not recorded.
  assertLatencyHistogram(histogram, true);
});

add_task(async function both_identical_with_more_than_max_results() {
  // Add letters A through Z to form history which will match the server
  for (
    let charCode = "A".charCodeAt();
    charCode <= "Z".charCodeAt();
    charCode++
  ) {
    await updateSearchHistory(
      "bump",
      "letter " + String.fromCharCode(charCode)
    );
  }

  let controller = new SearchSuggestionController();
  controller.maxLocalResults = 7;
  controller.maxRemoteResults = 10;
  let result = await controller.fetch("letter ", false, getEngine);
  Assert.equal(result.term, "letter ");
  Assert.equal(result.local.length, 7);
  for (let i = 0; i < controller.maxLocalResults; i++) {
    Assert.equal(
      result.local[i].value,
      "letter " + String.fromCharCode("A".charCodeAt() + i)
    );
  }
  Assert.equal(result.local.length + result.remote.length, 10);
  for (let i = 0; i < result.remote.length; i++) {
    Assert.equal(
      result.remote[i].value,
      "letter " +
        String.fromCharCode("A".charCodeAt() + controller.maxLocalResults + i)
    );
  }
});

add_task(async function noremote_maxLocal() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  controller.maxLocalResults = 2; // (should be ignored because no remote results)
  controller.maxRemoteResults = 0;
  let result = await controller.fetch("letter ", false, getEngine);
  Assert.equal(result.term, "letter ");
  Assert.equal(result.local.length, 26);
  for (let i = 0; i < result.local.length; i++) {
    Assert.equal(
      result.local[i].value,
      "letter " + String.fromCharCode("A".charCodeAt() + i)
    );
  }
  Assert.equal(result.remote.length, 0);

  assertLatencyHistogram(histogram, false);
});

add_task(async function someremote_maxLocal() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  controller.maxLocalResults = 2;
  controller.maxRemoteResults = 4;
  let result = await controller.fetch("letter ", false, getEngine);
  Assert.equal(result.term, "letter ");
  Assert.equal(result.local.length, 2);
  for (let i = 0; i < result.local.length; i++) {
    Assert.equal(
      result.local[i].value,
      "letter " + String.fromCharCode("A".charCodeAt() + i)
    );
  }
  Assert.equal(result.remote.length, 2);
  // "A" and "B" will have been de-duped, start at C for remote results
  for (let i = 0; i < result.remote.length; i++) {
    Assert.equal(
      result.remote[i].value,
      "letter " + String.fromCharCode("C".charCodeAt() + i)
    );
  }

  assertLatencyHistogram(histogram, true);
});

add_task(async function one_of_each() {
  let controller = new SearchSuggestionController();
  controller.maxLocalResults = 1;
  controller.maxRemoteResults = 2;
  let result = await controller.fetch("letter ", false, getEngine);
  Assert.equal(result.term, "letter ");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "letter A");
  Assert.equal(result.remote.length, 1);
  Assert.equal(result.remote[0].value, "letter B");
});

add_task(async function local_result_returned_remote_result_disabled() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  Services.prefs.setBoolPref("browser.search.suggest.enabled", false);
  let controller = new SearchSuggestionController();
  controller.maxLocalResults = 1;
  controller.maxRemoteResults = 1;
  let result = await controller.fetch("letter ", false, getEngine);
  Assert.equal(result.term, "letter ");
  Assert.equal(result.local.length, 26);
  for (let i = 0; i < 26; i++) {
    Assert.equal(
      result.local[i].value,
      "letter " + String.fromCharCode("A".charCodeAt() + i)
    );
  }
  Assert.equal(result.remote.length, 0);
  assertLatencyHistogram(histogram, false);
  Services.prefs.setBoolPref("browser.search.suggest.enabled", true);
});

add_task(
  async function local_result_returned_remote_result_disabled_after_creation_of_controller() {
    let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
      SEARCH_TELEMETRY_LATENCY
    );
    let controller = new SearchSuggestionController();
    controller.maxLocalResults = 1;
    controller.maxRemoteResults = 1;
    Services.prefs.setBoolPref("browser.search.suggest.enabled", false);
    let result = await controller.fetch("letter ", false, getEngine);
    Assert.equal(result.term, "letter ");
    Assert.equal(result.local.length, 26);
    for (let i = 0; i < 26; i++) {
      Assert.equal(
        result.local[i].value,
        "letter " + String.fromCharCode("A".charCodeAt() + i)
      );
    }
    Assert.equal(result.remote.length, 0);
    assertLatencyHistogram(histogram, false);
    Services.prefs.setBoolPref("browser.search.suggest.enabled", true);
  }
);

add_task(
  async function one_of_each_disabled_before_creation_enabled_after_creation_of_controller() {
    let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
      SEARCH_TELEMETRY_LATENCY
    );

    Services.prefs.setBoolPref("browser.search.suggest.enabled", false);
    let controller = new SearchSuggestionController();
    controller.maxLocalResults = 1;
    controller.maxRemoteResults = 2;
    Services.prefs.setBoolPref("browser.search.suggest.enabled", true);
    let result = await controller.fetch("letter ", false, getEngine);
    Assert.equal(result.term, "letter ");
    Assert.equal(result.local.length, 1);
    Assert.equal(result.local[0].value, "letter A");
    Assert.equal(result.remote.length, 1);
    Assert.equal(result.remote[0].value, "letter B");

    assertLatencyHistogram(histogram, true);

    Services.prefs.setBoolPref("browser.search.suggest.enabled", true);
  }
);

add_task(async function one_local_zero_remote() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );
  let controller = new SearchSuggestionController();
  controller.maxLocalResults = 1;
  controller.maxRemoteResults = 0;
  let result = await controller.fetch("letter ", false, getEngine);
  Assert.equal(result.term, "letter ");
  Assert.equal(result.local.length, 26);
  for (let i = 0; i < 26; i++) {
    Assert.equal(
      result.local[i].value,
      "letter " + String.fromCharCode("A".charCodeAt() + i)
    );
  }
  Assert.equal(result.remote.length, 0);
  assertLatencyHistogram(histogram, false);
});

add_task(async function zero_local_one_remote() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );
  let controller = new SearchSuggestionController();
  controller.maxLocalResults = 0;
  controller.maxRemoteResults = 1;
  let result = await controller.fetch("letter ", false, getEngine);
  Assert.equal(result.term, "letter ");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 1);
  Assert.equal(result.remote[0].value, "letter A");
  assertLatencyHistogram(histogram, true);
});

add_task(async function stop_search() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );
  let controller = new SearchSuggestionController(result => {
    do_throw("The callback shouldn't be called after stop()");
  });
  let resultPromise = controller.fetch("mo", false, getEngine);
  controller.stop();
  await resultPromise.then(result => {
    Assert.equal(null, result);
  });
  assertLatencyHistogram(histogram, false);
});

add_task(async function empty_searchTerm() {
  // Empty searches don't go to the server but still get form history.
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("", false, getEngine);
  Assert.equal(result.term, "");
  Assert.ok(!!result.local.length);
  Assert.equal(result.remote.length, 0);
  assertLatencyHistogram(histogram, false);
});

add_task(async function slow_timeout() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  // Make the server return suggestions on a delay longer than the timeout of
  // the suggestion controller.
  let delayMs = 3 * SearchSuggestionController.REMOTE_TIMEOUT_DEFAULT;
  let searchString = `delay${delayMs} `;

  // Add a local result.
  let localValue = searchString + " local result";
  await updateSearchHistory("bump", localValue);

  // Do a search. The remote fetch should time out but the local result should
  // be returned.
  let controller = new SearchSuggestionController();
  let result = await controller.fetch(searchString, false, getEngine);
  Assert.equal(result.term, searchString);
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, localValue);
  Assert.equal(result.remote.length, 0);

  // The remote fetch isn't done yet, so the latency histogram should not be
  // updated.
  assertLatencyHistogram(histogram, false);

  // Wait for the remote fetch to finish.
  await new Promise(r => setTimeout(r, delayMs));

  // Now the latency histogram should be updated.
  assertLatencyHistogram(histogram, true);
});

add_task(async function slow_timeout_2() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  // Make the server return suggestions on a delay longer the timeout of the
  // suggestion controller.
  let delayMs = 3 * SearchSuggestionController.REMOTE_TIMEOUT_DEFAULT;
  let searchString = `delay${delayMs} `;

  // Add a local result.
  let localValue = searchString + " local result";
  await updateSearchHistory("bump", localValue);

  // Do two searches using the same controller. Both times, the remote fetches
  // should time out and only the local result should be returned. The second
  // search should abort the remote fetch of the first search, and the remote
  // fetch of the second search should be ongoing when the second search
  // finishes.
  let controller = new SearchSuggestionController();
  for (let i = 0; i < 2; i++) {
    let result = await controller.fetch(searchString, false, getEngine);
    Assert.equal(result.term, searchString);
    Assert.equal(result.local.length, 1);
    Assert.equal(result.local[0].value, localValue);
    Assert.equal(result.remote.length, 0);
  }

  // The remote fetch of the second search isn't done yet, so the latency
  // histogram should not be updated.
  assertLatencyHistogram(histogram, false);

  // Wait for the second remote fetch to finish.
  await new Promise(r => setTimeout(r, delayMs));

  // Now the latency histogram should be updated, and only the remote fetch of
  // the second search should be recorded.
  assertLatencyHistogram(histogram, true);
});

add_task(async function slow_stop() {
  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  // Make the server return suggestions on a delay longer the timeout of the
  // suggestion controller.
  let delayMs = 3 * SearchSuggestionController.REMOTE_TIMEOUT_DEFAULT;
  let searchString = `delay${delayMs} `;

  // Do a search but stop it before it finishes. Wait a tick before stopping it
  // to better simulate the real world.
  let controller = new SearchSuggestionController();
  let resultPromise = controller.fetch(searchString, false, getEngine);
  await TestUtils.waitForTick();
  controller.stop();
  let result = await resultPromise;
  Assert.equal(result, null, "No result should be returned");

  // The remote fetch should have been aborted by stopping the controller, but
  // wait for the timeout period just to make sure it's done.
  await new Promise(r => setTimeout(r, delayMs));

  // Since the latencies of aborted fetches are not recorded, the latency
  // histogram should not be updated.
  assertLatencyHistogram(histogram, false);
});

// Error handling

add_task(async function remote_term_mismatch() {
  await updateSearchHistory("bump", "Query Mismatch Entry");

  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("Query Mismatch", false, getEngine);
  Assert.equal(result.term, "Query Mismatch");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "Query Mismatch Entry");
  Assert.equal(result.remote.length, 0);

  assertLatencyHistogram(histogram, true);
});

add_task(async function http_404() {
  await updateSearchHistory("bump", "HTTP 404 Entry");

  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("HTTP 404", false, getEngine);
  Assert.equal(result.term, "HTTP 404");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "HTTP 404 Entry");
  Assert.equal(result.remote.length, 0);

  assertLatencyHistogram(histogram, true);
});

add_task(async function http_500() {
  await updateSearchHistory("bump", "HTTP 500 Entry");

  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  let result = await controller.fetch("HTTP 500", false, getEngine);
  Assert.equal(result.term, "HTTP 500");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "HTTP 500 Entry");
  Assert.equal(result.remote.length, 0);

  assertLatencyHistogram(histogram, true);
});

add_task(async function unresolvable_server() {
  await updateSearchHistory("bump", "Unresolvable Server Entry");

  let histogram = TelemetryTestUtils.getAndClearKeyedHistogram(
    SEARCH_TELEMETRY_LATENCY
  );

  let controller = new SearchSuggestionController();
  let result = await controller.fetch(
    "Unresolvable Server",
    false,
    unresolvableEngine
  );
  Assert.equal(result.term, "Unresolvable Server");
  Assert.equal(result.local.length, 1);
  Assert.equal(result.local[0].value, "Unresolvable Server Entry");
  Assert.equal(result.remote.length, 0);

  // This latency assert fails on Windows 7 (NT version 6.1), so skip it there.
  if (!AppConstants.isPlatformAndVersionAtMost("win", "6.1")) {
    assertLatencyHistogram(histogram, true);
  }
});

// Exception handling

add_task(async function missing_pb() {
  Assert.throws(() => {
    let controller = new SearchSuggestionController();
    controller.fetch("No privacy");
  }, /priva/i);
});

add_task(async function missing_engine() {
  Assert.throws(() => {
    let controller = new SearchSuggestionController();
    controller.fetch("No engine", false);
  }, /engine/i);
});

add_task(async function invalid_engine() {
  Assert.throws(() => {
    let controller = new SearchSuggestionController();
    controller.fetch("invalid engine", false, {});
  }, /engine/i);
});

add_task(async function no_results_requested() {
  Assert.throws(() => {
    let controller = new SearchSuggestionController();
    controller.maxLocalResults = 0;
    controller.maxRemoteResults = 0;
    controller.fetch("No results requested", false, getEngine);
  }, /result/i);
});

add_task(async function minus_one_results_requested() {
  Assert.throws(() => {
    let controller = new SearchSuggestionController();
    controller.maxLocalResults = -1;
    controller.fetch("-1 results requested", false, getEngine);
  }, /result/i);
});

add_task(async function test_userContextId() {
  let controller = new SearchSuggestionController();
  controller._fetchRemote = function (
    searchTerm,
    engine,
    privateMode,
    userContextId
  ) {
    Assert.equal(userContextId, 1);
    return PromiseUtils.defer();
  };

  controller.fetch("test", false, getEngine, 1);
});

// Non-English characters

add_task(async function suggestions_contain_escaped_unicode() {
  let controller = new SearchSuggestionController();
  let result = await controller.fetch("stü", false, getEngine);
  Assert.equal(result.term, "stü");
  Assert.equal(result.local.length, 0);
  Assert.equal(result.remote.length, 2);
  Assert.equal(result.remote[0].value, "stühle");
  Assert.equal(result.remote[1].value, "stüssy");
});

// Helpers

function updateSearchHistory(operation, value) {
  return FormHistory.update({
    op: operation,
    fieldname: "searchbar-history",
    value,
  });
}

function assertLatencyHistogram(histogram, shouldRecord) {
  let snapshot = histogram.snapshot();
  info("Checking latency snapshot: " + JSON.stringify(snapshot));

  // Build a map from engine ID => number of non-zero values recorded for it.
  let valueCountByEngineId = Object.entries(snapshot).reduce(
    (memo, [key, data]) => {
      memo[key] = Object.values(data.values).filter(v => v != 0);
      return memo;
    },
    {}
  );

  let expected = shouldRecord ? { [ENGINE_NAME]: [1] } : {};
  Assert.deepEqual(
    valueCountByEngineId,
    expected,
    shouldRecord ? "Latency histogram updated" : "Latency histogram not updated"
  );
}