// Copyright 2013 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 "chrome/browser/net/net_error_tab_helper.h"

#include "base/message_loop.h"
#include "chrome/common/net/net_error_info.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/common/page_transition_types.h"
#include "content/public/test/test_browser_thread.h"
#include "net/base/net_errors.h"
#include "testing/gtest/include/gtest/gtest.h"

using base::MessageLoop;
using chrome_browser_net::NetErrorTabHelper;
using chrome_common_net::DnsProbeStatus;
using content::BrowserThread;
using content::TestBrowserThread;

class TestNetErrorTabHelper : public NetErrorTabHelper {
 public:
  TestNetErrorTabHelper()
      : NetErrorTabHelper(NULL),
        mock_probe_running_(false),
        last_status_sent_(chrome_common_net::DNS_PROBE_MAX),
        mock_sent_count_(0) {}

  void FinishProbe(DnsProbeStatus status) {
    EXPECT_TRUE(mock_probe_running_);
    OnDnsProbeFinished(status);
    mock_probe_running_ = false;
  }

  bool mock_probe_running() const { return mock_probe_running_; }
  DnsProbeStatus last_status_sent() const { return last_status_sent_; }
  int mock_sent_count() const { return mock_sent_count_; }

 private:
  virtual void StartDnsProbe() OVERRIDE {
    EXPECT_FALSE(mock_probe_running_);
    mock_probe_running_ = true;
  }

  virtual void SendInfo() OVERRIDE {
    last_status_sent_ = dns_probe_status();
    mock_sent_count_++;
  }

  bool mock_probe_running_;
  DnsProbeStatus last_status_sent_;
  int mock_sent_count_;
};

class NetErrorTabHelperTest : public testing::Test {
 protected:
  enum MainFrame { SUB_FRAME, MAIN_FRAME };
  enum ErrorPage { NORMAL_PAGE, ERROR_PAGE };
  enum ErrorType { DNS_ERROR, OTHER_ERROR };

  NetErrorTabHelperTest()
      : fake_ui_thread_(BrowserThread::UI, &message_loop_) {
    NetErrorTabHelper::set_state_for_testing(
        NetErrorTabHelper::TESTING_FORCE_ENABLED);
  }

  void StartProvisionalLoad(MainFrame main_frame, ErrorPage error_page) {
    tab_helper_.DidStartProvisionalLoadForFrame(
        1,  // frame_id
        0,  // parent_frame_id
        (main_frame == MAIN_FRAME),
        bogus_url_,  // validated_url
        (error_page == ERROR_PAGE),
        false,  // is_iframe_srcdoc
        NULL);  // render_view_host
  }

  void CommitProvisionalLoad(MainFrame main_frame) {
    tab_helper_.DidCommitProvisionalLoadForFrame(
        1,  // frame id
        (main_frame == MAIN_FRAME),
        bogus_url_,  // url
        content::PAGE_TRANSITION_TYPED,
        NULL);  // render_view_host
  }

  void FailProvisionalLoad(MainFrame main_frame, ErrorType error_type) {
    int net_error;

    if (error_type == DNS_ERROR)
      net_error = net::ERR_NAME_NOT_RESOLVED;
    else
      net_error = net::ERR_TIMED_OUT;

    tab_helper_.DidFailProvisionalLoad(
        1,  // frame id
        (main_frame == MAIN_FRAME),
        bogus_url_,  // validated_url
        net_error,
        string16(),
        NULL);  // render_view_host
  }

  void FinishProbe(DnsProbeStatus status) {
    tab_helper_.FinishProbe(status);
  }

  bool probe_running() { return tab_helper_.mock_probe_running(); }
  DnsProbeStatus last_status_sent() { return tab_helper_.last_status_sent(); }
  int sent_count() { return tab_helper_.mock_sent_count(); }

 private:
  MessageLoop message_loop_;
  TestBrowserThread fake_ui_thread_;
  TestNetErrorTabHelper tab_helper_;
  GURL bogus_url_;
};

TEST_F(NetErrorTabHelperTest, Null) {
  EXPECT_FALSE(probe_running());
}

TEST_F(NetErrorTabHelperTest, MainFrameNonDnsError) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, OTHER_ERROR);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(0, sent_count());
}

TEST_F(NetErrorTabHelperTest, NonMainFrameDnsError) {
  StartProvisionalLoad(SUB_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(SUB_FRAME, DNS_ERROR);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(0, sent_count());
}

// Test complete DNS error page loads.  Note that the helper can see two error
// page loads: Link Doctor loads an empty HTML page so the user knows something
// is going on, then fails over to the normal error page if and when Link
// Doctor fails to load or declines to provide a page.

TEST_F(NetErrorTabHelperTest, ProbeResponseBeforeFirstCommit) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(0, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(1, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(1, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(2, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());
}

TEST_F(NetErrorTabHelperTest, ProbeResponseBetweenFirstAndSecondCommit) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(2, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(2, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(3, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());
}

TEST_F(NetErrorTabHelperTest, ProbeResponseAfterSecondCommit) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(3, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());
}

// Send result even if a new page load has started; the error page is still
// visible, and the user might cancel the load.
TEST_F(NetErrorTabHelperTest, ProbeResponseAfterNewStart) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(3, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());
}

// Don't send result if a new page has committed; the result would go to the
// wrong page, and the error page is gone anyway.
TEST_F(NetErrorTabHelperTest, ProbeResponseAfterNewCommit) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());

  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(2, sent_count());
}

TEST_F(NetErrorTabHelperTest, MultipleDnsErrorsWithProbesWithoutErrorPages) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(0, sent_count());

  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NO_INTERNET);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(0, sent_count());
}

TEST_F(NetErrorTabHelperTest, MultipleDnsErrorsWithProbesAndErrorPages) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(0, sent_count());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(2, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());

  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(3, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NO_INTERNET);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(4, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NO_INTERNET,
            last_status_sent());
}

// If multiple DNS errors occur in a row before a probe result, don't start
// multiple probes.
TEST_F(NetErrorTabHelperTest, CoalesceFailures) {
  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(1, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(2, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  StartProvisionalLoad(MAIN_FRAME, NORMAL_PAGE);
  FailProvisionalLoad(MAIN_FRAME, DNS_ERROR);
  StartProvisionalLoad(MAIN_FRAME, ERROR_PAGE);
  CommitProvisionalLoad(MAIN_FRAME);
  EXPECT_TRUE(probe_running());
  EXPECT_EQ(3, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_STARTED, last_status_sent());

  FinishProbe(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN);
  EXPECT_FALSE(probe_running());
  EXPECT_EQ(4, sent_count());
  EXPECT_EQ(chrome_common_net::DNS_PROBE_FINISHED_NXDOMAIN, last_status_sent());
}