// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "components/omnibox/browser/autocomplete_result.h"

#include <stddef.h>

#include <memory>
#include <string>
#include <vector>

#include "base/cxx17_backports.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/field_trial_params.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_util.h"
#include "base/strings/utf_string_conversions.h"
#include "base/test/metrics/histogram_tester.h"
#include "base/test/scoped_feature_list.h"
#include "base/test/task_environment.h"
#include "build/build_config.h"
#include "components/omnibox/browser/autocomplete_input.h"
#include "components/omnibox/browser/autocomplete_match.h"
#include "components/omnibox/browser/autocomplete_match_type.h"
#include "components/omnibox/browser/autocomplete_provider.h"
#include "components/omnibox/browser/autocomplete_provider_client.h"
#include "components/omnibox/browser/fake_autocomplete_provider_client.h"
#include "components/omnibox/browser/intranet_redirector_state.h"
#include "components/omnibox/browser/omnibox_field_trial.h"
#include "components/omnibox/browser/omnibox_prefs.h"
#include "components/omnibox/browser/test_scheme_classifier.h"
#include "components/omnibox/common/omnibox_features.h"
#include "components/prefs/pref_registry_simple.h"
#include "components/prefs/testing_pref_service.h"
#include "components/search_engines/template_url_service.h"
#include "components/variations/variations_associated_data.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/metrics_proto/omnibox_event.pb.h"

using metrics::OmniboxEventProto;

namespace {

struct AutocompleteMatchTestData {
  std::string destination_url;
  AutocompleteMatch::Type type;
};

const AutocompleteMatchTestData kVerbatimMatches[] = {
  { "http://search-what-you-typed/",
    AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED },
  { "http://url-what-you-typed/", AutocompleteMatchType::URL_WHAT_YOU_TYPED },
};

const AutocompleteMatchTestData kNonVerbatimMatches[] = {
  { "http://search-history/", AutocompleteMatchType::SEARCH_HISTORY },
  { "http://history-title/", AutocompleteMatchType::HISTORY_TITLE },
};

// Adds |count| AutocompleteMatches to |matches|.
template <typename T>
void PopulateAutocompleteMatchesFromTestData(const T* data,
                                             size_t count,
                                             ACMatches* matches) {
  static_assert(std::is_base_of<AutocompleteMatchTestData, T>::value,
                "T must derive from AutocompleteMatchTestData");
  ASSERT_TRUE(matches != nullptr);
  for (size_t i = 0; i < count; ++i) {
    AutocompleteMatch match;
    match.destination_url = GURL(data[i].destination_url);
    match.relevance =
        matches->empty() ? 1300 : (matches->back().relevance - 100);
    match.allowed_to_be_default_match = true;
    match.type = data[i].type;
    matches->push_back(match);
  }
}

// A simple AutocompleteProvider that does nothing.
class FakeAutocompleteProvider : public AutocompleteProvider {
 public:
  explicit FakeAutocompleteProvider(Type type) : AutocompleteProvider(type) {}

  void Start(const AutocompleteInput& input, bool minimal_changes) override {}

  // For simplicity, |FakeAutocompleteProvider|'s retrieved through
  // |GetProvider| have types 0, 1, ... 5. This is fine for most tests, but for
  // tests where the provider type matters (e.g. tests that involve deduping
  // document suggestions), provider types need to be consistent with
  // |AutocompleteProvider::Type|.
  void SetType(Type type) { type_ = type; }

 private:
  ~FakeAutocompleteProvider() override = default;
};

}  // namespace

class AutocompleteResultTest : public testing::Test {
 public:
  struct TestData {
    // Used to build a url for the AutocompleteMatch. The URL becomes
    // "http://" + ('a' + |url_id|) (e.g. an ID of 2 yields "http://c").
    int url_id;

    // ID of the provider.
    int provider_id;

    // Relevance score.
    int relevance;

    // Allowed to be default match status.
    bool allowed_to_be_default_match;

    // Duplicate matches.
    std::vector<AutocompleteMatch> duplicate_matches;

    // Type of the match
    AutocompleteMatchType::Type type{AutocompleteMatchType::SEARCH_SUGGEST};

    // Suggestion Group ID for this suggestion
    absl::optional<int> suggestion_group_id;

    // Inline autocompletion.
    std::string inline_autocompletion;
  };

  AutocompleteResultTest() {
    variations::testing::ClearAllVariationParams();

    // Create the list of mock providers.  5 is enough.
    for (size_t i = 0; i < 5; ++i) {
      mock_provider_list_.push_back(new FakeAutocompleteProvider(
          static_cast<AutocompleteProvider::Type>(i)));
    }
  }
  AutocompleteResultTest(const AutocompleteResultTest&) = delete;
  AutocompleteResultTest& operator=(const AutocompleteResultTest&) = delete;

  void SetUp() override {
    template_url_service_ = std::make_unique<TemplateURLService>(nullptr, 0);
    template_url_service_->Load();
  }

  void TearDown() override { task_environment_.RunUntilIdle(); }

  // Configures |match| from |data|.
  void PopulateAutocompleteMatch(const TestData& data,
                                 AutocompleteMatch* match);

  // Adds |count| AutocompleteMatches to |matches|.
  void PopulateAutocompleteMatches(const TestData* data,
                                   size_t count,
                                   ACMatches* matches);

  // Asserts that |result| has |expected_count| matches matching |expected|.
  void AssertResultMatches(const AutocompleteResult& result,
                           const TestData* expected,
                           size_t expected_count);

  void AssertMatch(AutocompleteMatch match,
                   const TestData& expected_match_data,
                   int i);

  // Creates an AutocompleteResult from |last| and |current|. The two are
  // merged by |TransferOldMatches| and compared by |AssertResultMatches|.
  void RunTransferOldMatchesTest(const TestData* last,
                                 size_t last_size,
                                 const TestData* current,
                                 size_t current_size,
                                 const TestData* expected,
                                 size_t expected_size);
  void RunTransferOldMatchesTest(const TestData* last,
                                 size_t last_size,
                                 const TestData* current,
                                 size_t current_size,
                                 const TestData* expected,
                                 size_t expected_size,
                                 AutocompleteInput input);

  void SortMatchesAndVerifyOrder(
      const std::string& input_text,
      OmniboxEventProto::PageClassification page_classification,
      const ACMatches& matches,
      const std::vector<size_t>& expected_order,
      const AutocompleteMatchTestData data[]);

  // Returns a (mock) AutocompleteProvider of given |provider_id|.
  FakeAutocompleteProvider* GetProvider(int provider_id) {
    EXPECT_LT(provider_id, static_cast<int>(mock_provider_list_.size()));
    return mock_provider_list_[provider_id].get();
  }

 protected:
  std::unique_ptr<TemplateURLService> template_url_service_;

 private:
  base::test::TaskEnvironment task_environment_;

  // For every provider mentioned in TestData, we need a mock provider.
  std::vector<scoped_refptr<FakeAutocompleteProvider>> mock_provider_list_;
};

void AutocompleteResultTest::PopulateAutocompleteMatch(
    const TestData& data,
    AutocompleteMatch* match) {
  match->provider = GetProvider(data.provider_id);
  match->type = data.type;
  match->fill_into_edit = base::NumberToString16(data.url_id);
  std::string url_id(1, data.url_id + 'a');
  match->destination_url = GURL("http://" + url_id);
  match->relevance = data.relevance;
  match->allowed_to_be_default_match = data.allowed_to_be_default_match;
  match->duplicate_matches = data.duplicate_matches;
  match->suggestion_group_id = data.suggestion_group_id;
  match->inline_autocompletion = base::UTF8ToUTF16(data.inline_autocompletion);
}

void AutocompleteResultTest::PopulateAutocompleteMatches(
    const TestData* data,
    size_t count,
    ACMatches* matches) {
  for (size_t i = 0; i < count; ++i) {
    AutocompleteMatch match;
    PopulateAutocompleteMatch(data[i], &match);
    matches->push_back(match);
  }
}

void AutocompleteResultTest::AssertResultMatches(
    const AutocompleteResult& result,
    const TestData* expected,
    size_t expected_count) {
  ASSERT_EQ(expected_count, result.size());
  for (size_t i = 0; i < expected_count; ++i)
    AssertMatch(*(result.begin() + i), expected[i], i);
}

void AutocompleteResultTest::AssertMatch(AutocompleteMatch match,
                                         const TestData& expected_match_data,
                                         int i) {
  AutocompleteMatch expected_match;
  PopulateAutocompleteMatch(expected_match_data, &expected_match);
  EXPECT_EQ(expected_match.provider, match.provider) << i;
  EXPECT_EQ(expected_match.type, match.type) << i;
  EXPECT_EQ(expected_match.relevance, match.relevance) << i;
  EXPECT_EQ(expected_match.allowed_to_be_default_match,
            match.allowed_to_be_default_match)
      << i;
  EXPECT_EQ(expected_match.destination_url.spec(), match.destination_url.spec())
      << i;
  EXPECT_EQ(expected_match.inline_autocompletion, match.inline_autocompletion)
      << i;
}

void AutocompleteResultTest::RunTransferOldMatchesTest(const TestData* last,
                                                       size_t last_size,
                                                       const TestData* current,
                                                       size_t current_size,
                                                       const TestData* expected,
                                                       size_t expected_size) {
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  RunTransferOldMatchesTest(last, last_size, current, current_size, expected,
                            expected_size, input);
}

void AutocompleteResultTest::RunTransferOldMatchesTest(
    const TestData* last,
    size_t last_size,
    const TestData* current,
    size_t current_size,
    const TestData* expected,
    size_t expected_size,
    AutocompleteInput input) {
  ACMatches last_matches;
  PopulateAutocompleteMatches(last, last_size, &last_matches);
  AutocompleteResult last_result;
  last_result.AppendMatches(input, last_matches);
  last_result.SortAndCull(input, template_url_service_.get());

  ACMatches current_matches;
  PopulateAutocompleteMatches(current, current_size, &current_matches);
  AutocompleteResult current_result;
  current_result.AppendMatches(input, current_matches);
  current_result.SortAndCull(input, template_url_service_.get());
  current_result.TransferOldMatches(input, &last_result,
                                    template_url_service_.get());

  AssertResultMatches(current_result, expected, expected_size);
}

void AutocompleteResultTest::SortMatchesAndVerifyOrder(
    const std::string& input_text,
    OmniboxEventProto::PageClassification page_classification,
    const ACMatches& matches,
    const std::vector<size_t>& expected_order,
    const AutocompleteMatchTestData data[]) {
  AutocompleteInput input(base::ASCIIToUTF16(input_text), page_classification,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  ASSERT_EQ(expected_order.size(), result.size());
  for (size_t i = 0; i < expected_order.size(); ++i) {
    EXPECT_EQ(data[expected_order[i]].destination_url,
              result.match_at(i)->destination_url.spec())
        << "Unexpected item at position " << i;
  }
}

// Assertion testing for AutocompleteResult::Swap.
TEST_F(AutocompleteResultTest, Swap) {
  AutocompleteResult r1;
  AutocompleteResult r2;

  // Swap with empty shouldn't do anything interesting.
  r1.Swap(&r2);
  EXPECT_FALSE(r1.default_match());
  EXPECT_FALSE(r2.default_match());

  // Swap with a single match.
  ACMatches matches;
  AutocompleteMatch match;
  match.relevance = 1;
  match.allowed_to_be_default_match = true;
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  matches.push_back(match);
  r1.AppendMatches(input, matches);
  r1.SortAndCull(input, template_url_service_.get());
  EXPECT_TRUE(r1.default_match());
  EXPECT_EQ(&*r1.begin(), r1.default_match());

  r1.Swap(&r2);
  EXPECT_TRUE(r1.empty());
  EXPECT_FALSE(r1.default_match());
  ASSERT_FALSE(r2.empty());
  EXPECT_TRUE(r2.default_match());
  EXPECT_EQ(&*r2.begin(), r2.default_match());
}

TEST_F(AutocompleteResultTest, AlternateNavUrl) {
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());

  FakeAutocompleteProviderClient client;
  reinterpret_cast<TestingPrefServiceSimple*>(client.GetLocalState())
      ->registry()
      ->RegisterIntegerPref(omnibox::kIntranetRedirectBehavior, 0);

  // Against search matches, we should generate an alternate nav URL.
  {
    AutocompleteMatch match;
    match.type = AutocompleteMatchType::SEARCH_SUGGEST;
    match.destination_url = GURL("http://www.foo.com/s?q=foo");
    GURL alternate_nav_url =
        AutocompleteResult::ComputeAlternateNavUrl(input, match, &client);
    EXPECT_EQ("http://a/", alternate_nav_url.spec());
  }

  // Against matching URL matches, we should NOT generate an alternate nav URL.
  {
    AutocompleteMatch match;
    match.type = AutocompleteMatchType::SEARCH_SUGGEST;
    match.destination_url = GURL("http://a/");
    GURL alternate_nav_url =
        AutocompleteResult::ComputeAlternateNavUrl(input, match, &client);
    EXPECT_FALSE(alternate_nav_url.is_valid());
  }
}

TEST_F(AutocompleteResultTest, AlternateNavUrl_IntranetRedirectPolicy) {
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());

  FakeAutocompleteProviderClient client;
  reinterpret_cast<TestingPrefServiceSimple*>(client.GetLocalState())
      ->registry()
      ->RegisterIntegerPref(omnibox::kIntranetRedirectBehavior, 0);

  // Allow alternate nav URLs when policy allows.
  {
    client.GetLocalState()->SetInteger(
        omnibox::kIntranetRedirectBehavior,
        static_cast<int>(omnibox::IntranetRedirectorBehavior::
                             ENABLE_INTERCEPTION_CHECKS_AND_INFOBARS));

    AutocompleteMatch match;
    match.type = AutocompleteMatchType::SEARCH_SUGGEST;
    match.destination_url = GURL("http://www.foo.com/s?q=foo");
    GURL alternate_nav_url =
        AutocompleteResult::ComputeAlternateNavUrl(input, match, &client);
    EXPECT_EQ("http://a/", alternate_nav_url.spec());
  }

  // Disallow alternate nav URLs when policy disallows.
  {
    client.GetLocalState()->SetInteger(
        omnibox::kIntranetRedirectBehavior,
        static_cast<int>(omnibox::IntranetRedirectorBehavior::DISABLE_FEATURE));

    AutocompleteMatch match;
    match.type = AutocompleteMatchType::SEARCH_SUGGEST;
    match.destination_url = GURL("http://www.foo.com/s?q=foo");
    GURL alternate_nav_url =
        AutocompleteResult::ComputeAlternateNavUrl(input, match, &client);
    EXPECT_FALSE(alternate_nav_url.is_valid());
  }
}

// Tests that if the new results have a lower max relevance score than last,
// any copied results have their relevance shifted down.
TEST_F(AutocompleteResultTest, TransferOldMatches) {
  TestData last[] = {
    { 0, 1, 1000, true },
    { 1, 1, 500,  true },
  };
  TestData current[] = {
    { 2, 1, 400,  true },
  };
  TestData result[] = {
    { 2, 1, 400,  true },
    { 1, 1, 399,  true },
  };

  ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
      last, base::size(last), current, base::size(current), result,
      base::size(result)));
}

// Tests that if the new results have a lower max relevance score than last,
// any copied results have their relevance shifted down when the allowed to
// be default constraint comes into play.
TEST_F(AutocompleteResultTest, TransferOldMatchesAllowedToBeDefault) {
  TestData last[] = {
    { 0, 1, 1300,  true },
    { 1, 1, 1200,  true },
    { 2, 1, 1100,  true },
  };
  TestData current[] = {
    { 3, 1, 1000, false },
    { 4, 1, 900,  true  },
  };
  // The expected results are out of relevance order because the top-scoring
  // allowed to be default match is always pulled to the top.
  TestData result[] = {
    { 4, 1, 900,  true  },
    { 3, 1, 1000, false },
    { 2, 1, 899,  true },
  };

  ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
      last, base::size(last), current, base::size(current), result,
      base::size(result)));
}

// Tests |TransferOldMatches()| with an |AutocompleteInput| with
// |prevent_inline_autocomplete| set to true. Noteworthy, expect that resulting
// matches must have effectively empty autocompletions; i.e. either empty
// |inline_autocompletion|, or false |allowed_to_be_default|. Tests all 12
// combinations of 1) last match has a lower or higher relevance than current
// match, 2) last match was allowed to be default, 3) last match had
// autocompletion (only possible if its allowed to be default), and 4) current
// match is allowed to be default.
TEST_F(AutocompleteResultTest,
       TransferOldMatchesAllowedToBeDefaultWithPreventInlineAutocompletion) {
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  input.set_prevent_inline_autocomplete(true);

  {
    SCOPED_TRACE(
        "Current matches not allowed to be default and scored higher.");
    // 1) |allowed_to_be_default| should be true only for |last| matches without
    // autocompletion.
    // 2) When |allowed_to_be_default| is false, |current| matches should be
    // preferred as they're scored higher.
    // clang-format off
    TestData last[] = {
        {0, 1, 1020, true, {}, AutocompleteMatchType::SEARCH_SUGGEST, {}, "autocompletion"},
        {1, 1, 1010, true},
        {2, 1, 1000, false},
    };
    TestData current[] = {
        {0, 2, 1520, false},
        {1, 2, 1510, false},
        {2, 2, 1500, false},
    };
    TestData result[] = {
        {1, 1, 1510, true},
        {0, 2, 1520, false},
        {2, 1, 1500, true},
    };
    // clang-format on

    ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
        last, base::size(last), current, base::size(current), result,
        base::size(result), input));
  }

  {
    SCOPED_TRACE("Current matches not allowed to be default and scored lower.");
    // Similar to above, except |last| matches should be preferred in deduping
    // as they're scored higher.
    // clang-format off
    TestData last[] = {
        {0, 1, 1020, true, {}, AutocompleteMatchType::SEARCH_SUGGEST, {}, "autocompletion"},
        {1, 1, 1010, true},
        {2, 1, 1000, false},
    };
    TestData current[] = {
        // Need a high-scoring current match to avoid demoting last matches.
        {3, 2, 1500, false},
        {0, 2, 520, false},
        {1, 2, 510, false},
        {2, 2, 500, false},
    };
    TestData result[] = {
        {1, 1, 1010, true},
        {3, 2, 1500, false},
        {0, 1, 1020, false, {}, AutocompleteMatchType::SEARCH_SUGGEST, {}, "autocompletion"},
        {2, 1, 1000, true},
    };
    // clang-format on

    ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
        last, base::size(last), current, base::size(current), result,
        base::size(result), input));
  }

  {
    SCOPED_TRACE("Current matches allowed to be default and scored higher.");
    // Deduping should prefer the |current| matches as they're both allowed to
    // be default and scored higher.
    // clang-format off
    TestData last[] = {
        {0, 1, 1020, true, {}, AutocompleteMatchType::SEARCH_SUGGEST, {}, "autocompletion"},
        {1, 1, 1010, true},
        {2, 1, 1000, false},
    };
    TestData current[] = {
        {0, 2, 1520, true},
        {1, 2, 1510, true},
        {2, 2, 1500, true},
    };
    TestData result[] = {
        {0, 2, 1520, true},
        {1, 2, 1510, true},
        {2, 2, 1500, true},
    };
    // clang-format on

    ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
        last, base::size(last), current, base::size(current), result,
        base::size(result), input));
  }

  {
    SCOPED_TRACE("Current matches allowed to be default and scored lower.");
    // |last| matches with empty autocompletion should be made allowed to be
    // default and preferred in deduping as they're scored higher. Otherwise,
    // |current| matches should be preferred in deduping as they're allowed to
    // be default.
    // clang-format off
    TestData last[] = {
        {0, 1, 1020, true, {}, AutocompleteMatchType::SEARCH_SUGGEST, {}, "autocompletion"},
        {1, 1, 1010, true},
        {2, 1, 1000, false},
    };
    TestData current[] = {
        // Need a high-scoring current match to avoid demoting last matches.
        {3, 2, 1500, true},
        {0, 2, 520, true},
        {1, 2, 510, true},
        {2, 2, 500, true},
    };
    TestData result[] = {
        {3, 2, 1500, true},
        {0, 2, 1020, true},
        {1, 1, 1010, true},
        {2, 1, 1000, true},
    };
    // clang-format on

    ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
        last, base::size(last), current, base::size(current), result,
        base::size(result), input));
  }
}

// Tests that matches are copied correctly from two distinct providers.
TEST_F(AutocompleteResultTest, TransferOldMatchesMultipleProviders) {
  TestData last[] = {
    { 0, 1, 1300, false },
    { 1, 2, 1250, true  },
    { 2, 1, 1200, false },
    { 3, 2, 1150, true  },
    { 4, 1, 1100, false },
  };
  TestData current[] = {
    { 5, 1, 1000, false },
    { 6, 2, 800,  true  },
    { 7, 1, 500,  true  },
  };
  // The expected results are out of relevance order because the top-scoring
  // allowed to be default match is always pulled to the top.
  TestData result[] = {
    { 6, 2, 800,  true  },
    { 5, 1, 1000, false },
    { 3, 2, 799,  true  },
    { 7, 1, 500,  true  },
    { 4, 1, 499,  false  },
  };

  ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
      last, base::size(last), current, base::size(current), result,
      base::size(result)));
}

// Tests that matches are copied correctly from two distinct providers when
// one provider doesn't have a current legal default match.
TEST_F(AutocompleteResultTest,
       TransferOldMatchesWithOneProviderWithoutDefault) {
  TestData last[] = {
    { 0, 2, 1250, true  },
    { 1, 2, 1150, true  },
    { 2, 1, 900,  false },
    { 3, 1, 800,  false },
    { 4, 1, 700,  false },
  };
  TestData current[] = {
    { 5, 1, 1000, true },
    { 6, 2, 800,  false },
    { 7, 1, 500,  true  },
  };
  TestData result[] = {
    { 5, 1, 1000, true  },
    { 1, 2, 999,  true  },
    { 6, 2, 800,  false },
    { 4, 1, 700,  false },
    { 7, 1, 500,  true  },
  };

  ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
      last, base::size(last), current, base::size(current), result,
      base::size(result)));
}

// Tests that transferred matches do not include the specialized match types.
TEST_F(AutocompleteResultTest, TransferOldMatchesSkipsSpecializedSuggestions) {
  TestData last[] = {
      {0, 1, 1000, true, {}, AutocompleteMatchType::TILE_NAVSUGGEST},
      {1, 4, 999, true, {}, AutocompleteMatchType::TILE_SUGGESTION},
      {2, 2, 500, true},
  };
  TestData current[] = {
      {3, 1, 600, true},
  };
  TestData result[] = {
      {3, 1, 600, true},
      {2, 2, 500, true},
  };

  ASSERT_NO_FATAL_FAILURE(RunTransferOldMatchesTest(
      last, base::size(last), current, base::size(current), result,
      base::size(result)));
}

// Tests that matches with empty destination URLs aren't treated as duplicates
// and culled.
TEST_F(AutocompleteResultTest, SortAndCullEmptyDestinationURLs) {
  TestData data[] = {
    { 1, 1, 500,  true },
    { 0, 1, 1100, true },
    { 1, 1, 1000, true },
    { 0, 1, 1300, true },
    { 0, 1, 1200, true },
  };

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  matches[1].destination_url = GURL();
  matches[3].destination_url = GURL();
  matches[4].destination_url = GURL();

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // Of the two results with the same non-empty destination URL, the
  // lower-relevance one should be dropped.  All of the results with empty URLs
  // should be kept.
  ASSERT_EQ(4U, result.size());
  EXPECT_TRUE(result.match_at(0)->destination_url.is_empty());
  EXPECT_EQ(1300, result.match_at(0)->relevance);
  EXPECT_TRUE(result.match_at(1)->destination_url.is_empty());
  EXPECT_EQ(1200, result.match_at(1)->relevance);
  EXPECT_TRUE(result.match_at(2)->destination_url.is_empty());
  EXPECT_EQ(1100, result.match_at(2)->relevance);
  EXPECT_EQ("http://b/", result.match_at(3)->destination_url.spec());
  EXPECT_EQ(1000, result.match_at(3)->relevance);
}

#if !(defined(OS_ANDROID) || defined(OS_IOS))
// Tests which remove results only work on desktop.

TEST_F(AutocompleteResultTest, SortAndCullTailSuggestions) {
  // clang-format off
  TestData data[] = {
      {1, 1, 500,  true},
      {2, 1, 1100, false},
      {3, 1, 1000, false},
      {4, 1, 1300, false},
      {5, 1, 1200, false},
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  // These will get sorted up, but still removed.
  matches[3].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;
  matches[4].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  EXPECT_EQ(3UL, result.size());
  EXPECT_NE(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(0)->type);
  EXPECT_NE(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(1)->type);
  EXPECT_NE(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(2)->type);
}

TEST_F(AutocompleteResultTest, SortAndCullKeepDefaultTailSuggestions) {
  // clang-format off
  TestData data[] = {
      {1, 1, 500,  true},
      {2, 1, 1100, false},
      {3, 1, 1000, false},
      {4, 1, 1300, false},
      {5, 1, 1200, false},
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  // Make sure that even bad tail suggestions, if the only default match,
  // are kept.
  matches[0].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;
  matches[1].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;
  matches[2].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  EXPECT_EQ(3UL, result.size());
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(0)->type);
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(1)->type);
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(2)->type);
}

TEST_F(AutocompleteResultTest, SortAndCullKeepMoreDefaultTailSuggestions) {
  // clang-format off
  TestData data[] = {
      {1, 1, 500,  true},   // Low score non-tail default
      {2, 1, 1100, false},  // Tail
      {3, 1, 1000, true},   // Allow a tail suggestion to be the default.
      {4, 1, 1300, false},  // Tail
      {5, 1, 1200, false},  // Tail
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  // Make sure that even a bad non-tail default suggestion is kept.
  for (size_t i = 1; i < 5; ++i)
    matches[i].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  EXPECT_EQ(5UL, result.size());
  // Non-tail default must be first, regardless of score
  EXPECT_NE(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(0)->type);
  for (size_t i = 1; i < 5; ++i) {
    EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
              result.match_at(i)->type);
    EXPECT_FALSE(result.match_at(i)->allowed_to_be_default_match);
  }
}

TEST_F(AutocompleteResultTest, SortAndCullZeroRelevanceSuggestions) {
  // clang-format off
  TestData data[] = {
      {1, 1, 1000, true},   // A default non-tail suggestion.
      {2, 1, 0,    true},   // A no-relevance default non-tail suggestion.
      {3, 1, 1100, true},   // Default tail
      {4, 1, 1000, false},  // Tail
      {5, 1, 1300, false},  // Tail
      {6, 1, 0,    false},  // No-relevance tail suggestion.
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  for (size_t i = 2; i < base::size(data); ++i)
    matches[i].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  EXPECT_EQ(4UL, result.size());
  EXPECT_NE(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(0)->type);
  EXPECT_TRUE(result.match_at(0)->allowed_to_be_default_match);
  for (size_t i = 1; i < 4; ++i) {
    EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
              result.match_at(i)->type);
    EXPECT_FALSE(result.match_at(i)->allowed_to_be_default_match);
  }
}

TEST_F(AutocompleteResultTest, SortAndCullZeroRelevanceDefaultMatches) {
  // clang-format off
  TestData data[] = {
      {1, 1, 0,    true},   // A zero-relevance default non-tail suggestion.
      {2, 1, 1100, true},   // Default tail
      {3, 1, 1000, false},  // Tail
      {4, 1, 1300, false},  // Tail
      {5, 1, 0,    false},  // No-relevance tail suggestion.
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  for (size_t i = 1; i < base::size(data); ++i)
    matches[i].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // It should ignore the first suggestion, despite it being marked as
  // allowed to be default.
  EXPECT_EQ(3UL, result.size());
  EXPECT_TRUE(result.match_at(0)->allowed_to_be_default_match);
  for (size_t i = 0; i < 3; ++i) {
    EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
              result.match_at(i)->type);
    if (i > 0)
      EXPECT_FALSE(result.match_at(i)->allowed_to_be_default_match);
  }
}

#endif

TEST_F(AutocompleteResultTest, SortAndCullOnlyTailSuggestions) {
  // clang-format off
  TestData data[] = {
      {1, 1, 500,  true},   // Allow a bad non-tail default.
      {2, 1, 1100, false},  // Tail
      {3, 1, 1000, false},  // Tail
      {4, 1, 1300, false},  // Tail
      {5, 1, 1200, false},  // Tail
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  // These will not be removed.
  for (size_t i = 1; i < 5; ++i)
    matches[i].type = AutocompleteMatchType::SEARCH_SUGGEST_TAIL;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  EXPECT_EQ(5UL, result.size());
  EXPECT_NE(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
            result.match_at(0)->type);
  for (size_t i = 1; i < 5; ++i)
    EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
              result.match_at(i)->type);
}

TEST_F(AutocompleteResultTest, SortAndCullNoMatchesAllowedToBeDefault) {
  // clang-format off
  TestData data[] = {
      {1, 1, 500,  false},  // Not allowed_to_be_default_match
      {2, 1, 1100, false},  // Not allowed_to_be_default_match
      {3, 1, 1000, false},  // Not allowed_to_be_default_match
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);

  AutocompleteInput input(std::u16string(), metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  EXPECT_EQ(3UL, result.size());
  EXPECT_EQ(matches[1].destination_url, result.match_at(0)->destination_url);
  EXPECT_EQ(matches[2].destination_url, result.match_at(1)->destination_url);
  EXPECT_EQ(matches[0].destination_url, result.match_at(2)->destination_url);
  for (size_t i = 0; i < 3; ++i)
    EXPECT_FALSE(result.match_at(i)->allowed_to_be_default_match);
}

TEST_F(AutocompleteResultTest, SortAndCullDuplicateSearchURLs) {
  // Register a template URL that corresponds to 'foo' search engine.
  TemplateURLData url_data;
  url_data.SetShortName(u"unittest");
  url_data.SetKeyword(u"foo");
  url_data.SetURL("http://www.foo.com/s?q={searchTerms}");
  template_url_service_->Add(std::make_unique<TemplateURL>(url_data));

  TestData data[] = {
    { 0, 1, 1300, true },
    { 1, 1, 1200, true },
    { 2, 1, 1100, true },
    { 3, 1, 1000, true },
    { 4, 2, 900,  true },
  };

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  matches[0].destination_url = GURL("http://www.foo.com/s?q=foo");
  matches[1].destination_url = GURL("http://www.foo.com/s?q=foo2");
  matches[2].destination_url = GURL("http://www.foo.com/s?q=foo&oq=f");
  matches[3].destination_url = GURL("http://www.foo.com/s?q=foo&aqs=0");
  matches[4].destination_url = GURL("http://www.foo.com/");

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // We expect the 3rd and 4th results to be removed.
  ASSERT_EQ(3U, result.size());
  EXPECT_EQ("http://www.foo.com/s?q=foo",
            result.match_at(0)->destination_url.spec());
  EXPECT_EQ(1300, result.match_at(0)->relevance);
  EXPECT_EQ("http://www.foo.com/s?q=foo2",
            result.match_at(1)->destination_url.spec());
  EXPECT_EQ(1200, result.match_at(1)->relevance);
  EXPECT_EQ("http://www.foo.com/",
            result.match_at(2)->destination_url.spec());
  EXPECT_EQ(900, result.match_at(2)->relevance);
}

TEST_F(AutocompleteResultTest, SortAndCullWithMatchDups) {
  // Register a template URL that corresponds to 'foo' search engine.
  TemplateURLData url_data;
  url_data.SetShortName(u"unittest");
  url_data.SetKeyword(u"foo");
  url_data.SetURL("http://www.foo.com/s?q={searchTerms}");
  template_url_service_->Add(std::make_unique<TemplateURL>(url_data));

  AutocompleteMatch dup_match;
  dup_match.destination_url = GURL("http://www.foo.com/s?q=foo&oq=dup");
  std::vector<AutocompleteMatch> dups;
  dups.push_back(dup_match);

  TestData data[] = {
    { 0, 1, 1300, true, dups },
    { 1, 1, 1200, true  },
    { 2, 1, 1100, true  },
    { 3, 1, 1000, true, dups },
    { 4, 2, 900,  true  },
    { 5, 1, 800,  true  },
  };

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  matches[0].destination_url = GURL("http://www.foo.com/s?q=foo");
  matches[1].destination_url = GURL("http://www.foo.com/s?q=foo2");
  matches[2].destination_url = GURL("http://www.foo.com/s?q=foo&oq=f");
  matches[3].destination_url = GURL("http://www.foo.com/s?q=foo&aqs=0");
  matches[4].destination_url = GURL("http://www.foo.com/");
  matches[5].destination_url = GURL("http://www.foo.com/s?q=foo2&oq=f");

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // Expect 3 unique results after SortAndCull().
  ASSERT_EQ(3U, result.size());

  // Check that 3rd and 4th result got added to the first result as duplicates
  // and also duplicates of the 4th match got copied.
  ASSERT_EQ(4U, result.match_at(0)->duplicate_matches.size());
  const AutocompleteMatch* first_match = result.match_at(0);
  EXPECT_EQ(matches[2].destination_url,
            first_match->duplicate_matches.at(1).destination_url);
  EXPECT_EQ(matches[3].destination_url,
            first_match->duplicate_matches.at(2).destination_url);
  EXPECT_EQ(dup_match.destination_url,
            first_match->duplicate_matches.at(3).destination_url);

  // Check that 6th result started a new list of dups for the second result.
  ASSERT_EQ(1U, result.match_at(1)->duplicate_matches.size());
  EXPECT_EQ(matches[5].destination_url,
            result.match_at(1)->duplicate_matches.at(0).destination_url);
}

TEST_F(AutocompleteResultTest, SortAndCullWithDemotionsByType) {
  // Add some matches.
  ACMatches matches;
  const AutocompleteMatchTestData data[] = {
    { "http://history-url/", AutocompleteMatchType::HISTORY_URL },
    { "http://search-what-you-typed/",
      AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED },
    { "http://history-title/", AutocompleteMatchType::HISTORY_TITLE },
    { "http://search-history/", AutocompleteMatchType::SEARCH_HISTORY },
  };
  PopulateAutocompleteMatchesFromTestData(data, base::size(data), &matches);

  // Demote the search history match relevance score.
  matches.back().relevance = 500;

  // Add a rule demoting history-url and killing history-title.
  {
    std::map<std::string, std::string> params;
    params[std::string(OmniboxFieldTrial::kDemoteByTypeRule) + ":3:*"] =
        "1:50,7:100,2:0";  // 3 == HOME_PAGE
    ASSERT_TRUE(variations::AssociateVariationParams(
        OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A", params));
  }
  base::FieldTrialList::CreateFieldTrial(
      OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A");

  AutocompleteInput input(u"a", OmniboxEventProto::HOME_PAGE,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // Check the new ordering.  The history-title results should be omitted.
  // HistoryURL should still be first because type demotion is not applied to
  // the top match.
  size_t expected_order[] = {0, 1, 3};

  ASSERT_EQ(base::size(expected_order), result.size());
  for (size_t i = 0; i < base::size(expected_order); ++i) {
    EXPECT_EQ(data[expected_order[i]].destination_url,
              result.match_at(i)->destination_url.spec());
  }
}

// Test SortAndCull promoting a lower-scoring match to keep the default match
// stable during the asynchronous pass.
TEST_F(AutocompleteResultTest, SortAndCullWithPreserveDefaultMatch) {
  TestData last[] = {
      {0, 1, 500, true},
      {1, 1, 400, true},
  };
  // Same as |last|, but with the scores swapped.
  TestData current[] = {
      {1, 1, 500, true},
      {0, 1, 400, true},
  };

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());

  ACMatches last_matches;
  PopulateAutocompleteMatches(last, base::size(last), &last_matches);
  AutocompleteResult last_result;
  last_result.AppendMatches(input, last_matches);
  last_result.SortAndCull(input, template_url_service_.get());

  ACMatches current_matches;
  PopulateAutocompleteMatches(current, base::size(current), &current_matches);
  AutocompleteResult current_result;
  current_result.AppendMatches(input, current_matches);

  // Run SortAndCull, but try to keep the first entry of last_matches on top.
  current_result.SortAndCull(input, template_url_service_.get(),
                             last_result.match_at(0));

  // Assert that the lower scoring match has been promoted to the top to keep
  // the default match stable.
  TestData result[] = {
      {0, 1, 400, true},
      {1, 1, 500, true},
  };
  AssertResultMatches(current_result, result, base::size(result));
}

// Verify metrics logged for asynchronous result updates.
TEST_F(AutocompleteResultTest, LogAsynchronousUpdateMetrics) {
  TestData last[] = {
      {0, 1, 600, true}, {1, 1, 500, true}, {2, 1, 400, true},
      {3, 1, 300, true}, {4, 1, 200, true},
  };
  // Same as |last|, but with these changes:
  //  - Last two matches removed.
  //  - Default match updated to a new URL.
  //  - Third match updated to a new URL.
  TestData current[] = {
      {10, 1, 400, true},
      {1, 1, 300, true},
      {11, 1, 200, true},
  };

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());

  ACMatches last_matches;
  PopulateAutocompleteMatches(last, base::size(last), &last_matches);
  AutocompleteResult last_result;
  last_result.AppendMatches(input, last_matches);
  for (auto& match : last_result)
    match.ComputeStrippedDestinationURL(input, template_url_service_.get());
  const auto last_comparators = last_result.GetMatchDedupComparators();

  ACMatches current_matches;
  PopulateAutocompleteMatches(current, base::size(current), &current_matches);
  AutocompleteResult current_result;
  current_result.AppendMatches(input, current_matches);
  for (auto& match : current_result)
    match.ComputeStrippedDestinationURL(input, template_url_service_.get());

  // Constructor takes the snapshot of the current histogram state.
  base::HistogramTester histograms;

  // Do the logging.
  AutocompleteResult::LogAsynchronousUpdateMetrics(last_comparators,
                                                   current_result);

  // Expect the default match, third match, and last two matches to be logged
  // as changed, and nothing else.
  EXPECT_THAT(
      histograms.GetAllSamples("Omnibox.MatchStability.AsyncMatchChange2"),
      testing::ElementsAre(base::Bucket(0, 1), base::Bucket(2, 1),
                           base::Bucket(3, 1), base::Bucket(4, 1)));

  // Expect that we log that at least one of the matches has changed.
  EXPECT_THAT(histograms.GetAllSamples(
                  "Omnibox.MatchStability.AsyncMatchChangedInAnyPosition"),
              testing::ElementsAre(base::Bucket(1, 1)));
}

TEST_F(AutocompleteResultTest, DemoteOnDeviceSearchSuggestions) {
  // clang-format off
  TestData data[] = {
      {1, 1, 500,  true},
      {2, 2, 1100, true},
      {3, 2, 1000, true},
      {4, 1, 1300, true},
      {5, 1, 1200, true},
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  matches[0].type = AutocompleteMatchType::SEARCH_SUGGEST;
  matches[1].type = AutocompleteMatchType::SEARCH_SUGGEST;
  matches[2].type = AutocompleteMatchType::SEARCH_SUGGEST;
  matches[3].type = AutocompleteMatchType::SEARCH_SUGGEST;
  matches[4].type = AutocompleteMatchType::SEARCH_SUGGEST;

  // match1, match2 are set as on device head suggestion.
  matches[1].subtypes = {64, 271, 123};
  matches[2].subtypes = {64, 124, 271};
  matches[0].provider->type_ = AutocompleteProvider::TYPE_SEARCH;
  matches[1].provider->type_ = AutocompleteProvider::TYPE_ON_DEVICE_HEAD;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());

  // Test setting on device suggestion relevances to 0.
  {
    base::test::ScopedFeatureList feature_list;
    feature_list.InitAndEnableFeatureWithParameters(
        omnibox::kOnDeviceHeadProviderNonIncognito,
        {{"DemoteOnDeviceSearchSuggestionsMode", "remove-suggestions"}});
    AutocompleteResult result;
    result.AppendMatches(input, matches);
    result.DemoteOnDeviceSearchSuggestions();
    EXPECT_EQ(5UL, result.size());
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(0)->provider->type());
    EXPECT_EQ(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(1)->provider->type());
    EXPECT_EQ(0, result.match_at(1)->relevance);
    EXPECT_EQ(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(2)->provider->type());
    EXPECT_EQ(0, result.match_at(2)->relevance);
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(3)->provider->type());
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(4)->provider->type());
  }

  // Test setting on device suggestion relevances lower than search provider
  // suggestions.
  {
    base::test::ScopedFeatureList feature_list;
    feature_list.InitAndEnableFeatureWithParameters(
        omnibox::kOnDeviceHeadProviderNonIncognito,
        {{"DemoteOnDeviceSearchSuggestionsMode", "decrease-relevances"}});
    AutocompleteResult result;
    result.AppendMatches(input, matches);
    result.DemoteOnDeviceSearchSuggestions();
    EXPECT_EQ(5UL, result.size());
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(0)->provider->type());
    EXPECT_EQ(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(1)->provider->type());
    EXPECT_LT(result.match_at(1)->relevance, result.match_at(0)->relevance);
    EXPECT_EQ(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(2)->provider->type());
    EXPECT_LT(result.match_at(2)->relevance, result.match_at(0)->relevance);
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(3)->provider->type());
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(4)->provider->type());
  }

  // Test no demotion should happen if search provider only returns trivial
  // autocompletion, e.g. SEARCH_WHAT_YOU_TYPED or SEARCH_OTHER_ENGINE.
  {
    base::test::ScopedFeatureList feature_list;
    feature_list.InitAndEnableFeatureWithParameters(
        omnibox::kOnDeviceHeadProviderNonIncognito,
        {{"DemoteOnDeviceSearchSuggestionsMode", "remove-suggestions"}});

    matches[0].type = AutocompleteMatchType::SEARCH_OTHER_ENGINE;
    matches[3].type = AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED;
    matches[4].type = AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED;

    AutocompleteResult result;
    result.AppendMatches(input, matches);
    result.DemoteOnDeviceSearchSuggestions();
    EXPECT_EQ(5UL, result.size());
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(0)->provider->type());
    EXPECT_EQ(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(1)->provider->type());
    EXPECT_EQ(1100, result.match_at(1)->relevance);
    EXPECT_EQ(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(2)->provider->type());
    EXPECT_EQ(1000, result.match_at(2)->relevance);
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(3)->provider->type());
    EXPECT_NE(AutocompleteProvider::TYPE_ON_DEVICE_HEAD,
              result.match_at(4)->provider->type());
  }
}

TEST_F(AutocompleteResultTest, DemoteByType) {
  // Add some matches.
  ACMatches matches;
  const AutocompleteMatchTestData data[] = {
      {"http://history-url/", AutocompleteMatchType::HISTORY_URL},
      {"http://history-title/", AutocompleteMatchType::HISTORY_TITLE},
      {"http://search-what-you-typed/",
       AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED},
      {"http://search-history/", AutocompleteMatchType::SEARCH_HISTORY},
  };
  PopulateAutocompleteMatchesFromTestData(data, base::size(data), &matches);

  // Make history-title and search-history the only default matches, so that
  // they compete.
  matches[0].allowed_to_be_default_match = false;
  matches[2].allowed_to_be_default_match = false;

  // Add a rule demoting history-title.
  {
    std::map<std::string, std::string> params;
    params[std::string(OmniboxFieldTrial::kDemoteByTypeRule) + ":*:*"] = "2:50";
    ASSERT_TRUE(variations::AssociateVariationParams(
        OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A", params));
  }
  base::FieldTrialList::CreateFieldTrial(
      OmniboxFieldTrial::kBundledExperimentFieldTrialName, "A");

  // Where Grouping suggestions by Search vs URL kicks in, search gets
  // promoted to the top of the list.
  const std::vector<size_t> expected_natural_order{1, 2, 3, 0};
  const std::vector<size_t> expected_demoted_order{3, 2, 0, 1};

  // Because we want to ensure the highest naturally scoring
  // allowed-to-be default suggestion is the default, make sure history-title
  // is the default match despite demotion.
  // Make sure history-URL is the last match due to the logic which groups
  // searches and URLs together.
  SortMatchesAndVerifyOrder("a", OmniboxEventProto::HOME_PAGE, matches,
                            expected_natural_order, data);

  // However, in the fakebox/realbox, we do want to use the demoted score when
  // selecting the default match because we generally only expect it to be
  // used for queries and we demote URLs strongly. So here we re-sort with a
  // page classification of fakebox/realbox, and make sure history-title is now
  // demoted. We also make sure history-URL is the last match due to the logic
  // which groups searches and URLs together.
  SortMatchesAndVerifyOrder(
      "a", OmniboxEventProto::INSTANT_NTP_WITH_FAKEBOX_AS_STARTING_FOCUS,
      matches, expected_demoted_order, data);
  SortMatchesAndVerifyOrder("a", OmniboxEventProto::NTP_REALBOX, matches,
                            expected_demoted_order, data);

  // Unless, the user's input looks like a URL, in which case we want to use
  // the natural scoring again to make sure the user gets a URL if they're
  // clearly trying to navigate. So here we re-sort with a page classification
  // of fakebox/realbox and an input that's a URL, and make sure history-title
  // is once again the default match.
  SortMatchesAndVerifyOrder(
      "www.example.com",
      OmniboxEventProto::INSTANT_NTP_WITH_FAKEBOX_AS_STARTING_FOCUS, matches,
      expected_natural_order, data);
  SortMatchesAndVerifyOrder("www.example.com", OmniboxEventProto::NTP_REALBOX,
                            matches, expected_natural_order, data);
}

TEST_F(AutocompleteResultTest, SortAndCullReorderForDefaultMatch) {
  TestData data[] = {
    { 0, 1, 1300, true },
    { 1, 1, 1200, true },
    { 2, 1, 1100, true },
    { 3, 1, 1000, true }
  };
  TestSchemeClassifier test_scheme_classifier;

  {
    // Check that reorder doesn't do anything if the top result
    // is already a legal default match (which is the default from
    // PopulateAutocompleteMatches()).
    ACMatches matches;
    PopulateAutocompleteMatches(data, base::size(data), &matches);
    AutocompleteInput input(u"a", metrics::OmniboxEventProto::HOME_PAGE,
                            test_scheme_classifier);
    AutocompleteResult result;
    result.AppendMatches(input, matches);
    result.SortAndCull(input, template_url_service_.get());
    AssertResultMatches(result, data, 4);
  }

  {
    // Check that reorder swaps up a result appropriately.
    ACMatches matches;
    PopulateAutocompleteMatches(data, base::size(data), &matches);
    matches[0].allowed_to_be_default_match = false;
    matches[1].allowed_to_be_default_match = false;
    AutocompleteInput input(u"a", metrics::OmniboxEventProto::HOME_PAGE,
                            test_scheme_classifier);
    AutocompleteResult result;
    result.AppendMatches(input, matches);
    result.SortAndCull(input, template_url_service_.get());
    ASSERT_EQ(4U, result.size());
    EXPECT_EQ("http://c/", result.match_at(0)->destination_url.spec());
    EXPECT_EQ("http://a/", result.match_at(1)->destination_url.spec());
    EXPECT_EQ("http://b/", result.match_at(2)->destination_url.spec());
    EXPECT_EQ("http://d/", result.match_at(3)->destination_url.spec());
  }
}

TEST_F(AutocompleteResultTest, SortAndCullPromoteDefaultMatch) {
  TestData data[] = {
    { 0, 1, 1300, false },
    { 1, 1, 1200, false },
    { 2, 2, 1100, false },
    { 2, 3, 1000, false },
    { 2, 4, 900, true }
  };
  TestSchemeClassifier test_scheme_classifier;

  // Check that reorder swaps up a result, and promotes relevance,
  // appropriately.
  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::HOME_PAGE,
                          test_scheme_classifier);
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());
  ASSERT_EQ(3U, result.size());
  EXPECT_EQ("http://c/", result.match_at(0)->destination_url.spec());
  EXPECT_EQ(1100, result.match_at(0)->relevance);
  EXPECT_TRUE(result.match_at(0)->allowed_to_be_default_match);
  EXPECT_EQ(GetProvider(4), result.match_at(0)->provider);
  EXPECT_EQ("http://a/", result.match_at(1)->destination_url.spec());
  EXPECT_FALSE(result.match_at(1)->allowed_to_be_default_match);
  EXPECT_EQ("http://b/", result.match_at(2)->destination_url.spec());
  EXPECT_FALSE(result.match_at(2)->allowed_to_be_default_match);
}

TEST_F(AutocompleteResultTest, SortAndCullPromoteUnconsecutiveMatches) {
  TestData data[] = {
    { 0, 1, 1300, false },
    { 1, 1, 1200, true },
    { 3, 2, 1100, false },
    { 2, 1, 1000, false },
    { 3, 3, 900, true },
    { 4, 1, 800, false },
    { 3, 4, 700, false },
  };
  TestSchemeClassifier test_scheme_classifier;

  // Check that reorder swaps up a result, and promotes relevance,
  // even for a default match that isn't the best.
  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::HOME_PAGE,
                          test_scheme_classifier);
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());
  ASSERT_EQ(5U, result.size());
  EXPECT_EQ("http://b/", result.match_at(0)->destination_url.spec());
  EXPECT_EQ(1200, result.match_at(0)->relevance);
  EXPECT_EQ("http://a/", result.match_at(1)->destination_url.spec());
  EXPECT_EQ("http://d/", result.match_at(2)->destination_url.spec());
  EXPECT_EQ(1100, result.match_at(2)->relevance);
  EXPECT_EQ(GetProvider(3), result.match_at(2)->provider);
  EXPECT_EQ("http://c/", result.match_at(3)->destination_url.spec());
  EXPECT_EQ("http://e/", result.match_at(4)->destination_url.spec());
}

struct EntityTestData {
  AutocompleteMatchType::Type type;
  FakeAutocompleteProvider* provider;
  std::string destination_url;
  int relevance;
  bool allowed_to_be_default_match;
  std::string fill_into_edit;
  std::string inline_autocompletion;
};

void PopulateEntityTestCases(std::vector<EntityTestData>& test_cases,
                             ACMatches* matches) {
  for (const auto& test_case : test_cases) {
    AutocompleteMatch match;
    match.provider = test_case.provider;
    match.type = test_case.type;
    match.destination_url = GURL(test_case.destination_url);
    match.relevance = test_case.relevance;
    match.allowed_to_be_default_match = test_case.allowed_to_be_default_match;
    match.fill_into_edit = base::UTF8ToUTF16(test_case.fill_into_edit);
    match.inline_autocompletion =
        base::UTF8ToUTF16(test_case.inline_autocompletion);
    matches->push_back(match);
  }
}

TEST_F(AutocompleteResultTest, SortAndCullPreferEntities) {
  // clang-format off
  std::vector<EntityTestData> test_cases = {
    {
      AutocompleteMatchType::SEARCH_SUGGEST, GetProvider(1),
      "http://search/?q=foo", 1100, false, "foo", ""
    },
    {
      AutocompleteMatchType::SEARCH_SUGGEST_ENTITY, GetProvider(1),
      "http://search/?q=foo", 1000, false, "foo", ""
    },
    {
      AutocompleteMatchType::SEARCH_SUGGEST, GetProvider(1),
      "http://search/?q=foo", 900, true, "foo", "oo"
    },
    // This match will be the first result but it won't affect the entity
    // deduping because it has a different URL.
    //
    // Also keeping this as the default match allows us to test that Entities
    // and plain matches are deduplicated when they are not the default match.
    // See SortAndCullPreferEntitiesButKeepDefaultPlainMatches for details.
    {
      AutocompleteMatchType::SEARCH_SUGGEST_PERSONALIZED, GetProvider(1),
      "http://search/?q=bar", 1200, true, "foo", "oo"
    },
  };
  // clang-format on
  ACMatches matches;
  PopulateEntityTestCases(test_cases, &matches);

  AutocompleteInput input(u"f", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // The first result will be the personalized suggestion.
  EXPECT_EQ(2UL, result.size());
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_PERSONALIZED,
            result.match_at(0)->type);
  EXPECT_EQ(1200, result.match_at(0)->relevance);

  // The second result will be the result of deduping the other three.
  // The chosen match should be the entity suggestion and it should have been
  // promoted to receive the first match's relevance and the last match's
  // allowed_to_be_default_match and inline_autocompletion values.
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_ENTITY,
            result.match_at(1)->type);
  EXPECT_EQ(1100, result.match_at(1)->relevance);
  EXPECT_TRUE(result.match_at(1)->allowed_to_be_default_match);
  EXPECT_EQ(u"oo", result.match_at(1)->inline_autocompletion);
}

TEST_F(AutocompleteResultTest, SortAndCullPreferEntitiesFillIntoEditMustMatch) {
  // clang-format off
  std::vector<EntityTestData> test_cases = {
    {
      AutocompleteMatchType::SEARCH_SUGGEST_PERSONALIZED, GetProvider(1),
      "http://search/?q=foo", 1100, false, "foo", ""
    },
    {
      AutocompleteMatchType::SEARCH_SUGGEST_ENTITY, GetProvider(1),
      "http://search/?q=foo", 1000, false, "foobar", ""
    },
    {
      AutocompleteMatchType::SEARCH_SUGGEST, GetProvider(1),
      "http://search/?q=foo", 900, true, "foo", "oo"
    },
  };
  // clang-format on
  ACMatches matches;
  PopulateEntityTestCases(test_cases, &matches);

  AutocompleteInput input(u"f", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // The entity suggestion won't be chosen in this case because it has a non-
  // matching value for fill_into_edit.
  EXPECT_EQ(1UL, result.size());
  // But the final type will have the specialized Search History type, since
  // that's consumed into the final match during the merge step.
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_PERSONALIZED,
            result.match_at(0)->type);
  EXPECT_EQ(1100, result.match_at(0)->relevance);
  EXPECT_TRUE(result.match_at(0)->allowed_to_be_default_match);
  EXPECT_EQ(u"oo", result.match_at(0)->inline_autocompletion);
}

TEST_F(AutocompleteResultTest,
       SortAndCullPreferEntitiesButKeepDefaultPlainMatches) {
  // clang-format off
  std::vector<EntityTestData> test_cases = {
    {
      AutocompleteMatchType::SEARCH_SUGGEST, GetProvider(1),
      "http://search/?q=foo", 1001, true, "foo", ""
    },
    {
      AutocompleteMatchType::SEARCH_SUGGEST_ENTITY, GetProvider(1),
      "http://search/?q=foo", 1000, false, "foo", ""
    },
    {
      AutocompleteMatchType::SEARCH_SUGGEST, GetProvider(1),
      "http://search/?q=foo", 900, true, "foo", "oo"
    },
  };
  // clang-format on
  ACMatches matches;
  PopulateEntityTestCases(test_cases, &matches);

  AutocompleteInput input(u"f", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // The first result will be a plain match.
  EXPECT_EQ(2UL, result.size());
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST, result.match_at(0)->type);
  EXPECT_EQ(1001, result.match_at(0)->relevance);

  // The second result will be the result of deduping the Suggest Entity with
  // the third result. It should have still consumed the inline autocomplete
  // and allowed_to_be_default qualities from the other two.
  EXPECT_EQ(AutocompleteMatchType::SEARCH_SUGGEST_ENTITY,
            result.match_at(1)->type);
  EXPECT_EQ(1001, result.match_at(1)->relevance);
  EXPECT_TRUE(result.match_at(1)->allowed_to_be_default_match);
  EXPECT_EQ(u"oo", result.match_at(1)->inline_autocompletion);
}

TEST_F(AutocompleteResultTest, SortAndCullPromoteDuplicateSearchURLs) {
  // Register a template URL that corresponds to 'foo' search engine.
  TemplateURLData url_data;
  url_data.SetShortName(u"unittest");
  url_data.SetKeyword(u"foo");
  url_data.SetURL("http://www.foo.com/s?q={searchTerms}");
  template_url_service_->Add(std::make_unique<TemplateURL>(url_data));

  TestData data[] = {
    { 0, 1, 1300, false },
    { 1, 1, 1200, true },
    { 2, 1, 1100, true },
    { 3, 1, 1000, true },
    { 4, 2, 900,  true },
  };

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  // Note that 0, 2 and 3 will compare equal after stripping.
  matches[0].destination_url = GURL("http://www.foo.com/s?q=foo");
  matches[1].destination_url = GURL("http://www.foo.com/s?q=foo2");
  matches[2].destination_url = GURL("http://www.foo.com/s?q=foo&oq=f");
  matches[3].destination_url = GURL("http://www.foo.com/s?q=foo&aqs=0");
  matches[4].destination_url = GURL("http://www.foo.com/");

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // We expect the 3rd and 4th results to be removed.
  ASSERT_EQ(3U, result.size());
  EXPECT_EQ("http://www.foo.com/s?q=foo&oq=f",
            result.match_at(0)->destination_url.spec());
  EXPECT_EQ(1300, result.match_at(0)->relevance);
  EXPECT_EQ("http://www.foo.com/s?q=foo2",
            result.match_at(1)->destination_url.spec());
  EXPECT_EQ(1200, result.match_at(1)->relevance);
  EXPECT_EQ("http://www.foo.com/",
            result.match_at(2)->destination_url.spec());
  EXPECT_EQ(900, result.match_at(2)->relevance);
}

#if !defined(OS_ANDROID)
TEST_F(AutocompleteResultTest, SortAndCullGroupSuggestionsByType) {
  base::test::ScopedFeatureList feature_list;
  feature_list.InitWithFeaturesAndParameters(
      {{omnibox::kUIExperimentMaxAutocompleteMatches,
        {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}}},
      {/* nothing disabled */});
  TestData data[] = {
      {0, 1, 500, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
      {1, 2, 600, false, {}, AutocompleteMatchType::HISTORY_URL},
      {2, 1, 700, false, {}, AutocompleteMatchType::SEARCH_HISTORY},
      {3, 2, 800, true, {}, AutocompleteMatchType::HISTORY_TITLE},
      {4, 1, 900, false, {}, AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED},
      {5, 2, 1000, false, {}, AutocompleteMatchType::HISTORY_BODY},
      {6, 3, 1100, false, {}, AutocompleteMatchType::BOOKMARK_TITLE},
  };
  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  TestData expected_data[] = {
      // default match unmoved
      {3, 2, 800, true, {}, AutocompleteMatchType::HISTORY_TITLE},
      // search types
      {4, 1, 900, false, {}, AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED},
      {2, 1, 700, false, {}, AutocompleteMatchType::SEARCH_HISTORY},
      // other types
      {6, 3, 1100, false, {}, AutocompleteMatchType::BOOKMARK_TITLE},
      {5, 2, 1000, false, {}, AutocompleteMatchType::HISTORY_BODY},
      {1, 2, 600, false, {}, AutocompleteMatchType::HISTORY_URL},
  };

  AssertResultMatches(result, expected_data,
                      AutocompleteResult::GetMaxMatches());
}
#endif

TEST_F(AutocompleteResultTest, SortAndCullKeepGroupedSuggestionsLast) {
  base::test::ScopedFeatureList feature_list;
  feature_list.InitWithFeaturesAndParameters(
      {{omnibox::kUIExperimentMaxAutocompleteMatches,
        {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}}},
      {/* nothing disabled */});
  TestData data[] = {
      {0, 1, 500, false, {}, AutocompleteMatchType::SEARCH_SUGGEST, 1},
      {1, 2, 600, false, {}, AutocompleteMatchType::HISTORY_URL},
      {2, 1, 700, false, {}, AutocompleteMatchType::SEARCH_SUGGEST, 1},
      {3, 2, 800, true, {}, AutocompleteMatchType::HISTORY_TITLE},
      {4, 1, 900, false, {}, AutocompleteMatchType::SEARCH_SUGGEST, 2},
      {5, 2, 1000, false, {}, AutocompleteMatchType::SEARCH_SUGGEST, 2},
      {6, 3, 1100, false, {}, AutocompleteMatchType::BOOKMARK_TITLE},
  };
  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;

  SearchSuggestionParser::HeadersMap headers_map;
  headers_map[1] = u"1";
  headers_map[2] = u"2";
  result.MergeHeadersMap(headers_map);

  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  TestData expected_data[] = {
      // default match unmoved
      {3, 2, 800, true, {}, AutocompleteMatchType::HISTORY_TITLE},
      // search types
      {6, 3, 1100, false, {}, AutocompleteMatchType::BOOKMARK_TITLE},
      {1, 2, 600, false, {}, AutocompleteMatchType::HISTORY_URL},
      // Group <2> is scored higher
      {5, 2, 1000, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
      {4, 1, 900, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
      // Group <1> is scored lower
      {2, 1, 700, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
  };

  AssertResultMatches(result, expected_data,
                      AutocompleteResult::GetMaxMatches());
}

TEST_F(AutocompleteResultTest,
       GroupSuggestionsBySearchVsURLHonorsProtectedSuggestions) {
  base::test::ScopedFeatureList feature_list;
  feature_list.InitWithFeaturesAndParameters(
      {{omnibox::kUIExperimentMaxAutocompleteMatches,
        {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "7"}}}},
      {/* nothing disabled */});
  TestData data[] = {
      {0, 2, 400, true, {}, AutocompleteMatchType::HISTORY_TITLE},
      {1, 1, 800, false, {}, AutocompleteMatchType::CLIPBOARD_URL},
      {2, 1, 700, false, {}, AutocompleteMatchType::TILE_NAVSUGGEST},
      {3, 1, 600, false, {}, AutocompleteMatchType::TILE_SUGGESTION},
      {4, 1, 1000, false, {}, AutocompleteMatchType::HISTORY_URL},
      {5, 1, 900, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
      {6, 1, 800, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
  };

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.GroupSuggestionsBySearchVsURL(std::next(result.matches_.begin()),
                                       result.matches_.end());

  TestData expected_data[] = {
      {0, 2, 400, true, {}, AutocompleteMatchType::HISTORY_TITLE},
      {1, 1, 800, false, {}, AutocompleteMatchType::CLIPBOARD_URL},
      {2, 1, 700, false, {}, AutocompleteMatchType::TILE_NAVSUGGEST},
      {3, 1, 600, false, {}, AutocompleteMatchType::TILE_SUGGESTION},
      {5, 1, 900, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
      {6, 1, 800, false, {}, AutocompleteMatchType::SEARCH_SUGGEST},
      {4, 1, 1000, false, {}, AutocompleteMatchType::HISTORY_URL},
  };

  AssertResultMatches(result, expected_data,
                      AutocompleteResult::GetMaxMatches());
}

TEST_F(AutocompleteResultTest, SortAndCullMaxURLMatches) {
  base::test::ScopedFeatureList feature_list;
  feature_list.InitWithFeaturesAndParameters(
      {{omnibox::kUIExperimentMaxAutocompleteMatches,
        {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, "6"}}},
       {omnibox::kOmniboxMaxURLMatches,
        {{OmniboxFieldTrial::kOmniboxMaxURLMatchesParam, "3"}}}},
      {});

  EXPECT_TRUE(OmniboxFieldTrial::IsMaxURLMatchesFeatureEnabled());
  EXPECT_EQ(OmniboxFieldTrial::GetMaxURLMatches(), 3u);

  // Case 1: Eject URL match for a search.
  {
    ACMatches matches;
    const AutocompleteMatchTestData data[] = {
        {"http://search-what-you-typed/",
         AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED},
        {"http://search-history/", AutocompleteMatchType::SEARCH_HISTORY},
        {"http://history-url/", AutocompleteMatchType::HISTORY_URL},
        {"http://history-title/", AutocompleteMatchType::HISTORY_TITLE},
        {"http://url-what-you-typed/",
         AutocompleteMatchType::URL_WHAT_YOU_TYPED},
        {"http://clipboard-url/", AutocompleteMatchType::CLIPBOARD_URL},
        {"http://search-suggest/", AutocompleteMatchType::SEARCH_SUGGEST},
    };
    PopulateAutocompleteMatchesFromTestData(data, base::size(data), &matches);

    AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                            TestSchemeClassifier());
    AutocompleteResult result;
    result.AppendMatches(input, matches);
    result.SortAndCull(input, template_url_service_.get());

    // Expect the search suggest to be moved about URL suggestions due to
    // the logic which groups searches and URLs together.
    AutocompleteMatchType::Type expected_types[] = {
        AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED,
        AutocompleteMatchType::SEARCH_HISTORY,
        AutocompleteMatchType::SEARCH_SUGGEST,
        AutocompleteMatchType::HISTORY_URL,
        AutocompleteMatchType::HISTORY_TITLE,
        AutocompleteMatchType::URL_WHAT_YOU_TYPED,
    };
    EXPECT_EQ(result.size(), AutocompleteResult::GetMaxMatches());
    for (size_t i = 0; i < result.size(); ++i)
      EXPECT_EQ(result.match_at(i)->type, expected_types[i]);
  }

  // Case 2: Do not eject URL match because there's no replacement.
  {
    ACMatches matches;
    const AutocompleteMatchTestData data[] = {
        {"http://search-what-you-typed/",
         AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED},
        {"http://search-history/", AutocompleteMatchType::SEARCH_HISTORY},
        {"http://history-url/", AutocompleteMatchType::HISTORY_URL},
        {"http://history-title/", AutocompleteMatchType::HISTORY_TITLE},
        {"http://url-what-you-typed/",
         AutocompleteMatchType::URL_WHAT_YOU_TYPED},
        {"http://clipboard-url/", AutocompleteMatchType::CLIPBOARD_URL},
        {"http://bookmark-title/", AutocompleteMatchType::BOOKMARK_TITLE},
    };
    PopulateAutocompleteMatchesFromTestData(data, base::size(data), &matches);

    AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                            TestSchemeClassifier());
    AutocompleteResult result;
    result.AppendMatches(input, matches);
    result.SortAndCull(input, template_url_service_.get());

    EXPECT_EQ(result.size(), AutocompleteResult::GetMaxMatches());
    AutocompleteMatchType::Type expected_types[] = {
        AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED,
        AutocompleteMatchType::SEARCH_HISTORY,
        AutocompleteMatchType::HISTORY_URL,
        AutocompleteMatchType::HISTORY_TITLE,
        AutocompleteMatchType::URL_WHAT_YOU_TYPED,
        AutocompleteMatchType::CLIPBOARD_URL,
    };
    for (size_t i = 0; i < result.size(); ++i)
      EXPECT_EQ(result.match_at(i)->type, expected_types[i]);
  }
}

namespace {

bool EqualClassifications(const std::vector<ACMatchClassification>& lhs,
                          const std::vector<ACMatchClassification>& rhs) {
  if (lhs.size() != rhs.size())
    return false;
  for (size_t n = 0; n < lhs.size(); ++n)
    if (lhs[n].style != rhs[n].style || lhs[n].offset != rhs[n].offset)
      return false;
  return true;
}

}  // namespace

TEST_F(AutocompleteResultTest, InlineTailPrefixes) {
  struct TestData {
    AutocompleteMatchType::Type type;
    std::string before_contents, after_contents;
    std::vector<ACMatchClassification> before_contents_class;
    std::vector<ACMatchClassification> after_contents_class;
  } cases[] = {
      // It should not touch this, since it's not a tail suggestion.
      {
          AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED,
          "this is a test",
          "this is a test",
          {{0, ACMatchClassification::NONE}, {9, ACMatchClassification::MATCH}},
          {{0, ACMatchClassification::NONE}, {9, ACMatchClassification::MATCH}},
      },
      // Make sure it finds this tail suggestion, and prepends appropriately.
      {
          AutocompleteMatchType::SEARCH_SUGGEST_TAIL,
          "a recording",
          "... a recording",
          {{0, ACMatchClassification::MATCH}},
          {{0, ACMatchClassification::NONE}, {4, ACMatchClassification::MATCH}},
      },
  };
  ACMatches matches;
  for (const auto& test_case : cases) {
    AutocompleteMatch match;
    match.type = test_case.type;
    match.contents = base::UTF8ToUTF16(test_case.before_contents);
    for (const auto& classification : test_case.before_contents_class)
      match.contents_class.push_back(classification);
    matches.push_back(match);
  }
  // Tail suggestion needs one-off initialization.
  matches[1].RecordAdditionalInfo(kACMatchPropertyContentsStartIndex, "9");
  matches[1].RecordAdditionalInfo(kACMatchPropertySuggestionText,
                                  "this is a test");
  AutocompleteResult result;
  result.AppendMatches(AutocompleteInput(), matches);
  result.InlineTailPrefixes();
  for (size_t i = 0; i < base::size(cases); ++i) {
    EXPECT_EQ(result.match_at(i)->contents,
              base::UTF8ToUTF16(cases[i].after_contents));
    EXPECT_TRUE(EqualClassifications(result.match_at(i)->contents_class,
                                     cases[i].after_contents_class));
  }
  // Run twice and make sure that it doesn't re-prepend ellipsis.
  result.InlineTailPrefixes();
  for (size_t i = 0; i < base::size(cases); ++i) {
    EXPECT_EQ(result.match_at(i)->contents,
              base::UTF8ToUTF16(cases[i].after_contents));
    EXPECT_TRUE(EqualClassifications(result.match_at(i)->contents_class,
                                     cases[i].after_contents_class));
  }
}

TEST_F(AutocompleteResultTest, ConvertsOpenTabsCorrectly) {
  AutocompleteResult result;
  ACMatches matches;
  AutocompleteMatch match;
  match.destination_url = GURL("http://this-site-matches.com");
  matches.push_back(match);
  match.destination_url = GURL("http://other-site-matches.com");
  match.description = u"Some Other Site";
  matches.push_back(match);
  match.destination_url = GURL("http://doesnt-match.com");
  match.description = std::u16string();
  matches.push_back(match);
  result.AppendMatches({}, matches);

  // Have IsTabOpenWithURL() return true for some URLs.
  FakeAutocompleteProviderClient client;
  client.set_url_substring_match("matches");

  result.ConvertOpenTabMatches(&client, nullptr);

  EXPECT_TRUE(result.match_at(0)->has_tab_match);
  EXPECT_TRUE(result.match_at(1)->has_tab_match);
  EXPECT_FALSE(result.match_at(2)->has_tab_match);
}

TEST_F(AutocompleteResultTest, AttachesPedals) {
  FakeAutocompleteProviderClient client;
  EXPECT_NE(nullptr, client.GetPedalProvider());

  AutocompleteResult result;
  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());

  // Populate result with test matches.
  {
    ACMatches matches;
    struct TestData : AutocompleteMatchTestData {
      std::string contents;
      TestData(std::string url,
               AutocompleteMatch::Type type,
               std::string contents)
          : AutocompleteMatchTestData{url, type}, contents(contents) {}
    };
    const TestData data[] = {
        {"http://search-what-you-typed/",
         AutocompleteMatchType::SEARCH_WHAT_YOU_TYPED, "search what you typed"},
        {"http://search-history/", AutocompleteMatchType::SEARCH_HISTORY,
         "search history"},
        {"http://history-url/", AutocompleteMatchType::HISTORY_URL,
         "history url"},
        {"http://history-title/", AutocompleteMatchType::HISTORY_TITLE,
         "history title"},
        {"http://url-what-you-typed/",
         AutocompleteMatchType::URL_WHAT_YOU_TYPED, "url what you typed"},
        {"http://clipboard-url/", AutocompleteMatchType::CLIPBOARD_URL,
         "clipboard url"},
        {"http://bookmark-title/", AutocompleteMatchType::BOOKMARK_TITLE,
         "bookmark title"},
        {"http://entity-clear-history/",
         AutocompleteMatchType::SEARCH_SUGGEST_ENTITY, "clear history"},
        {"http://clear-history/", AutocompleteMatchType::SEARCH_SUGGEST,
         "clear history"},
    };
    PopulateAutocompleteMatchesFromTestData(data, base::size(data), &matches);
    for (size_t i = 0; i < base::size(data); i++) {
      matches[i].contents = base::UTF8ToUTF16(data[i].contents);
    }
    result.AppendMatches(input, matches);
  }

  // Attach |pedal| to result matches where appropriate.
  result.AttachPedalsToMatches(input, client);

  // Ensure the entity suggestion doesn't get a pedal even though its contents
  // form a concept match.
  EXPECT_EQ(nullptr, std::prev(std::prev(result.end()))->action);

  // The same concept-matching contents on a non-entity suggestion gets a pedal.
  EXPECT_NE(nullptr, std::prev(result.end())->action);
}

TEST_F(AutocompleteResultTest, DocumentSuggestionsCanMergeButNotToDefault) {
  // Types are populated below to avoid introducing a new test data creation
  // process.
  TestData data[] = {
      {1, 4, 500, false},   // DOCUMENT result for url [1].
      {1, 1, 1100, false},  // HISTORY result for url [1], higher priority.
      {2, 4, 600, false},   // DOCUMENT result for [2].
      {2, 1, 1200, true},   // HISTORY result for url [2], higher priority,
                            // Can be default.
      {3, 4, 1000, false},  // DOCUMENT result for [3], higher priority
      {3, 1, 400, false},   // HISTORY result for url [3].
  };
  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  matches[0].type = AutocompleteMatchType::DOCUMENT_SUGGESTION;
  static_cast<FakeAutocompleteProvider*>(matches[0].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_DOCUMENT);
  matches[1].type = AutocompleteMatchType::HISTORY_URL;
  matches[2].type = AutocompleteMatchType::DOCUMENT_SUGGESTION;
  static_cast<FakeAutocompleteProvider*>(matches[2].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_DOCUMENT);
  matches[3].type = AutocompleteMatchType::HISTORY_URL;
  matches[4].type = AutocompleteMatchType::DOCUMENT_SUGGESTION;
  static_cast<FakeAutocompleteProvider*>(matches[4].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_DOCUMENT);
  matches[5].type = AutocompleteMatchType::HISTORY_URL;

  AutocompleteInput input(u"a", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  // We expect three results:
  // The document result for [1] may override the history result.
  // The document result for [2] cannot override a potentially-default result.
  // The document result for [3] is already higher-priority.
  EXPECT_EQ(result.size(), 3u);

  // First result should be the default with its original top-ranking score.
  EXPECT_EQ(result.match_at(0)->relevance, 1200);
  EXPECT_EQ(AutocompleteMatchType::HISTORY_URL, result.match_at(0)->type);
  EXPECT_TRUE(result.match_at(0)->allowed_to_be_default_match);

  // Second result should be a document result with elevated score.
  // The second DOCUMENT result is deduped and effectively dropped.
  EXPECT_EQ(result.match_at(1)->relevance, 1100);
  EXPECT_EQ(AutocompleteMatchType::DOCUMENT_SUGGESTION,
            result.match_at(1)->type);
  EXPECT_FALSE(result.match_at(1)->allowed_to_be_default_match);

  // Third result should be a document with original score. The history result
  // it duped against is lower-priority.
  EXPECT_EQ(result.match_at(2)->relevance, 1000);
  EXPECT_EQ(AutocompleteMatchType::DOCUMENT_SUGGESTION,
            result.match_at(2)->type);
  EXPECT_FALSE(result.match_at(2)->allowed_to_be_default_match);
}

TEST_F(AutocompleteResultTest, CalculateNumMatchesPerUrlCountTest) {
  CompareWithDemoteByType<AutocompleteMatch> comparison_object(
      metrics::OmniboxEventProto::OTHER);
  enum SuggestionType { search, url };

  auto test = [comparison_object](std::string base_limit,
                                  std::string url_cutoff,
                                  std::string increased_limit,
                                  std::vector<SuggestionType> types,
                                  size_t expected_num_matches) {
    base::test::ScopedFeatureList feature_list;
    feature_list.InitWithFeaturesAndParameters(
        {{omnibox::kDynamicMaxAutocomplete,
          {{OmniboxFieldTrial::kDynamicMaxAutocompleteUrlCutoffParam,
            url_cutoff},
           {OmniboxFieldTrial::kDynamicMaxAutocompleteIncreasedLimitParam,
            increased_limit}}},
         {omnibox::kUIExperimentMaxAutocompleteMatches,
          {{OmniboxFieldTrial::kUIMaxAutocompleteMatchesParam, base_limit}}}},
        {});

    ACMatches matches;
    for (auto type : types) {
      AutocompleteMatch m;
      m.relevance = 100;
      if (type)
        m.type = AutocompleteMatchType::URL_WHAT_YOU_TYPED;
      matches.push_back(m);
    }
    const size_t num_matches = AutocompleteResult::CalculateNumMatches(
        false, matches, comparison_object);
    EXPECT_EQ(num_matches, expected_num_matches);
  };

  test("2", "0", "4", {search}, 1);
  test("2", "0", "4", {search, search, search, search, search}, 4);
  test("2", "0", "4", {search, search, search, search, url}, 4);
  test("2", "0", "4", {search, search, search, url, search}, 3);
  test("2", "0", "4", {search, search, url, search, search}, 2);
  test("2", "0", "4", {search, url, search, search, search}, 2);
  test("2", "1", "4", {search, url, search, search, search}, 4);
  test("2", "1", "4", {search, url, search, url, search}, 3);
}

TEST_F(AutocompleteResultTest, ClipboardSuggestionOnTopOfSearchSuggestionTest) {
  // clang-format off
  TestData data[] = {
      {1, 1, 500,  false},
      {2, 2, 1100, false},
      {3, 2, 1000, false},
      {4, 1, 1300, false},
      {5, 1, 1500, false},
  };
  // clang-format on

  ACMatches matches;
  PopulateAutocompleteMatches(data, base::size(data), &matches);
  matches[0].type = AutocompleteMatchType::SEARCH_SUGGEST;
  static_cast<FakeAutocompleteProvider*>(matches[0].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_ZERO_SUGGEST_LOCAL_HISTORY);
  matches[1].type = AutocompleteMatchType::SEARCH_SUGGEST;
  static_cast<FakeAutocompleteProvider*>(matches[1].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_ZERO_SUGGEST_LOCAL_HISTORY);
  matches[2].type = AutocompleteMatchType::SEARCH_SUGGEST;
  static_cast<FakeAutocompleteProvider*>(matches[2].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_ZERO_SUGGEST_LOCAL_HISTORY);
  matches[3].type = AutocompleteMatchType::SEARCH_SUGGEST;
  static_cast<FakeAutocompleteProvider*>(matches[3].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_ZERO_SUGGEST_LOCAL_HISTORY);
  matches[4].type = AutocompleteMatchType::CLIPBOARD_URL;
  static_cast<FakeAutocompleteProvider*>(matches[4].provider)
      ->SetType(AutocompleteProvider::Type::TYPE_CLIPBOARD);

  AutocompleteInput input(u"", metrics::OmniboxEventProto::OTHER,
                          TestSchemeClassifier());
  AutocompleteResult result;
  result.AppendMatches(input, matches);
  result.SortAndCull(input, template_url_service_.get());

  EXPECT_EQ(result.size(), 5u);
  EXPECT_EQ(result.match_at(0)->relevance, 1500);
  EXPECT_EQ(AutocompleteMatchType::CLIPBOARD_URL, result.match_at(0)->type);
}