// Copyright (c) 2012 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/ui/exclusive_access/fullscreen_controller_state_test.h"

#include <memory.h>

#include <iomanip>
#include <iostream>

#include "chrome/browser/fullscreen.h"
#include "chrome/browser/ui/browser.h"
#include "chrome/browser/ui/browser_window.h"
#include "chrome/browser/ui/exclusive_access/fullscreen_controller.h"
#include "chrome/browser/ui/exclusive_access/fullscreen_controller_test.h"
#include "chrome/browser/ui/tabs/tab_strip_model.h"
#include "content/public/browser/web_contents.h"
#include "content/public/common/url_constants.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace {

bool SupportsMacSystemFullscreen() {
#if defined(OS_MACOSX)
  return chrome::mac::SupportsSystemFullscreen();
#else
  return false;
#endif
}

}  // namespace

FullscreenControllerStateTest::FullscreenControllerStateTest()
    : state_(STATE_NORMAL),
      last_notification_received_state_(STATE_NORMAL) {
  // Human specified state machine data.
  // For each state, for each event, define the resulting state.
  State transition_table_data[][NUM_EVENTS] = {
    { // STATE_NORMAL:
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event TOGGLE_FULLSCREEN
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event TOGGLE_FULLSCREEN_CHROME
      STATE_TO_TAB_FULLSCREEN,                // Event TAB_FULLSCREEN_TRUE
      STATE_NORMAL,                           // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_NORMAL,                           // Event METRO_SNAP_FALSE
      STATE_NORMAL,                           // Event BUBBLE_EXIT_LINK
      STATE_NORMAL,                           // Event BUBBLE_ALLOW
      STATE_NORMAL,                           // Event BUBBLE_DENY
      STATE_NORMAL,                           // Event WINDOW_CHANGE
    },
    { // STATE_BROWSER_FULLSCREEN_NO_CHROME:
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event TOGGLE_FULLSCREEN_CHROME
      STATE_TAB_BROWSER_FULLSCREEN,           // Event TAB_FULLSCREEN_TRUE
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event METRO_SNAP_FALSE
      STATE_TO_NORMAL,                        // Event BUBBLE_EXIT_LINK
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event BUBBLE_ALLOW
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event BUBBLE_DENY
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event WINDOW_CHANGE
    },
    { // STATE_BROWSER_FULLSCREEN_WITH_CHROME:
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event TOGGLE_FULLSCREEN
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN_CHROME
      STATE_TAB_BROWSER_FULLSCREEN_CHROME,    // Event TAB_FULLSCREEN_TRUE
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event TAB_FULLSCREEN_FALSE
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event METRO_SNAP_TRUE
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event METRO_SNAP_FALSE
      STATE_TO_NORMAL,                        // Event BUBBLE_EXIT_LINK
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event BUBBLE_ALLOW
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event BUBBLE_DENY
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event WINDOW_CHANGE
    },
    { // STATE_METRO_SNAP:
      STATE_METRO_SNAP,                       // Event TOGGLE_FULLSCREEN
      STATE_METRO_SNAP,                       // Event TOGGLE_FULLSCREEN_CHROME
      STATE_METRO_SNAP,                       // Event TAB_FULLSCREEN_TRUE
      STATE_METRO_SNAP,                       // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_NORMAL,                           // Event METRO_SNAP_FALSE
      STATE_METRO_SNAP,                       // Event BUBBLE_EXIT_LINK
      STATE_METRO_SNAP,                       // Event BUBBLE_ALLOW
      STATE_METRO_SNAP,                       // Event BUBBLE_DENY
      STATE_METRO_SNAP,                       // Event WINDOW_CHANGE
    },
    { // STATE_TAB_FULLSCREEN:
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN_CHROME
      STATE_TAB_FULLSCREEN,                   // Event TAB_FULLSCREEN_TRUE
      STATE_TO_NORMAL,                        // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_TAB_FULLSCREEN,                   // Event METRO_SNAP_FALSE
      STATE_TO_NORMAL,                        // Event BUBBLE_EXIT_LINK
      STATE_TAB_FULLSCREEN,                   // Event BUBBLE_ALLOW
      STATE_TO_NORMAL,                        // Event BUBBLE_DENY
      STATE_TAB_FULLSCREEN,                   // Event WINDOW_CHANGE
    },
    { // STATE_TAB_BROWSER_FULLSCREEN:
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN_CHROME
      STATE_TAB_BROWSER_FULLSCREEN,           // Event TAB_FULLSCREEN_TRUE
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_TAB_BROWSER_FULLSCREEN,           // Event METRO_SNAP_FALSE
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event BUBBLE_EXIT_LINK
      STATE_TAB_BROWSER_FULLSCREEN,           // Event BUBBLE_ALLOW
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event BUBBLE_DENY
      STATE_TAB_BROWSER_FULLSCREEN,           // Event WINDOW_CHANGE
    },
    { // STATE_TAB_BROWSER_FULLSCREEN_CHROME:
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN_CHROME
      STATE_TAB_BROWSER_FULLSCREEN_CHROME,    // Event TAB_FULLSCREEN_TRUE
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_TAB_BROWSER_FULLSCREEN_CHROME,    // Event METRO_SNAP_FALSE
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event BUBBLE_EXIT_LINK
      STATE_TAB_BROWSER_FULLSCREEN_CHROME,    // Event BUBBLE_ALLOW
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event BUBBLE_DENY
      STATE_TAB_BROWSER_FULLSCREEN_CHROME,    // Event WINDOW_CHANGE
    },
    { // STATE_TO_NORMAL:
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event TOGGLE_FULLSCREEN_CHROME
      // TODO(scheib) Should be a route back to TAB. http://crbug.com/154196
      STATE_TO_NORMAL,                        // Event TAB_FULLSCREEN_TRUE
      STATE_TO_NORMAL,                        // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_TO_NORMAL,                        // Event METRO_SNAP_FALSE
      STATE_TO_NORMAL,                        // Event BUBBLE_EXIT_LINK
      STATE_TO_NORMAL,                        // Event BUBBLE_ALLOW
      STATE_TO_NORMAL,                        // Event BUBBLE_DENY
      STATE_NORMAL,                           // Event WINDOW_CHANGE
    },
    { // STATE_TO_BROWSER_FULLSCREEN_NO_CHROME:
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event TOGGLE_FULLSCREEN
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event TOGGLE_FULLSCREEN_CHROME
      // TODO(scheib) Should be a route to TAB_BROWSER http://crbug.com/154196
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event TAB_FULLSCREEN_TRUE
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event TAB_FULLSCREEN_FALSE
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event METRO_SNAP_FALSE
#if defined(OS_MACOSX)
      // Mac window reports fullscreen immediately and an exit triggers exit.
      STATE_TO_NORMAL,                        // Event BUBBLE_EXIT_LINK
#else
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event BUBBLE_EXIT_LINK
#endif
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event BUBBLE_ALLOW
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event BUBBLE_DENY
      STATE_BROWSER_FULLSCREEN_NO_CHROME,     // Event WINDOW_CHANGE
    },
    { // STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME:
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event TOGGLE_FULLSCREEN
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN_CHROME
      // TODO(scheib) Should be a route to TAB_BROWSER http://crbug.com/154196
      STATE_TAB_BROWSER_FULLSCREEN,           // Event TAB_FULLSCREEN_TRUE
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event TAB_FULLSCREEN_FALSE
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event METRO_SNAP_TRUE
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event METRO_SNAP_FALSE
      STATE_TO_NORMAL,                        // Event BUBBLE_EXIT_LINK
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event BUBBLE_ALLOW
      STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME,// Event BUBBLE_DENY
      STATE_BROWSER_FULLSCREEN_WITH_CHROME,   // Event WINDOW_CHANGE
    },
    { // STATE_TO_TAB_FULLSCREEN:
      // TODO(scheib) Should be a route to TAB_BROWSER http://crbug.com/154196
      STATE_TO_TAB_FULLSCREEN,                // Event TOGGLE_FULLSCREEN
      STATE_TO_NORMAL,                        // Event TOGGLE_FULLSCREEN_CHROME
      STATE_TO_TAB_FULLSCREEN,                // Event TAB_FULLSCREEN_TRUE
#if defined(OS_MACOSX)
      // Mac runs as expected due to a forced NotifyTabOfExitIfNecessary();
      STATE_TO_NORMAL,                        // Event TAB_FULLSCREEN_FALSE
#else
      // TODO(scheib) Should be a route back to NORMAL. http://crbug.com/154196
      STATE_TO_BROWSER_FULLSCREEN_NO_CHROME,  // Event TAB_FULLSCREEN_FALSE
#endif
      STATE_METRO_SNAP,                       // Event METRO_SNAP_TRUE
      STATE_TO_TAB_FULLSCREEN,                // Event METRO_SNAP_FALSE
#if defined(OS_MACOSX)
      // Mac window reports fullscreen immediately and an exit triggers exit.
      STATE_TO_NORMAL,                        // Event BUBBLE_EXIT_LINK
#else
      STATE_TO_TAB_FULLSCREEN,                // Event BUBBLE_EXIT_LINK
#endif
      STATE_TO_TAB_FULLSCREEN,                // Event BUBBLE_ALLOW
#if defined(OS_MACOSX)
      // Mac window reports fullscreen immediately and an exit triggers exit.
      STATE_TO_NORMAL,                        // Event BUBBLE_DENY
#else
      STATE_TO_TAB_FULLSCREEN,                // Event BUBBLE_DENY
#endif
      STATE_TAB_FULLSCREEN,                   // Event WINDOW_CHANGE
    },
  };
  static_assert(sizeof(transition_table_data) == sizeof(transition_table_),
                "transition_table has unexpected size");
  memcpy(transition_table_, transition_table_data,
         sizeof(transition_table_data));

  // Verify that transition_table_ has been completely defined.
  for (int source = 0; source < NUM_STATES; ++source) {
    for (int event = 0; event < NUM_EVENTS; ++event) {
      EXPECT_NE(transition_table_[source][event], STATE_INVALID);
      EXPECT_GE(transition_table_[source][event], 0);
      EXPECT_LT(transition_table_[source][event], NUM_STATES);
    }
  }

  // Copy transition_table_ data into state_transitions_ table.
  for (int source = 0; source < NUM_STATES; ++source) {
    for (int event = 0; event < NUM_EVENTS; ++event) {
      if (ShouldSkipStateAndEventPair(static_cast<State>(source),
                                      static_cast<Event>(event)))
        continue;
      State destination = transition_table_[source][event];
      state_transitions_[source][destination].event = static_cast<Event>(event);
      state_transitions_[source][destination].state = destination;
      state_transitions_[source][destination].distance = 1;
    }
  }
}

FullscreenControllerStateTest::~FullscreenControllerStateTest() {
}

// static
const char* FullscreenControllerStateTest::GetStateString(State state) {
  switch (state) {
    ENUM_TO_STRING(STATE_NORMAL);
    ENUM_TO_STRING(STATE_BROWSER_FULLSCREEN_NO_CHROME);
    ENUM_TO_STRING(STATE_BROWSER_FULLSCREEN_WITH_CHROME);
    ENUM_TO_STRING(STATE_METRO_SNAP);
    ENUM_TO_STRING(STATE_TAB_FULLSCREEN);
    ENUM_TO_STRING(STATE_TAB_BROWSER_FULLSCREEN);
    ENUM_TO_STRING(STATE_TAB_BROWSER_FULLSCREEN_CHROME);
    ENUM_TO_STRING(STATE_TO_NORMAL);
    ENUM_TO_STRING(STATE_TO_BROWSER_FULLSCREEN_NO_CHROME);
    ENUM_TO_STRING(STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME);
    ENUM_TO_STRING(STATE_TO_TAB_FULLSCREEN);
    ENUM_TO_STRING(STATE_INVALID);
    default:
      NOTREACHED() << "No string for state " << state;
      return "State-Unknown";
  }
}

// static
const char* FullscreenControllerStateTest::GetEventString(Event event) {
  switch (event) {
    ENUM_TO_STRING(TOGGLE_FULLSCREEN);
    ENUM_TO_STRING(TOGGLE_FULLSCREEN_CHROME);
    ENUM_TO_STRING(TAB_FULLSCREEN_TRUE);
    ENUM_TO_STRING(TAB_FULLSCREEN_FALSE);
    ENUM_TO_STRING(METRO_SNAP_TRUE);
    ENUM_TO_STRING(METRO_SNAP_FALSE);
    ENUM_TO_STRING(BUBBLE_EXIT_LINK);
    ENUM_TO_STRING(BUBBLE_ALLOW);
    ENUM_TO_STRING(BUBBLE_DENY);
    ENUM_TO_STRING(WINDOW_CHANGE);
    ENUM_TO_STRING(EVENT_INVALID);
    default:
      NOTREACHED() << "No string for event " << event;
      return "Event-Unknown";
  }
}

// static
bool FullscreenControllerStateTest::IsWindowFullscreenStateChangedReentrant() {
#if defined(OS_MACOSX)
  return false;
#else
  return true;
#endif
}

// static
bool FullscreenControllerStateTest::IsPersistentState(State state) {
  switch (state) {
    case STATE_NORMAL:
    case STATE_BROWSER_FULLSCREEN_NO_CHROME:
    case STATE_BROWSER_FULLSCREEN_WITH_CHROME:
    case STATE_METRO_SNAP:
    case STATE_TAB_FULLSCREEN:
    case STATE_TAB_BROWSER_FULLSCREEN:
    case STATE_TAB_BROWSER_FULLSCREEN_CHROME:
      return true;

    case STATE_TO_NORMAL:
    case STATE_TO_BROWSER_FULLSCREEN_NO_CHROME:
    case STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME:
    case STATE_TO_TAB_FULLSCREEN:
      return false;

    default:
      NOTREACHED();
      return false;
  }
}

void FullscreenControllerStateTest::TransitionToState(State final_state) {
  int max_steps = NUM_STATES;
  while (max_steps-- && TransitionAStepTowardState(final_state))
    continue;
  ASSERT_GE(max_steps, 0) << "TransitionToState was unable to achieve desired "
      << "target state. TransitionAStepTowardState iterated too many times."
      << GetAndClearDebugLog();
  ASSERT_EQ(final_state, state_) << "TransitionToState was unable to achieve "
      << "desired target state. TransitionAStepTowardState returned false."
      << GetAndClearDebugLog();
}

bool FullscreenControllerStateTest::TransitionAStepTowardState(
    State destination_state) {
  State source_state = state_;
  if (source_state == destination_state)
    return false;

  StateTransitionInfo next = NextTransitionInShortestPath(source_state,
                                                          destination_state,
                                                          NUM_STATES);
  if (next.state == STATE_INVALID) {
    NOTREACHED() << "TransitionAStepTowardState unable to transition. "
        << "NextTransitionInShortestPath("
        << GetStateString(source_state) << ", "
        << GetStateString(destination_state) << ") returned STATE_INVALID."
        << GetAndClearDebugLog();
    return false;
  }

  return InvokeEvent(next.event);
}

const char* FullscreenControllerStateTest::GetWindowStateString() {
  return NULL;
}

bool FullscreenControllerStateTest::InvokeEvent(Event event) {
  if (!fullscreen_notification_observer_.get()) {
    // Start observing NOTIFICATION_FULLSCREEN_CHANGED. Construct the
    // notification observer here instead of in
    // FullscreenControllerStateTest::FullscreenControllerStateTest() so that we
    // listen to notifications on the proper thread.
    fullscreen_notification_observer_.reset(
        new FullscreenNotificationObserver());
  }

  State source_state = state_;
  State next_state = transition_table_[source_state][event];

  EXPECT_FALSE(ShouldSkipStateAndEventPair(source_state, event))
      << GetAndClearDebugLog();

  // When simulating reentrant window change calls, expect the next state
  // automatically.
  if (IsWindowFullscreenStateChangedReentrant())
    next_state = transition_table_[next_state][WINDOW_CHANGE];

  debugging_log_ << "  InvokeEvent(" << std::left
      << std::setw(kMaxStateNameLength) << GetEventString(event)
      << ") to "
      << std::setw(kMaxStateNameLength) << GetStateString(next_state);

  state_ = next_state;

  switch (event) {
    case TOGGLE_FULLSCREEN:
      GetFullscreenController()->ToggleBrowserFullscreenMode();
      break;

    case TOGGLE_FULLSCREEN_CHROME:
#if defined(OS_MACOSX)
      if (chrome::mac::SupportsSystemFullscreen()) {
        GetFullscreenController()->ToggleBrowserFullscreenWithToolbar();
        break;
      }
#endif
      NOTREACHED() << GetAndClearDebugLog();
      break;

    case TAB_FULLSCREEN_TRUE:
    case TAB_FULLSCREEN_FALSE: {
      content::WebContents* const active_tab =
          GetBrowser()->tab_strip_model()->GetActiveWebContents();
      if (event == TAB_FULLSCREEN_TRUE) {
        GetFullscreenController()->EnterFullscreenModeForTab(active_tab,
                                                             GURL());
      } else {
        GetFullscreenController()->ExitFullscreenModeForTab(active_tab);
      }

      // Activating/Deactivating tab fullscreen on a captured tab should not
      // evoke a state change in the browser window.
      if (active_tab->GetCapturerCount() > 0)
        state_ = source_state;
      break;
    }

    case METRO_SNAP_TRUE:
#if defined(OS_WIN)
      GetFullscreenController()->SetMetroSnapMode(true);
#else
      NOTREACHED() << GetAndClearDebugLog();
#endif
      break;

    case METRO_SNAP_FALSE:
#if defined(OS_WIN)
      GetFullscreenController()->SetMetroSnapMode(false);
#else
      NOTREACHED() << GetAndClearDebugLog();
#endif
      break;

    case BUBBLE_EXIT_LINK:
      GetFullscreenController()->ExitExclusiveAccessToPreviousState();
      break;

    case BUBBLE_ALLOW:
      GetBrowser()
          ->exclusive_access_manager()
          ->OnAcceptExclusiveAccessPermission();
      break;

    case BUBBLE_DENY:
      GetBrowser()
          ->exclusive_access_manager()
          ->OnDenyExclusiveAccessPermission();
      break;

    case WINDOW_CHANGE:
      ChangeWindowFullscreenState();
      break;

    default:
      NOTREACHED() << "InvokeEvent needs a handler for event "
          << GetEventString(event) << GetAndClearDebugLog();
      return false;
  }

  if (GetWindowStateString())
    debugging_log_ << " Window state now " << GetWindowStateString() << "\n";
  else
    debugging_log_ << "\n";

  MaybeWaitForNotification();
  VerifyWindowState();

  return true;
}

void FullscreenControllerStateTest::VerifyWindowState() {
  switch (state_) {
    case STATE_NORMAL:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_FALSE,
                                    FULLSCREEN_FOR_BROWSER_FALSE,
                                    FULLSCREEN_FOR_TAB_FALSE,
                                    IN_METRO_SNAP_FALSE);
      break;
    case STATE_BROWSER_FULLSCREEN_NO_CHROME:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_FALSE,
                                    FULLSCREEN_FOR_BROWSER_TRUE,
                                    FULLSCREEN_FOR_TAB_FALSE,
                                    IN_METRO_SNAP_FALSE);
      break;
    case STATE_BROWSER_FULLSCREEN_WITH_CHROME:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_TRUE,
                                    FULLSCREEN_FOR_BROWSER_TRUE,
                                    FULLSCREEN_FOR_TAB_FALSE,
                                    IN_METRO_SNAP_FALSE);
      break;
    case STATE_METRO_SNAP:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_NO_EXPECTATION,
                                    FULLSCREEN_FOR_BROWSER_NO_EXPECTATION,
                                    FULLSCREEN_FOR_TAB_NO_EXPECTATION,
                                    IN_METRO_SNAP_TRUE);
      break;
    case STATE_TAB_FULLSCREEN:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_FALSE,
                                    FULLSCREEN_FOR_BROWSER_FALSE,
                                    FULLSCREEN_FOR_TAB_TRUE,
                                    IN_METRO_SNAP_FALSE);
      break;
    case STATE_TAB_BROWSER_FULLSCREEN:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_FALSE,
                                    FULLSCREEN_FOR_BROWSER_TRUE,
                                    FULLSCREEN_FOR_TAB_TRUE,
                                    IN_METRO_SNAP_FALSE);
      break;
    case STATE_TAB_BROWSER_FULLSCREEN_CHROME:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_FALSE,
                                    FULLSCREEN_FOR_BROWSER_TRUE,
                                    FULLSCREEN_FOR_TAB_TRUE,
                                    IN_METRO_SNAP_FALSE);
      break;
    case STATE_TO_NORMAL:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_FALSE,
                                    FULLSCREEN_FOR_BROWSER_NO_EXPECTATION,
                                    FULLSCREEN_FOR_TAB_NO_EXPECTATION,
                                    IN_METRO_SNAP_FALSE);
      break;

    case STATE_TO_BROWSER_FULLSCREEN_NO_CHROME:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_FALSE,
#if defined(OS_MACOSX)
                                    FULLSCREEN_FOR_BROWSER_TRUE,
#else
                                    FULLSCREEN_FOR_BROWSER_FALSE,
#endif
                                    FULLSCREEN_FOR_TAB_NO_EXPECTATION,
                                    IN_METRO_SNAP_FALSE);
      break;

    case STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME:
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_TRUE,
#if defined(OS_MACOSX)
                                    FULLSCREEN_FOR_BROWSER_TRUE,
#else
                                    FULLSCREEN_FOR_BROWSER_FALSE,
#endif
                                    FULLSCREEN_FOR_TAB_NO_EXPECTATION,
                                    IN_METRO_SNAP_FALSE);
      break;

    case STATE_TO_TAB_FULLSCREEN:
#if defined(OS_MACOSX)
      // TODO(scheib) InPresentationMode returns false when invoking events:
      // TAB_FULLSCREEN_TRUE, TOGGLE_FULLSCREEN. http://crbug.com/156645
      // It may be that a new testing state TO_TAB_BROWSER_FULLSCREEN
      // would help work around this http://crbug.com/154196
      // Test with: STATE_TO_TAB_FULLSCREEN__TOGGLE_FULLSCREEN
      //
      // EXPECT_TRUE(GetBrowser()->window()->InPresentationMode())
      //     << GetAndClearDebugLog();
#endif
      VerifyWindowStateExpectations(FULLSCREEN_WITH_CHROME_NO_EXPECTATION,
                                    FULLSCREEN_FOR_BROWSER_FALSE,
                                    FULLSCREEN_FOR_TAB_TRUE,
                                    IN_METRO_SNAP_FALSE);
      break;

    default:
      NOTREACHED() << GetAndClearDebugLog();
  }
}

void FullscreenControllerStateTest::MaybeWaitForNotification() {
  // We should get a fullscreen notification each time we get to a new
  // persistent state. If we don't get a notification, the test will
  // fail by timing out.
  if (state_ != last_notification_received_state_ &&
      IsPersistentState(state_)) {
    fullscreen_notification_observer_->Wait();
    last_notification_received_state_ = state_;
    fullscreen_notification_observer_.reset(
        new FullscreenNotificationObserver());
  }
}

void FullscreenControllerStateTest::TestTransitionsForEachState() {
  for (int source_int = 0; source_int < NUM_STATES; ++source_int) {
    for (int event1_int = 0; event1_int < NUM_EVENTS; ++event1_int) {
      State state = static_cast<State>(source_int);
      Event event1 = static_cast<Event>(event1_int);

      // Early out if skipping all tests for this state, reduces log noise.
      if (ShouldSkipTest(state, event1))
        continue;

      for (int event2_int = 0; event2_int < NUM_EVENTS; ++event2_int) {
        for (int event3_int = 0; event3_int < NUM_EVENTS; ++event3_int) {
          Event event2 = static_cast<Event>(event2_int);
          Event event3 = static_cast<Event>(event3_int);

          // Test each state and each event.
          ASSERT_NO_FATAL_FAILURE(TestStateAndEvent(state, event1))
              << GetAndClearDebugLog();

          // Then, add an additional event to the sequence.
          if (ShouldSkipStateAndEventPair(state_, event2))
            continue;
          ASSERT_TRUE(InvokeEvent(event2)) << GetAndClearDebugLog();

          // Then, add an additional event to the sequence.
          if (ShouldSkipStateAndEventPair(state_, event3))
            continue;
          ASSERT_TRUE(InvokeEvent(event3)) << GetAndClearDebugLog();
        }
      }
    }
  }
}

FullscreenControllerStateTest::StateTransitionInfo
    FullscreenControllerStateTest::NextTransitionInShortestPath(
    State source,
    State destination,
    int search_limit) {
  if (search_limit <= 0)
    return StateTransitionInfo();  // Return a default (invalid) state.

  if (state_transitions_[source][destination].state == STATE_INVALID) {
    // Don't know the next state yet, do a depth first search.
    StateTransitionInfo result;

    // Consider all states reachable via each event from the source state.
    for (int event_int = 0; event_int < NUM_EVENTS; ++event_int) {
      Event event = static_cast<Event>(event_int);
      State next_state_candidate = transition_table_[source][event];

      if (ShouldSkipStateAndEventPair(source, event))
        continue;

      // Recurse.
      StateTransitionInfo candidate = NextTransitionInShortestPath(
          next_state_candidate, destination, search_limit - 1);

      if (candidate.distance + 1 < result.distance) {
        result.event = event;
        result.state = next_state_candidate;
        result.distance = candidate.distance + 1;
      }
    }

    // Cache result so that a search is not required next time.
    state_transitions_[source][destination] = result;
  }

  return state_transitions_[source][destination];
}

std::string FullscreenControllerStateTest::GetAndClearDebugLog() {
  debugging_log_ << "(End of Debugging Log)\n";
  std::string output_log = "\nDebugging Log:\n" + debugging_log_.str();
  debugging_log_.str(std::string());
  return output_log;
}

bool FullscreenControllerStateTest::ShouldSkipStateAndEventPair(State state,
                                                                Event event) {
  // TODO(scheib) Toggling Tab fullscreen while pending Tab or
  // Browser fullscreen is broken currently http://crbug.com/154196
  if ((state == STATE_TO_BROWSER_FULLSCREEN_NO_CHROME ||
       state == STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME ||
       state == STATE_TO_TAB_FULLSCREEN) &&
      (event == TAB_FULLSCREEN_TRUE || event == TAB_FULLSCREEN_FALSE))
    return true;
  if (state == STATE_TO_NORMAL && event == TAB_FULLSCREEN_TRUE)
    return true;

  // Skip metro snap state and events when not on windows.
#if !defined(OS_WIN)
  if (state == STATE_METRO_SNAP ||
      event == METRO_SNAP_TRUE ||
      event == METRO_SNAP_FALSE)
    return true;
#endif

  // Skip Mac Lion Fullscreen state and events when not on OSX 10.7+.
  if (!SupportsMacSystemFullscreen()) {
    if (state == STATE_BROWSER_FULLSCREEN_WITH_CHROME ||
        state == STATE_TAB_BROWSER_FULLSCREEN_CHROME ||
        state == STATE_TO_BROWSER_FULLSCREEN_WITH_CHROME ||
        event == TOGGLE_FULLSCREEN_CHROME) {
      return true;
    }
  }

  return false;
}

bool FullscreenControllerStateTest::ShouldSkipTest(State state, Event event) {
  // Quietly skip metro snap tests when not on windows.
#if !defined(OS_WIN)
  if (state == STATE_METRO_SNAP ||
      event == METRO_SNAP_TRUE ||
      event == METRO_SNAP_FALSE) {
    debugging_log_ << "\nSkipping metro snap test on non-Windows.\n";
    return true;
  }
#endif

  // Quietly skip Mac Lion Fullscreen tests when not on OSX 10.7+.
  if (!SupportsMacSystemFullscreen()) {
    if (state == STATE_BROWSER_FULLSCREEN_WITH_CHROME ||
        event == TOGGLE_FULLSCREEN_CHROME) {
      debugging_log_ << "\nSkipping Lion Fullscreen test on non-OSX 10.7+.\n";
      return true;
    }
  }

  // When testing reentrancy there are states the fullscreen controller
  // will be unable to remain in, as they will progress due to the
  // reentrant window change call. Skip states that will be instantly
  // exited by the reentrant call.
  if (IsWindowFullscreenStateChangedReentrant() &&
      (transition_table_[state][WINDOW_CHANGE] != state)) {
    debugging_log_ << "\nSkipping reentrant test for transitory source state "
        << GetStateString(state) << ".\n";
    return true;
  }

  if (ShouldSkipStateAndEventPair(state, event)) {
    debugging_log_ << "\nSkipping test due to ShouldSkipStateAndEventPair("
        << GetStateString(state) << ", "
        << GetEventString(event) << ").\n";
    LOG(INFO) << "Skipping test due to ShouldSkipStateAndEventPair("
        << GetStateString(state) << ", "
        << GetEventString(event) << ").";
    return true;
  }

  return false;
}

void FullscreenControllerStateTest::TestStateAndEvent(State state,
                                                      Event event) {
  if (ShouldSkipTest(state, event))
    return;

  debugging_log_ << "\nTest transition from state "
      << GetStateString(state)
      << (IsWindowFullscreenStateChangedReentrant() ?
          " with reentrant calls.\n" : ".\n");

  // Spaced out text to line up with columns printed in InvokeEvent().
  debugging_log_ << "First,                                               from "
      << GetStateString(state_) << "\n";
  ASSERT_NO_FATAL_FAILURE(TransitionToState(state))
      << GetAndClearDebugLog();

  debugging_log_ << " Then,\n";
  ASSERT_TRUE(InvokeEvent(event)) << GetAndClearDebugLog();
}

void FullscreenControllerStateTest::VerifyWindowStateExpectations(
    FullscreenWithToolbarExpectation fullscreen_with_toolbar,
    FullscreenForBrowserExpectation fullscreen_for_browser,
    FullscreenForTabExpectation fullscreen_for_tab,
    InMetroSnapExpectation in_metro_snap) {
  if (fullscreen_with_toolbar != FULLSCREEN_WITH_CHROME_NO_EXPECTATION &&
      GetBrowser()->window()->SupportsFullscreenWithToolbar()) {
    EXPECT_EQ(GetBrowser()->window()->IsFullscreenWithToolbar(),
              !!fullscreen_with_toolbar) << GetAndClearDebugLog();
  }
  if (fullscreen_for_browser != FULLSCREEN_FOR_BROWSER_NO_EXPECTATION) {
    EXPECT_EQ(GetFullscreenController()->IsFullscreenForBrowser(),
              !!fullscreen_for_browser) << GetAndClearDebugLog();
  }
  if (fullscreen_for_tab != FULLSCREEN_FOR_TAB_NO_EXPECTATION) {
    EXPECT_EQ(GetFullscreenController()->IsWindowFullscreenForTabOrPending(),
              !!fullscreen_for_tab) << GetAndClearDebugLog();
  }

#if defined(OS_WIN)
  if (in_metro_snap != IN_METRO_SNAP_NO_EXPECTATION) {
    EXPECT_EQ(GetFullscreenController()->IsInMetroSnapMode(),
              !!in_metro_snap) << GetAndClearDebugLog();
  }
#endif  // OS_WIN
}

FullscreenController* FullscreenControllerStateTest::GetFullscreenController() {
  return GetBrowser()->exclusive_access_manager()->fullscreen_controller();
}

std::string FullscreenControllerStateTest::GetTransitionTableAsString() const {
  std::ostringstream output;
  output << "transition_table_[NUM_STATES = " << NUM_STATES
      << "][NUM_EVENTS = " << NUM_EVENTS
      << "] =\n";
  for (int state_int = 0; state_int < NUM_STATES; ++state_int) {
    State state = static_cast<State>(state_int);
    output << "    { // " << GetStateString(state) << ":\n";
    for (int event_int = 0; event_int < NUM_EVENTS; ++event_int) {
      Event event = static_cast<Event>(event_int);
      output << "      "
          << std::left << std::setw(kMaxStateNameLength+1)
          << std::string(GetStateString(transition_table_[state][event])) + ","
          << "// Event "
          << GetEventString(event) << "\n";
    }
    output << "    },\n";
  }
  output << "  };\n";
  return output.str();
}

std::string FullscreenControllerStateTest::GetStateTransitionsAsString() const {
  std::ostringstream output;
  output << "state_transitions_[NUM_STATES = " << NUM_STATES
      << "][NUM_STATES = " << NUM_STATES << "] =\n";
  for (int state1_int = 0; state1_int < NUM_STATES; ++state1_int) {
    State state1 = static_cast<State>(state1_int);
    output << "{ // " << GetStateString(state1) << ":\n";
    for (int state2_int = 0; state2_int < NUM_STATES; ++state2_int) {
      State state2 = static_cast<State>(state2_int);
      const StateTransitionInfo& info = state_transitions_[state1][state2];
      output << "  { "
        << std::left << std::setw(kMaxStateNameLength+1)
        << std::string(GetEventString(info.event)) + ","
        << std::left << std::setw(kMaxStateNameLength+1)
        << std::string(GetStateString(info.state)) + ","
        << std::right << std::setw(2)
        << info.distance
        << " }, // "
        << GetStateString(state2) << "\n";
    }
    output << "},\n";
  }
  output << "};";
  return output.str();
}