// Copyright (c) 2014 The Chromium Embedded Framework Authors.
// Portions 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 "libcef/browser/osr/render_widget_host_view_osr.h"

#include <algorithm>
#include <limits>
#include <utility>

#import <Cocoa/Cocoa.h>

#include "libcef/browser/browser_host_impl.h"

#include "base/compiler_specific.h"
#include "base/strings/utf_string_conversions.h"
#include "content/common/view_messages.h"
#include "ui/accelerated_widget_mac/accelerated_widget_mac.h"
#include "ui/display/screen.h"

namespace {

display::Display GetDisplay() {
  // TODO(cef): Get display info from callbacks.
  return display::Screen::GetScreen()->GetDisplayNearestView(nullptr);
}

}  // namespace

class MacHelper : public content::BrowserCompositorMacClient,
                  public ui::AcceleratedWidgetMacNSView {
 public:
  explicit MacHelper(CefRenderWidgetHostViewOSR* view) : view_(view) {}
  virtual ~MacHelper() {}

  // BrowserCompositorMacClient methods:

  SkColor BrowserCompositorMacGetGutterColor() const override {
    // When making an element on the page fullscreen the element's background
    // may not match the page's, so use black as the gutter color to avoid
    // flashes of brighter colors during the transition.
    if (view_->render_widget_host()->delegate() &&
        view_->render_widget_host()->delegate()->IsFullscreenForCurrentTab()) {
      return SK_ColorBLACK;
    }
    return view_->background_color();
  }

  void BrowserCompositorMacOnBeginFrame(base::TimeTicks frame_time) override {}

  void OnFrameTokenChanged(uint32_t frame_token) override {
    view_->render_widget_host()->DidProcessFrame(frame_token);
  }

  // AcceleratedWidgetMacNSView methods:

  NSView* AcceleratedWidgetGetNSView() const override {
    // Intentionally return nil so that BrowserCompositorMac::GetViewProperties
    // uses the layer size instead of the NSView size.
    return nil;
  }

  void AcceleratedWidgetGetVSyncParameters(
      base::TimeTicks* timebase,
      base::TimeDelta* interval) const override {
    *timebase = base::TimeTicks();
    *interval = base::TimeDelta();
  }

  void AcceleratedWidgetSwapCompleted() override {}

  void DidReceiveFirstFrameAfterNavigation() override {
    view_->render_widget_host()->DidReceiveFirstFrameAfterNavigation();
  }

  void DestroyCompositorForShutdown() override {}

  void WasResized() override { view_->render_widget_host()->WasResized(); }

 private:
  // Guaranteed to outlive this object.
  CefRenderWidgetHostViewOSR* view_;

  DISALLOW_COPY_AND_ASSIGN(MacHelper);
};

void CefRenderWidgetHostViewOSR::SetActive(bool active) {}

void CefRenderWidgetHostViewOSR::ShowDefinitionForSelection() {}

void CefRenderWidgetHostViewOSR::SpeakSelection() {}

bool CefRenderWidgetHostViewOSR::ShouldContinueToPauseForFrame() {
  return browser_compositor_->ShouldContinueToPauseForFrame();
}

ui::Compositor* CefRenderWidgetHostViewOSR::GetCompositor() const {
  return browser_compositor_->GetCompositor();
}

ui::Layer* CefRenderWidgetHostViewOSR::GetRootLayer() const {
  return browser_compositor_->GetRootLayer();
}

content::DelegatedFrameHost* CefRenderWidgetHostViewOSR::GetDelegatedFrameHost()
    const {
  return browser_compositor_->GetDelegatedFrameHost();
}

bool CefRenderWidgetHostViewOSR::UpdateNSViewAndDisplay() {
  return browser_compositor_->UpdateNSViewAndDisplay(
      GetRootLayer()->bounds().size(), GetDisplay());
}

void CefRenderWidgetHostViewOSR::PlatformCreateCompositorWidget(
    bool is_guest_view_hack) {
  // Create a borderless non-visible 1x1 window.
  window_ = [[NSWindow alloc] initWithContentRect:NSMakeRect(0, 0, 1, 1)
                                        styleMask:NSBorderlessWindowMask
                                          backing:NSBackingStoreBuffered
                                            defer:NO];

  // Create a CALayer which is used by BrowserCompositorViewMac for rendering.
  background_layer_ = [[[CALayer alloc] init] retain];
  [background_layer_ setBackgroundColor:CGColorGetConstantColor(kCGColorClear)];
  NSView* content_view = [window_ contentView];
  [content_view setLayer:background_layer_];
  [content_view setWantsLayer:YES];

  mac_helper_ = new MacHelper(this);
  browser_compositor_.reset(new content::BrowserCompositorMac(
      mac_helper_, mac_helper_, render_widget_host_->is_hidden(), true,
      GetDisplay(), AllocateFrameSinkId(is_guest_view_hack)));
}

void CefRenderWidgetHostViewOSR::PlatformResizeCompositorWidget(
    const gfx::Size&) {}

void CefRenderWidgetHostViewOSR::PlatformDestroyCompositorWidget() {
  DCHECK(window_);

  [window_ close];
  window_ = nil;
  [background_layer_ release];
  background_layer_ = nil;

  browser_compositor_.reset();

  delete mac_helper_;
  mac_helper_ = nullptr;
}