// Copyright 2025 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/views/frame/multi_contents_view.h"

#include "base/check_deref.h"
#include "base/files/file_path.h"
#include "base/notreached.h"
#include "base/test/run_until.h"
#include "base/test/scoped_feature_list.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/browser/ui/browser_commands.h"
#include "chrome/browser/ui/browser_window.h"
#include "chrome/browser/ui/tabs/split_tab_metrics.h"
#include "chrome/browser/ui/tabs/tab_model.h"
#include "chrome/browser/ui/ui_features.h"
#include "chrome/browser/ui/views/frame/multi_contents_drop_target_view.h"
#include "chrome/browser/ui/views/frame/multi_contents_view_drop_target_controller.h"
#include "chrome/browser/ui/views/tabs/dragging/tab_drag_controller.h"
#include "chrome/browser/ui/views/test/split_tabs_interactive_test_mixin.h"
#include "chrome/test/base/in_process_browser_test.h"
#include "chrome/test/base/ui_test_utils.h"
#include "components/tabs/public/split_tab_data.h"
#include "content/public/test/browser_test.h"
#include "content/public/test/browser_test_utils.h"
#include "testing/gmock/include/gmock/gmock.h"
#include "third_party/blink/public/mojom/frame/fullscreen.mojom.h"
#include "ui/base/dragdrop/drag_drop_types.h"
#include "ui/base/dragdrop/drop_target_event.h"
#include "ui/base/dragdrop/mojom/drag_drop_types.mojom.h"
#include "ui/base/dragdrop/os_exchange_data.h"
#include "ui/base/dragdrop/os_exchange_data_provider.h"
#include "ui/base/interaction/element_tracker.h"
#include "ui/base/ozone_buildflags.h"
#include "ui/compositor/layer_tree_owner.h"
#include "ui/ozone/public/ozone_platform.h"
#include "ui/views/interaction/element_tracker_views.h"
#include "ui/views/view_utils.h"
#include "url/gurl.h"
#include "url/url_constants.h"

using testing::Return;
using testing::ReturnRef;

namespace {

class MockDragController : public TabDragDelegate::DragController {
 public:
  MockDragController() = default;
  MockDragController(const MockDragController&) = delete;
  MockDragController& operator=(const MockDragController&) = delete;
  ~MockDragController() override = default;

  MOCK_METHOD(std::unique_ptr<tabs::TabModel>,
              DetachTabAtForInsertion,
              (int),
              (override));
  MOCK_METHOD(const DragSessionData&, GetSessionData, (), (const, override));
};

}  // namespace

class MultiContentsViewBrowserTest : public InProcessBrowserTest {
 protected:
  MultiContentsViewBrowserTest() {
    feature_list_.InitAndEnableFeature(features::kSideBySide);
  }

  MultiContentsDropTargetView& drop_target_view() {
    MultiContentsDropTargetView* view =
        views::ElementTrackerViews::GetInstance()
            ->GetFirstMatchingViewAs<MultiContentsDropTargetView>(
                MultiContentsDropTargetView::kMultiContentsDropTargetElementId,
                views::ElementTrackerViews::GetContextForWidget(
                    multi_contents_view().GetWidget()));

    CHECK(view);
    return *view;
  }

  MultiContentsView& multi_contents_view() {
    return CHECK_DEREF(BrowserView::GetBrowserViewForBrowser(browser())
                           ->multi_contents_view());
  }

 private:
  base::test::ScopedFeatureList feature_list_;
};

IN_PROC_BROWSER_TEST_F(MultiContentsViewBrowserTest,
                       HandleDropTargetViewLinkDrop_EndDropTarget) {
// TODO(crbug.com/425715421): Fix drag and drop on Wayland.
#if BUILDFLAG(IS_OZONE)
  if (!ui::OzonePlatform::GetInstance()
           ->GetPlatformProperties()
           .supports_split_view_drag_and_drop) {
    return;
  }
#endif

  ui::OSExchangeData data;
  const GURL kDropUrl("http://www.chromium.org/");
  data.SetURL(kDropUrl, u"Chromium");
  gfx::PointF point = {10, 10};
  ui::DropTargetEvent event(data, point, point, ui::DragDropTypes::DRAG_LINK);

  drop_target_view().Show(MultiContentsDropTargetView::DropSide::END);
  auto drop_cb = drop_target_view().GetDropCallback(event);
  EXPECT_FALSE(multi_contents_view().IsInSplitView());

  ui::mojom::DragOperation output_drag_op = ui::mojom::DragOperation::kNone;
  std::move(drop_cb).Run(event, output_drag_op,
                         /*drag_image_layer_owner=*/nullptr);

  EXPECT_TRUE(multi_contents_view().IsInSplitView());

  // After the drop, a new tab should be created in the split view.
  // The original tab is at index 0, the new tab from the drop is at index 1.
  ASSERT_EQ(2, browser()->tab_strip_model()->count());
  EXPECT_EQ(GURL(url::kAboutBlankURL),
            browser()->tab_strip_model()->GetWebContentsAt(0)->GetURL());
  EXPECT_EQ(kDropUrl,
            browser()->tab_strip_model()->GetWebContentsAt(1)->GetURL());
}

IN_PROC_BROWSER_TEST_F(MultiContentsViewBrowserTest,
                       HandleDropTargetViewLinkDrop_StartDropTarget) {
  // TODO(crbug.com/425715421): Fix drag and drop on Wayland.
#if BUILDFLAG(IS_OZONE)
  if (!ui::OzonePlatform::GetInstance()
           ->GetPlatformProperties()
           .supports_split_view_drag_and_drop) {
    return;
  }
#endif
  ui::OSExchangeData data;
  const GURL kDropUrl("http://www.chromium.org/");
  data.SetURL(kDropUrl, u"Chromium");
  gfx::PointF point = {10, 10};
  ui::DropTargetEvent event(data, point, point, ui::DragDropTypes::DRAG_LINK);

  drop_target_view().Show(MultiContentsDropTargetView::DropSide::START);
  auto drop_cb = drop_target_view().GetDropCallback(event);
  EXPECT_FALSE(multi_contents_view().IsInSplitView());

  ui::mojom::DragOperation output_drag_op = ui::mojom::DragOperation::kNone;
  std::move(drop_cb).Run(event, output_drag_op,
                         /*drag_image_layer_owner=*/nullptr);

  EXPECT_TRUE(multi_contents_view().IsInSplitView());

  // After the drop, a new tab should be created in the split view.
  // The original tab is at index 0, the new tab from the drop is at index 1.
  ASSERT_EQ(2, browser()->tab_strip_model()->count());
  EXPECT_EQ(kDropUrl,
            browser()->tab_strip_model()->GetWebContentsAt(0)->GetURL());
  EXPECT_EQ(GURL(url::kAboutBlankURL),
            browser()->tab_strip_model()->GetWebContentsAt(1)->GetURL());
}

IN_PROC_BROWSER_TEST_F(MultiContentsViewBrowserTest,
                       HandleTabDrop_EndDropTarget) {
  // TODO(crbug.com/425715421): Fix drag and drop on Wayland.
#if BUILDFLAG(IS_OZONE)
  if (!ui::OzonePlatform::GetInstance()
           ->GetPlatformProperties()
           .supports_split_view_drag_and_drop) {
    return;
  }
#endif

  TabStripModel* tab_strip_model = browser()->tab_strip_model();
  ASSERT_EQ(1, tab_strip_model->count());
  EXPECT_FALSE(multi_contents_view().IsInSplitView());

  // Show the drop target on the end side.
  drop_target_view().Show(MultiContentsDropTargetView::DropSide::END);

  // Create a second browser with a tab to be dragged.
  Browser* browser2 = CreateBrowser(browser()->profile());
  content::WebContents* contents_to_drop =
      browser2->GetTabStripModel()->GetActiveWebContents();

  // Mock the drag controller to simulate a tab drop.
  MockDragController controller;
  DragSessionData session_data;
  session_data.source_view_index_ = 0;
  EXPECT_CALL(controller, GetSessionData).WillOnce(ReturnRef(session_data));
  EXPECT_CALL(controller, DetachTabAtForInsertion(0))
      .WillOnce(
          Return(browser2->GetTabStripModel()->DetachTabAtForInsertion(0)));

  // Handle the tab drop.
  multi_contents_view().drop_target_controller().HandleTabDrop(controller);

  // Verify the state after the drop.
  EXPECT_TRUE(multi_contents_view().IsInSplitView());
  ASSERT_EQ(2, tab_strip_model->count());
  EXPECT_EQ(contents_to_drop, tab_strip_model->GetWebContentsAt(1));
  EXPECT_EQ(1, tab_strip_model->active_index());
}

IN_PROC_BROWSER_TEST_F(MultiContentsViewBrowserTest,
                       HandleTabDrop_StartDropTarget) {
  // TODO(crbug.com/425715421): Fix drag and drop on Wayland.
#if BUILDFLAG(IS_OZONE)
  if (!ui::OzonePlatform::GetInstance()
           ->GetPlatformProperties()
           .supports_split_view_drag_and_drop) {
    return;
  }
#endif

  TabStripModel* tab_strip_model = browser()->tab_strip_model();
  content::WebContents* original_contents =
      tab_strip_model->GetActiveWebContents();
  ASSERT_EQ(1, tab_strip_model->count());
  EXPECT_FALSE(multi_contents_view().IsInSplitView());

  // Show the drop target on the start side.
  drop_target_view().Show(MultiContentsDropTargetView::DropSide::START);

  // Create a second browser with a tab to be dragged.
  Browser* browser2 = CreateBrowser(browser()->profile());
  content::WebContents* contents_to_drop =
      browser2->GetTabStripModel()->GetActiveWebContents();

  // Mock the drag controller to simulate a tab drop.
  MockDragController controller;
  DragSessionData session_data;
  session_data.source_view_index_ = 0;
  EXPECT_CALL(controller, GetSessionData).WillOnce(ReturnRef(session_data));
  EXPECT_CALL(controller, DetachTabAtForInsertion(0))
      .WillOnce(
          Return(browser2->GetTabStripModel()->DetachTabAtForInsertion(0)));

  // Handle the tab drop.
  multi_contents_view().drop_target_controller().HandleTabDrop(controller);

  // Verify the state after the drop.
  EXPECT_TRUE(multi_contents_view().IsInSplitView());
  ASSERT_EQ(2, tab_strip_model->count());
  EXPECT_EQ(contents_to_drop, tab_strip_model->GetWebContentsAt(0));
  EXPECT_EQ(original_contents, tab_strip_model->GetWebContentsAt(1));
  EXPECT_EQ(0, tab_strip_model->active_index());
}

// Test class for WebContents ReLayout.
class MultiContentsViewWebContentsReLayoutBrowserTest
    : public InProcessBrowserTest {
 protected:
  MultiContentsViewWebContentsReLayoutBrowserTest() {
    feature_list_.InitAndEnableFeature(features::kSideBySide);
  }

  static constexpr char kReLayoutTestURL[] = "/re_layout_test.html";

  void SetUpOnMainThread() override {
    CreateTestServer(base::FilePath(FILE_PATH_LITERAL("chrome/test/data")));
    EXPECT_TRUE(embedded_test_server()->InitializeAndListen());
    embedded_test_server()->StartAcceptingConnections();
  }

  void CheckNoResizeHappened() {
    auto* tab_strip_model = browser()->tab_strip_model();
    for (int i = 0; i < tab_strip_model->count(); i++) {
      auto* web_contents = tab_strip_model->GetWebContentsAt(i);
      EXPECT_TRUE(content::WaitForLoadStop(web_contents));
      EXPECT_EQ(false, content::EvalJs(web_contents, "window.has_resized"));
    }
  }

  int GetResizeCount(content::WebContents* web_contents) {
    return content::EvalJs(web_contents, "window.resize_count").ExtractInt();
  }

  void CreateSplitTabAndLoadReLayoutTestPage() {
    CreateSplitView();
    LoadReLayoutTestPageInActiveSplitTabs();
  }

  void CreateSplitView() {
    auto* tab_strip_model = browser()->tab_strip_model();
    const int active_index = tab_strip_model->active_index();

    RunScheduledLayouts();
    chrome::NewSplitTab(browser(),
                        split_tabs::SplitTabCreatedSource::kToolbarButton);
    EXPECT_TRUE(content::WaitForLoadStop(
        tab_strip_model->GetWebContentsAt(active_index + 1)));
    RunScheduledLayouts();
  }

  void LoadReLayoutTestPageInActiveSplitTabs() {
    auto* tab_strip_model = browser()->tab_strip_model();
    const int active_index = tab_strip_model->active_index();
    split_tabs::SplitTabId split_id =
        tab_strip_model->GetSplitForTab(active_index).value();
    split_tabs::SplitTabData* split_data =
        tab_strip_model->GetSplitData(split_id);
    ASSERT_TRUE(split_data);

    const GURL test_url = embedded_test_server()->GetURL(kReLayoutTestURL);
    for (tabs::TabInterface* tab : split_data->ListTabs()) {
      tab->GetContents()->GetController().LoadURL(test_url, content::Referrer(),
                                                  ui::PAGE_TRANSITION_TYPED,
                                                  std::string());
      EXPECT_TRUE(content::WaitForLoadStop(tab->GetContents()));
    }
  }

  MultiContentsView& multi_contents_view() {
    return CHECK_DEREF(BrowserView::GetBrowserViewForBrowser(browser())
                           ->multi_contents_view());
  }

 private:
  base::test::ScopedFeatureList feature_list_;
};

// TODO(https://crbug.com/430525043): Flaky on Linux.
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
#define MAYBE_SwitchingTabsShouldNotTriggerWebContentsReLayout_SplitNoSplit \
  DISABLED_SwitchingTabsShouldNotTriggerWebContentsReLayout_SplitNoSplit
#else
#define MAYBE_SwitchingTabsShouldNotTriggerWebContentsReLayout_SplitNoSplit \
  SwitchingTabsShouldNotTriggerWebContentsReLayout_SplitNoSplit
#endif
IN_PROC_BROWSER_TEST_F(
    MultiContentsViewWebContentsReLayoutBrowserTest,
    MAYBE_SwitchingTabsShouldNotTriggerWebContentsReLayout_SplitNoSplit) {
  auto* tab_strip_model = browser()->tab_strip_model();

  const GURL test_url = embedded_test_server()->GetURL(kReLayoutTestURL);

  // Load the test page in the active tab.
  tab_strip_model->GetActiveWebContents()->GetController().LoadURL(
      test_url, content::Referrer(), ui::PAGE_TRANSITION_TYPED, std::string());
  EXPECT_TRUE(
      content::WaitForLoadStop(tab_strip_model->GetActiveWebContents()));

  // Add a new tab and open split view.
  EXPECT_TRUE(
      AddTabAtIndex(1, GURL(url::kAboutBlankURL), ui::PAGE_TRANSITION_TYPED));
  CreateSplitTabAndLoadReLayoutTestPage();

  // Focus on the split tab.
  tab_strip_model->GetWebContentsAt(1)->Focus();
  RunScheduledLayouts();

  // Switching tabs should not trigger a re-layout.
  tab_strip_model->ActivateTabAt(
      0, TabStripUserGestureDetails(
             TabStripUserGestureDetails::GestureType::kOther));
  RunScheduledLayouts();
  tab_strip_model->ActivateTabAt(
      1, TabStripUserGestureDetails(
             TabStripUserGestureDetails::GestureType::kOther));
  RunScheduledLayouts();

  // No resize should have happened in the web contents.
  CheckNoResizeHappened();
}

IN_PROC_BROWSER_TEST_F(
    MultiContentsViewWebContentsReLayoutBrowserTest,
    SwitchingTabsShouldNotTriggerWebContentsReLayout_SplitSplit) {
  auto* tab_strip_model = browser()->tab_strip_model();

  const GURL test_url = embedded_test_server()->GetURL(kReLayoutTestURL);

  // Open split view and test page.
  CreateSplitTabAndLoadReLayoutTestPage();

  // Focus on the split tab.
  tab_strip_model->GetWebContentsAt(1)->Focus();

  // Add a new tab and open split view.
  EXPECT_TRUE(
      AddTabAtIndex(2, GURL(url::kAboutBlankURL), ui::PAGE_TRANSITION_TYPED));
  CreateSplitView();

  // Change the size.
  multi_contents_view().OnResize(multi_contents_view().width() * 0.3, true);
  RunScheduledLayouts();

  // Load the test page in the active tab and split tab.
  LoadReLayoutTestPageInActiveSplitTabs();
  RunScheduledLayouts();

  // Switching tabs should not trigger a re-layout.
  tab_strip_model->ActivateTabAt(
      0, TabStripUserGestureDetails(
             TabStripUserGestureDetails::GestureType::kOther));
  RunScheduledLayouts();
  tab_strip_model->ActivateTabAt(
      2, TabStripUserGestureDetails(
             TabStripUserGestureDetails::GestureType::kOther));
  RunScheduledLayouts();

  // No resize should have happened in the web contents.
  CheckNoResizeHappened();
}

// TODO(crbug.com/429495554): Flaky on Mac and Windows.
#if BUILDFLAG(IS_MAC) || BUILDFLAG(IS_WIN)
#define MAYBE_EnterAndExitFullscreenInSplitTabShouldOnlyResizeTwice \
  DISABLED_EnterAndExitFullscreenInSplitTabShouldOnlyResizeTwice
#else
#define MAYBE_EnterAndExitFullscreenInSplitTabShouldOnlyResizeTwice \
  EnterAndExitFullscreenInSplitTabShouldOnlyResizeTwice
#endif
IN_PROC_BROWSER_TEST_F(
    MultiContentsViewWebContentsReLayoutBrowserTest,
    MAYBE_EnterAndExitFullscreenInSplitTabShouldOnlyResizeTwice) {
#if BUILDFLAG(IS_OZONE)
  // TODO(crbug.com/429495554): Investigate why this test failed on wayland.
  if (ui::OzonePlatform::GetPlatformNameForTest() == "wayland") {
    GTEST_SKIP();
  }
#endif
  auto* tab_strip_model = browser()->tab_strip_model();

  const GURL test_url = embedded_test_server()->GetURL(kReLayoutTestURL);

  CreateSplitView();

  // Change the size.
  multi_contents_view().OnResize(multi_contents_view().width() * 0.3, true);
  RunScheduledLayouts();

  // Load the test page in the active tab and split tab.
  LoadReLayoutTestPageInActiveSplitTabs();
  RunScheduledLayouts();

  // Focus on the split tab.
  tab_strip_model->GetWebContentsAt(1)->Focus();
  RunScheduledLayouts();

  // Enter fullscreen in the split tab.
  content::WebContents* split_tab = tab_strip_model->GetWebContentsAt(1);
  split_tab->GetDelegate()->EnterFullscreenModeForTab(
      split_tab->GetPrimaryMainFrame(), {});
  ui_test_utils::FullscreenWaiter(browser(), {.tab_fullscreen = true}).Wait();
  RunScheduledLayouts();

  EXPECT_TRUE(base::test::RunUntil(
      [this, split_tab]() { return GetResizeCount(split_tab) >= 1; }));

  // Exit fullscreen in the split tab.
  split_tab->GetDelegate()->ExitFullscreenModeForTab(split_tab);
  ui_test_utils::FullscreenWaiter(
      browser(), ui_test_utils::FullscreenWaiter::kNoFullscreen)
      .Wait();
  RunScheduledLayouts();

  EXPECT_TRUE(base::test::RunUntil(
      [this, split_tab]() { return GetResizeCount(split_tab) >= 2; }));
  RunScheduledLayouts();

  // Should resized twice.
  EXPECT_EQ(GetResizeCount(split_tab), 2);
}