// Copyright 2014 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 <vector>

#include "examples/wm_flow/wm/frame_controller.h"
#include "mojo/application/application_runner_chromium.h"
#include "mojo/public/c/system/main.h"
#include "mojo/public/cpp/application/application_delegate.h"
#include "mojo/public/cpp/application/application_impl.h"
#include "mojo/public/cpp/application/service_provider_impl.h"
#include "mojo/services/public/cpp/view_manager/view_manager.h"
#include "mojo/services/public/cpp/view_manager/view_manager_delegate.h"
#include "mojo/services/public/cpp/view_manager/view_observer.h"
#include "mojo/services/public/interfaces/input_events/input_events.mojom.h"
#include "mojo/services/window_manager/window_manager_app.h"
#include "mojo/services/window_manager/window_manager_delegate.h"
#include "mojo/views/views_init.h"
#include "ui/aura/window.h"
#include "ui/wm/core/focus_rules.h"
#include "ui/wm/public/activation_client.h"

namespace examples {

namespace {

class WMFocusRules : public wm::FocusRules {
 public:
  WMFocusRules(mojo::WindowManagerApp* window_manager_app,
               mojo::View* window_container)
      : window_container_(window_container),
        window_manager_app_(window_manager_app) {}
  virtual ~WMFocusRules() {}

 private:
  // Overridden from wm::FocusRules:
  virtual bool IsToplevelWindow(aura::Window* window) const override {
    return mojo::WindowManagerApp::GetViewForWindow(window)->parent() ==
        window_container_;
  }
  virtual bool CanActivateWindow(aura::Window* window) const override {
    return mojo::WindowManagerApp::GetViewForWindow(window)->parent() ==
        window_container_;
  }
  virtual bool CanFocusWindow(aura::Window* window) const override {
    return true;
  }
  virtual aura::Window* GetToplevelWindow(aura::Window* window) const override {
    mojo::View* view = mojo::WindowManagerApp::GetViewForWindow(window);
    while (view->parent() != window_container_) {
      view = view->parent();
      // Unparented hierarchy, there is no "top level" window.
      if (!view)
        return NULL;
    }

    return window_manager_app_->GetWindowForViewId(view->id());
  }
  virtual aura::Window* GetActivatableWindow(
      aura::Window* window) const override {
    return GetToplevelWindow(window);
  }
  virtual aura::Window* GetFocusableWindow(
      aura::Window* window) const override {
    return window;
  }
  virtual aura::Window* GetNextActivatableWindow(
      aura::Window* ignore) const override {
    aura::Window* activatable = GetActivatableWindow(ignore);
    const aura::Window::Windows& children = activatable->parent()->children();
    for (aura::Window::Windows::const_reverse_iterator it = children.rbegin();
         it != children.rend(); ++it) {
      if (*it != ignore)
        return *it;
    }
    return NULL;
  }

  mojo::View* window_container_;
  mojo::WindowManagerApp* window_manager_app_;

  DISALLOW_COPY_AND_ASSIGN(WMFocusRules);
};

}  // namespace

class SimpleWM : public mojo::ApplicationDelegate,
                 public mojo::ViewManagerDelegate,
                 public mojo::WindowManagerDelegate,
                 public mojo::ViewObserver {
 public:
  SimpleWM()
      : shell_(nullptr),
        window_manager_app_(new mojo::WindowManagerApp(this, this)),
        view_manager_(NULL),
        root_(NULL),
        window_container_(NULL),
        next_window_origin_(10, 10) {}
  virtual ~SimpleWM() {}

 private:
  // Overridden from mojo::ApplicationDelegate:
  virtual void Initialize(mojo::ApplicationImpl* impl) override {
    // Create views_init here as we need ApplicationRunnerChromium to install
    // an AtExitManager and CommandLine.
    if (!views_init_.get())
      views_init_.reset(new mojo::ViewsInit);
    shell_ = impl->shell();
    window_manager_app_->Initialize(impl);
  }
  virtual bool ConfigureIncomingConnection(
      mojo::ApplicationConnection* connection) override {
    window_manager_app_->ConfigureIncomingConnection(connection);
    return true;
  }

  // Overridden from mojo::ViewManagerDelegate:
  virtual void OnEmbed(
      mojo::ViewManager* view_manager,
      mojo::View* root,
      mojo::ServiceProviderImpl* exported_services,
      scoped_ptr<mojo::ServiceProvider> remote_service_provider) override {
    view_manager_ = view_manager;
    root_ = root;

    window_container_ = mojo::View::Create(view_manager_);
    window_container_->SetBounds(root_->bounds());
    root_->AddChild(window_container_);

    window_manager_app_->InitFocus(new WMFocusRules(window_manager_app_.get(),
                                                    window_container_));
  }
  virtual void OnViewManagerDisconnected(
      mojo::ViewManager* view_manager) override {
    view_manager_ = NULL;
    root_ = NULL;
  }

  // Overridden from mojo::WindowManagerDelegate:
  virtual void Embed(
      const mojo::String& url,
      mojo::InterfaceRequest<mojo::ServiceProvider> service_provider) override {
    DCHECK(view_manager_);
    mojo::View* app_view = NULL;
    mojo::View* frame_view = CreateTopLevelWindow(&app_view);
    window_container_->AddChild(frame_view);

    // TODO(beng): We're dropping the |service_provider| passed from the client
    //             on the floor here and passing our own. Seems like we should
    //             be sending both. I'm not yet sure how this sould work for
    //             N levels of proxying.
    app_view->Embed(url, scoped_ptr<mojo::ServiceProviderImpl>(
        new mojo::ServiceProviderImpl).Pass());
  }

  // Overridden from mojo::ViewObserver:
  virtual void OnViewInputEvent(mojo::View* view,
                                const mojo::EventPtr& event) override {
    if (event->action == mojo::EVENT_TYPE_MOUSE_RELEASED &&
        event->flags & mojo::EVENT_FLAGS_RIGHT_MOUSE_BUTTON &&
        view->parent() == window_container_) {
      CloseWindow(view);
    }
  }
  virtual void OnViewDestroyed(mojo::View* view) override {
    view->RemoveObserver(this);
  }

  void CloseWindow(mojo::View* view) {
    mojo::View* first_child = view->children().front();
    first_child->Destroy();
    view->Destroy();
    next_window_origin_.Offset(-50, -50);
  }

  mojo::View* CreateTopLevelWindow(mojo::View** app_view) {
    mojo::View* frame_view = mojo::View::Create(view_manager_);
    mojo::Rect rect;
    rect.x = next_window_origin_.x();
    rect.y = next_window_origin_.y();
    rect.width = rect.height = 400;
    frame_view->SetBounds(rect);
    next_window_origin_.Offset(50, 50);

    aura::client::ActivationClient* client = aura::client::GetActivationClient(
        window_manager_app_->host()->window());
    new FrameController(
        shell_, frame_view, app_view, client, window_manager_app_.get());
    return frame_view;
  }

  mojo::Shell* shell_;

  scoped_ptr<mojo::ViewsInit> views_init_;

  scoped_ptr<mojo::WindowManagerApp> window_manager_app_;

  mojo::ViewManager* view_manager_;
  mojo::View* root_;
  mojo::View* window_container_;

  gfx::Point next_window_origin_;

  DISALLOW_COPY_AND_ASSIGN(SimpleWM);
};

}  // namespace examples

MojoResult MojoMain(MojoHandle shell_handle) {
  mojo::ApplicationRunnerChromium runner(new examples::SimpleWM);
  return runner.Run(shell_handle);
}