// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/lookalikes/lookalike_url_navigation_throttle.h"

#include "base/containers/contains.h"
#include "base/functional/bind.h"
#include "base/path_service.h"
#include "base/strings/pattern.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/stringprintf.h"
#include "base/strings/utf_string_conversions.h"
#include "base/test/metrics/histogram_tester.h"
#include "base/test/simple_test_clock.h"
#include "build/build_config.h"
#include "chrome/browser/history/history_service_factory.h"
#include "chrome/browser/history/history_test_utils.h"
#include "chrome/browser/lookalikes/lookalike_test_helper.h"
#include "chrome/browser/lookalikes/lookalike_url_blocking_page.h"
#include "chrome/browser/lookalikes/lookalike_url_service.h"
#include "chrome/browser/lookalikes/lookalike_url_service_factory.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_commands.h"
#include "chrome/browser/ui/browser_window/public/browser_window_features.h"
#include "chrome/common/webui_url_constants.h"
#include "chrome/test/base/in_process_browser_test.h"
#include "chrome/test/base/ui_test_utils.h"
#include "components/lookalikes/core/lookalike_url_util.h"
#include "components/lookalikes/core/safety_tip_test_utils.h"
#include "components/lookalikes/core/safety_tips_config.h"
#include "components/network_session_configurator/common/network_switches.h"
#include "components/omnibox/browser/location_bar_model.h"
#include "components/security_interstitials/content/security_interstitial_page.h"
#include "components/security_interstitials/content/security_interstitial_tab_helper.h"
#include "components/security_interstitials/core/metrics_helper.h"
#include "components/site_engagement/content/site_engagement_score.h"
#include "components/site_engagement/content/site_engagement_service.h"
#include "components/ukm/test_ukm_recorder.h"
#include "components/url_formatter/spoof_checks/top_domains/test_top_bucket_domains.h"
#include "content/public/browser/web_contents.h"
#include "content/public/common/content_paths.h"
#include "content/public/test/browser_test.h"
#include "content/public/test/content_mock_cert_verifier.h"
#include "content/public/test/prerender_test_util.h"
#include "content/public/test/signed_exchange_browser_test_helper.h"
#include "content/public/test/test_navigation_observer.h"
#include "content/public/test/url_loader_interceptor.h"
#include "net/cert/mock_cert_verifier.h"
#include "net/cert/test_root_certs.h"
#include "net/dns/mock_host_resolver.h"
#include "net/test/cert_test_util.h"
#include "net/test/embedded_test_server/http_request.h"
#include "net/test/embedded_test_server/http_response.h"
#include "services/metrics/public/cpp/ukm_builders.h"
#include "services/metrics/public/cpp/ukm_source.h"
#include "services/network/public/cpp/network_switches.h"
#include "services/network/public/cpp/simple_url_loader.h"
#include "ui/base/window_open_disposition.h"

namespace {

using lookalikes::LookalikeUrlMatchType;
using lookalikes::NavigationSuggestionEvent;
using security_interstitials::MetricsHelper;
using security_interstitials::SecurityInterstitialCommand;
using UkmEntry = ukm::builders::LookalikeUrl_NavigationSuggestion;
using lookalikes::GetDomainInfo;
using lookalikes::kIncognitoInterstitialHistogramName;
using lookalikes::kInterstitialHistogramName;
using lookalikes::LookalikeUrlBlockingPageUserAction;

// An engagement score above MEDIUM.
const int kHighEngagement = 20;

// An engagement score below MEDIUM.
const int kLowEngagement = 1;

// The UMA metric names registered by metrics_helper.
const char kInterstitialDecisionMetric[] = "interstitial.lookalike.decision";
const char kInterstitialInteractionMetric[] =
    "interstitial.lookalike.interaction";

const char kConsoleMessage[] =
    "Chrome has determined that * could be fake or fraudulent*";

static std::unique_ptr<net::test_server::HttpResponse>
NetworkErrorResponseHandler(const net::test_server::HttpRequest& request) {
  return std::unique_ptr<net::test_server::HttpResponse>(
      new net::test_server::RawHttpResponse("", ""));
}

security_interstitials::SecurityInterstitialPage* GetCurrentInterstitial(
    content::WebContents* web_contents) {
  security_interstitials::SecurityInterstitialTabHelper* helper =
      security_interstitials::SecurityInterstitialTabHelper::FromWebContents(
          web_contents);
  if (!helper) {
    return nullptr;
  }
  return helper->GetBlockingPageForCurrentlyCommittedNavigationForTesting();
}

security_interstitials::SecurityInterstitialPage::TypeID GetInterstitialType(
    content::WebContents* web_contents) {
  security_interstitials::SecurityInterstitialPage* page =
      GetCurrentInterstitial(web_contents);
  if (!page) {
    return nullptr;
  }
  return page->GetTypeForTesting();
}

// Sets the absolute Site Engagement |score| for the testing origin.
void SetEngagementScore(Browser* browser, const GURL& url, double score) {
  site_engagement::SiteEngagementService::Get(browser->profile())
      ->ResetBaseScoreForURL(url, score);
}

bool IsUrlShowing(Browser* browser) {
  return !browser->GetFeatures()
              .location_bar_model()
              ->GetFormattedFullURL()
              .empty();
}

// Navigate to |url| and wait for the load to complete before returning.
// Simulates a link click navigation. We don't use
// ui_test_utils::NavigateToURL(const GURL&) because it simulates the user
// typing the URL, causing the site to have a site engagement score of at
// least LOW.
void NavigateToURLSync(Browser* browser, const GURL& url) {
  content::TestNavigationObserver navigation_observer(
      browser->tab_strip_model()->GetActiveWebContents(), 1);

  NavigateParams params(browser, url, ui::PAGE_TRANSITION_LINK);
  params.initiator_origin = url::Origin::Create(GURL("about:blank"));
  params.disposition = WindowOpenDisposition::CURRENT_TAB;
  params.is_renderer_initiated = true;
  ui_test_utils::NavigateToURL(&params);

  navigation_observer.Wait();
}

// Load given URL and verify that it loaded an interstitial and hid the URL.
void LoadAndCheckInterstitialAt(Browser* browser, const GURL& url) {
  content::WebContents* web_contents =
      browser->tab_strip_model()->GetActiveWebContents();
  content::WebContentsConsoleObserver console_observer(web_contents);
  console_observer.SetPattern(kConsoleMessage);

  EXPECT_EQ(nullptr, GetCurrentInterstitial(web_contents));

  NavigateToURLSync(browser, url);
  EXPECT_EQ(LookalikeUrlBlockingPage::kTypeForTesting,
            GetInterstitialType(web_contents));
  EXPECT_FALSE(IsUrlShowing(browser));

  ASSERT_TRUE(console_observer.Wait());
  EXPECT_TRUE(
      base::MatchPattern(console_observer.GetMessageAt(0u), kConsoleMessage));
}

void SendInterstitialCommand(content::WebContents* web_contents,
                             SecurityInterstitialCommand command) {
  GetCurrentInterstitial(web_contents)
      ->CommandReceived(base::NumberToString(command));
}

void SendInterstitialCommandSync(Browser* browser,
                                 SecurityInterstitialCommand command,
                                 bool punycode_interstitial = false) {
  content::WebContents* web_contents =
      browser->tab_strip_model()->GetActiveWebContents();

  EXPECT_EQ(LookalikeUrlBlockingPage::kTypeForTesting,
            GetInterstitialType(web_contents));

  content::TestNavigationObserver navigation_observer(web_contents, 1);
  SendInterstitialCommand(web_contents, command);
  navigation_observer.Wait();

  EXPECT_EQ(nullptr, GetCurrentInterstitial(web_contents));
  if (punycode_interstitial) {
    // "Back to safety" button on the punycode interstitial goes to the New
    // Tab Page which doesn't show the URL.
    EXPECT_FALSE(IsUrlShowing(browser));
  } else {
    EXPECT_TRUE(IsUrlShowing(browser));
  }
}

// Verify that no interstitial is shown, regardless of feature state.
void TestInterstitialNotShown(Browser* browser, const GURL& navigated_url) {
  content::WebContents* web_contents =
      browser->tab_strip_model()->GetActiveWebContents();

  NavigateToURLSync(browser, navigated_url);
  EXPECT_EQ(nullptr, GetCurrentInterstitial(web_contents));

  // Navigate to an empty page. This will happen after any
  // LookalikeUrlService tasks, so will effectively wait for those tasks to
  // finish.
  NavigateToURLSync(browser, GURL("about:blank"));
  EXPECT_EQ(nullptr, GetCurrentInterstitial(web_contents));
}

// Add an allowlist with entries that aren't allowlisted for all domains.
void ConfigureAllowlistWithScopes() {
  auto config_proto = lookalikes::GetOrCreateSafetyTipsConfig();
  config_proto->clear_allowed_pattern();
  config_proto->clear_canonical_pattern();
  config_proto->clear_cohort();

  // Note: allowed_pattern must be sorted, so "Allowed*" comes before "May*".

  // may-spoof-anyone.com has no cohort.
  auto* patternWildcard = config_proto->add_allowed_pattern();
  patternWildcard->set_pattern("may-spoof-anyone.com/");

  // may-spoof-google.com is only allowed to spoof google.com.
  config_proto->add_canonical_pattern()->set_pattern("google.com/");
  auto* pattern = config_proto->add_allowed_pattern();
  pattern->set_pattern("may-spoof-google.com/");
  auto* cohort = config_proto->add_cohort();
  cohort->add_canonical_index(0);  // google.com
  pattern->add_cohort_index(0);

  // example·com.com is xn--examplecom-rra.com in punycode & fails spoof checks.
  auto* idn_pattern = config_proto->add_allowed_pattern();  // Index 2
  idn_pattern->set_pattern("xn--examplecom-rra.com/");
  auto* idn_cohort = config_proto->add_cohort();  // Index 1
  idn_cohort->add_allowed_index(2);
  idn_pattern->add_cohort_index(1);

  lookalikes::SetSafetyTipsRemoteConfigProto(std::move(config_proto));
}

}  // namespace

class LookalikeUrlNavigationThrottleBrowserTest : public InProcessBrowserTest {
 protected:
  LookalikeUrlNavigationThrottleBrowserTest()
      : https_server_(std::make_unique<net::EmbeddedTestServer>(
            net::EmbeddedTestServer::TYPE_HTTPS)) {}

  void SetUpOnMainThread() override {
    host_resolver()->AddRule("*", "127.0.0.1");
    test_ukm_recorder_ = std::make_unique<ukm::TestAutoSetUkmRecorder>();
    test_helper_ =
        std::make_unique<LookalikeTestHelper>(test_ukm_recorder_.get());

    const base::Time kNow = base::Time::FromSecondsSinceUnixEpoch(1000);
    test_clock_.SetNow(kNow);

    LookalikeUrlService* lookalike_service =
        LookalikeUrlServiceFactory::GetForProfile(browser()->profile());
    lookalike_service->SetClockForTesting(&test_clock_);

    // Use HTTPS URLs in tests.
    mock_cert_verifier_.mock_cert_verifier()->set_default_result(net::OK);
    https_server_->AddDefaultHandlers(GetChromeTestDataDir());
    ASSERT_TRUE(https_server_->Start());

    LookalikeTestHelper::SetUpLookalikeTestParams();
    InProcessBrowserTest::SetUpOnMainThread();
  }

  void TearDownOnMainThread() override {
    InProcessBrowserTest::TearDownOnMainThread();
    LookalikeTestHelper::TearDownLookalikeTestParams();
  }

  void SetUpCommandLine(base::CommandLine* command_line) override {
    mock_cert_verifier_.SetUpCommandLine(command_line);
  }

  void SetUpInProcessBrowserTestFixture() override {
    mock_cert_verifier_.SetUpInProcessBrowserTestFixture();
  }

  void TearDownInProcessBrowserTestFixture() override {
    mock_cert_verifier_.TearDownInProcessBrowserTestFixture();
  }

  GURL GetURL(const char* hostname) const {
    return https_server()->GetURL(hostname, "/title1.html");
  }

  GURL GetURLWithoutPath(const char* hostname) const {
    return GetURL(hostname).GetWithEmptyPath();
  }

  GURL GetLongRedirect(const char* via_hostname1,
                       const char* via_hostname2,
                       const char* dest_hostname) const {
    GURL dest = GetURL(dest_hostname);
    GURL mid = https_server()->GetURL(via_hostname2,
                                      "/server-redirect?" + dest.spec());
    return https_server()->GetURL(via_hostname1,
                                  "/server-redirect?" + mid.spec());
  }

  // Checks that UKM recorded an event for each URL in |navigated_urls| with the
  // given metric value.
  template <typename T>
  void CheckInterstitialUkm(const std::vector<GURL>& navigated_urls,
                            const std::string& metric_name,
                            T metric_value) {
    auto entries = test_ukm_recorder()->GetEntriesByName(UkmEntry::kEntryName);
    ASSERT_EQ(navigated_urls.size(), entries.size());
    int entry_count = 0;
    for (const ukm::mojom::UkmEntry* const entry : entries) {
      test_ukm_recorder()->ExpectEntrySourceHasUrl(entry,
                                                   navigated_urls[entry_count]);
      test_ukm_recorder()->ExpectEntryMetric(entry, metric_name,
                                             static_cast<int>(metric_value));
      entry_count++;
    }
  }

  // Tests that the histogram event |expected_event| is recorded, the
  // interstitial is displayed and clicking the link on the interstitial works.
  void TestMetricsRecordedAndInterstitialShown(
      Browser* browser,
      const base::HistogramTester& histograms,
      const GURL& navigated_url,
      const GURL& expected_suggested_url,
      NavigationSuggestionEvent expected_event,
      bool expect_signed_exchange = false) {
    history::HistoryService* const history_service =
        HistoryServiceFactory::GetForProfile(
            browser->profile(), ServiceAccessType::EXPLICIT_ACCESS);
    ui_test_utils::WaitForHistoryToLoad(history_service);

    LoadAndCheckInterstitialAt(browser, navigated_url);

    if (expect_signed_exchange) {
      LookalikeUrlBlockingPage* interstitial =
          static_cast<LookalikeUrlBlockingPage*>(GetCurrentInterstitial(
              browser->tab_strip_model()->GetActiveWebContents()));
      EXPECT_TRUE(interstitial->is_signed_exchange_for_testing());
    }

    bool punycode_interstitial =
        expected_event == NavigationSuggestionEvent::kFailedSpoofChecks;
    SendInterstitialCommandSync(browser,
                                SecurityInterstitialCommand::CMD_DONT_PROCEED,
                                punycode_interstitial);

    EXPECT_EQ(
        expected_suggested_url,
        browser->tab_strip_model()->GetActiveWebContents()->GetVisibleURL());

    // Clicking the link in the interstitial should also remove the original
    // URL from history.
    ui_test_utils::HistoryEnumerator enumerator(browser->profile());
    EXPECT_FALSE(base::Contains(enumerator.urls(), navigated_url));

    bool is_incognito = browser->profile()->IsIncognitoProfile();
    histograms.ExpectUniqueSample(kInterstitialHistogramName, expected_event,
                                  is_incognito ? 0 : 1);
    histograms.ExpectUniqueSample(kIncognitoInterstitialHistogramName,
                                  expected_event, is_incognito ? 1 : 0);

    histograms.ExpectTotalCount(kInterstitialDecisionMetric, 2);
    histograms.ExpectBucketCount(kInterstitialDecisionMetric,
                                 MetricsHelper::SHOW, 1);
    histograms.ExpectBucketCount(kInterstitialDecisionMetric,
                                 MetricsHelper::DONT_PROCEED, 1);

    histograms.ExpectTotalCount(kInterstitialInteractionMetric, 1);
    histograms.ExpectBucketCount(kInterstitialInteractionMetric,
                                 MetricsHelper::TOTAL_VISITS, 1);
  }

  // Tests that the histogram event |expected_event| is recorded, the
  // interstitial is displayed and clicking "Back to safety" on the interstitial
  // works.
  void TestPunycodeInterstitialShown(Browser* browser,
                                     const GURL& navigated_url,
                                     NavigationSuggestionEvent expected_event) {
    base::HistogramTester histograms;

    history::HistoryService* const history_service =
        HistoryServiceFactory::GetForProfile(
            browser->profile(), ServiceAccessType::EXPLICIT_ACCESS);
    ui_test_utils::WaitForHistoryToLoad(history_service);

    LoadAndCheckInterstitialAt(browser, navigated_url);

    // Clicking "Back to safety" should go to the new tab page.
    SendInterstitialCommandSync(browser,
                                SecurityInterstitialCommand::CMD_DONT_PROCEED,
                                /*punycode_interstitial=*/true);
    EXPECT_EQ(
        GURL(chrome::kChromeUINewTabURL),
        browser->tab_strip_model()->GetActiveWebContents()->GetVisibleURL());

    histograms.ExpectTotalCount(kInterstitialHistogramName, 1);
    histograms.ExpectBucketCount(kInterstitialHistogramName, expected_event, 1);

    histograms.ExpectTotalCount(kInterstitialDecisionMetric, 2);
    histograms.ExpectBucketCount(kInterstitialDecisionMetric,
                                 MetricsHelper::SHOW, 1);
    histograms.ExpectBucketCount(kInterstitialDecisionMetric,
                                 MetricsHelper::DONT_PROCEED, 1);

    histograms.ExpectTotalCount(kInterstitialInteractionMetric, 1);
    histograms.ExpectBucketCount(kInterstitialInteractionMetric,
                                 MetricsHelper::TOTAL_VISITS, 1);
  }

  // Tests that the histogram event |expected_event| is recorded, the
  // interstitial is displayed and clicking through the interstitial works.
  void TestHistogramEventsRecordedWhenInterstitialIgnored(
      Browser* browser,
      base::HistogramTester* histograms,
      const GURL& navigated_url,
      NavigationSuggestionEvent expected_event) {

    history::HistoryService* const history_service =
        HistoryServiceFactory::GetForProfile(
            browser->profile(), ServiceAccessType::EXPLICIT_ACCESS);
    ui_test_utils::WaitForHistoryToLoad(history_service);

    LoadAndCheckInterstitialAt(browser, navigated_url);

    // Clicking the ignore button in the interstitial should remove the
    // interstitial and navigate to the original URL.
    SendInterstitialCommandSync(browser,
                                SecurityInterstitialCommand::CMD_PROCEED);
    EXPECT_EQ(
        navigated_url,
        browser->tab_strip_model()->GetActiveWebContents()->GetVisibleURL());

    // Clicking the link should cause the original URL to appear in history.
    ui_test_utils::HistoryEnumerator enumerator(browser->profile());
    EXPECT_TRUE(base::Contains(enumerator.urls(), navigated_url));

    histograms->ExpectTotalCount(kInterstitialHistogramName, 1);
    histograms->ExpectBucketCount(kInterstitialHistogramName, expected_event,
                                  1);

    histograms->ExpectTotalCount(kInterstitialDecisionMetric, 2);
    histograms->ExpectBucketCount(kInterstitialDecisionMetric,
                                  MetricsHelper::SHOW, 1);
    histograms->ExpectBucketCount(kInterstitialDecisionMetric,
                                  MetricsHelper::PROCEED, 1);

    histograms->ExpectTotalCount(kInterstitialInteractionMetric, 1);
    histograms->ExpectBucketCount(kInterstitialInteractionMetric,
                                  MetricsHelper::TOTAL_VISITS, 1);

    TestInterstitialNotShown(browser, navigated_url);
  }

  LookalikeTestHelper* test_helper() { return test_helper_.get(); }
  ukm::TestUkmRecorder* test_ukm_recorder() { return test_ukm_recorder_.get(); }

  base::SimpleTestClock* test_clock() { return &test_clock_; }
  net::EmbeddedTestServer* https_server() const { return https_server_.get(); }

 private:
  std::unique_ptr<ukm::TestAutoSetUkmRecorder> test_ukm_recorder_;
  std::unique_ptr<LookalikeTestHelper> test_helper_;
  std::unique_ptr<net::EmbeddedTestServer> https_server_;
  content::ContentMockCertVerifier mock_cert_verifier_;
  base::SimpleTestClock test_clock_;
};

// Navigating to a non-IDN shouldn't show an interstitial or record metrics.
// TODO(https://crbug.com1207573): re-enable when flakiness is fixed.
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_WIN) || BUILDFLAG(IS_MAC)
#define MAYBE_NonIdn_NoMatch DISABLED_NonIdn_NoMatch
#else
#define MAYBE_NonIdn_NoMatch NonIdn_NoMatch
#endif
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       MAYBE_NonIdn_NoMatch) {
  TestInterstitialNotShown(browser(), GetURL("google.com"));
  test_helper()->CheckNoLookalikeUkm();
}

// Navigating to a domain whose visual representation does not look like a
// top domain shouldn't show an interstitial or record metrics.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       NonTopDomainIdn_NoInterstitial) {
  TestInterstitialNotShown(browser(), GetURL("éxample.com"));
  test_helper()->CheckNoLookalikeUkm();
}

// If the user has engaged with the domain before, metrics shouldn't be recorded
// and the interstitial shouldn't be shown, even if the domain is visually
// similar to a top domain.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_TopDomain_EngagedSite_NoMatch) {
  const GURL url = GetURL("googlé.com");
  SetEngagementScore(browser(), url, kHighEngagement);
  TestInterstitialNotShown(browser(), url);
  test_helper()->CheckNoLookalikeUkm();
}

// Navigate to a domain whose visual representation looks like a top domain.
// This should record metrics. It should also show a lookalike warning
// interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_TopDomain_Match) {
  const GURL kNavigatedUrl = GetURL("googlé.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("google.com");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchSkeletonTop500);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kSkeletonMatchTop500);
  CheckInterstitialUkm({kNavigatedUrl}, "TriggeredByInitialUrl", false);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Navigate to a domain that contains an unsafe ligature.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       UnsafeLigature) {
  const GURL kNavigatedUrl = GetURL("GOOGLELOGOLIGATURE.com");
  // Ligature checks show the punycode interstitial which doesn't have a
  // suggested URL. Its "Don't proceed" button goes back, which is the new tab
  // page here.
  const GURL kSuggestedURL("chrome://newtab");

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kSuggestedURL,
      NavigationSuggestionEvent::kFailedSpoofChecks);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kFailedSpoofChecks);
  CheckInterstitialUkm({kNavigatedUrl}, "TriggeredByInitialUrl", false);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Navigate to a domain that would trigger the warning, but doesn't because it
// fails-safe when the allowlist isn't available.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       NoMatchOnAllowlistMissing) {
  const GURL kNavigatedUrl = GetURL("googlé.com");

  // Clear out any existing proto.
  lookalikes::SetSafetyTipsRemoteConfigProto(nullptr);

  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// Embedding a top domain should show an interstitial when enabled.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_TopDomain_Match) {
  const GURL kNavigatedUrl = GetURL("google.com-test.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("google.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  base::HistogramTester histograms;

  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchTargetEmbedding);
  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kTargetEmbedding);
  CheckInterstitialUkm({kNavigatedUrl}, "TriggeredByInitialUrl", false);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Embedding a top domain would normally show an interstitial, but shouldn't
// here because it's narrowly allowlisted.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_ScopedAllowlistMatch) {
  ConfigureAllowlistWithScopes();
  const GURL kNavigatedUrl = GetURL("google.com.may-spoof-google.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// Same as TargetEmbedding_ScopedAllowlistMatch, but the attacker-controlled
// domain is spoofing an unauthorized victim. This should show a warning.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_ScopedAllowlistMatchWrongDomain) {
  ConfigureAllowlistWithScopes();
  const GURL kNavigatedUrl = GetURL("blogspot.com.may-spoof-google.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("blogspot.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchTargetEmbedding);
  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kTargetEmbedding);
  CheckInterstitialUkm({kNavigatedUrl}, "TriggeredByInitialUrl", false);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Same as TargetEmbedding_TopDomain_Match, but has a redirect where the first
// and last URLs are both target embedding matches. Should only record
// metrics for the first URL. Regression test for crbug.com/1136296.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_TopDomain_Redirect_Match) {
  const GURL kNavigatedUrl = GetLongRedirect("google.com-test.com", "site.test",
                                             "youtube.com-test.com");
  // UKM will record the final URL of the redirect:
  const GURL kLastUrl = GetURL("youtube.com-test.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("google.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  base::HistogramTester histograms;

  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchTargetEmbedding);
  CheckInterstitialUkm({kLastUrl}, "MatchType",
                       LookalikeUrlMatchType::kTargetEmbedding);
  CheckInterstitialUkm({kLastUrl}, "TriggeredByInitialUrl", true);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Target embedding should not trigger on allowlisted embedder domains.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_EmbedderAllowlist) {
  const GURL kNavigatedUrl = GetURL("google.com.allowlisted.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  lookalikes::SetSafetyTipAllowlistPatterns({"allowlisted.com/"}, {}, {});
  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// Target embedding should not trigger on allowlisted target domains.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_TargetAllowlist) {
  const GURL kNavigatedUrl = GetURL("foo.scholar.google.com.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  lookalikes::SetSafetyTipAllowlistPatterns({}, {"scholar\\.google\\.com"}, {});
  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// Target embedding shouldn't trigger on component-delivered common words.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_ComponentCommonWords) {
  const GURL kNavigatedUrl = GetURL("google.com.example.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  lookalikes::SetSafetyTipAllowlistPatterns({}, {}, {"google"});
  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// Navigate to a domain target embedding a domain with no separators, but that
// matches the target allowlist.  Regression test for crbug.com/1127450.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TargetEmbedding_TargetAllowlistWithNoSeparators) {
  const GURL kNavigatedUrl = GetURL("googlecom.example.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  lookalikes::SetSafetyTipAllowlistPatterns({}, {"google\\.com"}, {});
  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// Similar to Idn_TopDomain_Match but the domain is not in top 500. Should not
// show an interstitial, but should still record metrics.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_TopDomain_Match_Not500) {
  const GURL kNavigatedUrl = GetURL("googlé.sk");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  base::HistogramTester histograms;
  TestInterstitialNotShown(browser(), kNavigatedUrl);
  histograms.ExpectTotalCount(kInterstitialHistogramName, 1);
  histograms.ExpectBucketCount(kInterstitialHistogramName,
                               NavigationSuggestionEvent::kMatchSkeletonTop5k,
                               1);

  // Navigate away so that safety tip metrics are recorded.
  ASSERT_TRUE(ui_test_utils::NavigateToURL(browser(), GURL("about:blank")));

  // This heuristic shows a safety tip, so no interstitial UKM should be
  // recorded.
  test_helper()->CheckInterstitialUkmCount(0);
  test_helper()->CheckSafetyTipUkmCount(1);
}

// Same as Idn_TopDomain_Match, but this time the domain contains characters
// from different scripts, failing the checks in IDN spoof checker before
// reaching the top domain check. In this case, the end result is the same, but
// the reason we fall back to punycode is different.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_TopDomainMixedScript_Match) {
  const GURL kNavigatedUrl = GetURL("аррӏе.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("apple.com");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchSkeletonTop500);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kSkeletonMatchTop500);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// The navigated domain will fall back to punycode because it fails standard
// ICU spoof checks in the IDN spoof checker. However, no interstitial will be
// shown as the domain name is single character.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Punycode_ShortHostname_NoInterstitial) {
  const GURL kNavigatedUrl = GetURL("τ.com");

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// Same as Punycode_ShortHostname_NoInterstitial but also has target embedding.
// Should show an interstitial this time.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Punycode_ShortHostname_TargetEmbedding_Interstitial) {
  const GURL kNavigatedUrl = GetURL("google-com.τ.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("google.com");

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchTargetEmbedding);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kTargetEmbedding);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// The navigated domain will fall back to punycode because it fails spoof checks
// in IDN spoof checker. The heuristic that changes this domain to punycode
// (latin middle dot) is configured to show a punycode interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Punycode_NoSuggestedUrl_Interstitial) {
  const GURL kNavigatedUrl = GetURL("example·com.com");
  TestPunycodeInterstitialShown(browser(), kNavigatedUrl,
                                NavigationSuggestionEvent::kFailedSpoofChecks);
  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kFailedSpoofChecks);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// The navigated domain will fall back to punycode because it fails spoof checks
// in IDN spoof checker. The heuristic that changes this domain to punycode
// (latin middle dot) is configured to show a punycode interstitial, but the
// domain is allowlisted.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Punycode_NoSuggestedUrl_Allowlisted) {
  ConfigureAllowlistWithScopes();
  const GURL kNavigatedUrl = GetURL("example·com.com");

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

// The navigated domain will fall back to punycode because it fails spoof checks
// in IDN spoof checker. The heuristic that changes this domain to punycode
// (latin middle dot) is configured to show a punycode interstitial. The domain
// is also caught by the target embedding heuristic. Target embedding should
// take priority.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       PunycodeAndTargetEmbedding_NoSuggestedUrl_Interstitial) {
  // Navigate to a domain that triggers target embedding:
  const GURL kNavigatedUrl = GetURL("google·com.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("google.com");
  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchTargetEmbedding);
  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kTargetEmbedding);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// The navigated domain itself is a top domain or a subdomain of a top domain.
// Should not record metrics. The top domain list doesn't contain any IDN, so
// this only tests the case where the subdomains are IDNs.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TopDomainIdnSubdomain_NoMatch) {
  TestInterstitialNotShown(browser(), GetURL("tést.google.com"));
  test_helper()->CheckNoLookalikeUkm();

  // blogspot.com is a private registry, so the eTLD+1 of "tést.blogspot.com" is
  // itself, instead of just "blogspot.com". This is different than
  // tést.google.com whose eTLD+1 is google.com, and it should be handled
  // correctly.
  TestInterstitialNotShown(browser(), GetURL("tést.blogspot.com"));
  test_helper()->CheckNoLookalikeUkm();
}

// Schemes other than HTTP and HTTPS should be ignored.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       TopDomainChromeUrl_NoMatch) {
  TestInterstitialNotShown(browser(), GURL("chrome://googlé.com"));
  test_helper()->CheckNoLookalikeUkm();
}

// Navigate to a domain within an edit distance of 1 to an engaged domain.
// This should record metrics, but should not show a lookalike warning
// interstitial yet.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       EditDistance_EngagedDomain_Match) {
  base::HistogramTester histograms;
  SetEngagementScore(browser(), GURL("https://test-site.com"), kHighEngagement);

  // The skeleton of this domain is one 1 edit away from the skeleton of
  // test-site.com.
  const GURL kNavigatedUrl = GetURL("best-sité.com");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  // Advance clock to force a fetch of new engaged sites list.
  test_clock()->Advance(base::Hours(1));

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  histograms.ExpectTotalCount(kInterstitialHistogramName, 1);
  histograms.ExpectBucketCount(
      kInterstitialHistogramName,
      NavigationSuggestionEvent::kMatchEditDistanceSiteEngagement, 1);

  // Navigate away so that safety tip metrics are recorded.
  ASSERT_TRUE(ui_test_utils::NavigateToURL(browser(), GURL("about:blank")));

  test_helper()->CheckInterstitialUkmCount(0);
  test_helper()->CheckSafetyTipUkmCount(1);
}

// Navigate to a domain within a character swap of 1 to a top domain.
// This should not record interstitial metrics as it'll display a safety tip.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       CharacterSwap_TopDomain_Match_ShouldNotRecordMetrics) {
  base::HistogramTester histograms;
  const GURL kNavigatedUrl = GetURL("goolge.com");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  histograms.ExpectTotalCount(kInterstitialHistogramName, 1);
  histograms.ExpectBucketCount(
      kInterstitialHistogramName,
      NavigationSuggestionEvent::kMatchCharacterSwapTop500, 1);

  // Navigate away so that safety tip metrics are recorded.
  ASSERT_TRUE(ui_test_utils::NavigateToURL(browser(), GURL("about:blank")));

  test_helper()->CheckInterstitialUkmCount(0);
  test_helper()->CheckSafetyTipUkmCount(1);
}

// Tests that a hostname on a safe TLD can spoof another hostname without a
// lookalike warning.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_SafeTLD_CanSpoof) {
  base::HistogramTester histograms;
  SetEngagementScore(browser(), GURL("https://digital.gov"), kHighEngagement);
  const GURL kNavigatedUrl = GetURL("digitál.gov");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  // Advance clock to force a fetch of new engaged sites list.
  test_clock()->Advance(base::Hours(1));

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  histograms.ExpectTotalCount(kInterstitialHistogramName, 0);
  test_helper()->CheckNoLookalikeUkm();
}

// Navigate to a domain within an edit distance of 1 to a top domain.
// This should record metrics, but should not show a lookalike warning
// interstitial yet.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       EditDistance_TopDomain_Match) {
  base::HistogramTester histograms;

  // The skeleton of this domain, gooogle.corn, is one 1 edit away from
  // google.corn, the skeleton of google.com.
  const GURL kNavigatedUrl = GetURL("goooglé.com");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  histograms.ExpectTotalCount(kInterstitialHistogramName, 1);
  histograms.ExpectBucketCount(kInterstitialHistogramName,
                               NavigationSuggestionEvent::kMatchEditDistance,
                               1);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kEditDistance);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Navigate to a domain within an edit distance of 1 to a top domain, but that
// matches the allowlist. This should neither record metrics nor show an
// interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       EditDistance_TopDomain_Target_Allowlist) {
  base::HistogramTester histograms;
  lookalikes::SetSafetyTipAllowlistPatterns({}, {"google\\.com"}, {});

  // The skeleton of this domain, gooogle.corn, is one 1 edit away from
  // google.corn, the skeleton of google.com.
  const GURL kNavigatedUrl = GetURL("goooglé.com");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  histograms.ExpectTotalCount(kInterstitialHistogramName, 0);
  test_helper()->CheckNoLookalikeUkm();
}

// Navigate to a domain within an edit distance of 1 to an engaged domain, but
// that matches the allowlist. This should neither record metrics nor show an
// interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       EditDistance_EngagedDomain_Target_Allowlist) {
  base::HistogramTester histograms;
  SetEngagementScore(browser(), GURL("https://test-site.com"), kHighEngagement);
  lookalikes::SetSafetyTipAllowlistPatterns({}, {"test-site\\.com"}, {});

  // The skeleton of this domain is one 1 edit away from the skeleton of
  // test-site.com.
  const GURL kNavigatedUrl = GetURL("best-sité.com");
  // Even if the navigated site has a low engagement score, it should be
  // considered for lookalike suggestions.
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  // Advance clock to force a fetch of new engaged sites list.
  test_clock()->Advance(base::Hours(1));

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  histograms.ExpectTotalCount(kInterstitialHistogramName, 0);
  test_helper()->CheckNoLookalikeUkm();
}

// Tests negative examples for the edit distance.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       EditDistance_TopDomain_NoMatch) {
  // Matches google.com.tr but only differs in registry.
  ASSERT_TRUE(IsTopDomain(GetDomainInfo("google.com.tr")));
  TestInterstitialNotShown(browser(), GetURL("google.com.tw"));

  // Matches academia.edu but is a top domain itself.
  ASSERT_TRUE(IsTopDomain(GetDomainInfo("academia.edu")));
  ASSERT_TRUE(IsTopDomain(GetDomainInfo("academic.ru")));
  TestInterstitialNotShown(browser(), GetURL("academic.ru"));

  // Matches ask.com but is too short.
  ASSERT_TRUE(IsTopDomain(GetDomainInfo("ask.com")));
  TestInterstitialNotShown(browser(), GetURL("bsk.com"));

  test_helper()->CheckNoLookalikeUkm();
}

// Tests negative examples for the edit distance with engaged sites.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       EditDistance_SiteEngagement_NoMatch) {
  SetEngagementScore(browser(), GURL("https://test-site.com.tr"),
                     kHighEngagement);
  SetEngagementScore(browser(), GURL("https://1234.com"), kHighEngagement);
  SetEngagementScore(browser(), GURL("https://gooogle.com"), kHighEngagement);
  // Advance clock to force a fetch of new engaged sites list.
  test_clock()->Advance(base::Hours(1));

  // Matches test-site.com.tr but only differs in registry.
  TestInterstitialNotShown(browser(), GetURL("test-site.com.tw"));

  // Matches gooogle.com but is a top domain itself.
  TestInterstitialNotShown(browser(), GetURL("google.com"));

  // Matches 1234.com but is too short.
  TestInterstitialNotShown(browser(), GetURL("123.com"));

  test_helper()->CheckNoLookalikeUkm();
}

// Test that the heuristics are not triggered with net errors.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       NetError_SiteEngagement_Interstitial) {
  // Create a test server that returns invalid responses.
  net::EmbeddedTestServer custom_test_server;
  custom_test_server.RegisterRequestHandler(
      base::BindRepeating(&NetworkErrorResponseHandler));
  ASSERT_TRUE(custom_test_server.Start());

  SetEngagementScore(browser(), GURL("http://site1.com"), kHighEngagement);
  // Advance clock to force a fetch of new engaged sites list.
  test_clock()->Advance(base::Hours(1));

  TestInterstitialNotShown(
      browser(), custom_test_server.GetURL("sité1.com", "/title1.html"));

  test_helper()->CheckNoLookalikeUkm();
}

// Same as NetError_SiteEngagement_Interstitial, but triggered by a top domain.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       NetError_TopDomain_Interstitial) {
  // Create a test server that returns invalid responses.
  net::EmbeddedTestServer custom_test_server;
  custom_test_server.RegisterRequestHandler(
      base::BindRepeating(&NetworkErrorResponseHandler));
  ASSERT_TRUE(custom_test_server.Start());
  TestInterstitialNotShown(browser(),
                           custom_test_server.GetURL("googlé.com", "/"));

  test_helper()->CheckNoLookalikeUkm();
}

// TODO(crbug.com/40146482): Enable test when MacOS flake is fixed.
// TODO(crbug.com/40706320): Enable test when Win/Linux flake is fixed.
#if BUILDFLAG(IS_MAC) || BUILDFLAG(IS_WIN) || BUILDFLAG(IS_LINUX)
#define MAYBE_Idn_SiteEngagement_Match DISABLED_Idn_SiteEngagement_Match
#else
#define MAYBE_Idn_SiteEngagement_Match Idn_SiteEngagement_Match
#endif

// Navigate to a domain whose visual representation looks like a domain with a
// site engagement score above a certain threshold. This should record metrics.
// It should also show lookalike warning interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       MAYBE_Idn_SiteEngagement_Match) {
  const char* const kEngagedSites[] = {
      "http://site1.com", "http://www.site2.com", "http://sité3.com",
      "http://www.sité4.com"};

  for (const char* const kSite : kEngagedSites) {
    SetEngagementScore(browser(), GURL(kSite), kHighEngagement);
  }

  // The domains here should not be private domains (e.g. site.test), otherwise
  // they might test the wrong thing. Also note that site5.com is in the top
  // domain list, so it shouldn't be used here.
  const struct SiteEngagementTestCase {
    const char* const navigated;
    const char* const suggested;
  } kSiteEngagementTestCases[] = {
      {"sité1.com", "site1.com"},
      {"mail.www.sité1.com", "site1.com"},
      // Same as above two but ending with dots.
      {"sité1.com.", "site1.com"},
      {"mail.www.sité1.com.", "site1.com"},

      // These should match since the comparison uses eTLD+1s.
      {"sité2.com", "site2.com"},
      {"mail.sité2.com", "site2.com"},

      {"síté3.com", "sité3.com"},
      {"mail.síté3.com", "sité3.com"},

      {"síté4.com", "sité4.com"},
      {"mail.síté4.com", "sité4.com"},
  };

  std::vector<GURL> ukm_urls;
  for (const auto& test_case : kSiteEngagementTestCases) {
    const GURL kNavigatedUrl = GetURL(test_case.navigated);
    const GURL kExpectedSuggestedUrl = GetURLWithoutPath(test_case.suggested);

    // Even if the navigated site has a low engagement score, it should be
    // considered for lookalike suggestions.
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    // Advance the clock to force LookalikeUrlService to fetch a new engaged
    // site list.
    test_clock()->Advance(base::Hours(1));

    base::HistogramTester histograms;
    TestMetricsRecordedAndInterstitialShown(
        browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
        NavigationSuggestionEvent::kMatchSiteEngagement);

    ukm_urls.push_back(kNavigatedUrl);
    CheckInterstitialUkm(ukm_urls, "MatchType",
                         LookalikeUrlMatchType::kSkeletonMatchSiteEngagement);
  }

  test_helper()->CheckSafetyTipUkmCount(0);
}

// The site redirects to the matched site, this should not show
// an interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_SiteEngagement_SafeRedirect) {
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("site1.com");
  const GURL kNavigatedUrl = https_server()->GetURL(
      "sité1.com", "/server-redirect?" + kExpectedSuggestedUrl.spec());
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  SetEngagementScore(browser(), kExpectedSuggestedUrl, kHighEngagement);

  TestInterstitialNotShown(browser(), kNavigatedUrl);

  test_helper()->CheckNoLookalikeUkm();
}

// The site redirects to the matched site, but the redirect chain has more than
// two redirects.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_SiteEngagement_MidRedirectSpoofsIgnored) {
  const GURL kFinalUrl = GetURLWithoutPath("site1.com");
  const GURL kMidUrl = https_server()->GetURL(
      "sité1.com", "/server-redirect?" + kFinalUrl.spec());
  const GURL kNavigatedUrl = https_server()->GetURL(
      "other-site.test", "/server-redirect?" + kMidUrl.spec());

  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  SetEngagementScore(browser(), kFinalUrl, kHighEngagement);
  TestInterstitialNotShown(browser(), kNavigatedUrl);

  test_helper()->CheckNoLookalikeUkm();
}

// The site is allowed by the component updater.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       AllowedByComponentUpdater) {
  lookalikes::SetSafetyTipAllowlistPatterns(
      {"xn--googl-fsa.com/",  // googlé.com in punycode
       "site.test/", "another-site.test/"},
      {}, {});
  TestInterstitialNotShown(browser(), GetURL("googlé.com"));

  // Try a non-HTTP URL. Shouldn't crash.
  TestInterstitialNotShown(browser(), GURL("data:text/html, test"));

  test_helper()->CheckNoLookalikeUkm();
}

// The site is allowed by enterprise policy.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       AllowedByPolicy) {
  const GURL kNavigatedUrl = GetURL("xn--googl-fsa.com");
  lookalikes::SetEnterpriseAllowlistForTesting(browser()->profile()->GetPrefs(),
                                               {"xn--googl-fsa.com"});
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  TestInterstitialNotShown(browser(), kNavigatedUrl);

  test_helper()->CheckNoLookalikeUkm();
}

// Tests negative examples for all heuristics.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       NonUniqueDomains_NoMatch) {
  // Unknown registry.
  TestInterstitialNotShown(browser(), GetURL("google.cóm"));
  test_helper()->CheckNoLookalikeUkm();

  // Engaged site is localhost, navigated site has unknown registry. This
  // is intended to test that nonunique domains in the engaged site list is
  // filtered out. However, it doesn't quite test that: We'll bail out early
  // because the navigated site has unknown registry (and not because there is
  // no engaged nonunique site).
  SetEngagementScore(browser(), GURL("http://localhost6.localhost"),
                     kHighEngagement);
  test_clock()->Advance(base::Hours(1));
  // The skeleton of this URL is localhost6.localpost which is at one edit
  // distance from localhost6.localhost. We use localpost here to prevent an
  // early return in LookalikeUrlNavigationThrottle::HandleThrottleRequest().
  TestInterstitialNotShown(browser(), GURL("http://localhóst6.localpost"));
  test_helper()->CheckNoLookalikeUkm();
}

// Navigate to a domain whose visual representation looks both like a domain
// with a site engagement score and also a top domain. This should record
// metrics for a site engagement match because of the order of checks. It should
// also show lookalike warning interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_SiteEngagementAndTopDomain_Match) {
  const GURL kNavigatedUrl = GetURL("googlé.com");
  const GURL kExpectedSuggestedUrl = GetURLWithoutPath("google.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  SetEngagementScore(browser(), kExpectedSuggestedUrl, kHighEngagement);

  // Advance the clock to force LookalikeUrlService to fetch a new engaged
  // site list.
  test_clock()->Advance(base::Hours(1));

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchSiteEngagement);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kSkeletonMatchSiteEngagement);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Similar to Idn_SiteEngagement_Match, but tests a single domain. Also checks
// that the list of engaged sites in incognito and the main profile don't affect
// each other.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_SiteEngagement_Match_Incognito) {
  const GURL kNavigatedUrl = GetURL("sité1.com");
  const GURL kEngagedUrl = GetURLWithoutPath("site1.com");

  // Set high engagement scores in the main profile and low engagement scores
  // in incognito. Main profile should record metrics, incognito shouldn't.
  Browser* incognito = CreateIncognitoBrowser();
  LookalikeUrlServiceFactory::GetForProfile(incognito->profile())
      ->SetClockForTesting(test_clock());
  SetEngagementScore(browser(), kEngagedUrl, kHighEngagement);
  SetEngagementScore(incognito, kEngagedUrl, kLowEngagement);

  std::vector<GURL> ukm_urls;
  // Main profile should record metrics because there are engaged sites.
  {
    // Advance the clock to force LookalikeUrlService to fetch a new engaged
    // site list.
    test_clock()->Advance(base::Hours(1));
    base::HistogramTester histograms;
    TestMetricsRecordedAndInterstitialShown(
        browser(), histograms, kNavigatedUrl, kEngagedUrl,
        NavigationSuggestionEvent::kMatchSiteEngagement);

    ukm_urls.push_back(kNavigatedUrl);
    CheckInterstitialUkm(ukm_urls, "MatchType",
                         LookalikeUrlMatchType::kSkeletonMatchSiteEngagement);
  }

  // Incognito shouldn't record metrics because there are no engaged sites.
  {
    base::HistogramTester histograms;
    test_clock()->Advance(base::Hours(1));
    TestInterstitialNotShown(incognito, kNavigatedUrl);
    histograms.ExpectTotalCount(kIncognitoInterstitialHistogramName, 0);
  }

  // Now reverse the scores: Set low engagement in the main profile and high
  // engagement in incognito.
  SetEngagementScore(browser(), kEngagedUrl, kLowEngagement);
  SetEngagementScore(incognito, kEngagedUrl, kHighEngagement);

  // Incognito should start recording metrics and main profile should stop.
  {
    test_clock()->Advance(base::Hours(1));

    base::HistogramTester histograms;
    TestMetricsRecordedAndInterstitialShown(
        incognito, histograms, kNavigatedUrl, kEngagedUrl,
        NavigationSuggestionEvent::kMatchSiteEngagement);
    ukm_urls.push_back(kNavigatedUrl);
    CheckInterstitialUkm(ukm_urls, "MatchType",
                         LookalikeUrlMatchType::kSkeletonMatchSiteEngagement);
  }

  // Main profile shouldn't record metrics because there are no engaged sites.
  {
    base::HistogramTester histograms;
    test_clock()->Advance(base::Hours(1));
    TestInterstitialNotShown(browser(), kNavigatedUrl);
    histograms.ExpectTotalCount(kInterstitialHistogramName, 0);
  }

  test_helper()->CheckSafetyTipUkmCount(0);
}

// Test that navigations to a site with a high engagement score shouldn't
// record metrics or show interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_SiteEngagement_Match_IgnoreHighlyEngagedSite) {
  base::HistogramTester histograms;
  SetEngagementScore(browser(), GURL("http://site-not-in-top-domain-list.com"),
                     kHighEngagement);
  const GURL high_engagement_url = GetURL("síte-not-ín-top-domaín-líst.com");
  SetEngagementScore(browser(), high_engagement_url, kHighEngagement);
  TestInterstitialNotShown(browser(), high_engagement_url);

  histograms.ExpectTotalCount(kInterstitialHistogramName, 0);
  test_helper()->CheckNoLookalikeUkm();
}

// Test that an engaged site with a scheme other than HTTP or HTTPS should be
// ignored.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Idn_SiteEngagement_IgnoreChromeUrl) {
  base::HistogramTester histograms;
  SetEngagementScore(browser(),
                     GURL("chrome://site-not-in-top-domain-list.com"),
                     kHighEngagement);
  const GURL low_engagement_url("https://síte-not-ín-top-domaín-líst.com");
  SetEngagementScore(browser(), low_engagement_url, kLowEngagement);
  TestInterstitialNotShown(browser(), low_engagement_url);

  histograms.ExpectTotalCount(kInterstitialHistogramName, 0);
  test_helper()->CheckNoLookalikeUkm();
}

// IDNs with a single label should be properly handled. There are two cases
// where this might occur:
// 1. The navigated URL is an IDN with a single label.
// 2. One of the engaged sites is an IDN with a single label.
// Neither of these should cause a crash.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       IdnWithSingleLabelShouldNotCauseACrash) {
  base::HistogramTester histograms;

  // Case 1: Navigating to an IDN with a single label shouldn't cause a crash.
  TestInterstitialNotShown(browser(), GetURL("é"));

  // Case 2: An IDN with a single label with a site engagement score shouldn't
  // cause a crash.
  SetEngagementScore(browser(), GURL("http://tést"), kHighEngagement);
  TestInterstitialNotShown(browser(), GetURL("tést.com"));

  histograms.ExpectTotalCount(kInterstitialHistogramName, 0);
  test_helper()->CheckNoLookalikeUkm();
}

// Ensure that dismissing the interstitial works, and the result is remembered
// in the current tab.  This should record metrics on the first visit, but not
// the second.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Interstitial_Dismiss) {
  base::HistogramTester histograms;

  const GURL kNavigatedUrl = GetURL("sité1.com");
  const GURL kEngagedUrl = GetURL("site1.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  SetEngagementScore(browser(), kEngagedUrl, kHighEngagement);

  TestHistogramEventsRecordedWhenInterstitialIgnored(
      browser(), &histograms, kNavigatedUrl,
      NavigationSuggestionEvent::kMatchSiteEngagement);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kSkeletonMatchSiteEngagement);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Navigate to lookalike domains that redirect to benign domains and ensure that
// we display an interstitial along the way.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       Interstitial_CapturesRedirects) {
  {
    // Verify it works when the lookalike domain is the first in the chain
    const GURL kNavigatedUrl =
        GetLongRedirect("googlé.com", "example.net", "example.com");
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);
  }

  // LoadAndCheckInterstitialAt assumes there's not an interstitial already
  // showing (since otherwise it can't be sure that the navigation caused it).
  NavigateToURLSync(browser(), GetURL("example.com"));

  {
    // ...but not when it's in the middle of the chain
    const GURL kNavigatedUrl =
        GetLongRedirect("example.net", "googlé.com", "example.com");
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    TestInterstitialNotShown(browser(), kNavigatedUrl);
  }

  NavigateToURLSync(browser(), GetURL("example.com"));

  {
    // ...but definitely when it's last in the chain.
    const GURL kNavigatedUrl =
        GetLongRedirect("example.net", "example.com", "googlé.com");
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);
  }

  test_helper()->CheckSafetyTipUkmCount(0);
}

// Verify that a warning, when ignored, applies to the entire eTLD+1, not just
// the navigated origin.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       AllowlistAppliesToETLDPlusOne) {
  {
    const GURL kNavigatedUrl = GetURL("sub1.googlé.com");
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);
    SendInterstitialCommandSync(browser(),
                                SecurityInterstitialCommand::CMD_PROCEED);

    test_helper()->CheckInterstitialUkmCount(1);
    test_helper()->CheckSafetyTipUkmCount(0);
  }

  // TestInterstitialNotShown assumes there's not an interstitial already
  // showing (since otherwise it can't be sure that the navigation caused it).
  NavigateToURLSync(browser(), GetURL("example.com"));

  {
    const GURL kNavigatedUrl = GetURL("sub2.googlé.com");
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    TestInterstitialNotShown(browser(), kNavigatedUrl);

    test_helper()->CheckInterstitialUkmCount(1);
    test_helper()->CheckSafetyTipUkmCount(0);
  }

  // We respect private registries for this manual allowlisting so that
  // different (independent) subdomains each show their own warning.
  NavigateToURLSync(browser(), GetURL("example.com"));
  {
    // We must use a private registry that isn't a top domain, since top domains
    // don't show warnings.
    const GURL kNavigatedUrl = GetURL("google-com.bluebite.io");
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);
    SendInterstitialCommandSync(browser(),
                                SecurityInterstitialCommand::CMD_PROCEED);

    test_helper()->CheckInterstitialUkmCount(2);
    test_helper()->CheckSafetyTipUkmCount(0);
  }
  NavigateToURLSync(browser(), GetURL("example.com"));
  {
    const GURL kNavigatedUrl = GetURL("google-com-unrelated.bluebite.io");
    SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
    LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);
    SendInterstitialCommandSync(browser(),
                                SecurityInterstitialCommand::CMD_PROCEED);

    test_helper()->CheckInterstitialUkmCount(3);
    test_helper()->CheckSafetyTipUkmCount(0);
  }
}

// Verify that the user action in UKM is recorded even when we navigate away
// from the interstitial without interacting with it.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       UkmRecordedAfterNavigateAway) {
  const GURL navigated_url = GetURL("googlé.com");
  const GURL subsequent_url = GetURL("example.com");

  LoadAndCheckInterstitialAt(browser(), navigated_url);
  NavigateToURLSync(browser(), subsequent_url);

  CheckInterstitialUkm({navigated_url}, "UserAction",
                       LookalikeUrlBlockingPageUserAction::kCloseOrBack);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Verify that the user action in UKM is recorded properly when the user accepts
// the navigation suggestion.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       UkmRecordedAfterSuggestionAccepted) {
  const GURL navigated_url = GetURL("googlé.com");

  LoadAndCheckInterstitialAt(browser(), navigated_url);
  SendInterstitialCommandSync(browser(),
                              SecurityInterstitialCommand::CMD_DONT_PROCEED);

  CheckInterstitialUkm({navigated_url}, "UserAction",
                       LookalikeUrlBlockingPageUserAction::kAcceptSuggestion);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Verify that the user action in UKM is recorded properly when the user ignores
// the navigation suggestion.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       UkmRecordedAfterSuggestionIgnored) {
  const GURL navigated_url = GetURL("googlé.com");

  LoadAndCheckInterstitialAt(browser(), navigated_url);
  SendInterstitialCommandSync(browser(),
                              SecurityInterstitialCommand::CMD_PROCEED);

  CheckInterstitialUkm({navigated_url}, "UserAction",
                       LookalikeUrlBlockingPageUserAction::kClickThrough);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Verify that the URL shows normally on pages after a lookalike interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       UrlShownAfterInterstitial) {
  LoadAndCheckInterstitialAt(browser(), GetURL("googlé.com"));

  // URL should be showing again when we navigate to a normal URL
  NavigateToURLSync(browser(), GetURL("example.com"));
  EXPECT_TRUE(IsUrlShowing(browser()));
}

// Verify that bypassing warnings in the main profile does not affect incognito.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       MainProfileDoesNotAffectIncognito) {
  const GURL kNavigatedUrl = GetURL("googlé.com");

  // Set low engagement scores in the main profile and in incognito.
  Browser* incognito = CreateIncognitoBrowser();
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  SetEngagementScore(incognito, kNavigatedUrl, kLowEngagement);

  LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);
  // PROCEEDing will disable the interstitial on subsequent navigations
  SendInterstitialCommandSync(browser(),
                              SecurityInterstitialCommand::CMD_PROCEED);

  LoadAndCheckInterstitialAt(incognito, kNavigatedUrl);
}

// Verify that bypassing warnings in incognito does not affect the main profile.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       IncognitoDoesNotAffectMainProfile) {
  const GURL kNavigatedUrl = GetURL("sité1.com");
  const GURL kEngagedUrl = GetURL("site1.com");

  // Set engagement scores in the main profile and in incognito.
  Browser* incognito = CreateIncognitoBrowser();
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  SetEngagementScore(incognito, kNavigatedUrl, kLowEngagement);
  SetEngagementScore(browser(), kEngagedUrl, kHighEngagement);
  SetEngagementScore(incognito, kEngagedUrl, kHighEngagement);

  LoadAndCheckInterstitialAt(incognito, kNavigatedUrl);
  // PROCEEDing will disable the interstitial on subsequent navigations
  SendInterstitialCommandSync(incognito,
                              SecurityInterstitialCommand::CMD_PROCEED);

  LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);
}

// Verify reloading the page does not result in dismissing an interstitial.
// Regression test for crbug/941886.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       RefreshDoesntDismiss) {
  // Verify it works when the lookalike domain is the first in the chain.
  const GURL kNavigatedUrl =
      GetLongRedirect("googlé.com", "example.net", "example.com");

  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  LoadAndCheckInterstitialAt(browser(), kNavigatedUrl);

  content::WebContents* web_contents =
      browser()->tab_strip_model()->GetActiveWebContents();

  // Reload the interstitial twice. Should still work.
  for (size_t i = 0; i < 2; i++) {
    content::TestNavigationObserver navigation_observer(web_contents);
    chrome::Reload(browser(), WindowOpenDisposition::CURRENT_TAB);
    navigation_observer.Wait();

    EXPECT_EQ(LookalikeUrlBlockingPage::kTypeForTesting,
              GetInterstitialType(web_contents));
    EXPECT_FALSE(IsUrlShowing(browser()));
  }

  // Go to the affected site directly. This should not result in an
  // interstitial.
  TestInterstitialNotShown(browser(),
                           https_server()->GetURL("example.net", "/"));
}

// Navigate to a URL that triggers combo squatting heuristic via the
// hard coded brand name list. This should record metrics but shouldn't show
// an interstitial.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       ComboSquatting_ShouldRecordMetricsWithoutUI) {
  base::HistogramTester histograms;
  const GURL kNavigatedUrl = GetURL("google-login.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  TestInterstitialNotShown(browser(), kNavigatedUrl);

  histograms.ExpectTotalCount(kInterstitialHistogramName, 1);
  histograms.ExpectBucketCount(kInterstitialHistogramName,
                               NavigationSuggestionEvent::kComboSquatting, 1);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kComboSquatting);
  CheckInterstitialUkm({kNavigatedUrl}, "TriggeredByInitialUrl", false);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Navigate to a URL that triggers combo squatting heuristic via a
// brand name from engaged sites. This should record metrics but shouldn't show
// an interstitial.
IN_PROC_BROWSER_TEST_F(
    LookalikeUrlNavigationThrottleBrowserTest,
    ComboSquatting_EngagedSites_ShouldRecordMetricsWithoutUI) {
  base::HistogramTester histograms;
  SetEngagementScore(browser(), GURL("https://example.com"), kHighEngagement);
  const GURL kNavigatedUrl = GetURL("example-login.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);

  TestInterstitialNotShown(browser(), kNavigatedUrl);

  histograms.ExpectTotalCount(kInterstitialHistogramName, 1);
  histograms.ExpectBucketCount(
      kInterstitialHistogramName,
      NavigationSuggestionEvent::kComboSquattingSiteEngagement, 1);

  CheckInterstitialUkm({kNavigatedUrl}, "MatchType",
                       LookalikeUrlMatchType::kComboSquattingSiteEngagement);
  CheckInterstitialUkm({kNavigatedUrl}, "TriggeredByInitialUrl", false);
  test_helper()->CheckSafetyTipUkmCount(0);
}

// Combo Squatting shouldn't trigger on allowlisted sites and no
// UKM should be recorded.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleBrowserTest,
                       ComboSquatting_ShouldNotTriggeredForAllowlist) {
  const GURL kNavigatedUrl = GetURL("google-login.com");
  SetEngagementScore(browser(), kNavigatedUrl, kLowEngagement);
  lookalikes::SetSafetyTipAllowlistPatterns({"google-login.com/"}, {}, {});

  TestInterstitialNotShown(browser(), kNavigatedUrl);
  test_helper()->CheckNoLookalikeUkm();
}

scoped_refptr<net::X509Certificate> LoadCertificate() {
  constexpr char kCertFileName[] = "prime256v1-sha256-google-com.public.pem";

  base::ScopedAllowBlockingForTesting allow_io;
  base::FilePath dir_path;
  base::PathService::Get(content::DIR_TEST_DATA, &dir_path);
  dir_path = dir_path.Append(FILE_PATH_LITERAL("sxg"));

  return net::CreateCertificateChainFromFile(
      dir_path, kCertFileName, net::X509Certificate::FORMAT_PEM_CERT_SEQUENCE);
}

// Tests for Signed Exchanges.
class LookalikeUrlNavigationThrottleSignedExchangeBrowserTest
    : public LookalikeUrlNavigationThrottleBrowserTest {
 public:
  LookalikeUrlNavigationThrottleSignedExchangeBrowserTest() {
    scoped_test_root_ = net::EmbeddedTestServer::RegisterTestCerts();
  }

  void SetUpCommandLine(base::CommandLine* command_line) override {
    // HTTPS server only serves a valid cert for localhost, so this is needed
    // to load pages from other hosts without an error.
    command_line->AppendSwitch(switches::kIgnoreCertificateErrors);
    mock_cert_verifier_.SetUpCommandLine(command_line);
  }

  void SetUpInProcessBrowserTestFixture() override {
    mock_cert_verifier_.SetUpInProcessBrowserTestFixture();
  }

  void TearDownInProcessBrowserTestFixture() override {
    mock_cert_verifier_.TearDownInProcessBrowserTestFixture();
  }

  void SetUp() override {
    sxg_test_helper_.SetUp();
    LookalikeUrlNavigationThrottleBrowserTest::SetUp();
  }

  void SetUpOnMainThread() override {
    https_server_.AddDefaultHandlers(
        base::FilePath(FILE_PATH_LITERAL("content/test/data")));
    https_server_.ServeFilesFromSourceDirectory("content/test/data");
    https_server_.RegisterRequestMonitor(base::BindRepeating(
        &LookalikeUrlNavigationThrottleSignedExchangeBrowserTest::
            MonitorRequest,
        base::Unretained(this)));
    ASSERT_TRUE(https_server_.Start());

    LookalikeUrlNavigationThrottleBrowserTest::SetUpOnMainThread();
  }

  void TearDownOnMainThread() override {
    sxg_test_helper_.TearDownOnMainThread();
  }

  bool HadSignedExchangeInAcceptHeader(const GURL& url) const {
    const auto it = url_accept_header_map_.find(url);
    if (it == url_accept_header_map_.end())
      return false;
    return it->second.find("application/signed-exchange") != std::string::npos;
  }

  void InstallMockCert() {
    sxg_test_helper_.InstallMockCert(mock_cert_verifier_.mock_cert_verifier());

    // Make the MockCertVerifier treat the certificate
    // "prime256v1-sha256-google-com.public.pem" as valid for
    // "google-com.example.org".
    scoped_refptr<net::X509Certificate> original_cert = LoadCertificate();
    net::CertVerifyResult dummy_result;
    dummy_result.verified_cert = original_cert;
    dummy_result.cert_status = net::OK;
    dummy_result.ocsp_result.response_status = bssl::OCSPVerifyResult::PROVIDED;
    dummy_result.ocsp_result.revocation_status =
        bssl::OCSPRevocationStatus::GOOD;
    mock_cert_verifier_.mock_cert_verifier()->AddResultForCertAndHost(
        original_cert, "google-com.example.org", dummy_result, net::OK);
  }

  void InstallMockCertChainInterceptor() {
    sxg_test_helper_.InstallMockCertChainInterceptor();
    sxg_test_helper_.InstallUrlInterceptor(
        GURL("https://google-com.example.org/cert.msg"),
        "content/test/data/sxg/google-com.example.org.public.pem.cbor");
  }

 protected:
  net::EmbeddedTestServer https_server_{net::EmbeddedTestServer::TYPE_HTTPS};
  content::SignedExchangeBrowserTestHelper sxg_test_helper_;
  content::ContentMockCertVerifier mock_cert_verifier_;

 private:
  void MonitorRequest(const net::test_server::HttpRequest& request) {
    const auto it = request.headers.find("Accept");
    if (it == request.headers.end())
      return;
    url_accept_header_map_[request.base_url.Resolve(request.relative_url)] =
        it->second;
  }

  net::ScopedTestRoot scoped_test_root_;
  std::map<GURL, std::string> url_accept_header_map_;
};

// Navigates to a 127.0.0.1 URL that serves a signed exchange for
// google-com.example.org. This navigation should be blocked by the target
// embedding interstitial. We only test target embedding here because we can
// test it with a subdomain of example.org (which is the domain used by SGX test
// code). Testing an ETLD+1 such as googlé.com would require generating a custom
// cert.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleSignedExchangeBrowserTest,
                       InnerUrlIsLookalike_ShouldBlock) {
  InstallMockCert();
  InstallMockCertChainInterceptor();

  sxg_test_helper_.InstallUrlInterceptor(
      GURL("https://google-com.example.org/test/"),
      "content/test/data/sxg/fallback.html");
  const GURL kNavigatedUrl =
      https_server_.GetURL("/sxg/google-com.example.org_test.sxg");
  const GURL kExpectedSuggestedUrl("https://google.com");

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchTargetEmbedding,
      true /* expect_signed_exchange */);

  // Check that the SXG file was handled as a Signed Exchange.
  ASSERT_TRUE(HadSignedExchangeInAcceptHeader(kNavigatedUrl));
}

// Navigates to a lookalike URL (google-com.test.com) that serves a signed
// exchange for test.example.org. This should not be blocked.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleSignedExchangeBrowserTest,
                       OuterUrlIsLookalike_ShouldNotBlock) {
  InstallMockCert();
  InstallMockCertChainInterceptor();

  const GURL kSgxTargetUrl("https://test.example.org/test/");
  sxg_test_helper_.InstallUrlInterceptor(kSgxTargetUrl,
                                         "content/test/data/sxg/fallback.html");
  const GURL kNavigatedUrl = https_server_.GetURL(
      "google-com.test.com", "/sxg/test.example.org_test.sxg");

  TestInterstitialNotShown(browser(), kNavigatedUrl);

  // Check that the SXG file was handled as a Signed Exchange.
  // MonitorRequest() sees kNavigatedUrl with an IP address instead of
  // domain name, so check it instead.
  const GURL kResolvedNavigatedUrl =
      https_server_.GetURL("/sxg/test.example.org_test.sxg");
  ASSERT_TRUE(HadSignedExchangeInAcceptHeader(kResolvedNavigatedUrl));
}

// Navigates to a lookalike URL (google-com.test.com) that serves a signed
// exchange for test.example.org. This should not be blocked.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleSignedExchangeBrowserTest,
                       OuterUrlIsLookalikeButNotSignedExchange_ShouldNotBlock) {
  InstallMockCert();
  InstallMockCertChainInterceptor();

  const GURL kSgxTargetUrl("https://test.example.org/test/");
  sxg_test_helper_.InstallUrlInterceptor(kSgxTargetUrl,
                                         "content/test/data/sxg/fallback.html");
  const GURL kSgxCacheUrl = https_server_.GetURL(
      "google-com.test.com", "/sxg/test.example.org_test.sxg");
  const GURL kNavigatedUrl = https_server()->GetURL(
      "apple-com.site.test", "/server-redirect?" + kSgxCacheUrl.spec());

  TestInterstitialNotShown(browser(), kNavigatedUrl);

  // Check that the SXG file was handled as a Signed Exchange.
  // MonitorRequest() sees kNavigatedUrl with an IP address instead of
  // domain name, so check it instead.
  const GURL kResolvedNavigatedUrl =
      https_server_.GetURL("/sxg/test.example.org_test.sxg");
  ASSERT_TRUE(HadSignedExchangeInAcceptHeader(kResolvedNavigatedUrl));
}

// Navigates to a lookalike URL (google-com.test.com) that serves a signed
// exchange for google-com.example.org.
// Both the outer URL (i.e. cache) and the inner URL are lookalikes so this
// should be blocked.
IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottleSignedExchangeBrowserTest,
                       InnerAndOuterUrlsAreLookalikes_ShouldBlock) {
  InstallMockCert();
  InstallMockCertChainInterceptor();

  sxg_test_helper_.InstallUrlInterceptor(
      GURL("https://google-com.example.org/test/"),
      "content/test/data/sxg/fallback.html");
  const GURL kNavigatedUrl = https_server_.GetURL(
      "google-com.test.com", "/sxg/google-com.example.org_test.sxg");
  const GURL kExpectedSuggestedUrl("https://google.com");

  base::HistogramTester histograms;
  TestMetricsRecordedAndInterstitialShown(
      browser(), histograms, kNavigatedUrl, kExpectedSuggestedUrl,
      NavigationSuggestionEvent::kMatchTargetEmbedding,
      true /* expect_signed_exchange */);

  // Check that the SXG file was handled as a Signed Exchange.
  // MonitorRequest() sees kNavigatedUrl with an IP address instead of
  // domain name, so check it instead.
  const GURL kResolvedNavigatedUrl =
      https_server_.GetURL("/sxg/google-com.example.org_test.sxg");
  ASSERT_TRUE(HadSignedExchangeInAcceptHeader(kResolvedNavigatedUrl));
}

// TODO(meacer): Add a test for a failed SGX response. It should be treated
// as a normal redirect. In fact, InnerAndOuterUrlsLookalikes_ShouldBlock
// is actually testing this right now, fix it.

class LookalikeUrlNavigationThrottlePrerenderBrowserTest
    : public LookalikeUrlNavigationThrottleBrowserTest {
 public:
  LookalikeUrlNavigationThrottlePrerenderBrowserTest() = default;
  ~LookalikeUrlNavigationThrottlePrerenderBrowserTest() override = default;

  void SetUpCommandLine(base::CommandLine* command_line) override {
    LookalikeUrlNavigationThrottleBrowserTest::SetUpCommandLine(command_line);
    prerender_helper_ = std::make_unique<content::test::PrerenderTestHelper>(
        base::BindRepeating(
            &LookalikeUrlNavigationThrottlePrerenderBrowserTest::web_contents,
            base::Unretained(this)));
  }

  void SetUpOnMainThread() override {
    prerender_helper_->RegisterServerRequestMonitor(https_server());
    LookalikeUrlNavigationThrottleBrowserTest::SetUpOnMainThread();
  }

  content::WebContents* web_contents() {
    return browser()->tab_strip_model()->GetActiveWebContents();
  }

 protected:
  std::unique_ptr<content::test::PrerenderTestHelper> prerender_helper_;
};

IN_PROC_BROWSER_TEST_F(LookalikeUrlNavigationThrottlePrerenderBrowserTest,
                       ShowInterstitialAfterActivation) {
  // TODO(crbug.com/40168192): Cross-origin prerender isn't yet supported, so we
  // trigger prerendering a page that needs to show an interstitial like this.
  // Once cross-origin prerender is supported, this should be updated to more
  // realistic use-case. i.e. navigate to an primary page with a normal URL and
  // prerender/activate with a lookalike URL.
  const GURL kNavigateUrl = GetURL("googlé.com");
  LoadAndCheckInterstitialAt(browser(), kNavigateUrl);
  SendInterstitialCommandSync(browser(),
                              SecurityInterstitialCommand::CMD_PROCEED);
  LookalikeUrlServiceFactory::GetForProfile(browser()->profile())
      ->ResetWarningDismissedETLDPlusOnesForTesting();

  // Start a prerender.
  const GURL kPrerenderUrl =
      https_server()->GetURL("googlé.com", "/title1.html?prerender");
  content::test::PrerenderHostObserver host_observer(*web_contents(),
                                                     kPrerenderUrl);
  prerender_helper_->AddPrerenderAsync(kPrerenderUrl);

  // Wait until the prerender destroyed.
  host_observer.WaitForDestroyed();
  EXPECT_EQ(nullptr, GetCurrentInterstitial(web_contents()));

  // Activate the prerendered page.
  prerender_helper_->NavigatePrimaryPage(kPrerenderUrl);
  EXPECT_EQ(LookalikeUrlBlockingPage::kTypeForTesting,
            GetInterstitialType(web_contents()));
  EXPECT_FALSE(IsUrlShowing(browser()));
}