// Copyright 2017 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/browser/android/dialog_overlay_impl.h"

#include "content/browser/renderer_host/render_frame_host_impl.h"
#include "content/browser/renderer_host/render_widget_host_view_base.h"
#include "content/browser/web_contents/web_contents_impl.h"
#include "content/public/android/content_jni_headers/DialogOverlayImpl_jni.h"
#include "content/public/browser/browser_task_traits.h"
#include "content/public/browser/browser_thread.h"
#include "content/public/browser/content_browser_client.h"
#include "content/public/browser/web_contents_delegate.h"
#include "content/public/common/content_client.h"
#include "gpu/ipc/common/gpu_surface_tracker.h"
#include "media/mojo/mojom/android_overlay.mojom.h"
#include "mojo/public/cpp/bindings/sync_call_restrictions.h"
#include "third_party/abseil-cpp/absl/types/variant.h"
#include "ui/android/view_android_observer.h"
#include "ui/android/window_android.h"

using base::android::AttachCurrentThread;
using base::android::JavaParamRef;
using base::android::ScopedJavaLocalRef;

namespace content {

static jlong JNI_DialogOverlayImpl_Init(JNIEnv* env,
                                        const JavaParamRef<jobject>& obj,
                                        jlong high,
                                        jlong low,
                                        jboolean power_efficient) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  absl::optional<base::UnguessableToken> token =
      base::UnguessableToken::Deserialize(high, low);
  if (!token.has_value()) {
    return 0;
  }

  RenderFrameHostImpl* rfhi =
      content::RenderFrameHostImpl::FromOverlayRoutingToken(token.value());

  if (!rfhi)
    return 0;

  // If the RenderFrameHost does not have a live RenderFrame, immediately bail
  // out: not only is there nothing to do, the `RenderFrameDeleted()`
  // notification to clean up the overlay would never be called.
  if (!rfhi->IsRenderFrameLive())
    return 0;

  WebContentsImpl* web_contents_impl = static_cast<WebContentsImpl*>(
      content::WebContents::FromRenderFrameHost(rfhi));

  // If the overlay would not be immediately used, fail the request.
  if (!rfhi->IsActive() || !web_contents_impl || web_contents_impl->IsHidden())
    return 0;

  // Dialog-based overlays are not supported for persistent video.
  if (web_contents_impl->has_persistent_video())
    return 0;

  // If we require a power-efficient overlay, then approximate that with "is
  // fullscreen".  The reason is that we want to be somewhat sure that we don't
  // have more layers than HWC can support, else SurfaceFlinger will fall back
  // to GLES composition.  In fullscreen mode, the android status bar is hidden,
  // as is the nav bar (if present).  The chrome activity surface also gets
  // hidden when possible.
  if (power_efficient && !web_contents_impl->IsFullscreen())
    return 0;

  bool observe_container_view =
      GetContentClient()
          ->browser()
          ->ShouldObserveContainerViewLocationForDialogOverlays();

  return reinterpret_cast<jlong>(new DialogOverlayImpl(
      obj, rfhi, web_contents_impl, power_efficient, observe_container_view));
}

DialogOverlayImpl::DialogOverlayImpl(const JavaParamRef<jobject>& obj,
                                     RenderFrameHostImpl* rfhi,
                                     WebContents* web_contents,
                                     bool power_efficient,
                                     bool observe_container_view)
    : WebContentsObserver(web_contents),
      rfhi_(rfhi),
      power_efficient_(power_efficient),
      observed_window_android_(false),
      observe_container_view_(observe_container_view) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  DCHECK(rfhi_);

  JNIEnv* env = AttachCurrentThread();
  obj_ = JavaObjectWeakGlobalRef(env, obj);

  // Make sure RenderFrameDeleted will be called on RFH and thus we will clean
  // up.
  CHECK(rfhi_->IsRenderFrameLive());
  web_contents->GetNativeView()->AddObserver(this);

  // Note that we're not allowed to call back into |obj| before it calls
  // CompleteInit.  However, the observer won't actually call us back until the
  // token changes.  As long as the java side calls us from the ui thread before
  // returning, we won't send a callback before then.
}

void DialogOverlayImpl::CompleteInit(JNIEnv* env,
                                     const JavaParamRef<jobject>& obj) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  WebContentsDelegate* delegate = web_contents()->GetDelegate();

  if (!delegate) {
    Stop();
    return;
  }

  // Note: It's ok to call SetOverlayMode() directly here, because there can be
  // at most one overlay alive at the time. This logic needs to be updated if
  // ever AndroidOverlayProviderImpl.MAX_OVERLAYS > 1.
  delegate->SetOverlayMode(true);

  Java_DialogOverlayImpl_onWebContents(env, obj,
                                       web_contents()->GetJavaWebContents());

  // Send the initial token, if there is one.  The observer will notify us about
  // changes only.
  if (auto* window = web_contents()->GetNativeView()->GetWindowAndroid()) {
    RegisterWindowObserverIfNeeded(window);
    Java_DialogOverlayImpl_onWindowAndroid(env, obj, window->GetJavaObject());
  }

  // Pass up a reference to the container view so we can observe its location.
  // The observer will notify us if there is none yet.
  StartObservingContainerView();
}

DialogOverlayImpl::~DialogOverlayImpl() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
}

void DialogOverlayImpl::Stop() {
  UnregisterCallbacksIfNeeded();

  JNIEnv* env = AttachCurrentThread();
  ScopedJavaLocalRef<jobject> obj = obj_.get(env);
  if (!obj.is_null())
    Java_DialogOverlayImpl_onDismissed(env, obj);

  obj_.reset();
}

void DialogOverlayImpl::Destroy(JNIEnv* env, const JavaParamRef<jobject>& obj) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  UnregisterCallbacksIfNeeded();
  // We delete soon since this might be part of an onDismissed callback.
  GetUIThreadTaskRunner({})->DeleteSoon(FROM_HERE, this);
}

void DialogOverlayImpl::GetCompositorOffset(
    JNIEnv* env,
    const base::android::JavaParamRef<jobject>& obj,
    const base::android::JavaParamRef<jobject>& rect) {
  gfx::Point point =
      web_contents()->GetNativeView()->GetLocationOfContainerViewInWindow();

  Java_DialogOverlayImpl_receiveCompositorOffset(env, rect, point.x(),
                                                 point.y());
}

void DialogOverlayImpl::UnregisterCallbacksIfNeeded() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  if (!rfhi_)
    return;

  // No need to track the container view location anymore.
  StopObservingContainerView();

  // We clear overlay mode here rather than in Destroy(), because we may have
  // been called via a WebContentsDestroyed() event, and this might be the last
  // opportunity we have to access web_contents().
  WebContentsDelegate* delegate = web_contents()->GetDelegate();
  if (delegate)
    delegate->SetOverlayMode(false);
  if (observed_window_android_) {
    auto* window_android = web_contents()->GetNativeView()->GetWindowAndroid();
    if (window_android)
      window_android->RemoveObserver(this);
    observed_window_android_ = false;
  }
  web_contents()->GetNativeView()->RemoveObserver(this);
  rfhi_ = nullptr;
}

void DialogOverlayImpl::RenderFrameDeleted(RenderFrameHost* render_frame_host) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  if (render_frame_host == rfhi_)
    Stop();
}

void DialogOverlayImpl::RenderFrameHostChanged(RenderFrameHost* old_host,
                                               RenderFrameHost* new_host) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  if (old_host == rfhi_)
    Stop();
}

void DialogOverlayImpl::OnVisibilityChanged(content::Visibility visibility) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  if (visibility == content::Visibility::HIDDEN)
    Stop();
}

void DialogOverlayImpl::OnRootWindowVisibilityChanged(bool visible) {
  if (!visible)
    Stop();
}

void DialogOverlayImpl::WebContentsDestroyed() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  Stop();
}

void DialogOverlayImpl::DidToggleFullscreenModeForTab(bool entered_fullscreen,
                                                      bool will_cause_resize) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);

  // If the caller doesn't care about power-efficient overlays, then don't send
  // any callbacks about state change.
  if (!power_efficient_)
    return;

  JNIEnv* env = AttachCurrentThread();
  ScopedJavaLocalRef<jobject> obj = obj_.get(env);
  if (!obj.is_null())
    Java_DialogOverlayImpl_onPowerEfficientState(env, obj, entered_fullscreen);
}

void DialogOverlayImpl::OnAttachedToWindow() {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  JNIEnv* env = AttachCurrentThread();

  auto* window = web_contents()->GetNativeView()->GetWindowAndroid();
  if (window)
    RegisterWindowObserverIfNeeded(window);

  ScopedJavaLocalRef<jobject> obj = obj_.get(env);
  if (!obj.is_null())
    Java_DialogOverlayImpl_onWindowAndroid(env, obj, window->GetJavaObject());

  StartObservingContainerView();
}

void DialogOverlayImpl::OnDetachedFromWindow() {
  JNIEnv* env = AttachCurrentThread();
  ScopedJavaLocalRef<jobject> obj = obj_.get(env);
  if (!obj.is_null())
    Java_DialogOverlayImpl_onWindowAndroid(env, obj, nullptr);
  Stop();
}

void DialogOverlayImpl::RegisterWindowObserverIfNeeded(
    ui::WindowAndroid* window) {
  if (!observed_window_android_) {
    observed_window_android_ = true;
    window->AddObserver(this);
  }
}

void DialogOverlayImpl::StartObservingContainerView() {
  ObserveContainerViewIfNeeded(
      web_contents()->GetNativeView()->GetContainerView());
}

void DialogOverlayImpl::StopObservingContainerView() {
  ObserveContainerViewIfNeeded(/*container_view=*/nullptr);
}

void DialogOverlayImpl::ObserveContainerViewIfNeeded(
    const ScopedJavaLocalRef<jobject>& container_view) {
  if (!observe_container_view_)
    return;

  JNIEnv* env = AttachCurrentThread();
  ScopedJavaLocalRef<jobject> obj = obj_.get(env);
  if (!obj.is_null())
    Java_DialogOverlayImpl_observeContainerView(env, obj, container_view);
}

// Helper class that has permission to talk to SyncCallRestrictions.  Rather
// than friend the function directly, which has an odd signature, friend a class
// that knows how to do the work.
class AndroidOverlaySyncHelper {
 public:
  static void MakeSyncCall(media::mojom::AndroidOverlayClient* remote) {
    mojo::SyncCallRestrictions::ScopedAllowSyncCall scoped_allow;
    remote->OnSynchronouslyDestroyed();
  }
};

static void JNI_DialogOverlayImpl_NotifyDestroyedSynchronously(
    JNIEnv* env,
    jlong message_pipe_handle) {
  mojo::MessagePipeHandle handle(message_pipe_handle);
  mojo::ScopedMessagePipeHandle scoped_handle(handle);
  mojo::Remote<media::mojom::AndroidOverlayClient> remote(
      mojo::PendingRemote<media::mojom::AndroidOverlayClient>(
          std::move(scoped_handle),
          media::mojom::AndroidOverlayClient::Version_));
  // This prevents crashes, though it's unclear how we'd have a null remote.
  // https://crbug.com/1155313 .
  if (!remote.is_bound())
    return;
  AndroidOverlaySyncHelper::MakeSyncCall(remote.get());
  // Note that we don't take back the mojo message pipe.  We let it close when
  // `remote` goes out of scope.
}

static jint JNI_DialogOverlayImpl_RegisterSurface(
    JNIEnv* env,
    const JavaParamRef<jobject>& surface) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  return gpu::GpuSurfaceTracker::Get()->AddSurfaceForNativeWidget(
      gpu::GpuSurfaceTracker::SurfaceRecord(
          gl::ScopedJavaSurface(surface, /*auto_release=*/false),
          /*can_be_used_with_surface_control=*/false));
}

static void JNI_DialogOverlayImpl_UnregisterSurface(
    JNIEnv* env,
    jint surface_id) {
  DCHECK_CURRENTLY_ON(BrowserThread::UI);
  gpu::GpuSurfaceTracker::Get()->RemoveSurface(surface_id);
}

static ScopedJavaLocalRef<jobject>
JNI_DialogOverlayImpl_LookupSurfaceForTesting(
    JNIEnv* env,
    jint surfaceId) {
  bool can_be_used_with_surface_control = false;
  auto surface_variant = gpu::GpuSurfaceTracker::Get()->AcquireJavaSurface(
      surfaceId, &can_be_used_with_surface_control);
  if (!absl::holds_alternative<gl::ScopedJavaSurface>(surface_variant)) {
    return nullptr;
  }
  return ScopedJavaLocalRef<jobject>(
      absl::get<gl::ScopedJavaSurface>(surface_variant).j_surface());
}

}  // namespace content