// Copyright 2015 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 <string>

#include "chrome/browser/browser_process.h"
#include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings.h"
#include "chrome/browser/net/spdyproxy/data_reduction_proxy_chrome_settings_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/tabs/tab_strip_model.h"
#include "chrome/common/pref_names.h"
#include "chrome/test/base/in_process_browser_test.h"
#include "chrome/test/base/ui_test_utils.h"
#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_service.h"
#include "components/prefs/pref_service.h"
#include "content/public/test/browser_test_base.h"
#include "content/public/test/browser_test_utils.h"
#include "net/test/embedded_test_server/embedded_test_server.h"
#include "net/test/embedded_test_server/http_request.h"
#include "net/test/embedded_test_server/http_response.h"
#include "services/network/public/cpp/network_quality_tracker.h"

namespace {

// Test version of the observer. Used to wait for the event when the network
// quality tracker sends the network quality change notification.
class TestEffectiveConnectionTypeObserver
    : public network::NetworkQualityTracker::EffectiveConnectionTypeObserver {
 public:
  explicit TestEffectiveConnectionTypeObserver(
      network::NetworkQualityTracker* tracker)
      : run_loop_wait_effective_connection_type_(
            net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN),
        run_loop_(std::make_unique<base::RunLoop>()),
        tracker_(tracker),
        effective_connection_type_(net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN) {
    tracker_->AddEffectiveConnectionTypeObserver(this);
  }

  ~TestEffectiveConnectionTypeObserver() override {
    tracker_->RemoveEffectiveConnectionTypeObserver(this);
  }

  void WaitForNotification(
      net::EffectiveConnectionType run_loop_wait_effective_connection_type) {
    if (effective_connection_type_ == run_loop_wait_effective_connection_type)
      return;
    ASSERT_NE(net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN,
              run_loop_wait_effective_connection_type);
    run_loop_wait_effective_connection_type_ =
        run_loop_wait_effective_connection_type;
    run_loop_->Run();
    run_loop_.reset(new base::RunLoop());
  }

 private:
  // NetworkQualityTracker::EffectiveConnectionTypeObserver implementation:
  void OnEffectiveConnectionTypeChanged(
      net::EffectiveConnectionType type) override {
    DCHECK_CURRENTLY_ON(content::BrowserThread::UI);

    net::EffectiveConnectionType queried_type =
        tracker_->GetEffectiveConnectionType();
    EXPECT_EQ(type, queried_type);

    effective_connection_type_ = type;
    if (effective_connection_type_ != run_loop_wait_effective_connection_type_)
      return;
    run_loop_->Quit();
  }

  net::EffectiveConnectionType run_loop_wait_effective_connection_type_;
  std::unique_ptr<base::RunLoop> run_loop_;
  network::NetworkQualityTracker* tracker_;
  net::EffectiveConnectionType effective_connection_type_;

  DISALLOW_COPY_AND_ASSIGN(TestEffectiveConnectionTypeObserver);
};

// Test version of the observer. Used to wait for the event when the network
// quality tracker sends the network quality change notification.
class TestRTTAndThroughputEstimatesObserver
    : public network::NetworkQualityTracker::RTTAndThroughputEstimatesObserver {
 public:
  explicit TestRTTAndThroughputEstimatesObserver(
      network::NetworkQualityTracker* tracker)
      : tracker_(tracker),
        downstream_throughput_kbps_(std::numeric_limits<int32_t>::max()) {
    tracker_->AddRTTAndThroughputEstimatesObserver(this);
  }

  ~TestRTTAndThroughputEstimatesObserver() override {
    tracker_->RemoveRTTAndThroughputEstimatesObserver(this);
  }

  void WaitForNotification(base::TimeDelta expected_http_rtt) {
    // It's not meaningful to wait for notification with RTT set to
    // base::TimeDelta() since that value implies that the network quality
    // estimate was unavailable.
    EXPECT_NE(base::TimeDelta(), expected_http_rtt);
    http_rtt_notification_wait_ = expected_http_rtt;
    if (http_rtt_notification_wait_ == http_rtt_)
      return;

    // WaitForNotification should not be called twice.
    EXPECT_EQ(nullptr, run_loop_);
    run_loop_ = std::make_unique<base::RunLoop>();
    run_loop_->Run();
    EXPECT_EQ(expected_http_rtt, http_rtt_);
    run_loop_.reset();
  }

 private:
  // RTTAndThroughputEstimatesObserver implementation:
  void OnRTTOrThroughputEstimatesComputed(
      base::TimeDelta http_rtt,
      base::TimeDelta transport_rtt,
      int32_t downstream_throughput_kbps) override {
    EXPECT_EQ(http_rtt, tracker_->GetHttpRTT());
    EXPECT_EQ(downstream_throughput_kbps,
              tracker_->GetDownstreamThroughputKbps());

    http_rtt_ = http_rtt;
    downstream_throughput_kbps_ = downstream_throughput_kbps;

    if (run_loop_ && http_rtt == http_rtt_notification_wait_)
      run_loop_->Quit();
  }

  network::NetworkQualityTracker* tracker_;
  // May be null.
  std::unique_ptr<base::RunLoop> run_loop_;
  base::TimeDelta http_rtt_;
  int32_t downstream_throughput_kbps_;
  base::TimeDelta http_rtt_notification_wait_;

  DISALLOW_COPY_AND_ASSIGN(TestRTTAndThroughputEstimatesObserver);
};

}  // namespace

class DataSaverBrowserTest : public InProcessBrowserTest {
 protected:
  void EnableDataSaver(bool enabled) {
    PrefService* prefs = browser()->profile()->GetPrefs();
    prefs->SetBoolean(prefs::kDataSaverEnabled, enabled);
    // Give the setting notification a chance to propagate.
    content::RunAllPendingInMessageLoop();
  }

  void VerifySaveDataHeader(const std::string& expected_header_value) {
    ui_test_utils::NavigateToURL(
        browser(), embedded_test_server()->GetURL("/echoheader?Save-Data"));
    std::string header_value;
    EXPECT_TRUE(content::ExecuteScriptAndExtractString(
        browser()->tab_strip_model()->GetActiveWebContents(),
        "window.domAutomationController.send(document.body.textContent);",
        &header_value));
    EXPECT_EQ(expected_header_value, header_value);
  }
};

IN_PROC_BROWSER_TEST_F(DataSaverBrowserTest, DataSaverEnabled) {
  ASSERT_TRUE(embedded_test_server()->Start());
  EnableDataSaver(true);
  VerifySaveDataHeader("on");
}

IN_PROC_BROWSER_TEST_F(DataSaverBrowserTest, DataSaverDisabled) {
  ASSERT_TRUE(embedded_test_server()->Start());
  EnableDataSaver(false);
  VerifySaveDataHeader("None");
}

class DataSaverWithServerBrowserTest : public InProcessBrowserTest {
 protected:
  void Init() {
    test_server_.reset(new net::EmbeddedTestServer());
    test_server_->RegisterRequestHandler(
        base::Bind(&DataSaverWithServerBrowserTest::VerifySaveDataHeader,
                   base::Unretained(this)));
    test_server_->ServeFilesFromSourceDirectory("chrome/test/data");
  }
  void EnableDataSaver(bool enabled) {
    PrefService* prefs = browser()->profile()->GetPrefs();
    prefs->SetBoolean(prefs::kDataSaverEnabled, enabled);
    // Give the setting notification a chance to propagate.
    content::RunAllPendingInMessageLoop();
  }

  net::EffectiveConnectionType GetEffectiveConnectionType() const {
    return DataReductionProxyChromeSettingsFactory::GetForBrowserContext(
               browser()->profile())
        ->data_reduction_proxy_service()
        ->GetEffectiveConnectionType();
  }

  base::Optional<base::TimeDelta> GetHttpRttEstimate() const {
    return DataReductionProxyChromeSettingsFactory::GetForBrowserContext(
               browser()->profile())
        ->data_reduction_proxy_service()
        ->GetHttpRttEstimate();
  }

  std::unique_ptr<net::test_server::HttpResponse> VerifySaveDataHeader(
      const net::test_server::HttpRequest& request) {
    auto save_data_header_it = request.headers.find("save-data");

    if (request.relative_url == "/favicon.ico") {
      // Favicon request could be received for the previous page load.
      return std::unique_ptr<net::test_server::HttpResponse>();
    }

    if (!expected_save_data_header_.empty()) {
      EXPECT_TRUE(save_data_header_it != request.headers.end())
          << request.relative_url;
      EXPECT_EQ(expected_save_data_header_, save_data_header_it->second)
          << request.relative_url;
    } else {
      EXPECT_TRUE(save_data_header_it == request.headers.end())
          << request.relative_url;
    }
    return std::unique_ptr<net::test_server::HttpResponse>();
  }

  std::unique_ptr<net::EmbeddedTestServer> test_server_;
  std::string expected_save_data_header_;
};

IN_PROC_BROWSER_TEST_F(DataSaverWithServerBrowserTest, ReloadPage) {
  Init();
  ASSERT_TRUE(test_server_->Start());
  EnableDataSaver(true);

  expected_save_data_header_ = "on";
  ui_test_utils::NavigateToURL(browser(),
                               test_server_->GetURL("/google/google.html"));

  // Reload the webpage and expect the main and the subresources will get the
  // correct save-data header.
  expected_save_data_header_ = "on";
  chrome::Reload(browser(), WindowOpenDisposition::CURRENT_TAB);
  content::WaitForLoadStop(
      browser()->tab_strip_model()->GetActiveWebContents());

  // Reload the webpage with data saver disabled, and expect all the resources
  // will get no save-data header.
  EnableDataSaver(false);
  expected_save_data_header_ = "";
  chrome::Reload(browser(), WindowOpenDisposition::CURRENT_TAB);
  content::WaitForLoadStop(
      browser()->tab_strip_model()->GetActiveWebContents());
}

// Test that the data saver receives changes in effective connection type.
IN_PROC_BROWSER_TEST_F(DataSaverWithServerBrowserTest,
                       EffectiveConnectionType) {
  Init();

  // Add a test observer. To determine if data reduction proxy component has
  // received the network quality change notification, we check if the test
  // observer has received the notification. Note that all the observers are
  // notified in the same message loop by the network quality tracker.
  TestEffectiveConnectionTypeObserver observer(
      g_browser_process->network_quality_tracker());

  g_browser_process->network_quality_tracker()
      ->ReportEffectiveConnectionTypeForTesting(
          net::EFFECTIVE_CONNECTION_TYPE_4G);
  observer.WaitForNotification(net::EFFECTIVE_CONNECTION_TYPE_4G);
  base::RunLoop().RunUntilIdle();
  EXPECT_EQ(net::EFFECTIVE_CONNECTION_TYPE_4G, GetEffectiveConnectionType());

  g_browser_process->network_quality_tracker()
      ->ReportEffectiveConnectionTypeForTesting(
          net::EFFECTIVE_CONNECTION_TYPE_2G);
  observer.WaitForNotification(net::EFFECTIVE_CONNECTION_TYPE_2G);
  base::RunLoop().RunUntilIdle();
  EXPECT_EQ(net::EFFECTIVE_CONNECTION_TYPE_2G, GetEffectiveConnectionType());

  g_browser_process->network_quality_tracker()
      ->ReportEffectiveConnectionTypeForTesting(
          net::EFFECTIVE_CONNECTION_TYPE_3G);
  observer.WaitForNotification(net::EFFECTIVE_CONNECTION_TYPE_3G);
  base::RunLoop().RunUntilIdle();
  EXPECT_EQ(net::EFFECTIVE_CONNECTION_TYPE_3G, GetEffectiveConnectionType());
}

// Test that the data saver receives changes in HTTP RTT estimate.
IN_PROC_BROWSER_TEST_F(DataSaverWithServerBrowserTest, HttpRttEstimate) {
  Init();

  // Add a test observer. To determine if data reduction proxy component has
  // received the network quality change notification, we check if the test
  // observer has received the notification. Note that all the observers are
  // notified in the same message loop by the network quality tracker.
  TestRTTAndThroughputEstimatesObserver observer(
      g_browser_process->network_quality_tracker());

  g_browser_process->network_quality_tracker()
      ->ReportRTTsAndThroughputForTesting(
          base::TimeDelta::FromMilliseconds(100), 0);
  observer.WaitForNotification(base::TimeDelta::FromMilliseconds(100));
  base::RunLoop().RunUntilIdle();
  EXPECT_EQ(base::TimeDelta::FromMilliseconds(100), GetHttpRttEstimate());

  g_browser_process->network_quality_tracker()
      ->ReportRTTsAndThroughputForTesting(
          base::TimeDelta::FromMilliseconds(500), 0);
  observer.WaitForNotification(base::TimeDelta::FromMilliseconds(500));
  base::RunLoop().RunUntilIdle();
  EXPECT_EQ(base::TimeDelta::FromMilliseconds(500), GetHttpRttEstimate());
}